tests/PathOpsAsWindingTest.cpp

/*
 * Copyright 2018 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "include/core/SkPath.h"
#include "include/core/SkPathTypes.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkScalar.h"
#include "include/core/SkTypes.h"
#include "include/pathops/SkPathOps.h"
#include "include/utils/SkParsePath.h"
#include "tests/Test.h"

#include <initializer_list>
#include <string>

static SkPath build_squircle(SkPath::Verb verb, const SkRect& rect, SkPathDirection dir) {
    SkPath path;
    bool reverse = SkPathDirection::kCCW == dir;
    switch (verb) {
        case SkPath::kLine_Verb:
            path.addRect(rect, dir);
            reverse = false;
            break;
        case SkPath::kQuad_Verb:
            path.moveTo(rect.centerX(), rect.fTop);
            path.quadTo(rect.fRight, rect.fTop, rect.fRight, rect.centerY());
            path.quadTo(rect.fRight, rect.fBottom, rect.centerX(), rect.fBottom);
            path.quadTo(rect.fLeft, rect.fBottom, rect.fLeft, rect.centerY());
            path.quadTo(rect.fLeft, rect.fTop, rect.centerX(), rect.fTop);
            break;
        case SkPath::kConic_Verb:
            path.addCircle(rect.centerX(), rect.centerY(), rect.width() / 2, dir);
            reverse = false;
            break;
        case SkPath::kCubic_Verb: {
            SkScalar aX14 = rect.fLeft + rect.width() * 1 / 4;
            SkScalar aX34 = rect.fLeft + rect.width() * 3 / 4;
            SkScalar aY14 = rect.fTop + rect.height() * 1 / 4;
            SkScalar aY34 = rect.fTop + rect.height() * 3 / 4;
            path.moveTo(rect.centerX(), rect.fTop);
            path.cubicTo(aX34, rect.fTop, rect.fRight, aY14, rect.fRight, rect.centerY());
            path.cubicTo(rect.fRight, aY34, aX34, rect.fBottom, rect.centerX(), rect.fBottom);
            path.cubicTo(aX14, rect.fBottom, rect.fLeft, aY34, rect.fLeft, rect.centerY());
            path.cubicTo(rect.fLeft, aY14, aX14, rect.fTop, rect.centerX(), rect.fTop);
            } break;
        default:
            SkASSERT(0);
    }
    if (reverse) {
        SkPath temp;
        temp.reverseAddPath(path);
        path.swap(temp);
    }
    return path;
}

void bug12040_1(skiatest::Reporter* reporter) {
    SkPath path;
    path.setFillType(SkPathFillType::kWinding);
    path.moveTo(375, -30);
    path.cubicTo(578, -30, 749, 176, 749, 422);
    path.cubicTo(749, 583, 666, 706, 518, 765);
    path.lineTo(163, 611);
    path.lineTo(163, 579);
    path.lineTo(405, 684);
    path.cubicTo(551, 609, 645, 468, 645, 322);
    path.cubicTo(645, 183, 563, 82, 450, 82);
    path.cubicTo(303, 82, 179, 249, 179, 446);
    path.cubicTo(179, 579, 235, 689, 341, 768);
    path.lineTo(327, 786);
    path.cubicTo(165, 717, 56, 536, 56, 335);
    path.cubicTo(56, 125, 192, -30, 375, -30);
    path.close();
    path.moveTo(214, 225);
    path.cubicTo(333, 248, 396, 311, 396, 405);
    path.lineTo(396, 695);
    path.lineTo(267, 641);
    path.lineTo(267, 395);
    path.cubicTo(267, 324, 249, 285, 201, 254);
    path.cubicTo(201, 254, 214, 225, 214, 225);
    path.close();
    path.moveTo(682, -106);
    path.lineTo(832, 12);
    path.lineTo(813, 33);
    path.lineTo(772, 0);
    path.cubicTo(716, 29, 668, 76, 628, 140);
    path.lineTo(527, 44);
    path.cubicTo(575, -26, 628, -77, 682, -106);
    path.close();
    path.moveTo(450, 59);
    path.lineTo(480, 59);
    path.lineTo(480, 678);
    path.lineTo(450, 678);
    path.cubicTo(450, 678, 450, 59, 450, 59);
    path.close();
    path.moveTo(463, 374);
    path.lineTo(633, 459);
    path.lineTo(633, 490);
    path.lineTo(463, 406);
    path.cubicTo(463, 406, 463, 374, 463, 374);
    path.close();
    path.moveTo(463, 269);
    path.lineTo(667, 372);
    path.lineTo(667, 403);
    path.lineTo(463, 301);
    path.cubicTo(463, 301, 463, 269, 463, 269);
    path.close();

