/******************************************************************************
 *
 * Project:  DXF Translator
 * Purpose:  Implements OGRDXFLayer class.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 2009, Frank Warmerdam <warmerdam@pobox.com>
 * Copyright (c) 2011-2013, Even Rouault <even dot rouault at spatialys.com>
 * Copyright (c) 2017-2020, Alan Thomas <alant@outlook.com.au>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#include "ogr_dxf.h"
#include "cpl_conv.h"
#include "ogrdxf_polyline_smooth.h"
#include "ogr_api.h"

#include <cmath>
#include <algorithm>
#include <limits>
#include <stdexcept>
#include <memory>

/************************************************************************/
/*                                push()                               */
/************************************************************************/

void OGRDXFFeatureQueue::push(OGRDXFFeature *poFeature)
{
    apoFeatures.push(poFeature);
}

/************************************************************************/
/*                                 pop()                                */
/************************************************************************/

void OGRDXFFeatureQueue::pop()
{
    CPLAssert(!apoFeatures.empty());
    apoFeatures.pop();
}

/************************************************************************/
/*                            OGRDXFLayer()                             */
/************************************************************************/

OGRDXFLayer::OGRDXFLayer(OGRDXFDataSource *poDSIn)
    : poDS(poDSIn), poFeatureDefn(new OGRFeatureDefn("entities")), iNextFID(0)
{
    poFeatureDefn->Reference();

    int nModes = ODFM_None;
    if (!poDS->InlineBlocks())
        nModes |= ODFM_IncludeBlockFields;
    if (poDS->ShouldIncludeRawCodeValues())
        nModes |= ODFM_IncludeRawCodeValues;
    if (poDS->In3DExtensibleMode())
        nModes |= ODFM_Include3DModeFields;
    OGRDXFDataSource::AddStandardFields(poFeatureDefn, nModes);

    SetDescription(poFeatureDefn->GetName());
}

/************************************************************************/
/*                           ~OGRDXFLayer()                           */
/************************************************************************/

OGRDXFLayer::~OGRDXFLayer()

{
    ClearPendingFeatures();
    if (m_nFeaturesRead > 0 && poFeatureDefn != nullptr)
    {
        CPLDebug("DXF", "%d features read on layer '%s'.", (int)m_nFeaturesRead,
                 poFeatureDefn->GetName());
    }

    if (poFeatureDefn)
        poFeatureDefn->Release();
}

/************************************************************************/
/*                        ClearPendingFeatures()                        */
/************************************************************************/

void OGRDXFLayer::ClearPendingFeatures()

{
    while (!apoPendingFeatures.empty())
    {
        OGRDXFFeature *poFeature = apoPendingFeatures.front();
        apoPendingFeatures.pop();
        delete poFeature;
    }
}

/************************************************************************/
/*                            ResetReading()                            */
/************************************************************************/

void OGRDXFLayer::ResetReading()

{
    iNextFID = 0;
    ClearPendingFeatures();
    m_oInsertState.m_nRowCount = 0;
    m_oInsertState.m_nColumnCount = 0;
    poDS->RestartEntities();
}

/************************************************************************/
/*                      TranslateGenericProperty()                      */
/*                                                                      */
/*      Try and convert entity properties handled similarly for most    */
/*      or all entity types.                                            */
/************************************************************************/

void OGRDXFLayer::TranslateGenericProperty(OGRDXFFeature *poFeature, int nCode,
                                           char *pszValue)

{
    switch (nCode)
    {
        case 8:
            poFeature->SetField("Layer", TextRecode(pszValue));
            break;

        case 100:
        {
            CPLString osSubClass = poFeature->GetFieldAsString("SubClasses");
            if (!osSubClass.empty())
                osSubClass += ":";
            osSubClass += pszValue;
            poFeature->SetField("SubClasses", osSubClass.c_str());
        }
        break;

        case 101:
            // Embedded objects mark the end of meaningful DXF data
            // See
            // http://docs.autodesk.com/ACDMAC/2016/ENU/ObjectARX_Dev_Guide/files/GUID-C953866F-A335-4FFD-AE8C-256A76065552.htm
            {
                char szLineBuf[257];
                // Eat the rest of this entity
                while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) >
                       0)
                {
                }

                if (nCode < 0)
                {
                    // Let the entity reader function discover this error for
                    // itself
                    return;
                }

                CPLAssert(nCode == 0);
                poDS->UnreadValue();
            }
            break;

        case 60:
            if (atoi(pszValue))
                poFeature->oStyleProperties["Hidden"] = "1";
            break;

        case 67:
            if (atoi(pszValue))
                poFeature->SetField("PaperSpace", 1);
            break;

        case 62:
            poFeature->oStyleProperties["Color"] = pszValue;
            break;

        case 420:
            poFeature->oStyleProperties["TrueColor"] = pszValue;
            break;

        case 6:
            poFeature->SetField("Linetype", TextRecode(pszValue));
            break;

        case 48:
            poFeature->oStyleProperties["LinetypeScale"] = pszValue;
            break;

        case 370:
        case 39:
            poFeature->oStyleProperties["LineWeight"] = pszValue;
            break;

        case 5:
            poFeature->SetField("EntityHandle", pszValue);
            break;

        // OCS vector.
        case 210:
            poFeature->oOCS.dfX = CPLAtof(pszValue);
            break;

        case 220:
            poFeature->oOCS.dfY = CPLAtof(pszValue);
            break;

        case 230:
            poFeature->oOCS.dfZ = CPLAtof(pszValue);
            break;

        default:
            if (poDS->ShouldIncludeRawCodeValues())
            {
                char **papszRawCodeValues =
                    poFeature->GetFieldAsStringList("RawCodeValues");

                papszRawCodeValues = CSLDuplicate(papszRawCodeValues);

                papszRawCodeValues = CSLAddString(
                    papszRawCodeValues,
                    CPLString()
                        .Printf("%d %s", nCode, TextRecode(pszValue).c_str())
                        .c_str());

                poFeature->SetField("RawCodeValues", papszRawCodeValues);

                CSLDestroy(papszRawCodeValues);
            }
            break;
    }
}

/************************************************************************/
/*                        PrepareFeatureStyle()                         */
/*                                                                      */
/*     - poBlockFeature: If this is not NULL, style properties on       */
/*       poFeature with ByBlock values will be replaced with the        */
/*       corresponding property from poBlockFeature.  If this           */
/*       parameter is supplied it is assumed that poFeature is a        */
/*       clone, not an "original" feature object.                       */
/************************************************************************/

void OGRDXFLayer::PrepareFeatureStyle(
    OGRDXFFeature *const poFeature,
    OGRDXFFeature *const poBlockFeature /* = NULL */)

{
    const char *pszStyleString = poFeature->GetStyleString();

    if (pszStyleString && STARTS_WITH_CI(pszStyleString, "BRUSH("))
    {
        PrepareBrushStyle(poFeature, poBlockFeature);
    }
    else if (pszStyleString && STARTS_WITH_CI(pszStyleString, "LABEL("))
    {
        // Find the new color of this feature, and replace it into
        // the style string
        const CPLString osNewColor = poFeature->GetColor(poDS, poBlockFeature);

        CPLString osNewStyle = pszStyleString;
        const size_t nColorStartPos = osNewStyle.rfind(",c:");
        if (nColorStartPos != std::string::npos)
        {
            const size_t nColorEndPos =
                osNewStyle.find_first_of(",)", nColorStartPos + 3);

            if (nColorEndPos != std::string::npos)
            {
                osNewStyle.replace(nColorStartPos + 3,
                                   nColorEndPos - (nColorStartPos + 3),
                                   osNewColor);
                poFeature->SetStyleString(osNewStyle);
            }
        }
    }
    else
    {
        PrepareLineStyle(poFeature, poBlockFeature);
    }
}

/************************************************************************/
/*                         PrepareBrushStyle()                          */
/************************************************************************/

void OGRDXFLayer::PrepareBrushStyle(
    OGRDXFFeature *const poFeature,
    OGRDXFFeature *const poBlockFeature /* = NULL */)

{
    CPLString osStyle = "BRUSH(fc:";
    osStyle += poFeature->GetColor(poDS, poBlockFeature);
    osStyle += ")";

    poFeature->SetStyleString(osStyle);
}

/************************************************************************/
/*                          PrepareLineStyle()                          */
/************************************************************************/

void OGRDXFLayer::PrepareLineStyle(
    OGRDXFFeature *const poFeature,
    OGRDXFFeature *const poBlockFeature /* = NULL */)

{
    const CPLString osLayer = poFeature->GetFieldAsString("Layer");

    /* -------------------------------------------------------------------- */
    /*      Get line weight if available.                                   */
    /* -------------------------------------------------------------------- */
    double dfWeight = 0.0;
    CPLString osWeight = "-1";

    if (poFeature->oStyleProperties.count("LineWeight") > 0)
        osWeight = poFeature->oStyleProperties["LineWeight"];

    // Use ByBlock lineweight?
    if (CPLAtof(osWeight) == -2 && poBlockFeature)
    {
        if (poBlockFeature->oStyleProperties.count("LineWeight") > 0)
        {
            // Inherit lineweight from the owning block
            osWeight = poBlockFeature->oStyleProperties["LineWeight"];

            // Use the inherited lineweight if we regenerate the style
            // string again during block insertion
            poFeature->oStyleProperties["LineWeight"] = osWeight;
        }
        else
        {
            // If the owning block has no explicit lineweight,
            // assume ByLayer
            osWeight = "-1";
        }
    }

    // Use layer lineweight?
    if (CPLAtof(osWeight) == -1)
    {
        osWeight = poDS->LookupLayerProperty(osLayer, "LineWeight");
    }

    // Will be zero in the case of an invalid value
    dfWeight = CPLAtof(osWeight) / 100.0;

    /* -------------------------------------------------------------------- */
    /*      Do we have a dash/dot line style?                               */
    /* -------------------------------------------------------------------- */
    const char *pszLinetype = poFeature->GetFieldAsString("Linetype");

    // Use ByBlock line style?
    if (pszLinetype && EQUAL(pszLinetype, "ByBlock") && poBlockFeature)
    {
        pszLinetype = poBlockFeature->GetFieldAsString("Linetype");

        // Use the inherited line style if we regenerate the style string
        // again during block insertion
        if (pszLinetype)
            poFeature->SetField("Linetype", pszLinetype);
    }

    // Use layer line style?
    if (pszLinetype && EQUAL(pszLinetype, ""))
    {
        pszLinetype = poDS->LookupLayerProperty(osLayer, "Linetype");
    }

    const std::vector<double> oLineType = poDS->LookupLineType(pszLinetype);

    // Linetype scale is not inherited from the block feature
    double dfLineTypeScale = CPLAtof(poDS->GetVariable("$LTSCALE", "1.0"));
    if (poFeature->oStyleProperties.count("LinetypeScale") > 0)
        dfLineTypeScale *=
            CPLAtof(poFeature->oStyleProperties["LinetypeScale"]);

    CPLString osPattern;
    for (std::vector<double>::const_iterator oIt = oLineType.begin();
         oIt != oLineType.end(); ++oIt)
    {
        // this is the format specifier %g followed by a literal 'g'
        osPattern +=
            CPLString().Printf("%.11gg ", fabs(*oIt) * dfLineTypeScale);
    }

    if (osPattern.length() > 0)
        osPattern.erase(osPattern.end() - 1);

    /* -------------------------------------------------------------------- */
    /*      Format the style string.                                        */
    /* -------------------------------------------------------------------- */

    CPLString osStyle = "PEN(c:";
    osStyle += poFeature->GetColor(poDS, poBlockFeature);

    if (dfWeight > 0.0)
    {
        char szBuffer[64];
        CPLsnprintf(szBuffer, sizeof(szBuffer), "%.2g", dfWeight);
        osStyle += CPLString().Printf(",w:%sg", szBuffer);
    }

    if (osPattern != "")
    {
        osStyle += ",p:\"";
        osStyle += osPattern;
        osStyle += "\"";
    }

    osStyle += ")";

    poFeature->SetStyleString(osStyle);
}

/************************************************************************/
/*                             TextRecode()                             */
/************************************************************************/

CPLString OGRDXFLayer::TextRecode(const char *pszInput)

{
    return CPLString(pszInput).Recode(poDS->GetEncoding(), CPL_ENC_UTF8);
}

/************************************************************************/
/*                            TextUnescape()                            */
/*                                                                      */
/*      Unexcape DXF style escape sequences such as \P for newline      */
/*      and \~ for space, and do the recoding to UTF8.                  */
/************************************************************************/

CPLString OGRDXFLayer::TextUnescape(const char *pszInput, bool bIsMText)

