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META-INF.assets.rjzjh.zrender.contain.path.js Maven / Gradle / Ivy

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define(function (require) {

    'use strict';

    var CMD = require('../core/PathProxy').CMD;
    var line = require('./line');
    var cubic = require('./cubic');
    var quadratic = require('./quadratic');
    var arc = require('./arc');
    var normalizeRadian = require('./util').normalizeRadian;
    var curve = require('../core/curve');

    var windingLine = require('./windingLine');

    var containStroke = line.containStroke;

    var PI2 = Math.PI * 2;

    var EPSILON = 1e-4;

    function isAroundEqual(a, b) {
        return Math.abs(a - b) < EPSILON;
    }

    // 临时数组
    var roots = [-1, -1, -1];
    var extrema = [-1, -1];

    function swapExtrema() {
        var tmp = extrema[0];
        extrema[0] = extrema[1];
        extrema[1] = tmp;
    }

    function windingCubic(x0, y0, x1, y1, x2, y2, x3, y3, x, y) {
        // Quick reject
        if (
            (y > y0 && y > y1 && y > y2 && y > y3)
            || (y < y0 && y < y1 && y < y2 && y < y3)
        ) {
            return 0;
        }
        var nRoots = curve.cubicRootAt(y0, y1, y2, y3, y, roots);
        if (nRoots === 0) {
            return 0;
        }
        else {
            var w = 0;
            var nExtrema = -1;
            var y0_, y1_;
            for (var i = 0; i < nRoots; i++) {
                var t = roots[i];

                // Avoid winding error when intersection point is the connect point of two line of polygon
                var unit = (t === 0 || t === 1) ? 0.5 : 1;

                var x_ = curve.cubicAt(x0, x1, x2, x3, t);
                if (x_ < x) { // Quick reject
                    continue;
                }
                if (nExtrema < 0) {
                    nExtrema = curve.cubicExtrema(y0, y1, y2, y3, extrema);
                    if (extrema[1] < extrema[0] && nExtrema > 1) {
                        swapExtrema();
                    }
                    y0_ = curve.cubicAt(y0, y1, y2, y3, extrema[0]);
                    if (nExtrema > 1) {
                        y1_ = curve.cubicAt(y0, y1, y2, y3, extrema[1]);
                    }
                }
                if (nExtrema == 2) {
                    // 分成三段单调函数
                    if (t < extrema[0]) {
                        w += y0_ < y0 ? unit : -unit;
                    }
                    else if (t < extrema[1]) {
                        w += y1_ < y0_ ? unit : -unit;
                    }
                    else {
                        w += y3 < y1_ ? unit : -unit;
                    }
                }
                else {
                    // 分成两段单调函数
                    if (t < extrema[0]) {
                        w += y0_ < y0 ? unit : -unit;
                    }
                    else {
                        w += y3 < y0_ ? unit : -unit;
                    }
                }
            }
            return w;
        }
    }

    function windingQuadratic(x0, y0, x1, y1, x2, y2, x, y) {
        // Quick reject
        if (
            (y > y0 && y > y1 && y > y2)
            || (y < y0 && y < y1 && y < y2)
        ) {
            return 0;
        }
        var nRoots = curve.quadraticRootAt(y0, y1, y2, y, roots);
        if (nRoots === 0) {
            return 0;
        }
        else {
            var t = curve.quadraticExtremum(y0, y1, y2);
            if (t >= 0 && t <= 1) {
                var w = 0;
                var y_ = curve.quadraticAt(y0, y1, y2, t);
                for (var i = 0; i < nRoots; i++) {
                    // Remove one endpoint.
                    var unit = (roots[i] === 0 || roots[i] === 1) ? 0.5 : 1;

                    var x_ = curve.quadraticAt(x0, x1, x2, roots[i]);
                    if (x_ < x) {   // Quick reject
                        continue;
                    }
                    if (roots[i] < t) {
                        w += y_ < y0 ? unit : -unit;
                    }
                    else {
                        w += y2 < y_ ? unit : -unit;
                    }
                }
                return w;
            }
            else {
                // Remove one endpoint.
                var unit = (roots[0] === 0 || roots[0] === 1) ? 0.5 : 1;

                var x_ = curve.quadraticAt(x0, x1, x2, roots[0]);
                if (x_ < x) {   // Quick reject
                    return 0;
                }
                return y2 < y0 ? unit : -unit;
            }
        }
    }