    SkPath path2;
    path2.setFillType(SkPathFillType::kWinding);
    path2.moveTo(-83.5464f, 188);
    path2.cubicTo(-83.5464f, 184.285f, -84.8599f, 181.114f, -87.4868f, 178.487f);
    path2.cubicTo(-90.1138f, 175.86f, -93.2849f, 174.546f, -97, 174.546f);
    path2.cubicTo(-100.715f, 174.546f, -103.886f, 175.86f, -106.513f, 178.487f);
    path2.cubicTo(-109.14f, 181.114f, -110.454f, 184.285f, -110.454f, 188);
    path2.cubicTo(-110.454f, 191.715f, -109.14f, 194.886f, -106.513f, 197.513f);
    path2.cubicTo(-103.886f, 200.14f, -100.715f, 201.454f, -97, 201.454f);
    path2.cubicTo(-93.2849f, 201.454f, -90.1138f, 200.14f, -87.4868f, 197.513f);
    path2.cubicTo(-84.8599f, 194.886f, -83.5464f, 191.715f, -83.5464f, 188);
    path2.close();

    SkPath opResult;
    Op(path, path2, kDifference_SkPathOp, &opResult);

    SkPath winding;
    REPORTER_ASSERT(reporter, AsWinding(opResult, &winding));
    REPORTER_ASSERT(reporter, winding.getFillType() == SkPathFillType::kWinding);

    SkPath difference;
    Op(winding, opResult, kXOR_SkPathOp, &difference);
    REPORTER_ASSERT(reporter, difference.isEmpty());
}

void bug12040_2(skiatest::Reporter* reporter) {
    SkPath path;
    path.setFillType(SkPathFillType::kWinding);
    path.moveTo(375, -30);
    path.cubicTo(578, -30, 749, 176, 749, 422);
    path.cubicTo(749, 583, 666, 706, 518, 765);
    path.lineTo(163, 611);
    path.lineTo(163, 579);
    path.lineTo(405, 684);
    path.cubicTo(551, 609, 645, 468, 645, 322);
    path.cubicTo(645, 183, 563, 82, 450, 82);
    path.cubicTo(303, 82, 179, 249, 179, 446);
    path.cubicTo(179, 579, 235, 689, 341, 768);
    path.lineTo(327, 786);
    path.cubicTo(165, 717, 56, 536, 56, 335);
    path.cubicTo(56, 125, 192, -30, 375, -30);
    path.close();
    path.moveTo(214, 225);
    path.cubicTo(333, 248, 396, 311, 396, 405);
    path.lineTo(396, 695);
    path.lineTo(267, 641);
    path.lineTo(267, 395);
    path.cubicTo(267, 324, 249, 285, 201, 254);
    path.cubicTo(201, 254, 214, 225, 214, 225);
    path.close();
    path.moveTo(682, -106);
    path.lineTo(832, 12);
    path.lineTo(813, 33);
    path.lineTo(772, 0);
    path.cubicTo(716, 29, 668, 76, 628, 140);
    path.lineTo(527, 44);
    path.cubicTo(575, -26, 628, -77, 682, -106);
    path.close();
    path.moveTo(450, 59);
    path.lineTo(480, 59);
    path.lineTo(480, 678);
    path.lineTo(450, 678);
    path.cubicTo(450, 678, 450, 59, 450, 59);
    path.close();
    path.moveTo(463, 374);
    path.lineTo(633, 459);
    path.lineTo(633, 490);
    path.lineTo(463, 406);
    path.cubicTo(463, 406, 463, 374, 463, 374);
    path.close();
    path.moveTo(463, 269);
    path.lineTo(667, 372);
    path.lineTo(667, 403);
    path.lineTo(463, 301);
    path.cubicTo(463, 301, 463, 269, 463, 269);
    path.close();

    SkPath path2;
    path2.setFillType(SkPathFillType::kWinding);
    path2.moveTo(269.134f, 71.3392f);
    path2.cubicTo(269.134f, 67.6241f, 267.82f, 64.453f, 265.193f, 61.826f);
    path2.cubicTo(262.566f, 59.1991f, 259.395f, 57.8856f, 255.68f, 57.8856f);
    path2.cubicTo(251.965f, 57.8856f, 248.794f, 59.1991f, 246.167f, 61.826f);
    path2.cubicTo(243.54f, 64.453f, 242.226f, 67.6241f, 242.226f, 71.3392f);
    path2.cubicTo(242.226f, 75.0543f, 243.54f, 78.2255f, 246.167f, 80.8524f);
    path2.cubicTo(248.794f, 83.4794f, 251.965f, 84.7928f, 255.68f, 84.7928f);
    path2.cubicTo(259.395f, 84.7928f, 262.566f, 83.4794f, 265.193f, 80.8524f);
    path2.cubicTo(267.82f, 78.2255f, 269.134f, 75.0543f, 269.134f, 71.3392f);
    path2.close();

