zrender/lib/tool/convertPath.js

import { cubicSubdivide } from '../core/curve.js';
import PathProxy from '../core/PathProxy.js';
var CMD = PathProxy.CMD;
function aroundEqual(a, b) {
    return Math.abs(a - b) < 1e-5;
}
export function pathToBezierCurves(path) {
    var data = path.data;
    var len = path.len();
    var bezierArrayGroups = [];
    var currentSubpath;
    var xi = 0;
    var yi = 0;
    var x0 = 0;
    var y0 = 0;
    function createNewSubpath(x, y) {
        if (currentSubpath && currentSubpath.length > 2) {
            bezierArrayGroups.push(currentSubpath);
        }
        currentSubpath = [x, y];
    }
    function addLine(x0, y0, x1, y1) {
        if (!(aroundEqual(x0, x1) && aroundEqual(y0, y1))) {
            currentSubpath.push(x0, y0, x1, y1, x1, y1);
        }
    }
    function addArc(startAngle, endAngle, cx, cy, rx, ry) {
        var delta = Math.abs(endAngle - startAngle);
        var len = Math.tan(delta / 4) * 4 / 3;
        var dir = endAngle < startAngle ? -1 : 1;
        var c1 = Math.cos(startAngle);
        var s1 = Math.sin(startAngle);
        var c2 = Math.cos(endAngle);
        var s2 = Math.sin(endAngle);
        var x1 = c1 * rx + cx;
        var y1 = s1 * ry + cy;
        var x4 = c2 * rx + cx;
        var y4 = s2 * ry + cy;
        var hx = rx * len * dir;
        var hy = ry * len * dir;
        currentSubpath.push(x1 - hx * s1, y1 + hy * c1, x4 + hx * s2, y4 - hy * c2, x4, y4);
    }
    var x1;
    var y1;
    var x2;
    var y2;
    for (var i = 0; i < len;) {
        var cmd = data[i++];
        var isFirst = i === 1;
        if (isFirst) {
            xi = data[i];
            yi = data[i + 1];
            x0 = xi;
            y0 = yi;
            if (cmd === CMD.L || cmd === CMD.C || cmd === CMD.Q) {
                currentSubpath = [x0, y0];
            }
        }
        switch (cmd) {
            case CMD.M:
                xi = x0 = data[i++];
                yi = y0 = data[i++];
                createNewSubpath(x0, y0);
                break;
            case CMD.L:
                x1 = data[i++];
                y1 = data[i++];
                addLine(xi, yi, x1, y1);
                xi = x1;
                yi = y1;
                break;
            case CMD.C:
                currentSubpath.push(data[i++], data[i++], data[i++], data[i++], xi = data[i++], yi = data[i++]);
                break;
            case CMD.Q:
                x1 = data[i++];
                y1 = data[i++];
                x2 = data[i++];
                y2 = data[i++];
                currentSubpath.push(xi + 2 / 3 * (x1 - xi), yi + 2 / 3 * (y1 - yi), x2 + 2 / 3 * (x1 - x2), y2 + 2 / 3 * (y1 - y2), x2, y2);
                xi = x2;
                yi = y2;
                break;
            case CMD.A:
                var cx = data[i++];
                var cy = data[i++];
                var rx = data[i++];
                var ry = data[i++];
                var startAngle = data[i++];
                var endAngle = data[i++] + startAngle;
                i += 1;
                var anticlockwise = !data[i++];
                x1 = Math.cos(startAngle) * rx + cx;
                y1 = Math.sin(startAngle) * ry + cy;
                if (isFirst) {
                    x0 = x1;
                    y0 = y1;
                    createNewSubpath(x0, y0);
                }
                else {
                    addLine(xi, yi, x1, y1);
                }
                xi = Math.cos(endAngle) * rx + cx;