    // TODO
    // Arc 旋转
    function windingArc(
        cx, cy, r, startAngle, endAngle, anticlockwise, x, y
    ) {
        y -= cy;
        if (y > r || y < -r) {
            return 0;
        }
        var tmp = Math.sqrt(r * r - y * y);
        roots[0] = -tmp;
        roots[1] = tmp;

        var diff = Math.abs(startAngle - endAngle);
        if (diff < 1e-4) {
            return 0;
        }
        if (diff % PI2 < 1e-4) {
            // Is a circle
            startAngle = 0;
            endAngle = PI2;
            var dir = anticlockwise ? 1 : -1;
            if (x >= roots[0] + cx && x <= roots[1] + cx) {
                return dir;
            } else {
                return 0;
            }
        }

        if (anticlockwise) {
            var tmp = startAngle;
            startAngle = normalizeRadian(endAngle);
            endAngle = normalizeRadian(tmp);
        }
        else {
            startAngle = normalizeRadian(startAngle);
            endAngle = normalizeRadian(endAngle);
        }
        if (startAngle > endAngle) {
            endAngle += PI2;
        }

        var w = 0;
        for (var i = 0; i < 2; i++) {
            var x_ = roots[i];
            if (x_ + cx > x) {
                var angle = Math.atan2(y, x_);
                var dir = anticlockwise ? 1 : -1;
                if (angle < 0) {
                    angle = PI2 + angle;
                }
                if (
                    (angle >= startAngle && angle <= endAngle)
                    || (angle + PI2 >= startAngle && angle + PI2 <= endAngle)
                ) {
                    if (angle > Math.PI / 2 && angle < Math.PI * 1.5) {
                        dir = -dir;
                    }
                    w += dir;
                }
            }
        }
        return w;
    }

    function containPath(data, lineWidth, isStroke, x, y) {
        var w = 0;
        var xi = 0;
        var yi = 0;
        var x0 = 0;
        var y0 = 0;

        for (var i = 0; i < data.length;) {
            var cmd = data[i++];
            // Begin a new subpath
            if (cmd === CMD.M && i > 1) {
                // Close previous subpath
                if (!isStroke) {
                    w += windingLine(xi, yi, x0, y0, x, y);
                }
                // 如果被任何一个 subpath 包含
                // if (w !== 0) {
                //     return true;
                // }
            }

            if (i == 1) {
                // 如果第一个命令是 L, C, Q
                // 则 previous point 同绘制命令的第一个 point
                //
                // 第一个命令为 Arc 的情况下会在后面特殊处理
                xi = data[i];
                yi = data[i + 1];

