// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/***************************************************************************

    bitmap.c

    Core bitmap routines.

***************************************************************************/

#include "bitmap.h"

#include <cassert>
#include <cstring>
#include <new>


//**************************************************************************
//  INLINE HELPERS
//**************************************************************************

//-------------------------------------------------
//  compute_rowpixels - compute a rowpixels value
//-------------------------------------------------

inline int32_t bitmap_t::compute_rowpixels(int width, int xslop) noexcept
{
	return width + 2 * xslop;
}


//-------------------------------------------------
//  compute_base - compute a bitmap base address
//  with the given slop values
//-------------------------------------------------

inline void bitmap_t::compute_base(int xslop, int yslop) noexcept
{
	m_base = &m_alloc[(m_rowpixels * yslop + xslop) * (m_bpp / 8)];
}


//-------------------------------------------------
//  valid_format - return true if the bitmap format
//  is valid and agrees with the BPP
//-------------------------------------------------

inline bool bitmap_t::valid_format() const noexcept
{
	switch (m_format)
	{
	// invalid format
	case BITMAP_FORMAT_INVALID:
		return false;

	// 8bpp formats
	case BITMAP_FORMAT_IND8:
		return m_bpp == 8;

	// 16bpp formats
	case BITMAP_FORMAT_IND16:
	case BITMAP_FORMAT_YUY16:
		return m_bpp == 16;

	// 32bpp formats
	case BITMAP_FORMAT_IND32:
	case BITMAP_FORMAT_RGB32:
	case BITMAP_FORMAT_ARGB32:
		return m_bpp == 32;

	// 64bpp formats
	case BITMAP_FORMAT_IND64:
		return m_bpp == 64;
	}

	return false;
}


//**************************************************************************
//  BITMAP ALLOCATION/CONFIGURATION
//**************************************************************************

bitmap_t::bitmap_t(bitmap_t &&that) noexcept
	: m_alloc(std::move(that.m_alloc))
	, m_allocbytes(that.m_allocbytes)
	, m_base(that.m_base)
	, m_rowpixels(that.m_rowpixels)
	, m_width(that.m_width)
	, m_height(that.m_height)
	, m_format(that.m_format)
	, m_bpp(that.m_bpp)
	, m_palette(nullptr)
	, m_cliprect(that.m_cliprect)
{
	set_palette(that.m_palette);
	that.reset();
}

/**
 * @fn  bitmap_t::bitmap_t(bitmap_format format, uint8_t bpp, int width, int height, int xslop, int yslop)
 *
 * @brief   -------------------------------------------------
 *            bitmap_t - basic constructor
 *          -------------------------------------------------.
 *
 * @param   format  Describes the format to use.
 * @param   bpp     The bits per pixel.
 * @param   width   The width.
 * @param   height  The height.
 * @param   xslop   The xslop.
 * @param   yslop   The yslop.
 */

bitmap_t::bitmap_t(bitmap_format format, uint8_t bpp, int width, int height, int xslop, int yslop) noexcept
	: m_alloc()
	, m_allocbytes(0)
	, m_format(format)
	, m_bpp(bpp)
	, m_palette(nullptr)
{
	assert(valid_format());

	// allocate intializes all other fields
	allocate(width, height, xslop, yslop);
}

/**
 * @fn  bitmap_t::bitmap_t(bitmap_format format, uint8_t bpp, void *base, int width, int height, int rowpixels)
 *
 * @brief   Constructor.
 *
 * @param   format          Describes the format to use.
 * @param   bpp             The bits per pixel.
 * @param [in,out]  base    If non-null, the base.
 * @param   width           The width.
 * @param   height          The height.
 * @param   rowpixels       The rowpixels.
 */

bitmap_t::bitmap_t(bitmap_format format, uint8_t bpp, void *base, int width, int height, int rowpixels) noexcept
	: m_alloc()
	, m_allocbytes(0)
	, m_base(base)
	, m_rowpixels(rowpixels)
	, m_width(width)
	, m_height(height)
	, m_format(format)
	, m_bpp(bpp)
	, m_palette(nullptr)
	, m_cliprect(0, width - 1, 0, height - 1)
{
	assert(valid_format());
}