{
    if (poDS->ShouldTranslateEscapes())
        return ACTextUnescape(pszInput, poDS->GetEncoding(), bIsMText);

    return TextRecode(pszInput);
}

/************************************************************************/
/*                           TranslateMTEXT()                           */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslateMTEXT()

{
    char szLineBuf[512];
    int nCode = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);
    double dfX = 0.0;
    double dfY = 0.0;
    double dfZ = 0.0;
    double dfAngle = 0.0;
    double dfHeight = 0.0;
    double dfXDirection = 0.0;
    double dfYDirection = 0.0;
    bool bHaveZ = false;
    int nAttachmentPoint = -1;
    CPLString osText;
    CPLString osStyleName = "STANDARD";

    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 10:
                dfX = CPLAtof(szLineBuf);
                break;

            case 20:
                dfY = CPLAtof(szLineBuf);
                break;

            case 30:
                dfZ = CPLAtof(szLineBuf);
                bHaveZ = true;
                break;

            case 40:
                dfHeight = CPLAtof(szLineBuf);
                break;

            case 71:
                nAttachmentPoint = atoi(szLineBuf);
                break;

            case 11:
                dfXDirection = CPLAtof(szLineBuf);
                break;

            case 21:
                dfYDirection = CPLAtof(szLineBuf);
                dfAngle = atan2(dfYDirection, dfXDirection) * 180.0 / M_PI;
                break;

            case 1:
            case 3:
                osText += TextUnescape(szLineBuf, true);
                break;

            case 50:
                dfAngle = CPLAtof(szLineBuf);
                break;

            case 7:
                osStyleName = TextRecode(szLineBuf);
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0)
        poDS->UnreadValue();

    OGRPoint *poGeom = nullptr;
    if (bHaveZ)
        poGeom = new OGRPoint(dfX, dfY, dfZ);
    else
        poGeom = new OGRPoint(dfX, dfY);

    /* We do NOT apply the OCS for MTEXT. See
     * https://trac.osgeo.org/gdal/ticket/7049 */
    /* ApplyOCSTransformer( poGeom ); */

    poFeature->SetGeometryDirectly(poGeom);

    /* -------------------------------------------------------------------- */
    /*      Apply text after stripping off any extra terminating newline.   */
    /* -------------------------------------------------------------------- */
    if (!osText.empty() && osText.back() == '\n')
        osText.resize(osText.size() - 1);

    poFeature->SetField("Text", osText);

    /* -------------------------------------------------------------------- */
    /*      We need to escape double quotes with backslashes before they    */
    /*      can be inserted in the style string.                            */
    /* -------------------------------------------------------------------- */
    if (strchr(osText, '"') != nullptr)
    {
        std::string osEscaped;

        for (size_t iC = 0; iC < osText.size(); iC++)
        {
            if (osText[iC] == '"')
                osEscaped += "\\\"";
            else
                osEscaped += osText[iC];
        }
        osText = std::move(osEscaped);
    }

    /* -------------------------------------------------------------------- */
    /*      Prepare style string.                                           */
    /* -------------------------------------------------------------------- */
    CPLString osStyle;
    char szBuffer[64];

    // Font name
    osStyle.Printf("LABEL(f:\"");

    // Preserve legacy behavior of specifying "Arial" as a default font name.
    osStyle += poDS->LookupTextStyleProperty(osStyleName, "Font", "Arial");

    osStyle += "\"";

    // Bold, italic
    if (EQUAL(poDS->LookupTextStyleProperty(osStyleName, "Bold", "0"), "1"))
    {
        osStyle += ",bo:1";
    }
    if (EQUAL(poDS->LookupTextStyleProperty(osStyleName, "Italic", "0"), "1"))
    {
        osStyle += ",it:1";
    }

    // Text string itself
    osStyle += ",t:\"";
    osStyle += osText;
    osStyle += "\"";

    if (dfAngle != 0.0)
    {
        CPLsnprintf(szBuffer, sizeof(szBuffer), "%.3g", dfAngle);
        osStyle += CPLString().Printf(",a:%s", szBuffer);
    }

    if (dfHeight != 0.0)
    {
        CPLsnprintf(szBuffer, sizeof(szBuffer), "%.3g", dfHeight);
        osStyle += CPLString().Printf(",s:%sg", szBuffer);
    }

    const char *pszWidthFactor =
        poDS->LookupTextStyleProperty(osStyleName, "Width", "1");
    if (pszWidthFactor && CPLAtof(pszWidthFactor) != 1.0)
    {
        CPLsnprintf(szBuffer, sizeof(szBuffer), "%.4g",
                    CPLAtof(pszWidthFactor) * 100.0);
        osStyle += CPLString().Printf(",w:%s", szBuffer);
    }

    if (nAttachmentPoint >= 0 && nAttachmentPoint <= 9)
    {
        const static int anAttachmentMap[10] = {-1, 7, 8, 9, 4, 5, 6, 1, 2, 3};

        osStyle +=
            CPLString().Printf(",p:%d", anAttachmentMap[nAttachmentPoint]);
    }

    // Color
    osStyle += ",c:";
    osStyle += poFeature->GetColor(poDS);

    osStyle += ")";

    poFeature->SetStyleString(osStyle);

    return poFeature.release();
}

/************************************************************************/
/*                           TranslateTEXT()                            */
/*                                                                      */
/*      This function translates TEXT and ATTRIB entities, as well as   */
/*      ATTDEF entities when we are not inlining blocks.                */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslateTEXT(const bool bIsAttribOrAttdef)

{
    char szLineBuf[257];
    int nCode = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);

    double dfX = 0.0;
    double dfY = 0.0;
    double dfZ = 0.0;
    bool bHaveZ = false;

    double dfAngle = 0.0;
    double dfHeight = 0.0;
    double dfWidthFactor = 1.0;
    bool bHasAlignmentPoint = false;
    double dfAlignmentPointX = 0.0;
    double dfAlignmentPointY = 0.0;

    CPLString osText;
    CPLString osStyleName = "STANDARD";

    int nAnchorPosition = 1;
    int nHorizontalAlignment = 0;
    int nVerticalAlignment = 0;

    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 10:
                dfX = CPLAtof(szLineBuf);
                break;

            case 20:
                dfY = CPLAtof(szLineBuf);
                break;

            case 11:
                dfAlignmentPointX = CPLAtof(szLineBuf);
                break;

            case 21:
                dfAlignmentPointY = CPLAtof(szLineBuf);
                bHasAlignmentPoint = true;
                break;

            case 30:
                dfZ = CPLAtof(szLineBuf);
                bHaveZ = true;
                break;

            case 40:
                dfHeight = CPLAtof(szLineBuf);
                break;

            case 41:
                dfWidthFactor = CPLAtof(szLineBuf);
                break;

            case 1:
                osText += TextUnescape(szLineBuf, false);
                break;

            case 50:
                dfAngle = CPLAtof(szLineBuf);
                break;

            case 72:
                nHorizontalAlignment = atoi(szLineBuf);
                break;

            case 73:
                if (!bIsAttribOrAttdef)
                    nVerticalAlignment = atoi(szLineBuf);
                break;

            case 74:
                if (bIsAttribOrAttdef)
                    nVerticalAlignment = atoi(szLineBuf);
                break;

            case 7:
                osStyleName = TextRecode(szLineBuf);
                break;

            // 2 and 70 are for ATTRIB and ATTDEF entities only
            case 2:
                if (bIsAttribOrAttdef)
                {
                    // Attribute tags are not supposed to contain spaces (but
                    // sometimes they do)
                    while (char *pchSpace = strchr(szLineBuf, ' '))
                        *pchSpace = '_';

                    poFeature->osAttributeTag = szLineBuf;
                }
                break;

            case 70:
                if (bIsAttribOrAttdef)
                {
                    // When the LSB is set, this ATTRIB is "invisible"
                    if (atoi(szLineBuf) & 1)
                        poFeature->oStyleProperties["Hidden"] = "1";
                    // If the next bit is set, this ATTDEF is to be preserved
                    // and treated as constant TEXT
                    else if (atoi(szLineBuf) & 2)
                        poFeature->osAttributeTag.Clear();
                }
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0)
        poDS->UnreadValue();

    OGRPoint *poGeom = nullptr;
    if (bHaveZ)
        poGeom = new OGRPoint(dfX, dfY, dfZ);
    else
        poGeom = new OGRPoint(dfX, dfY);
    poFeature->ApplyOCSTransformer(poGeom);
    poFeature->SetGeometryDirectly(poGeom);

    /* -------------------------------------------------------------------- */
    /*      Determine anchor position.                                      */
    /* -------------------------------------------------------------------- */
    if (nHorizontalAlignment > 0 || nVerticalAlignment > 0)
    {
        switch (nVerticalAlignment)
        {
            case 1:  // bottom
                nAnchorPosition = 10;
                break;

            case 2:  // middle
                nAnchorPosition = 4;
                break;

            case 3:  // top
                nAnchorPosition = 7;
                break;

            default:
                // Handle "Middle" alignment approximately (this is rather like
                // MTEXT alignment in that it uses the actual height of the text
                // string to position the text, and thus requires knowledge of
                // text metrics)
                if (nHorizontalAlignment == 4)
                    nAnchorPosition = 5;
                break;
        }
        if (nHorizontalAlignment < 3)
            nAnchorPosition += nHorizontalAlignment;
        // TODO other alignment options
    }

    poFeature->SetField("Text", osText);

    /* -------------------------------------------------------------------- */
    /*      We need to escape double quotes with backslashes before they    */
    /*      can be inserted in the style string.                            */
    /* -------------------------------------------------------------------- */
    if (strchr(osText, '"') != nullptr)
    {
        CPLString osEscaped;

        for (size_t iC = 0; iC < osText.size(); iC++)
        {
            if (osText[iC] == '"')
                osEscaped += "\\\"";
            else
                osEscaped += osText[iC];
        }
        osText = std::move(osEscaped);
    }

    /* -------------------------------------------------------------------- */
    /*      Prepare style string.                                           */
    /* -------------------------------------------------------------------- */
    CPLString osStyle;
    char szBuffer[64];

    // Font name
    osStyle.Printf("LABEL(f:\"");

    // Preserve legacy behavior of specifying "Arial" as a default font name.
    osStyle += poDS->LookupTextStyleProperty(osStyleName, "Font", "Arial");

    osStyle += "\"";

    // Bold, italic
    if (EQUAL(poDS->LookupTextStyleProperty(osStyleName, "Bold", "0"), "1"))
    {
        osStyle += ",bo:1";
    }
    if (EQUAL(poDS->LookupTextStyleProperty(osStyleName, "Italic", "0"), "1"))
    {
        osStyle += ",it:1";
    }

    // Text string itself
    osStyle += ",t:\"";
    osStyle += osText;
    osStyle += "\"";

    // Other attributes
    osStyle += CPLString().Printf(",p:%d", nAnchorPosition);

    if (dfAngle != 0.0)
    {
        CPLsnprintf(szBuffer, sizeof(szBuffer), "%.3g", dfAngle);
        osStyle += CPLString().Printf(",a:%s", szBuffer);
    }

    if (dfHeight != 0.0)
    {
        CPLsnprintf(szBuffer, sizeof(szBuffer), "%.3g", dfHeight);
        osStyle += CPLString().Printf(",s:%sg", szBuffer);
    }

    if (dfWidthFactor != 1.0)
    {
        CPLsnprintf(szBuffer, sizeof(szBuffer), "%.4g", dfWidthFactor * 100.0);
        osStyle += CPLString().Printf(",w:%s", szBuffer);
    }

    if (bHasAlignmentPoint && dfAlignmentPointX != dfX)
    {
        CPLsnprintf(szBuffer, sizeof(szBuffer), "%.6g",
                    dfAlignmentPointX - dfX);
        osStyle += CPLString().Printf(",dx:%sg", szBuffer);
    }

    if (bHasAlignmentPoint && dfAlignmentPointY != dfY)
    {
        CPLsnprintf(szBuffer, sizeof(szBuffer), "%.6g",
                    dfAlignmentPointY - dfY);
        osStyle += CPLString().Printf(",dy:%sg", szBuffer);
    }

    // Color
    osStyle += ",c:";
    osStyle += poFeature->GetColor(poDS);

    osStyle += ")";

    poFeature->SetStyleString(osStyle);

    return poFeature.release();
}

/************************************************************************/
/*                           TranslatePOINT()                           */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslatePOINT()

{
    char szLineBuf[257];
    int nCode = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);
    double dfX = 0.0;
    double dfY = 0.0;
    double dfZ = 0.0;
    bool bHaveZ = false;