                x0 = xi;
                y0 = yi;
            }

            switch (cmd) {
                case CMD.M:
                    // moveTo 命令重新创建一个新的 subpath, 并且更新新的起点
                    // 在 closePath 的时候使用
                    x0 = data[i++];
                    y0 = data[i++];
                    xi = x0;
                    yi = y0;
                    break;
                case CMD.L:
                    if (isStroke) {
                        if (containStroke(xi, yi, data[i], data[i + 1], lineWidth, x, y)) {
                            return true;
                        }
                    }
                    else {
                        // NOTE 在第一个命令为 L, C, Q 的时候会计算出 NaN
                        w += windingLine(xi, yi, data[i], data[i + 1], x, y) || 0;
                    }
                    xi = data[i++];
                    yi = data[i++];
                    break;
                case CMD.C:
                    if (isStroke) {
                        if (cubic.containStroke(xi, yi,
                            data[i++], data[i++], data[i++], data[i++], data[i], data[i + 1],
                            lineWidth, x, y
                        )) {
                            return true;
                        }
                    }
                    else {
                        w += windingCubic(
                            xi, yi,
                            data[i++], data[i++], data[i++], data[i++], data[i], data[i + 1],
                            x, y
                        ) || 0;
                    }
                    xi = data[i++];
                    yi = data[i++];
                    break;
                case CMD.Q:
                    if (isStroke) {
                        if (quadratic.containStroke(xi, yi,
                            data[i++], data[i++], data[i], data[i + 1],
                            lineWidth, x, y
                        )) {
                            return true;
                        }
                    }
                    else {
                        w += windingQuadratic(
                            xi, yi,
                            data[i++], data[i++], data[i], data[i + 1],
                            x, y
                        ) || 0;
                    }
                    xi = data[i++];
                    yi = data[i++];
                    break;
                case CMD.A:
                    // TODO Arc 判断的开销比较大
                    var cx = data[i++];
                    var cy = data[i++];
                    var rx = data[i++];
                    var ry = data[i++];
                    var theta = data[i++];
                    var dTheta = data[i++];
                    // TODO Arc 旋转
                    var psi = data[i++];
                    var anticlockwise = 1 - data[i++];
                    var x1 = Math.cos(theta) * rx + cx;
                    var y1 = Math.sin(theta) * ry + cy;
                    // 不是直接使用 arc 命令
                    if (i > 1) {
                        w += windingLine(xi, yi, x1, y1, x, y);
                    }
                    else {
                        // 第一个命令起点还未定义
                        x0 = x1;
                        y0 = y1;
                    }
                    // zr 使用scale来模拟椭圆, 这里也对x做一定的缩放
                    var _x = (x - cx) * ry / rx + cx;
                    if (isStroke) {
                        if (arc.containStroke(
                            cx, cy, ry, theta, theta + dTheta, anticlockwise,
                            lineWidth, _x, y
                        )) {
                            return true;
                        }
                    }
                    else {
                        w += windingArc(
                            cx, cy, ry, theta, theta + dTheta, anticlockwise,
                            _x, y
                        );
                    }
                    xi = Math.cos(theta + dTheta) * rx + cx;
                    yi = Math.sin(theta + dTheta) * ry + cy;
                    break;
                case CMD.R:
                    x0 = xi = data[i++];
                    y0 = yi = data[i++];
                    var width = data[i++];
                    var height = data[i++];
                    var x1 = x0 + width;
                    var y1 = y0 + height;
                    if (isStroke) {
                        if (containStroke(x0, y0, x1, y0, lineWidth, x, y)
                          || containStroke(x1, y0, x1, y1, lineWidth, x, y)
                          || containStroke(x1, y1, x0, y1, lineWidth, x, y)
                          || containStroke(x0, y1, x0, y0, lineWidth, x, y)
                        ) {
                            return true;
                        }
                    }
                    else {
                        // FIXME Clockwise ?
                        w += windingLine(x1, y0, x1, y1, x, y);
                        w += windingLine(x0, y1, x0, y0, x, y);
                    }
                    break;
                case CMD.Z:
                    if (isStroke) {
                        if (containStroke(
                            xi, yi, x0, y0, lineWidth, x, y
                        )) {
                            return true;
                        }
                    }
                    else {
                        // Close a subpath
                        w += windingLine(xi, yi, x0, y0, x, y);
                        // 如果被任何一个 subpath 包含
                        // FIXME subpaths may overlap
                        // if (w !== 0) {
                        //     return true;
                        // }
                    }
                    xi = x0;
                    yi = y0;
                    break;
            }
        }
        if (!isStroke && !isAroundEqual(yi, y0)) {
            w += windingLine(xi, yi, x0, y0, x, y) || 0;
        }
        return w !== 0;
    }

    return {
        contain: function (pathData, x, y) {
            return containPath(pathData, 0, false, x, y);
        },

        containStroke: function (pathData, lineWidth, x, y) {
            return containPath(pathData, lineWidth, true, x, y);
        }
    };
});




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