/**
 * @fn  bitmap_t::bitmap_t(bitmap_format format, uint8_t bpp, bitmap_t &source, const rectangle &subrect)
 *
 * @brief   Constructor.
 *
 * @param   format          Describes the format to use.
 * @param   bpp             The bits per pixel.
 * @param [in,out]  source  Source for the.
 * @param   subrect         The subrect.
 */

bitmap_t::bitmap_t(bitmap_format format, uint8_t bpp, bitmap_t &source, const rectangle &subrect) noexcept
	: m_alloc()
	, m_allocbytes(0)
	, m_base(source.raw_pixptr(subrect.top(), subrect.left()))
	, m_rowpixels(source.m_rowpixels)
	, m_width(subrect.width())
	, m_height(subrect.height())
	, m_format(format)
	, m_bpp(bpp)
	, m_palette(nullptr)
	, m_cliprect(0, subrect.width() - 1, 0, subrect.height() - 1)
{
	assert(format == source.m_format);
	assert(bpp == source.m_bpp);
	assert(source.cliprect().contains(subrect));
}

/**
 * @fn  bitmap_t::~bitmap_t()
 *
 * @brief   -------------------------------------------------
 *            ~bitmap_t - basic destructor
 *          -------------------------------------------------.
 */

bitmap_t::~bitmap_t()
{
	// delete any existing stuff
	reset();
}

bitmap_t &bitmap_t::operator=(bitmap_t &&that) noexcept
{
	m_alloc = std::move(that.m_alloc);
	m_allocbytes = that.m_allocbytes;
	m_base = that.m_base;
	m_rowpixels = that.m_rowpixels;
	m_width = that.m_width;
	m_height = that.m_height;
	m_format = that.m_format;
	m_bpp = that.m_bpp;
	set_palette(that.m_palette);
	m_cliprect = that.m_cliprect;
	that.reset();
	return *this;
}

/**
 * @fn  void bitmap_t::allocate(int width, int height, int xslop, int yslop)
 *
 * @brief   -------------------------------------------------
 *            allocate -- (re)allocate memory for the bitmap at the given size, destroying
 *            anything that already exists
 *          -------------------------------------------------.
 *
 * @param   width   The width.
 * @param   height  The height.
 * @param   xslop   The xslop.
 * @param   yslop   The yslop.
 */

void bitmap_t::allocate(int width, int height, int xslop, int yslop) noexcept
{
	assert(m_format != BITMAP_FORMAT_INVALID);
	assert(m_bpp == 8 || m_bpp == 16 || m_bpp == 32 || m_bpp == 64);

	// delete any existing stuff
	reset();

	// handle empty requests cleanly
	if ((0 < width) && (0 < height))
	{
		// allocate memory for the bitmap itself
		int32_t const new_rowpixels = compute_rowpixels(width, xslop);
		uint32_t const new_allocbytes = new_rowpixels * (height + 2 * yslop) * m_bpp / 8;
		m_alloc.reset(new (std::nothrow) uint8_t[new_allocbytes]);
		if (m_alloc)
		{
			// initialize fields
			m_allocbytes = new_allocbytes;
			m_rowpixels = new_rowpixels;
			m_width = width;
			m_height = height;
			m_cliprect.set(0, width - 1, 0, height - 1);

			// clear to 0 by default
			memset(m_alloc.get(), 0, m_allocbytes);

			// compute the base
			compute_base(xslop, yslop);
		}
	}
}

/**
 * @fn  void bitmap_t::resize(int width, int height, int xslop, int yslop)
 *
 * @brief   -------------------------------------------------
 *            resize -- resize a bitmap, reusing existing memory if the new size is smaller than
 *            the current size
 *          -------------------------------------------------.
 *
 * @param   width   The width.
 * @param   height  The height.
 * @param   xslop   The xslop.
 * @param   yslop   The yslop.
 */

void bitmap_t::resize(int width, int height, int xslop, int yslop) noexcept
{
	assert(m_format != BITMAP_FORMAT_INVALID);
	assert(m_bpp == 8 || m_bpp == 16 || m_bpp == 32 || m_bpp == 64);

	// handle empty requests cleanly
	if ((width <= 0) || (height <= 0))
		width = height = 0;

	// determine how much memory we need for the new bitmap
	int32_t const new_rowpixels = compute_rowpixels(width, xslop);
	uint32_t const new_allocbytes = new_rowpixels * (height + 2 * yslop) * m_bpp / 8;

	if (new_allocbytes > m_allocbytes)
	{
		// if we need more memory, just realloc
		palette_t *const palette = m_palette;
		if (palette)
			palette->ref();
		allocate(width, height, xslop, yslop);
		set_palette(palette);
		if (palette)
			palette->deref();
	}
	else
	{
		// otherwise, reconfigure
		m_rowpixels = new_rowpixels;
		m_width = width;
		m_height = height;
		m_cliprect.set(0, width - 1, 0, height - 1);