    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 10:
                dfX = CPLAtof(szLineBuf);
                break;

            case 20:
                dfY = CPLAtof(szLineBuf);
                break;

            case 30:
                dfZ = CPLAtof(szLineBuf);
                bHaveZ = true;
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0)
        poDS->UnreadValue();

    OGRPoint *poGeom = nullptr;
    if (bHaveZ)
        poGeom = new OGRPoint(dfX, dfY, dfZ);
    else
        poGeom = new OGRPoint(dfX, dfY);

    poFeature->SetGeometryDirectly(poGeom);

    // Set style pen color
    PrepareLineStyle(poFeature.get());

    return poFeature.release();
}

/************************************************************************/
/*                           TranslateLINE()                            */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslateLINE()

{
    char szLineBuf[257];
    int nCode = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);
    double dfX1 = 0.0;
    double dfY1 = 0.0;
    double dfZ1 = 0.0;
    double dfX2 = 0.0;
    double dfY2 = 0.0;
    double dfZ2 = 0.0;
    bool bHaveZ = false;

    /* -------------------------------------------------------------------- */
    /*      Process values.                                                 */
    /* -------------------------------------------------------------------- */
    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 10:
                dfX1 = CPLAtof(szLineBuf);
                break;

            case 11:
                dfX2 = CPLAtof(szLineBuf);
                break;

            case 20:
                dfY1 = CPLAtof(szLineBuf);
                break;

            case 21:
                dfY2 = CPLAtof(szLineBuf);
                break;

            case 30:
                dfZ1 = CPLAtof(szLineBuf);
                bHaveZ = true;
                break;

            case 31:
                dfZ2 = CPLAtof(szLineBuf);
                bHaveZ = true;
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0)
        poDS->UnreadValue();

    /* -------------------------------------------------------------------- */
    /*      Create geometry                                                 */
    /* -------------------------------------------------------------------- */
    auto poLS = std::make_unique<OGRLineString>();
    if (bHaveZ)
    {
        poLS->addPoint(dfX1, dfY1, dfZ1);
        poLS->addPoint(dfX2, dfY2, dfZ2);
    }
    else
    {
        poLS->addPoint(dfX1, dfY1);
        poLS->addPoint(dfX2, dfY2);
    }

    poFeature->SetGeometryDirectly(poLS.release());

    PrepareLineStyle(poFeature.get());

    return poFeature.release();
}

/************************************************************************/
/*                         TranslateLWPOLYLINE()                        */
/************************************************************************/
OGRDXFFeature *OGRDXFLayer::TranslateLWPOLYLINE()

{
    // Collect vertices and attributes into a smooth polyline.
    // If there are no bulges, then we are a straight-line polyline.
    // Single-vertex polylines become points.
    // Group code 30 (vertex Z) is not part of this entity.
    char szLineBuf[257];
    int nCode = 0;
    int nPolylineFlag = 0;

    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);
    double dfX = 0.0;
    double dfY = 0.0;
    double dfZ = 0.0;
    bool bHaveX = false;
    bool bHaveY = false;

    int nNumVertices = 1;  // use 1 based index
    int npolyarcVertexCount = 1;
    double dfBulge = 0.0;
    DXFSmoothPolyline smoothPolyline;

    smoothPolyline.setCoordinateDimension(2);

    /* -------------------------------------------------------------------- */
    /*      Collect information from the LWPOLYLINE object itself.          */
    /* -------------------------------------------------------------------- */
    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        if (npolyarcVertexCount > nNumVertices)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Too many vertices found in LWPOLYLINE.");
            return nullptr;
        }

        switch (nCode)
        {
            case 38:
                // Constant elevation.
                dfZ = CPLAtof(szLineBuf);
                smoothPolyline.setCoordinateDimension(3);
                break;

            case 90:
                nNumVertices = atoi(szLineBuf);
                break;

            case 70:
                nPolylineFlag = atoi(szLineBuf);
                break;

            case 10:
                if (bHaveX && bHaveY)
                {
                    smoothPolyline.AddPoint(dfX, dfY, dfZ, dfBulge);
                    npolyarcVertexCount++;
                    dfBulge = 0.0;
                    bHaveY = false;
                }
                dfX = CPLAtof(szLineBuf);
                bHaveX = true;
                break;

            case 20:
                if (bHaveX && bHaveY)
                {
                    smoothPolyline.AddPoint(dfX, dfY, dfZ, dfBulge);
                    npolyarcVertexCount++;
                    dfBulge = 0.0;
                    bHaveX = false;
                }
                dfY = CPLAtof(szLineBuf);
                bHaveY = true;
                break;

            case 42:
                dfBulge = CPLAtof(szLineBuf);
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0)
        poDS->UnreadValue();

    if (bHaveX && bHaveY)
        smoothPolyline.AddPoint(dfX, dfY, dfZ, dfBulge);

    if (smoothPolyline.IsEmpty())
    {
        return nullptr;
    }

    /* -------------------------------------------------------------------- */
    /*      Close polyline if necessary.                                    */
    /* -------------------------------------------------------------------- */
    if (nPolylineFlag & 0x01)
        smoothPolyline.Close();

    smoothPolyline.SetUseMaxGapWhenTessellatingArcs(poDS->InlineBlocks());
    auto poGeom = std::unique_ptr<OGRGeometry>(smoothPolyline.Tessellate());
    poFeature->ApplyOCSTransformer(poGeom.get());
    poFeature->SetGeometryDirectly(poGeom.release());

    PrepareLineStyle(poFeature.get());

    return poFeature.release();
}

/************************************************************************/
/*                             SafeAbs()                                */
/************************************************************************/

static inline int SafeAbs(int x)
{
    if (x == std::numeric_limits<int>::min())
        return std::numeric_limits<int>::max();
    return abs(x);
}

/************************************************************************/
/*                         TranslatePOLYLINE()                          */
/*                                                                      */
/*      We also capture the following vertices.                         */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslatePOLYLINE()

{
    char szLineBuf[257];
    int nCode = 0;
    int nPolylineFlag = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);

    /* -------------------------------------------------------------------- */
    /*      Collect information from the POLYLINE object itself.            */
    /* -------------------------------------------------------------------- */
    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 70:
                nPolylineFlag = atoi(szLineBuf);
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if ((nPolylineFlag & 16) != 0)
    {
        CPLDebug("DXF", "Polygon mesh not supported.");
        return nullptr;
    }

    /* -------------------------------------------------------------------- */
    /*      Collect vertices as a smooth polyline.                          */
    /* -------------------------------------------------------------------- */
    double dfX = 0.0;
    double dfY = 0.0;
    double dfZ = 0.0;
    double dfBulge = 0.0;
    int nVertexFlag = 0;
    DXFSmoothPolyline smoothPolyline;
    unsigned int vertexIndex71 = 0;
    unsigned int vertexIndex72 = 0;
    unsigned int vertexIndex73 = 0;
    unsigned int vertexIndex74 = 0;
    std::vector<OGRPoint> aoPoints;
    auto poPS = std::make_unique<OGRPolyhedralSurface>();

    smoothPolyline.setCoordinateDimension(2);

    while (nCode == 0 && !EQUAL(szLineBuf, "SEQEND"))
    {
        // Eat non-vertex objects.
        if (!EQUAL(szLineBuf, "VERTEX"))
        {
            while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
            {
            }
            if (nCode < 0)
            {
                DXF_LAYER_READER_ERROR();
                return nullptr;
            }

            continue;
        }

        // process a Vertex
        while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
        {
            switch (nCode)
            {
                case 10:
                    dfX = CPLAtof(szLineBuf);
                    break;

                case 20:
                    dfY = CPLAtof(szLineBuf);
                    break;

                case 30:
                    dfZ = CPLAtof(szLineBuf);
                    smoothPolyline.setCoordinateDimension(3);
                    break;

                case 42:
                    dfBulge = CPLAtof(szLineBuf);
                    break;

                case 70:
                    nVertexFlag = atoi(szLineBuf);
                    break;

                case 71:
                    // See comment below about negative values for 71, 72, 73,
                    // 74
                    vertexIndex71 = SafeAbs(atoi(szLineBuf));
                    break;

                case 72:
                    vertexIndex72 = SafeAbs(atoi(szLineBuf));
                    break;

                case 73:
                    vertexIndex73 = SafeAbs(atoi(szLineBuf));
                    break;

                case 74:
                    vertexIndex74 = SafeAbs(atoi(szLineBuf));
                    break;

                default:
                    break;
            }
        }

        if (((nVertexFlag & 64) != 0) && ((nVertexFlag & 128) != 0))
        {
            // add the point to the list of points
            try
            {
                aoPoints.emplace_back(dfX, dfY, dfZ);
            }
            catch (const std::exception &e)
            {
                CPLError(CE_Failure, CPLE_OutOfMemory, "%s", e.what());
                return nullptr;
            }
        }

        // Note - If any index out of vertexIndex71, vertexIndex72,
        // vertexIndex73 or vertexIndex74 is negative, it means that the line
        // starting from that vertex is invisible. However, it still needs to be
        // constructed as part of the resultant polyhedral surface; there is no
        // way to specify the visibility of individual edges in a polyhedral
        // surface at present

        if (nVertexFlag == 128)
        {
            // create a polygon and add it to the Polyhedral Surface
            auto poLR = std::make_unique<OGRLinearRing>();
            int iPoint = 0;
            int startPoint = -1;
            poLR->set3D(TRUE);
            if (vertexIndex71 != 0 && vertexIndex71 <= aoPoints.size())
            {
                // if (startPoint == -1)
                startPoint = vertexIndex71 - 1;
                poLR->setPoint(iPoint, &aoPoints[vertexIndex71 - 1]);
                iPoint++;
                vertexIndex71 = 0;
            }
            if (vertexIndex72 != 0 && vertexIndex72 <= aoPoints.size())
            {
                if (startPoint == -1)
                    startPoint = vertexIndex72 - 1;
                poLR->setPoint(iPoint, &aoPoints[vertexIndex72 - 1]);
                iPoint++;
                vertexIndex72 = 0;
            }
            if (vertexIndex73 != 0 && vertexIndex73 <= aoPoints.size())
            {
                if (startPoint == -1)
                    startPoint = vertexIndex73 - 1;
                poLR->setPoint(iPoint, &aoPoints[vertexIndex73 - 1]);
                iPoint++;
                vertexIndex73 = 0;
            }
            if (vertexIndex74 != 0 && vertexIndex74 <= aoPoints.size())
            {
                if (startPoint == -1)
                    startPoint = vertexIndex74 - 1;
                poLR->setPoint(iPoint, &aoPoints[vertexIndex74 - 1]);
                iPoint++;
                vertexIndex74 = 0;
            }
            if (startPoint >= 0)
            {
                // complete the ring
                poLR->setPoint(iPoint, &aoPoints[startPoint]);

                OGRPolygon *poPolygon = new OGRPolygon();
                poPolygon->addRingDirectly(poLR.release());

                poPS->addGeometryDirectly(poPolygon);
            }
        }

        if (nCode < 0)
        {
            DXF_LAYER_READER_ERROR();
            return nullptr;
        }

        // Ignore Spline frame control points ( see #4683 )
        if ((nVertexFlag & 16) == 0)
            smoothPolyline.AddPoint(dfX, dfY, dfZ, dfBulge);
        dfBulge = 0.0;
    }

    if (smoothPolyline.IsEmpty())
    {
        return nullptr;
    }

    if (poPS->getNumGeometries() > 0)
    {
        poFeature->SetGeometryDirectly(poPS.release());
        PrepareBrushStyle(poFeature.get());
        return poFeature.release();
    }

    /* -------------------------------------------------------------------- */
    /*      Close polyline if necessary.                                    */
    /* -------------------------------------------------------------------- */
    if (nPolylineFlag & 0x01)
        smoothPolyline.Close();

    smoothPolyline.SetUseMaxGapWhenTessellatingArcs(poDS->InlineBlocks());
    OGRGeometry *poGeom = smoothPolyline.Tessellate();

    if ((nPolylineFlag & 8) == 0)
        poFeature->ApplyOCSTransformer(poGeom);
    poFeature->SetGeometryDirectly(poGeom);

    PrepareLineStyle(poFeature.get());

    return poFeature.release();
}

/************************************************************************/
/*                           TranslateMLINE()                           */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslateMLINE()

{
    char szLineBuf[257];
    int nCode = 0;

    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);

    bool bIsClosed = false;
    int nNumVertices = 0;
    int nNumElements = 0;