                yi = Math.sin(endAngle) * ry + cy;
                var step = (anticlockwise ? -1 : 1) * Math.PI / 2;
                for (var angle = startAngle; anticlockwise ? angle > endAngle : angle < endAngle; angle += step) {
                    var nextAngle = anticlockwise ? Math.max(angle + step, endAngle)
                        : Math.min(angle + step, endAngle);
                    addArc(angle, nextAngle, cx, cy, rx, ry);
                }
                break;
            case CMD.R:
                x0 = xi = data[i++];
                y0 = yi = data[i++];
                x1 = x0 + data[i++];
                y1 = y0 + data[i++];
                createNewSubpath(x1, y0);
                addLine(x1, y0, x1, y1);
                addLine(x1, y1, x0, y1);
                addLine(x0, y1, x0, y0);
                addLine(x0, y0, x1, y0);
                break;
            case CMD.Z:
                currentSubpath && addLine(xi, yi, x0, y0);
                xi = x0;
                yi = y0;
                break;
        }
    }
    if (currentSubpath && currentSubpath.length > 2) {
        bezierArrayGroups.push(currentSubpath);
    }
    return bezierArrayGroups;
}
function adpativeBezier(x0, y0, x1, y1, x2, y2, x3, y3, out, scale) {
    if (aroundEqual(x0, x1) && aroundEqual(y0, y1) && aroundEqual(x2, x3) && aroundEqual(y2, y3)) {
        out.push(x3, y3);
        return;
    }
    var PIXEL_DISTANCE = 2 / scale;
    var PIXEL_DISTANCE_SQR = PIXEL_DISTANCE * PIXEL_DISTANCE;
    var dx = x3 - x0;
    var dy = y3 - y0;
    var d = Math.sqrt(dx * dx + dy * dy);
    dx /= d;
    dy /= d;
    var dx1 = x1 - x0;
    var dy1 = y1 - y0;
    var dx2 = x2 - x3;
    var dy2 = y2 - y3;
    var cp1LenSqr = dx1 * dx1 + dy1 * dy1;
    var cp2LenSqr = dx2 * dx2 + dy2 * dy2;
    if (cp1LenSqr < PIXEL_DISTANCE_SQR && cp2LenSqr < PIXEL_DISTANCE_SQR) {
        out.push(x3, y3);
        return;
    }
    var projLen1 = dx * dx1 + dy * dy1;
    var projLen2 = -dx * dx2 - dy * dy2;
    var d1Sqr = cp1LenSqr - projLen1 * projLen1;
    var d2Sqr = cp2LenSqr - projLen2 * projLen2;
    if (d1Sqr < PIXEL_DISTANCE_SQR && projLen1 >= 0
        && d2Sqr < PIXEL_DISTANCE_SQR && projLen2 >= 0) {
        out.push(x3, y3);
        return;
    }
    var tmpSegX = [];
    var tmpSegY = [];
    cubicSubdivide(x0, x1, x2, x3, 0.5, tmpSegX);
    cubicSubdivide(y0, y1, y2, y3, 0.5, tmpSegY);
    adpativeBezier(tmpSegX[0], tmpSegY[0], tmpSegX[1], tmpSegY[1], tmpSegX[2], tmpSegY[2], tmpSegX[3], tmpSegY[3], out, scale);
    adpativeBezier(tmpSegX[4], tmpSegY[4], tmpSegX[5], tmpSegY[5], tmpSegX[6], tmpSegY[6], tmpSegX[7], tmpSegY[7], out, scale);
}
export function pathToPolygons(path, scale) {
    var bezierArrayGroups = pathToBezierCurves(path);
    var polygons = [];
    scale = scale || 1;
    for (var i = 0; i < bezierArrayGroups.length; i++) {
        var beziers = bezierArrayGroups[i];
        var polygon = [];
        var x0 = beziers[0];
        var y0 = beziers[1];
        polygon.push(x0, y0);
        for (var k = 2; k < beziers.length;) {
            var x1 = beziers[k++];
            var y1 = beziers[k++];
            var x2 = beziers[k++];
            var y2 = beziers[k++];
            var x3 = beziers[k++];
            var y3 = beziers[k++];
            adpativeBezier(x0, y0, x1, y1, x2, y2, x3, y3, polygon, scale);
            x0 = x3;
            y0 = y3;
        }
        polygons.push(polygon);
    }
    return polygons;
}