		// re-compute the base
		compute_base(xslop, yslop);
	}
}

/**
 * @fn  void bitmap_t::reset()
 *
 * @brief   -------------------------------------------------
 *            reset -- reset to an invalid bitmap, deleting all allocated stuff
 *          -------------------------------------------------.
 */

void bitmap_t::reset() noexcept
{
	// delete any existing stuff
	set_palette(nullptr);
	m_alloc.reset();
	m_base = nullptr;

	// reset all fields
	m_allocbytes = 0;
	m_rowpixels = 0;
	m_width = 0;
	m_height = 0;
	m_cliprect.set(0, -1, 0, -1);
}

/**
 * @fn  void bitmap_t::wrap(void *base, int width, int height, int rowpixels)
 *
 * @brief   -------------------------------------------------
 *            wrap -- wrap an array of memory; the target bitmap does not own the memory
 *          -------------------------------------------------.
 *
 * @param [in,out]  base    If non-null, the base.
 * @param   width           The width.
 * @param   height          The height.
 * @param   rowpixels       The rowpixels.
 */

void bitmap_t::wrap(void *base, int width, int height, int rowpixels) noexcept
{
	assert(base || (!width && !height));
	assert(!m_alloc || (&m_alloc[0] > base) || (&m_alloc[m_allocbytes] <= base));

	// delete any existing stuff
	reset();

	// initialize relevant fields
	m_base = base;
	m_rowpixels = rowpixels;
	m_width = width;
	m_height = height;
	m_cliprect.set(0, m_width - 1, 0, m_height - 1);
}

/**
 * @fn  void bitmap_t::wrap(const bitmap_t &source, const rectangle &subrect)
 *
 * @brief   -------------------------------------------------
 *            wrap -- wrap a subrectangle of an existing bitmap by copying its fields; the target
 *            bitmap does not own the memory
 *          -------------------------------------------------.
 *
 * @param   source  Source for the.
 * @param   subrect The subrect.
 */

void bitmap_t::wrap(bitmap_t &source, const rectangle &subrect) noexcept
{
	assert(&source != this);
	assert(m_format == source.m_format);
	assert(m_bpp == source.m_bpp);
	assert(source.cliprect().contains(subrect));

	// delete any existing stuff
	reset();

	// copy relevant fields
	m_base = source.raw_pixptr(subrect.top(), subrect.left());
	m_rowpixels = source.m_rowpixels;
	m_width = subrect.width();
	m_height = subrect.height();
	set_palette(source.m_palette);
	m_cliprect.set(0, m_width - 1, 0, m_height - 1);
}

/**
 * @fn  void bitmap_t::set_palette(palette_t *palette)
 *
 * @brief   -------------------------------------------------
 *            set_palette -- associate a palette with a bitmap
 *          -------------------------------------------------.
 *
 * @param [in,out]  palette If non-null, the palette.
 */

void bitmap_t::set_palette(palette_t *palette) noexcept
{
	// first reference the new palette
	if (palette)
		palette->ref();

	// then dereference any existing palette
	if (m_palette)
		m_palette->deref();

	m_palette = palette;
}

/**
 * @fn  void bitmap_t::fill(uint64_t color, const rectangle &bounds)
 *
 * @brief   -------------------------------------------------
 *            fill -- fill a bitmap with a solid color
 *          -------------------------------------------------.
 *
 * @param   color       The color.
 * @param   bounds      The bounds.
 */

void bitmap_t::fill(uint64_t color, const rectangle &bounds) noexcept
{
	// if we have a cliprect, intersect with that
	rectangle fill(bounds);
	fill &= m_cliprect;
	if (!fill.empty())
	{
		// based on the bpp go from there
		switch (m_bpp)
		{
		case 8:
			for (int32_t y = fill.top(); y <= fill.bottom(); y++)
				std::fill_n(&pixt<uint8_t>(y, fill.left()), fill.width(), uint8_t(color));
			break;

		case 16:
			for (int32_t y = fill.top(); y <= fill.bottom(); ++y)
				std::fill_n(&pixt<uint16_t>(y, fill.left()), fill.width(), uint16_t(color));
			break;

		case 32:
			for (int32_t y = fill.top(); y <= fill.bottom(); ++y)
				std::fill_n(&pixt<uint32_t>(y, fill.left()), fill.width(), uint32_t(color));
			break;

		case 64:
			for (int32_t y = fill.top(); y <= fill.bottom(); ++y)
				std::fill_n(&pixt<uint64_t>(y, fill.left()), fill.width(), uint64_t(color));
			break;
		}
	}
}


//**************************************************************************
//  EXPLICIT TEMPLATE INSTANTIATIONS
//**************************************************************************

template class bitmap_specific<uint8_t>;
template class bitmap_specific<uint16_t>;
template class bitmap_specific<uint32_t>;
template class bitmap_specific<uint64_t>;