    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0 &&
           nCode != 11)
    {
        switch (nCode)
        {
            case 71:
                bIsClosed = (atoi(szLineBuf) & 2) == 2;
                break;

            case 72:
                nNumVertices = atoi(szLineBuf);
                break;

            case 73:
                nNumElements = atoi(szLineBuf);
                // No-one should ever need more than 1000 elements!
                if (nNumElements <= 0 || nNumElements > 1000)
                {
                    CPLDebug("DXF", "Invalid number of MLINE elements (73): %s",
                             szLineBuf);
                    DXF_LAYER_READER_ERROR();
                    return nullptr;
                }
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0 || nCode == 11)
        poDS->UnreadValue();

    /* -------------------------------------------------------------------- */
    /*      Read in the position and parameters for each vertex, and        */
    /*      translate these values into line geometries.                    */
    /* -------------------------------------------------------------------- */

    auto poMLS = std::make_unique<OGRMultiLineString>();
    std::vector<std::unique_ptr<OGRLineString>> apoCurrentLines(nNumElements);

    // For use when bIsClosed is true
    std::vector<DXFTriple> aoInitialVertices(nNumElements);

#define EXPECT_CODE(code)                                                      \
    if (poDS->ReadValue(szLineBuf, sizeof(szLineBuf)) != (code))               \
    {                                                                          \
        DXF_LAYER_READER_ERROR();                                              \
        return nullptr;                                                        \
    }

    for (int iVertex = 0; iVertex < nNumVertices; iVertex++)
    {
        EXPECT_CODE(11);
        const double dfVertexX = CPLAtof(szLineBuf);
        EXPECT_CODE(21);
        const double dfVertexY = CPLAtof(szLineBuf);
        EXPECT_CODE(31);
        const double dfVertexZ = CPLAtof(szLineBuf);

        EXPECT_CODE(12);
        const double dfSegmentDirectionX = CPLAtof(szLineBuf);
        EXPECT_CODE(22);
        const double dfSegmentDirectionY = CPLAtof(szLineBuf);
        EXPECT_CODE(32);
        const double dfSegmentDirectionZ = CPLAtof(szLineBuf);

        EXPECT_CODE(13);
        const double dfMiterDirectionX = CPLAtof(szLineBuf);
        EXPECT_CODE(23);
        const double dfMiterDirectionY = CPLAtof(szLineBuf);
        EXPECT_CODE(33);
        const double dfMiterDirectionZ = CPLAtof(szLineBuf);

        for (int iElement = 0; iElement < nNumElements; iElement++)
        {
            double dfStartSegmentX = 0.0;
            double dfStartSegmentY = 0.0;
            double dfStartSegmentZ = 0.0;

            EXPECT_CODE(74);
            const int nNumParameters = atoi(szLineBuf);

            // The first parameter is special: it is a distance along the
            // miter vector from the initial vertex to the start of the
            // element line.
            if (nNumParameters > 0)
            {
                EXPECT_CODE(41);
                const double dfDistance = CPLAtof(szLineBuf);

                dfStartSegmentX = dfVertexX + dfMiterDirectionX * dfDistance;
                dfStartSegmentY = dfVertexY + dfMiterDirectionY * dfDistance;
                dfStartSegmentZ = dfVertexZ + dfMiterDirectionZ * dfDistance;

                if (bIsClosed && iVertex == 0)
                {
                    aoInitialVertices[iElement] = DXFTriple(
                        dfStartSegmentX, dfStartSegmentY, dfStartSegmentZ);
                }

                // If we have an unfinished line for this element, we need
                // to close it off.
                if (apoCurrentLines[iElement])
                {
                    apoCurrentLines[iElement]->addPoint(
                        dfStartSegmentX, dfStartSegmentY, dfStartSegmentZ);
                    poMLS->addGeometryDirectly(
                        apoCurrentLines[iElement].release());
                }
            }

            // Parameters with an odd index give pen-up distances (breaks),
            // while even indexes are pen-down distances (line segments).
            for (int iParameter = 1; iParameter < nNumParameters; iParameter++)
            {
                EXPECT_CODE(41);
                const double dfDistance = CPLAtof(szLineBuf);

                const double dfCurrentX =
                    dfStartSegmentX + dfSegmentDirectionX * dfDistance;
                const double dfCurrentY =
                    dfStartSegmentY + dfSegmentDirectionY * dfDistance;
                const double dfCurrentZ =
                    dfStartSegmentZ + dfSegmentDirectionZ * dfDistance;

                if (iParameter % 2 == 0)
                {
                    // The dfCurrent(X,Y,Z) point is the end of a line segment
                    CPLAssert(apoCurrentLines[iElement]);
                    apoCurrentLines[iElement]->addPoint(dfCurrentX, dfCurrentY,
                                                        dfCurrentZ);
                    poMLS->addGeometryDirectly(
                        apoCurrentLines[iElement].release());
                }
                else
                {
                    // The dfCurrent(X,Y,Z) point is the end of a break
                    apoCurrentLines[iElement] =
                        std::make_unique<OGRLineString>();
                    apoCurrentLines[iElement]->addPoint(dfCurrentX, dfCurrentY,
                                                        dfCurrentZ);
                }
            }

            EXPECT_CODE(75);
            const int nNumAreaFillParams = atoi(szLineBuf);

            for (int iParameter = 0; iParameter < nNumAreaFillParams;
                 iParameter++)
            {
                EXPECT_CODE(42);
            }
        }
    }

#undef EXPECT_CODE

    // Close the MLINE if required.
    if (bIsClosed)
    {
        for (int iElement = 0; iElement < nNumElements; iElement++)
        {
            if (apoCurrentLines[iElement])
            {
                apoCurrentLines[iElement]->addPoint(
                    aoInitialVertices[iElement].dfX,
                    aoInitialVertices[iElement].dfY,
                    aoInitialVertices[iElement].dfZ);
                poMLS->addGeometryDirectly(apoCurrentLines[iElement].release());
            }
        }
    }

    // Apparently extrusions are ignored for MLINE entities.
    // poFeature->ApplyOCSTransformer( poMLS );
    poFeature->SetGeometryDirectly(poMLS.release());

    PrepareLineStyle(poFeature.get());

    return poFeature.release();
}

/************************************************************************/
/*                          TranslateCIRCLE()                           */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslateCIRCLE()

{
    char szLineBuf[257];
    int nCode = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);
    double dfX1 = 0.0;
    double dfY1 = 0.0;
    double dfZ1 = 0.0;
    double dfRadius = 0.0;
    double dfThickness = 0.0;
    bool bHaveZ = false;

    /* -------------------------------------------------------------------- */
    /*      Process values.                                                 */
    /* -------------------------------------------------------------------- */
    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 10:
                dfX1 = CPLAtof(szLineBuf);
                break;

            case 20:
                dfY1 = CPLAtof(szLineBuf);
                break;

            case 30:
                dfZ1 = CPLAtof(szLineBuf);
                bHaveZ = true;
                break;

            case 39:
                dfThickness = CPLAtof(szLineBuf);
                break;

            case 40:
                dfRadius = CPLAtof(szLineBuf);
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0)
        poDS->UnreadValue();

    /* -------------------------------------------------------------------- */
    /*      Create geometry                                                 */
    /* -------------------------------------------------------------------- */
    auto poCircle = std::unique_ptr<OGRLineString>(
        OGRGeometryFactory::approximateArcAngles(dfX1, dfY1, dfZ1, dfRadius,
                                                 dfRadius, 0.0, 0.0, 360.0, 0.0,
                                                 poDS->InlineBlocks())
            ->toLineString());

    const int nPoints = poCircle->getNumPoints();

    // If dfThickness is nonzero, we need to extrude a cylinder of height
    // dfThickness in the Z axis.
    if (dfThickness != 0.0 && nPoints > 1)
    {
        OGRPolyhedralSurface *poSurface = new OGRPolyhedralSurface();

        // Add the bottom base as a polygon
        OGRLinearRing *poRing1 = new OGRLinearRing();
        poRing1->addSubLineString(poCircle.get());

        OGRPolygon *poBase1 = new OGRPolygon();
        poBase1->addRingDirectly(poRing1);
        poSurface->addGeometryDirectly(poBase1);

        // Create and add the top base
        OGRLinearRing *poRing2 = poRing1->clone();

        OGRDXFInsertTransformer oTransformer;
        oTransformer.dfZOffset = dfThickness;
        poRing2->transform(&oTransformer);

        OGRPolygon *poBase2 = new OGRPolygon();
        poBase2->addRingDirectly(poRing2);
        poSurface->addGeometryDirectly(poBase2);

        // Add the side of the cylinder as two "semicylindrical" polygons
        auto poRect = std::make_unique<OGRLinearRing>();
        OGRPoint oPoint;

        for (int iPoint = nPoints / 2; iPoint >= 0; iPoint--)
        {
            poRing1->getPoint(iPoint, &oPoint);
            poRect->addPoint(&oPoint);
        }
        for (int iPoint = 0; iPoint <= nPoints / 2; iPoint++)
        {
            poRing2->getPoint(iPoint, &oPoint);
            poRect->addPoint(&oPoint);
        }

        poRect->closeRings();

        OGRPolygon *poRectPolygon = new OGRPolygon();
        poRectPolygon->addRingDirectly(poRect.release());
        poSurface->addGeometryDirectly(poRectPolygon);

        poRect = std::make_unique<OGRLinearRing>();

        for (int iPoint = nPoints - 1; iPoint >= nPoints / 2; iPoint--)
        {
            poRing1->getPoint(iPoint, &oPoint);
            poRect->addPoint(&oPoint);
        }
        for (int iPoint = nPoints / 2; iPoint < nPoints; iPoint++)
        {
            poRing2->getPoint(iPoint, &oPoint);
            poRect->addPoint(&oPoint);
        }

        poRect->closeRings();

        poRectPolygon = new OGRPolygon();
        poRectPolygon->addRingDirectly(poRect.release());
        poSurface->addGeometryDirectly(poRectPolygon);

        // That's your cylinder, folks
        poFeature->ApplyOCSTransformer(poSurface);
        poFeature->SetGeometryDirectly(poSurface);
    }
    else
    {
        if (!bHaveZ)
            poCircle->flattenTo2D();

        poFeature->ApplyOCSTransformer(poCircle.get());
        poFeature->SetGeometryDirectly(poCircle.release());
    }

    PrepareLineStyle(poFeature.get());

    return poFeature.release();
}

/************************************************************************/
/*                          TranslateELLIPSE()                          */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslateELLIPSE()

{
    char szLineBuf[257];
    int nCode = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);
    double dfX1 = 0.0;
    double dfY1 = 0.0;
    double dfZ1 = 0.0;
    double dfRatio = 0.0;
    double dfStartAngle = 0.0;
    double dfEndAngle = 360.0;
    double dfAxisX = 0.0;
    double dfAxisY = 0.0;
    double dfAxisZ = 0.0;
    bool bHaveZ = false;
    bool bApplyOCSTransform = false;

    /* -------------------------------------------------------------------- */
    /*      Process values.                                                 */
    /* -------------------------------------------------------------------- */
    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 10:
                dfX1 = CPLAtof(szLineBuf);
                break;

            case 20:
                dfY1 = CPLAtof(szLineBuf);
                break;

            case 30:
                dfZ1 = CPLAtof(szLineBuf);
                bHaveZ = true;
                break;

            case 11:
                dfAxisX = CPLAtof(szLineBuf);
                break;

            case 21:
                dfAxisY = CPLAtof(szLineBuf);
                break;

            case 31:
                dfAxisZ = CPLAtof(szLineBuf);
                break;

            case 40:
                dfRatio = CPLAtof(szLineBuf);
                break;

            case 41:
                // These *seem* to always be in radians regardless of $AUNITS
                dfEndAngle = -1 * CPLAtof(szLineBuf) * 180.0 / M_PI;
                break;

            case 42:
                // These *seem* to always be in radians regardless of $AUNITS
                dfStartAngle = -1 * CPLAtof(szLineBuf) * 180.0 / M_PI;
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0)
        poDS->UnreadValue();

    /* -------------------------------------------------------------------- */
    /*      Setup coordinate system                                         */
    /* -------------------------------------------------------------------- */
    double adfN[3];
    poFeature->oOCS.ToArray(adfN);

    if ((adfN[0] == 0.0 && adfN[1] == 0.0 && adfN[2] == 1.0) == false)
    {
        OGRDXFOCSTransformer oTransformer(adfN, true);

        bApplyOCSTransform = true;

        double *x = &dfX1;
        double *y = &dfY1;
        double *z = &dfZ1;
        oTransformer.InverseTransform(1, x, y, z);

        x = &dfAxisX;
        y = &dfAxisY;
        z = &dfAxisZ;
        oTransformer.InverseTransform(1, x, y, z);
    }

    /* -------------------------------------------------------------------- */
    /*      Compute primary and secondary axis lengths, and the angle of    */
    /*      rotation for the ellipse.                                       */
    /* -------------------------------------------------------------------- */
    double dfPrimaryRadius =
        sqrt(dfAxisX * dfAxisX + dfAxisY * dfAxisY + dfAxisZ * dfAxisZ);

    double dfSecondaryRadius = dfRatio * dfPrimaryRadius;

    double dfRotation = -1 * atan2(dfAxisY, dfAxisX) * 180 / M_PI;

    /* -------------------------------------------------------------------- */
    /*      Create geometry                                                 */
    /* -------------------------------------------------------------------- */
    if (dfStartAngle > dfEndAngle)
        dfEndAngle += 360.0;

    if (fabs(dfEndAngle - dfStartAngle) <= 361.0)
    {
        // Only honor OGR_DXF_MAX_GAP if this geometry isn't at risk of
        // being enlarged or shrunk as part of a block insertion.
        auto poEllipse = std::unique_ptr<OGRGeometry>(
            OGRGeometryFactory::approximateArcAngles(
                dfX1, dfY1, dfZ1, dfPrimaryRadius, dfSecondaryRadius,
                dfRotation, dfStartAngle, dfEndAngle, 0.0,
                poDS->InlineBlocks()));

        if (!bHaveZ)
            poEllipse->flattenTo2D();

        if (bApplyOCSTransform == true)
            poFeature->ApplyOCSTransformer(poEllipse.get());
        poFeature->SetGeometryDirectly(poEllipse.release());
    }
    else
    {
        // TODO: emit error ?
    }

    PrepareLineStyle(poFeature.get());

    return poFeature.release();
}

/************************************************************************/
/*                            TranslateARC()                            */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslateARC()

{
    char szLineBuf[257];
    int nCode = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);
    double dfX1 = 0.0;
    double dfY1 = 0.0;
    double dfZ1 = 0.0;
    double dfRadius = 0.0;
    double dfStartAngle = 0.0;
    double dfEndAngle = 360.0;
    bool bHaveZ = false;

    /* -------------------------------------------------------------------- */
    /*      Process values.                                                 */
    /* -------------------------------------------------------------------- */
    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 10:
                dfX1 = CPLAtof(szLineBuf);
                break;

            case 20:
                dfY1 = CPLAtof(szLineBuf);
                break;

            case 30:
                dfZ1 = CPLAtof(szLineBuf);
                bHaveZ = true;
                break;

            case 40:
                dfRadius = CPLAtof(szLineBuf);
                break;

            case 50:
                // This is apparently always degrees regardless of AUNITS
                dfEndAngle = -1 * CPLAtof(szLineBuf);
                break;

            case 51:
                // This is apparently always degrees regardless of AUNITS
                dfStartAngle = -1 * CPLAtof(szLineBuf);
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0)
        poDS->UnreadValue();

    /* -------------------------------------------------------------------- */
    /*      Create geometry                                                 */
    /* -------------------------------------------------------------------- */
    if (dfStartAngle > dfEndAngle)
        dfEndAngle += 360.0;

    if (fabs(dfEndAngle - dfStartAngle) <= 361.0)
    {
        auto poArc = std::unique_ptr<OGRGeometry>(
            OGRGeometryFactory::approximateArcAngles(
                dfX1, dfY1, dfZ1, dfRadius, dfRadius, 0.0, dfStartAngle,
                dfEndAngle, 0.0, poDS->InlineBlocks()));
        if (!bHaveZ)
            poArc->flattenTo2D();

        poFeature->ApplyOCSTransformer(poArc.get());
        poFeature->SetGeometryDirectly(poArc.release());
    }
    else
    {
        // TODO: emit error ?
    }

    PrepareLineStyle(poFeature.get());

    return poFeature.release();
}

/************************************************************************/
/*                          TranslateSPLINE()                           */
/************************************************************************/

void rbspline2(int npts, int k, int p1, double b[], double h[],
               bool bCalculateKnots, double knots[], double p[]);

OGRDXFFeature *OGRDXFLayer::TranslateSPLINE()

{
    char szLineBuf[257];
    int nCode;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);

    std::vector<double> adfControlPoints(1, 0.0);
    std::vector<double> adfKnots(1, 0.0);
    std::vector<double> adfWeights(1, 0.0);
    int nDegree = -1;
    int nControlPoints = -1;
    int nKnots = -1;

    /* -------------------------------------------------------------------- */
    /*      Process values.                                                 */
    /* -------------------------------------------------------------------- */
    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        bool bStop = false;
        switch (nCode)
        {
            case 10:
                adfControlPoints.push_back(CPLAtof(szLineBuf));
                break;

            case 20:
                adfControlPoints.push_back(CPLAtof(szLineBuf));
                adfControlPoints.push_back(0.0);
                break;

            case 40:
            {
                double dfVal = CPLAtof(szLineBuf);
                // Ad-hoc fix for https://github.com/OSGeo/gdal/issues/1969
                // where the first knot is at a very very close to zero negative
                // value and following knots are at 0.
                if (dfVal < 0 && dfVal > -1.0e-10)
                    dfVal = 0;
                adfKnots.push_back(dfVal);
                break;
            }

            case 41:
                adfWeights.push_back(CPLAtof(szLineBuf));
                break;

            case 70:
                break;

            case 71:
                nDegree = atoi(szLineBuf);
                // Arbitrary threshold
                if (nDegree < 0 || nDegree > 100)
                {
                    DXF_LAYER_READER_ERROR();
                    return nullptr;
                }
                break;

            case 72:
                nKnots = atoi(szLineBuf);
                // Arbitrary threshold
                if (nKnots < 0 || nKnots > 10000000)
                {
                    DXF_LAYER_READER_ERROR();
                    return nullptr;
                }
                break;

            case 73:
                nControlPoints = atoi(szLineBuf);
                // Arbitrary threshold
                if (nControlPoints < 0 || nControlPoints > 10000000)
                {
                    DXF_LAYER_READER_ERROR();
                    return nullptr;
                }
                break;

            case 100:
                if (EQUAL(szLineBuf, "AcDbHelix"))
                    bStop = true;
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }

        if (bStop)
            break;
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0)
        poDS->UnreadValue();

    /* -------------------------------------------------------------------- */
    /*      Use the helper function to check the input data and insert      */
    /*      the spline.                                                     */
    /* -------------------------------------------------------------------- */
    auto poLS =
        InsertSplineWithChecks(nDegree, adfControlPoints, nControlPoints,
                               adfKnots, nKnots, adfWeights);

    if (!poLS)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    poFeature->SetGeometryDirectly(poLS.release());

    PrepareLineStyle(poFeature.get());

    return poFeature.release();
}

/************************************************************************/
/*                       InsertSplineWithChecks()                       */
/*                                                                      */
/*     Inserts a spline based on unchecked DXF input.  The arrays are   */
/*     one-based.                                                       */
/************************************************************************/

std::unique_ptr<OGRLineString> OGRDXFLayer::InsertSplineWithChecks(
    const int nDegree, std::vector<double> &adfControlPoints,
    int nControlPoints, std::vector<double> &adfKnots, int nKnots,
    std::vector<double> &adfWeights)
{
    /* -------------------------------------------------------------------- */
    /*      Sanity checks                                                   */
    /* -------------------------------------------------------------------- */
    const int nOrder = nDegree + 1;

    bool bResult = (nOrder >= 2);
    if (bResult == true)
    {
        // Check whether nctrlpts value matches number of vertices read
        int nCheck = (static_cast<int>(adfControlPoints.size()) - 1) / 3;

        if (nControlPoints == -1)
            nControlPoints =
                (static_cast<int>(adfControlPoints.size()) - 1) / 3;

        // min( num(ctrlpts) ) = order
        bResult = (nControlPoints >= nOrder && nControlPoints == nCheck);
    }

    bool bCalculateKnots = false;
    if (bResult == true)
    {
        int nCheck = static_cast<int>(adfKnots.size()) - 1;

        // Recalculate knots when:
        // - no knots data present, nknots is -1 and ncheck is 0
        // - nknots value present, no knot vertices
        //   nknots is (nctrlpts + order), ncheck is 0
        if (nCheck == 0)
        {
            bCalculateKnots = true;
            for (int i = 0; i < (nControlPoints + nOrder); i++)
                adfKnots.push_back(0.0);

            nCheck = static_cast<int>(adfKnots.size()) - 1;
        }
        // Adjust nknots value when:
        // - nknots value not present, knot vertices present
        //   nknots is -1, ncheck is (nctrlpts + order)
        if (nKnots == -1)
            nKnots = static_cast<int>(adfKnots.size()) - 1;

        // num(knots) = num(ctrlpts) + order
        bResult = (nKnots == (nControlPoints + nOrder) && nKnots == nCheck);
    }

    if (bResult == true)
    {
        int nWeights = static_cast<int>(adfWeights.size()) - 1;

        if (nWeights == 0)
        {
            for (int i = 0; i < nControlPoints; i++)
                adfWeights.push_back(1.0);

            nWeights = static_cast<int>(adfWeights.size()) - 1;
        }

        // num(weights) = num(ctrlpts)
        bResult = (nWeights == nControlPoints);
    }

    if (bResult == false)
        return nullptr;

    /* -------------------------------------------------------------------- */
    /*      Interpolate spline                                              */
    /* -------------------------------------------------------------------- */
    int p1 = nControlPoints * 8;
    std::vector<double> p;

    p.push_back(0.0);
    for (int i = 0; i < 3 * p1; i++)
        p.push_back(0.0);

    rbspline2(nControlPoints, nOrder, p1, &(adfControlPoints[0]),
              &(adfWeights[0]), bCalculateKnots, &(adfKnots[0]), &(p[0]));

    /* -------------------------------------------------------------------- */
    /*      Turn into OGR geometry.                                         */
    /* -------------------------------------------------------------------- */
    auto poLS = std::make_unique<OGRLineString>();

    poLS->setNumPoints(p1);
    for (int i = 0; i < p1; i++)
        poLS->setPoint(i, p[i * 3 + 1], p[i * 3 + 2]);

    return poLS;
}

/************************************************************************/
/*                          Translate3DFACE()                           */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::Translate3DFACE()

{
    char szLineBuf[257];
    int nCode = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);
    double dfX1 = 0.0;
    double dfY1 = 0.0;
    double dfZ1 = 0.0;
    double dfX2 = 0.0;
    double dfY2 = 0.0;
    double dfZ2 = 0.0;
    double dfX3 = 0.0;
    double dfY3 = 0.0;
    double dfZ3 = 0.0;
    double dfX4 = 0.0;
    double dfY4 = 0.0;
    double dfZ4 = 0.0;

    /* -------------------------------------------------------------------- */
    /*      Process values.                                                 */
    /* -------------------------------------------------------------------- */
    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 10:
                dfX1 = CPLAtof(szLineBuf);
                break;

            case 11:
                dfX2 = CPLAtof(szLineBuf);
                break;

            case 12:
                dfX3 = CPLAtof(szLineBuf);
                break;

            case 13:
                dfX4 = CPLAtof(szLineBuf);
                break;

            case 20:
                dfY1 = CPLAtof(szLineBuf);
                break;

            case 21:
                dfY2 = CPLAtof(szLineBuf);
                break;

            case 22:
                dfY3 = CPLAtof(szLineBuf);
                break;

            case 23:
                dfY4 = CPLAtof(szLineBuf);
                break;

            case 30:
                dfZ1 = CPLAtof(szLineBuf);
                break;

            case 31:
                dfZ2 = CPLAtof(szLineBuf);
                break;

            case 32:
                dfZ3 = CPLAtof(szLineBuf);
                break;

            case 33:
                dfZ4 = CPLAtof(szLineBuf);
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    if (nCode == 0)
        poDS->UnreadValue();

    /* -------------------------------------------------------------------- */
    /*      Create geometry                                                 */
    /* -------------------------------------------------------------------- */
    auto poPoly = std::make_unique<OGRPolygon>();
    OGRLinearRing *poLR = new OGRLinearRing();
    poLR->addPoint(dfX1, dfY1, dfZ1);
    poLR->addPoint(dfX2, dfY2, dfZ2);
    poLR->addPoint(dfX3, dfY3, dfZ3);
    if (dfX4 != dfX3 || dfY4 != dfY3 || dfZ4 != dfZ3)
        poLR->addPoint(dfX4, dfY4, dfZ4);
    poPoly->addRingDirectly(poLR);
    poPoly->closeRings();

    poFeature->ApplyOCSTransformer(poLR);
    poFeature->SetGeometryDirectly(poPoly.release());

    PrepareLineStyle(poFeature.get());

    return poFeature.release();
}

/* -------------------------------------------------------------------- */
/*      PointXAxisComparer                                              */
/*                                                                      */
/*      Returns true if oP1 is to the left of oP2, or they have the     */
/*      same x-coordinate and oP1 is below oP2.                         */
/* -------------------------------------------------------------------- */

static bool PointXAxisComparer(const OGRPoint &oP1, const OGRPoint &oP2)
{
    return oP1.getX() == oP2.getX() ? oP1.getY() < oP2.getY()
                                    : oP1.getX() < oP2.getX();
}

/* -------------------------------------------------------------------- */
/*      PointXYZEqualityComparer                                        */
/*                                                                      */
/*      Returns true if oP1 is equal to oP2 in the X, Y and Z axes.     */
/* -------------------------------------------------------------------- */

static bool PointXYZEqualityComparer(const OGRPoint &oP1, const OGRPoint &oP2)
{
    return oP1.getX() == oP2.getX() && oP1.getY() == oP2.getY() &&
           oP1.getZ() == oP2.getZ();
}

/************************************************************************/
/*                           TranslateSOLID()                           */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslateSOLID()

{
    char szLineBuf[257];
    int nCode = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);
    double dfX1 = 0.0;
    double dfY1 = 0.0;
    double dfZ1 = 0.0;
    double dfX2 = 0.0;
    double dfY2 = 0.0;
    double dfZ2 = 0.0;
    double dfX3 = 0.0;
    double dfY3 = 0.0;
    double dfZ3 = 0.0;
    double dfX4 = 0.0;
    double dfY4 = 0.0;
    double dfZ4 = 0.0;

    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 10:
                dfX1 = CPLAtof(szLineBuf);
                break;

            case 20:
                dfY1 = CPLAtof(szLineBuf);
                break;

            case 30:
                dfZ1 = CPLAtof(szLineBuf);
                break;

            case 11:
                dfX2 = CPLAtof(szLineBuf);
                break;

            case 21:
                dfY2 = CPLAtof(szLineBuf);
                break;

            case 31:
                dfZ2 = CPLAtof(szLineBuf);
                break;

            case 12:
                dfX3 = CPLAtof(szLineBuf);
                break;

            case 22:
                dfY3 = CPLAtof(szLineBuf);
                break;

            case 32:
                dfZ3 = CPLAtof(szLineBuf);
                break;

            case 13:
                dfX4 = CPLAtof(szLineBuf);
                break;

            case 23:
                dfY4 = CPLAtof(szLineBuf);
                break;

            case 33:
                dfZ4 = CPLAtof(szLineBuf);
                break;

            default:
                TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }
    if (nCode == 0)
        poDS->UnreadValue();

    // do we want Z-coordinates?
    const bool bWantZ =
        dfZ1 != 0.0 || dfZ2 != 0.0 || dfZ3 != 0.0 || dfZ4 != 0.0;

    // check how many unique corners we have
    OGRPoint oCorners[4];
    oCorners[0].setX(dfX1);
    oCorners[0].setY(dfY1);
    if (bWantZ)
        oCorners[0].setZ(dfZ1);
    oCorners[1].setX(dfX2);
    oCorners[1].setY(dfY2);
    if (bWantZ)
        oCorners[1].setZ(dfZ2);
    oCorners[2].setX(dfX3);
    oCorners[2].setY(dfY3);
    if (bWantZ)
        oCorners[2].setZ(dfZ3);
    oCorners[3].setX(dfX4);
    oCorners[3].setY(dfY4);
    if (bWantZ)
        oCorners[3].setZ(dfZ4);

    std::sort(&oCorners[0], &oCorners[4], PointXAxisComparer);
    int nCornerCount = static_cast<int>(
        std::unique(&oCorners[0], &oCorners[4], PointXYZEqualityComparer) -
        &oCorners[0]);
    if (nCornerCount < 1)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    std::unique_ptr<OGRGeometry> poFinalGeom;

    // what kind of object do we need?
    if (nCornerCount == 1)
    {
        poFinalGeom.reset(oCorners[0].clone());

        PrepareLineStyle(poFeature.get());
    }
    else if (nCornerCount == 2)
    {
        auto poLS = std::make_unique<OGRLineString>();
        poLS->setPoint(0, &oCorners[0]);
        poLS->setPoint(1, &oCorners[1]);
        poFinalGeom.reset(poLS.release());

        PrepareLineStyle(poFeature.get());
    }
    else
    {
        // SOLID vertices seem to be joined in the order 1-2-4-3-1.
        // See trac ticket #7089
        OGRLinearRing *poLinearRing = new OGRLinearRing();
        int iIndex = 0;
        poLinearRing->setPoint(iIndex++, dfX1, dfY1, dfZ1);
        if (dfX1 != dfX2 || dfY1 != dfY2 || dfZ1 != dfZ2)
            poLinearRing->setPoint(iIndex++, dfX2, dfY2, dfZ2);
        if (dfX2 != dfX4 || dfY2 != dfY4 || dfZ2 != dfZ4)
            poLinearRing->setPoint(iIndex++, dfX4, dfY4, dfZ4);
        if (dfX4 != dfX3 || dfY4 != dfY3 || dfZ4 != dfZ3)
            poLinearRing->setPoint(iIndex++, dfX3, dfY3, dfZ3);
        poLinearRing->closeRings();

        if (!bWantZ)
            poLinearRing->flattenTo2D();

        auto poPoly = std::make_unique<OGRPolygon>();
        poPoly->addRingDirectly(poLinearRing);
        poFinalGeom.reset(poPoly.release());

        PrepareBrushStyle(poFeature.get());
    }

    poFeature->ApplyOCSTransformer(poFinalGeom.get());
    poFeature->SetGeometryDirectly(poFinalGeom.release());

    return poFeature.release();
}

/************************************************************************/
/*                         TranslateASMEntity()                         */
/*                                                                      */
/*     Translate Autodesk ShapeManager entities (3DSOLID, REGION,       */
/*     SURFACE), also known as ACIS entities.                           */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::TranslateASMEntity()

{
    char szLineBuf[257];
    int nCode = 0;
    auto poFeature = std::make_unique<OGRDXFFeature>(poFeatureDefn);

    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        TranslateGenericProperty(poFeature.get(), nCode, szLineBuf);
    }

    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        return nullptr;
    }

    poDS->UnreadValue();

    const char *pszEntityHandle = poFeature->GetFieldAsString("EntityHandle");

    // The actual data is located at the end of the DXF file (sigh).
    const GByte *pabyBinaryData;
    size_t nDataLength =
        poDS->GetEntryFromAcDsDataSection(pszEntityHandle, &pabyBinaryData);
    if (!pabyBinaryData)
    {
        CPLError(CE_Warning, CPLE_AppDefined,
                 "ACDSRECORD data for entity %s was not found.",
                 pszEntityHandle);
        return poFeature.release();
    }

    // Return a feature with no geometry but with one very interesting field.
    poFeature->SetField(poFeatureDefn->GetFieldIndex("ASMData"),
                        static_cast<int>(nDataLength), pabyBinaryData);

    // Set up an affine transformation matrix so the user will be able to
    // transform the resulting 3D geometry
    poFeature->poASMTransform = std::make_unique<OGRDXFAffineTransform>();

    poFeature->poASMTransform->SetField(poFeature.get(), "ASMTransform");

#ifdef notdef
    FILE *fp;
    fopen_s(&fp,
            CPLString().Printf("C:\\Projects\\output.sab", pszEntityHandle),
            "wb");

    if (fp != nullptr)
    {
        fprintf(fp, "Entity handle:  %s\r\n\r\n", pszEntityHandle);
        fwrite(pabyBinaryData, sizeof(GByte), nDataLength, fp);
        if (ferror(fp) != 0)
        {
            fputs("Error writing .sab file", stderr);
        }
        fclose(fp);
    }
#endif

    PrepareBrushStyle(poFeature.get());

    return poFeature.release();
}

/************************************************************************/
/*                       SimplifyBlockGeometry()                        */
/************************************************************************/

OGRGeometry *
OGRDXFLayer::SimplifyBlockGeometry(OGRGeometryCollection *poCollection)
{
    /* -------------------------------------------------------------------- */
    /*      If there is only one geometry in the collection, just return    */
    /*      it.                                                             */
    /* -------------------------------------------------------------------- */
    if (poCollection->getNumGeometries() == 1)
    {
        OGRGeometry *poReturn = poCollection->getGeometryRef(0);
        poCollection->removeGeometry(0, FALSE);
        delete poCollection;
        return poReturn;
    }

    /* -------------------------------------------------------------------- */
    /*      Convert to polygon, multipolygon, multilinestring or multipoint */
    /* -------------------------------------------------------------------- */

    OGRwkbGeometryType eType =
        wkbFlatten(poCollection->getGeometryRef(0)->getGeometryType());
    int i;
    for (i = 1; i < poCollection->getNumGeometries(); i++)
    {
        if (wkbFlatten(poCollection->getGeometryRef(i)->getGeometryType()) !=
            eType)
        {
            eType = wkbUnknown;
            break;
        }
    }
    if (eType == wkbPoint || eType == wkbLineString)
    {
        OGRGeometryCollection *poNewColl;
        if (eType == wkbPoint)
            poNewColl = new OGRMultiPoint();
        else
            poNewColl = new OGRMultiLineString();
        while (poCollection->getNumGeometries() > 0)
        {
            OGRGeometry *poGeom = poCollection->getGeometryRef(0);
            poCollection->removeGeometry(0, FALSE);
            poNewColl->addGeometryDirectly(poGeom);
        }
        delete poCollection;
        return poNewColl;
    }
    else if (eType == wkbPolygon)
    {
        std::vector<OGRGeometry *> aosPolygons;
        while (poCollection->getNumGeometries() > 0)
        {
            OGRGeometry *poGeom = poCollection->getGeometryRef(0);
            poCollection->removeGeometry(0, FALSE);
            if (!aosPolygons.empty() && aosPolygons[0]->Equals(poGeom))
            {
                // Avoids a performance issue as in
                // https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=8067
                delete poGeom;
            }
            else
            {
                aosPolygons.push_back(poGeom);
            }
        }
        delete poCollection;
        int bIsValidGeometry;
        return OGRGeometryFactory::organizePolygons(&aosPolygons[0],
                                                    (int)aosPolygons.size(),
                                                    &bIsValidGeometry, nullptr);
    }

    return poCollection;
}

/************************************************************************/
/*                       InsertBlockReference()                         */
/*                                                                      */
/*     Returns a point geometry located at the block's insertion        */
/*     point.                                                           */
/************************************************************************/
OGRDXFFeature *
OGRDXFLayer::InsertBlockReference(const CPLString &osBlockName,
                                  const OGRDXFInsertTransformer &oTransformer,
                                  OGRDXFFeature *const poFeature)
{
    // Store the block's properties in the special DXF-specific members
    // on the feature object
    poFeature->bIsBlockReference = true;
    poFeature->osBlockName = osBlockName;
    poFeature->dfBlockAngle = oTransformer.dfAngle * 180 / M_PI;
    poFeature->oBlockScale = DXFTriple(
        oTransformer.dfXScale, oTransformer.dfYScale, oTransformer.dfZScale);
    poFeature->oOriginalCoords = DXFTriple(
        oTransformer.dfXOffset, oTransformer.dfYOffset, oTransformer.dfZOffset);

    // Only if DXF_INLINE_BLOCKS is false should we ever need to expose these
    // to the end user as fields.
    if (poFeature->GetFieldIndex("BlockName") != -1)
    {
        poFeature->SetField("BlockName", poFeature->osBlockName);
        poFeature->SetField("BlockAngle", poFeature->dfBlockAngle);
        poFeature->SetField("BlockScale", 3, &(poFeature->oBlockScale.dfX));
        poFeature->SetField("BlockOCSNormal", 3, &(poFeature->oOCS.dfX));
        poFeature->SetField("BlockOCSCoords", 3,
                            &(poFeature->oOriginalCoords.dfX));
    }

    // For convenience to the end user, the point geometry will be located
    // at the WCS coordinates of the insertion point.
    OGRPoint *poInsertionPoint = new OGRPoint(
        oTransformer.dfXOffset, oTransformer.dfYOffset, oTransformer.dfZOffset);

    poFeature->ApplyOCSTransformer(poInsertionPoint);
    poFeature->SetGeometryDirectly(poInsertionPoint);

    return poFeature;
}

/************************************************************************/
/*                         InsertBlockInline()                          */
/*                                                                      */
/*     Inserts the given block at the location specified by the given   */
/*     transformer.  Returns poFeature, or NULL if all features on      */
/*     the block have been pushed to the extra feature queue.           */
/*     If poFeature is not returned, it is deleted.                     */
/*     Throws std::invalid_argument if the requested block              */
/*     doesn't exist.                                                   */
/*                                                                      */
/*     - poFeature: The feature to use as a template. This feature's    */
/*       OCS will be applied to the block.                              */
/*     - bInlineRecursively: If true, INSERTs within this block         */
/*       will be recursively inserted.  Otherwise, they will be         */
/*       represented as a point geometry using InsertBlockReference.    */
/*     - bMergeGeometry: If true, all features in the block,            */
/*       apart from text features, are merged into a                    */
/*       GeometryCollection which is returned by the function.          */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::InsertBlockInline(
    GUInt32 nInitialErrorCounter, const CPLString &osBlockName,
    OGRDXFInsertTransformer oTransformer, OGRDXFFeature *const poFeature,
    OGRDXFFeatureQueue &apoExtraFeatures, const bool bInlineRecursively,
    const bool bMergeGeometry)
{
    /* -------------------------------------------------------------------- */
    /*      Set up protection against excessive recursion on this layer.    */
    /* -------------------------------------------------------------------- */
    if (!poDS->PushBlockInsertion(osBlockName))
    {
        delete poFeature;
        return nullptr;
    }

    /* -------------------------------------------------------------------- */
    /*      Transform the insertion point from OCS into                     */
    /*      world coordinates.                                              */
    /* -------------------------------------------------------------------- */
    OGRPoint oInsertionPoint(oTransformer.dfXOffset, oTransformer.dfYOffset,
                             oTransformer.dfZOffset);

    poFeature->ApplyOCSTransformer(&oInsertionPoint);

    oTransformer.dfXOffset = oInsertionPoint.getX();
    oTransformer.dfYOffset = oInsertionPoint.getY();
    oTransformer.dfZOffset = oInsertionPoint.getZ();

    /* -------------------------------------------------------------------- */
    /*      Lookup the block.                                               */
    /* -------------------------------------------------------------------- */
    DXFBlockDefinition *poBlock = poDS->LookupBlock(osBlockName);

    if (poBlock == nullptr)
    {
        // CPLDebug( "DXF", "Attempt to insert missing block %s", osBlockName );
        poDS->PopBlockInsertion();
        throw std::invalid_argument("osBlockName");
    }

    /* -------------------------------------------------------------------- */
    /*      If we have complete features associated with the block, push    */
    /*      them on the pending feature stack copying over key override     */
    /*      information.                                                    */
    /*                                                                      */
    /*      If bMergeGeometry is true, we merge the features                */
    /*      (except text) into a single GeometryCollection.                 */
    /* -------------------------------------------------------------------- */
    OGRGeometryCollection *poMergedGeometry = nullptr;
    if (bMergeGeometry)
        poMergedGeometry = new OGRGeometryCollection();

    OGRDXFFeatureQueue apoInnerExtraFeatures;

    for (unsigned int iSubFeat = 0; iSubFeat < poBlock->apoFeatures.size();
         iSubFeat++)
    {
        OGRDXFFeature *poSubFeature =
            poBlock->apoFeatures[iSubFeat]->CloneDXFFeature();

        // If the template feature is in PaperSpace, set this on the
        // subfeature too
        if (poFeature->GetFieldAsInteger("PaperSpace"))
            poSubFeature->SetField("PaperSpace", 1);

        // Does this feature represent a block reference? If so,
        // insert that block
        if (bInlineRecursively && poSubFeature->IsBlockReference())
        {
            // Unpack the transformation data stored in fields of this
            // feature
            OGRDXFInsertTransformer oInnerTransformer;
            oInnerTransformer.dfXOffset = poSubFeature->oOriginalCoords.dfX;
            oInnerTransformer.dfYOffset = poSubFeature->oOriginalCoords.dfY;
            oInnerTransformer.dfZOffset = poSubFeature->oOriginalCoords.dfZ;
            oInnerTransformer.dfAngle = poSubFeature->dfBlockAngle * M_PI / 180;
            oInnerTransformer.dfXScale = poSubFeature->oBlockScale.dfX;
            oInnerTransformer.dfYScale = poSubFeature->oBlockScale.dfY;
            oInnerTransformer.dfZScale = poSubFeature->oBlockScale.dfZ;

            poSubFeature->bIsBlockReference = false;

            // Keep a reference to the attributes that need to be inserted
            std::vector<std::unique_ptr<OGRDXFFeature>> apoInnerAttribFeatures =
                std::move(poSubFeature->apoAttribFeatures);

            // Insert this block recursively
            try
            {
                poSubFeature = InsertBlockInline(
                    nInitialErrorCounter, poSubFeature->osBlockName,
                    std::move(oInnerTransformer), poSubFeature,
                    apoInnerExtraFeatures, true, bMergeGeometry);
            }
            catch (const std::invalid_argument &)
            {
                // Block doesn't exist. Skip it and keep going
                delete poSubFeature;
                if (CPLGetErrorCounter() > nInitialErrorCounter + 1000)
                {
                    break;
                }
                continue;
            }

            if (!poSubFeature)
            {
                if (CPLGetErrorCounter() > nInitialErrorCounter + 1000)
                {
                    break;
                }

                // Append the attribute features to the pending feature stack
                for (auto &poAttribFeature : apoInnerAttribFeatures)
                {
                    // Clear the attribute tag so the feature doesn't get mistaken
                    // for an ATTDEF and skipped
                    poAttribFeature->osAttributeTag = "";

                    apoInnerExtraFeatures.push(poAttribFeature.release());
                }

                if (apoInnerExtraFeatures.empty())
                {
                    // Block is empty and has no attributes. Skip it and keep going
                    continue;
                }
                else
                {
                    // Load up the first extra feature ready for
                    // transformation
                    poSubFeature = apoInnerExtraFeatures.front();
                    apoInnerExtraFeatures.pop();
                }
            }
        }

        // Go through the current feature and any extra features generated
        // by the recursive insert, and apply transformations
        while (true)
        {
            OGRGeometry *poSubFeatGeom = poSubFeature->GetGeometryRef();
            if (poSubFeatGeom != nullptr)
            {
                // Rotation and scaling first
                OGRDXFInsertTransformer oInnerTrans =
                    oTransformer.GetRotateScaleTransformer();
                poSubFeatGeom->transform(&oInnerTrans);

                // Then the OCS to WCS transformation
                poFeature->ApplyOCSTransformer(poSubFeatGeom);

                // Offset translation last
                oInnerTrans = oTransformer.GetOffsetTransformer();
                poSubFeatGeom->transform(&oInnerTrans);
            }
            // Transform the specially-stored data for ASM entities
            else if (poSubFeature->poASMTransform)
            {
                // Rotation and scaling first
                OGRDXFInsertTransformer oInnerTrans =
                    oTransformer.GetRotateScaleTransformer();
                poSubFeature->poASMTransform->ComposeWith(oInnerTrans);

                // Then the OCS to WCS transformation
                poFeature->ApplyOCSTransformer(
                    poSubFeature->poASMTransform.get());

                // Offset translation last
                oInnerTrans = oTransformer.GetOffsetTransformer();
                poSubFeature->poASMTransform->ComposeWith(oInnerTrans);

                poSubFeature->poASMTransform->SetField(poSubFeature,
                                                       "ASMTransform");
            }

            // If we are merging features, and this is not text or a block
            // reference, merge it into the GeometryCollection
            if (bMergeGeometry &&
                (poSubFeature->GetStyleString() == nullptr ||
                 strstr(poSubFeature->GetStyleString(), "LABEL") == nullptr) &&
                !poSubFeature->IsBlockReference() &&
                poSubFeature->GetGeometryRef())
            {
                poMergedGeometry->addGeometryDirectly(
                    poSubFeature->StealGeometry());
                delete poSubFeature;
            }
            // Import all other features, except ATTDEFs when inlining
            // recursively
            else if (!bInlineRecursively || poSubFeature->osAttributeTag == "")
            {
                // If the subfeature is on layer 0, this is a special case: the
                // subfeature should take on the style properties of the layer
                // the block is being inserted onto.
                // But don't do this if we are inserting onto a Blocks layer
                // (that is, the owning feature has no layer).
                if (EQUAL(poSubFeature->GetFieldAsString("Layer"), "0") &&
                    !EQUAL(poFeature->GetFieldAsString("Layer"), ""))
                {
                    poSubFeature->SetField(
                        "Layer", poFeature->GetFieldAsString("Layer"));
                }

                // Update the style string to replace ByBlock and ByLayer
                // values.
                PrepareFeatureStyle(poSubFeature, poFeature);

                ACAdjustText(oTransformer.dfAngle * 180 / M_PI,
                             oTransformer.dfXScale, oTransformer.dfYScale,
                             poSubFeature);

                if (!EQUAL(poFeature->GetFieldAsString("EntityHandle"), ""))
                {
                    poSubFeature->SetField(
                        "EntityHandle",
                        poFeature->GetFieldAsString("EntityHandle"));
                }

                apoExtraFeatures.push(poSubFeature);
            }
            else
            {
                delete poSubFeature;
            }

            if (apoInnerExtraFeatures.empty())
            {
                break;
            }
            else
            {
                poSubFeature = apoInnerExtraFeatures.front();
                apoInnerExtraFeatures.pop();
            }
        }
    }

    while (!apoInnerExtraFeatures.empty())
    {
        auto poFeatureToDelete = apoInnerExtraFeatures.front();
        apoInnerExtraFeatures.pop();
        delete poFeatureToDelete;
    }

    poDS->PopBlockInsertion();

    /* -------------------------------------------------------------------- */
    /*      Return the merged geometry if applicable.  Otherwise            */
    /*      return NULL and let the machinery find the rest of the          */
    /*      features in the pending feature stack.                          */
    /* -------------------------------------------------------------------- */
    if (bMergeGeometry)
    {
        if (poMergedGeometry->getNumGeometries() == 0)
        {
            delete poMergedGeometry;
        }
        else
        {
            poFeature->SetGeometryDirectly(
                SimplifyBlockGeometry(poMergedGeometry));

            PrepareLineStyle(poFeature);
            return poFeature;
        }
    }

    delete poFeature;
    return nullptr;
}

/************************************************************************/
/*                          TranslateINSERT()                           */
/************************************************************************/

bool OGRDXFLayer::TranslateINSERT()

{
    char szLineBuf[257];
    int nCode = 0;

    m_oInsertState.m_poTemplateFeature.reset(new OGRDXFFeature(poFeatureDefn));
    m_oInsertState.m_oTransformer = OGRDXFInsertTransformer();
    m_oInsertState.m_osBlockName.clear();
    m_oInsertState.m_nColumnCount = 1;
    m_oInsertState.m_nRowCount = 1;
    m_oInsertState.m_iCurCol = 0;
    m_oInsertState.m_iCurRow = 0;
    m_oInsertState.m_dfColumnSpacing = 0.0;
    m_oInsertState.m_dfRowSpacing = 0.0;

    bool bHasAttribs = false;
    m_oInsertState.m_apoAttribs.clear();
    m_oInsertState.m_aosAttribs.Clear();

    /* -------------------------------------------------------------------- */
    /*      Process values.                                                 */
    /* -------------------------------------------------------------------- */
    while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
    {
        switch (nCode)
        {
            case 10:
                m_oInsertState.m_oTransformer.dfXOffset = CPLAtof(szLineBuf);
                break;

            case 20:
                m_oInsertState.m_oTransformer.dfYOffset = CPLAtof(szLineBuf);
                break;

            case 30:
                m_oInsertState.m_oTransformer.dfZOffset = CPLAtof(szLineBuf);
                break;

            case 41:
                m_oInsertState.m_oTransformer.dfXScale = CPLAtof(szLineBuf);
                break;

            case 42:
                m_oInsertState.m_oTransformer.dfYScale = CPLAtof(szLineBuf);
                break;

            case 43:
                m_oInsertState.m_oTransformer.dfZScale = CPLAtof(szLineBuf);
                break;

            case 44:
                m_oInsertState.m_dfColumnSpacing = CPLAtof(szLineBuf);
                break;

            case 45:
                m_oInsertState.m_dfRowSpacing = CPLAtof(szLineBuf);
                break;

            case 50:
                // We want to transform this to radians.
                // It is apparently always in degrees regardless of $AUNITS
                m_oInsertState.m_oTransformer.dfAngle =
                    CPLAtof(szLineBuf) * M_PI / 180.0;
                break;

            case 66:
                bHasAttribs = atoi(szLineBuf) == 1;
                break;

            case 70:
                m_oInsertState.m_nColumnCount = atoi(szLineBuf);
                if (m_oInsertState.m_nColumnCount <= 0)
                {
                    DXF_LAYER_READER_ERROR();
                    m_oInsertState.m_nRowCount = 0;
                    m_oInsertState.m_nColumnCount = 0;
                    return false;
                }
                break;

            case 71:
                m_oInsertState.m_nRowCount = atoi(szLineBuf);
                if (m_oInsertState.m_nRowCount <= 0)
                {
                    DXF_LAYER_READER_ERROR();
                    m_oInsertState.m_nRowCount = 0;
                    m_oInsertState.m_nColumnCount = 0;
                    return false;
                }
                break;

            case 2:
                m_oInsertState.m_osBlockName = szLineBuf;
                break;

            default:
                TranslateGenericProperty(
                    m_oInsertState.m_poTemplateFeature.get(), nCode, szLineBuf);
                break;
        }
    }
    if (nCode < 0)
    {
        DXF_LAYER_READER_ERROR();
        m_oInsertState.m_nRowCount = 0;
        m_oInsertState.m_nColumnCount = 0;
        return false;
    }

    /* -------------------------------------------------------------------- */
    /*      Process any attribute entities.                                 */
    /* -------------------------------------------------------------------- */

    if (bHasAttribs)
    {
        while (nCode == 0 && !EQUAL(szLineBuf, "SEQEND"))
        {
            if (!EQUAL(szLineBuf, "ATTRIB"))
            {
                DXF_LAYER_READER_ERROR();
                m_oInsertState.m_nRowCount = 0;
                m_oInsertState.m_nColumnCount = 0;
                return false;
            }

            auto poAttribFeature =
                std::unique_ptr<OGRDXFFeature>(TranslateTEXT(true));

            if (poAttribFeature && poAttribFeature->osAttributeTag != "")
            {
                m_oInsertState.m_apoAttribs.emplace_back(
                    std::move(poAttribFeature));
            }

            nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf));
        }
    }
    else if (nCode == 0)
    {
        poDS->UnreadValue();
    }

    /* -------------------------------------------------------------------- */
    /*      Prepare a string list of the attributes and their text values   */
    /*      as space-separated entries, to be stored in the                 */
    /*      BlockAttributes field if we are not inlining blocks.            */
    /* -------------------------------------------------------------------- */

    if (!poDS->InlineBlocks() && bHasAttribs &&
        poFeatureDefn->GetFieldIndex("BlockAttributes") != -1)
    {
        for (const auto &poAttr : m_oInsertState.m_apoAttribs)
        {
            CPLString osAttribString = poAttr->osAttributeTag;
            osAttribString += " ";
            osAttribString += poAttr->GetFieldAsString("Text");

            m_oInsertState.m_aosAttribs.AddString(osAttribString);
        }
    }

    return true;
}

/************************************************************************/
/*                       GenerateINSERTFeatures()                       */
/************************************************************************/

bool OGRDXFLayer::GenerateINSERTFeatures()
{
    OGRDXFFeature *poFeature =
        m_oInsertState.m_poTemplateFeature->CloneDXFFeature();

    const double dfExtraXOffset =
        m_oInsertState.m_iCurCol * m_oInsertState.m_dfColumnSpacing *
            cos(m_oInsertState.m_oTransformer.dfAngle) +
        m_oInsertState.m_iCurRow * m_oInsertState.m_dfRowSpacing *
            -sin(m_oInsertState.m_oTransformer.dfAngle);
    const double dfExtraYOffset =
        m_oInsertState.m_iCurCol * m_oInsertState.m_dfColumnSpacing *
            sin(m_oInsertState.m_oTransformer.dfAngle) +
        m_oInsertState.m_iCurRow * m_oInsertState.m_dfRowSpacing *
            cos(m_oInsertState.m_oTransformer.dfAngle);

    OGRDXFInsertTransformer oTransformer(m_oInsertState.m_oTransformer);
    oTransformer.dfXOffset += dfExtraXOffset;
    oTransformer.dfYOffset += dfExtraYOffset;

    // If we are not inlining blocks, just insert a point that refers
    // to this block
    if (!poDS->InlineBlocks())
    {
        poFeature = InsertBlockReference(m_oInsertState.m_osBlockName,
                                         oTransformer, poFeature);

        auto papszAttribs = m_oInsertState.m_aosAttribs.List();
        if (papszAttribs)
            poFeature->SetField("BlockAttributes", papszAttribs);

        poFeature->apoAttribFeatures = std::move(m_oInsertState.m_apoAttribs);

        apoPendingFeatures.push(poFeature);
    }
    // Otherwise, try inlining the contents of this block
    else
    {
        OGRDXFFeatureQueue apoExtraFeatures;
        try
        {
            poFeature = InsertBlockInline(
                CPLGetErrorCounter(), m_oInsertState.m_osBlockName,
                std::move(oTransformer), poFeature, apoExtraFeatures, true,
                poDS->ShouldMergeBlockGeometries());
        }
        catch (const std::invalid_argument &)
        {
            // Block doesn't exist
            CPLError(CE_Warning, CPLE_AppDefined, "Block %s does not exist",
                     m_oInsertState.m_osBlockName.c_str());
            delete poFeature;
            return false;
        }

        if (poFeature)
            apoPendingFeatures.push(poFeature);

        while (!apoExtraFeatures.empty())
        {
            apoPendingFeatures.push(apoExtraFeatures.front());
            apoExtraFeatures.pop();
        }

        // Append the attribute features to the pending feature stack
        if (!m_oInsertState.m_apoAttribs.empty())
        {
            OGRDXFInsertTransformer oAttribTransformer;
            oAttribTransformer.dfXOffset = dfExtraXOffset;
            oAttribTransformer.dfYOffset = dfExtraYOffset;

            for (const auto &poAttr : m_oInsertState.m_apoAttribs)
            {
                OGRDXFFeature *poAttribFeature = poAttr->CloneDXFFeature();

                if (poAttribFeature->GetGeometryRef())
                {
                    poAttribFeature->GetGeometryRef()->transform(
                        &oAttribTransformer);
                }

                apoPendingFeatures.push(poAttribFeature);
            }
        }
    }
    return true;
}

/************************************************************************/
/*                      GetNextUnfilteredFeature()                      */
/************************************************************************/

OGRDXFFeature *OGRDXFLayer::GetNextUnfilteredFeature()

{
    OGRDXFFeature *poFeature = nullptr;
    while (poFeature == nullptr)
    {
        /* --------------------------------------------------------------------
         */
        /*      If we have pending features, return one of them. */
        /* --------------------------------------------------------------------
         */
        if (!apoPendingFeatures.empty())
        {
            poFeature = apoPendingFeatures.front();
            apoPendingFeatures.pop();

            poFeature->SetFID(iNextFID++);
            return poFeature;
        }

        /* --------------------------------------------------------------------
         */
        /*      Emit INSERT features. */
        /* --------------------------------------------------------------------
         */
        if (m_oInsertState.m_iCurRow < m_oInsertState.m_nRowCount)
        {
            if (m_oInsertState.m_iCurCol == m_oInsertState.m_nColumnCount)
            {
                m_oInsertState.m_iCurRow++;
                m_oInsertState.m_iCurCol = 0;
                if (m_oInsertState.m_iCurRow == m_oInsertState.m_nRowCount)
                {
                    m_oInsertState.m_nRowCount = 0;
                    m_oInsertState.m_nColumnCount = 0;
                    continue;
                }
            }
            if (GenerateINSERTFeatures())
            {
                m_oInsertState.m_iCurCol++;
            }
            else
            {
                m_oInsertState.m_nRowCount = 0;
                m_oInsertState.m_nColumnCount = 0;
            }
            continue;
        }

        // read ahead to an entity.
        char szLineBuf[257];
        int nCode = 0;
        while ((nCode = poDS->ReadValue(szLineBuf, sizeof(szLineBuf))) > 0)
        {
        }
        if (nCode < 0)
        {
            DXF_LAYER_READER_ERROR();
            return nullptr;
        }

        if (EQUAL(szLineBuf, "ENDSEC"))
        {
            // CPLDebug( "DXF", "Clean end of features at ENDSEC." );
            poDS->UnreadValue();
            return nullptr;
        }

        if (EQUAL(szLineBuf, "ENDBLK"))
        {
            // CPLDebug( "DXF", "Clean end of block at ENDBLK." );
            poDS->UnreadValue();
            return nullptr;
        }

        /* --------------------------------------------------------------------
         */
        /*      Handle the entity. */
        /* --------------------------------------------------------------------
         */
        if (EQUAL(szLineBuf, "POINT"))
        {
            poFeature = TranslatePOINT();
        }
        else if (EQUAL(szLineBuf, "MTEXT"))
        {
            poFeature = TranslateMTEXT();
        }
        else if (EQUAL(szLineBuf, "TEXT"))
        {
            poFeature = TranslateTEXT(false);
        }
        else if (EQUAL(szLineBuf, "ATTDEF"))
        {
            poFeature = TranslateTEXT(true);
        }
        else if (EQUAL(szLineBuf, "LINE"))
        {
            poFeature = TranslateLINE();
        }
        else if (EQUAL(szLineBuf, "POLYLINE"))
        {
            poFeature = TranslatePOLYLINE();
        }
        else if (EQUAL(szLineBuf, "LWPOLYLINE"))
        {
            poFeature = TranslateLWPOLYLINE();
        }
        else if (EQUAL(szLineBuf, "MLINE"))
        {
            poFeature = TranslateMLINE();
        }
        else if (EQUAL(szLineBuf, "CIRCLE"))
        {
            poFeature = TranslateCIRCLE();
        }
        else if (EQUAL(szLineBuf, "ELLIPSE"))
        {
            poFeature = TranslateELLIPSE();
        }
        else if (EQUAL(szLineBuf, "ARC"))
        {
            poFeature = TranslateARC();
        }
        else if (EQUAL(szLineBuf, "SPLINE") || EQUAL(szLineBuf, "HELIX"))
        {
            poFeature = TranslateSPLINE();
        }
        else if (EQUAL(szLineBuf, "3DFACE"))
        {
            poFeature = Translate3DFACE();
        }
        else if (EQUAL(szLineBuf, "INSERT"))
        {
            if (!TranslateINSERT())
                return nullptr;
        }
        else if (EQUAL(szLineBuf, "DIMENSION"))
        {
            poFeature = TranslateDIMENSION();
        }
        else if (EQUAL(szLineBuf, "HATCH"))
        {
            poFeature = TranslateHATCH();
        }
        else if (EQUAL(szLineBuf, "SOLID") || EQUAL(szLineBuf, "TRACE"))
        {
            poFeature = TranslateSOLID();
        }
        else if (EQUAL(szLineBuf, "LEADER"))
        {
            poFeature = TranslateLEADER();
        }
        else if (EQUAL(szLineBuf, "MLEADER") || EQUAL(szLineBuf, "MULTILEADER"))
        {
            poFeature = TranslateMLEADER();
        }
        else if (EQUAL(szLineBuf, "3DSOLID") || EQUAL(szLineBuf, "BODY") ||
                 EQUAL(szLineBuf, "REGION") || EQUAL(szLineBuf, "SURFACE"))
        {
            if (poDS->In3DExtensibleMode())
            {
                poFeature = TranslateASMEntity();
            }
            else if (oIgnoredEntities.count(szLineBuf) == 0)
            {
                oIgnoredEntities.insert(szLineBuf);
                CPLDebug("DXF", "3D mode is off; ignoring all '%s' entities.",
                         szLineBuf);
            }
        }
        else
        {
            if (oIgnoredEntities.count(szLineBuf) == 0)
            {
                oIgnoredEntities.insert(szLineBuf);
                CPLDebug("DXF", "Ignoring one or more of entity '%s'.",
                         szLineBuf);
            }
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Set FID.                                                        */
    /* -------------------------------------------------------------------- */
    poFeature->SetFID(iNextFID++);
    m_nFeaturesRead++;

    return poFeature;
}

/************************************************************************/
/*                           GetNextFeature()                           */
/************************************************************************/

OGRFeature *OGRDXFLayer::GetNextFeature()

{
    while (true)
    {
        OGRFeature *poFeature = GetNextUnfilteredFeature();

        if (poFeature == nullptr)
            return nullptr;

        if ((m_poFilterGeom == nullptr ||
             FilterGeometry(poFeature->GetGeometryRef())) &&
            (m_poAttrQuery == nullptr || m_poAttrQuery->Evaluate(poFeature)))
        {
            return poFeature;
        }

        delete poFeature;
    }
}

/************************************************************************/
/*                           TestCapability()                           */
/************************************************************************/

int OGRDXFLayer::TestCapability(const char *pszCap)

{
    if (EQUAL(pszCap, OLCStringsAsUTF8))
        return true;
    else if (EQUAL(pszCap, OLCZGeometries))
        return true;
    return false;
}

/************************************************************************/
/*                             GetDataset()                             */
/************************************************************************/

GDALDataset *OGRDXFLayer::GetDataset()
{
    return poDS;
}