    SkPath opResult;
    Op(path, path2, kDifference_SkPathOp, &opResult);

    // This produces the correct result in all the cases I've tried.
    // So it appears to be a winding issue.
    // canvas->drawPath(opResult, p);

    SkPath winding;
    path2.setFillType(SkPathFillType::kWinding);
    REPORTER_ASSERT(reporter, AsWinding(opResult, &winding));
    REPORTER_ASSERT(reporter, winding.getFillType() == SkPathFillType::kWinding);

    SkPath difference;
    Op(winding, opResult, kXOR_SkPathOp, &difference);
    REPORTER_ASSERT(reporter, difference.isEmpty());
}

void bug12040_3(skiatest::Reporter* reporter) {
    SkPath path;
    path.setFillType(SkPathFillType::kWinding);
    path.moveTo(375, -30);
    path.cubicTo(578, -30, 749, 176, 749, 422);
    path.cubicTo(749, 583, 666, 706, 518, 765);
    path.lineTo(163, 611);
    path.lineTo(163, 579);
    path.lineTo(405, 684);
    path.cubicTo(551, 609, 645, 468, 645, 322);
    path.cubicTo(645, 183, 563, 82, 450, 82);
    path.cubicTo(303, 82, 179, 249, 179, 446);
    path.cubicTo(179, 579, 235, 689, 341, 768);
    path.lineTo(327, 786);
    path.cubicTo(165, 717, 56, 536, 56, 335);
    path.cubicTo(56, 125, 192, -30, 375, -30);
    path.close();
    path.moveTo(214, 225);
    path.cubicTo(333, 248, 396, 311, 396, 405);
    path.lineTo(396, 695);
    path.lineTo(267, 641);
    path.lineTo(267, 395);
    path.cubicTo(267, 324, 249, 285, 201, 254);
    path.cubicTo(201, 254, 214, 225, 214, 225);
    path.close();
    path.moveTo(682, -106);
    path.lineTo(832, 12);
    path.lineTo(813, 33);
    path.lineTo(772, 0);
    path.cubicTo(716, 29, 668, 76, 628, 140);
    path.lineTo(527, 44);
    path.cubicTo(575, -26, 628, -77, 682, -106);
    path.close();
    path.moveTo(450, 59);
    path.lineTo(480, 59);
    path.lineTo(480, 678);
    path.lineTo(450, 678);
    path.cubicTo(450, 678, 450, 59, 450, 59);
    path.close();
    path.moveTo(463, 374);
    path.lineTo(633, 459);
    path.lineTo(633, 490);
    path.lineTo(463, 406);
    path.cubicTo(463, 406, 463, 374, 463, 374);
    path.close();
    path.moveTo(463, 269);
    path.lineTo(667, 372);
    path.lineTo(667, 403);
    path.lineTo(463, 301);
    path.cubicTo(463, 301, 463, 269, 463, 269);
    path.close();

    SkPath path2;
    path2.setFillType(SkPathFillType::kWinding);
    path2.moveTo(492.041f, 525.339f);
    path2.cubicTo(492.041f, 521.624f, 490.727f, 518.453f, 488.1f, 515.826f);
    path2.cubicTo(485.473f, 513.199f, 482.302f, 511.886f, 478.587f, 511.886f);
    path2.cubicTo(474.872f, 511.886f, 471.701f, 513.199f, 469.074f, 515.826f);
    path2.cubicTo(466.447f, 518.453f, 465.134f, 521.624f, 465.134f, 525.339f);
    path2.cubicTo(465.134f, 529.054f, 466.447f, 532.226f, 469.074f, 534.853f);
    path2.cubicTo(471.701f, 537.479f, 474.872f, 538.793f, 478.587f, 538.793f);
    path2.cubicTo(482.302f, 538.793f, 485.473f, 537.479f, 488.1f, 534.853f);
    path2.cubicTo(490.727f, 532.226f, 492.041f, 529.054f, 492.041f, 525.339f);
    path2.close();

    SkPath opResult;
    Op(path, path2, kDifference_SkPathOp, &opResult);

    SkPath winding;
    path2.setFillType(SkPathFillType::kWinding);
    REPORTER_ASSERT(reporter, AsWinding(opResult, &winding));
    REPORTER_ASSERT(reporter, winding.getFillType() == SkPathFillType::kWinding);

    SkPath difference;
    Op(winding, opResult, kXOR_SkPathOp, &difference);
    REPORTER_ASSERT(reporter, difference.isEmpty());
}

void bug12040_4(skiatest::Reporter* reporter) {
    for (int moveX = 199; moveX <= 201; ++moveX) {
        for (int moveY = 299; moveY <= 301; ++moveY) {
            for (int lineX = 199; lineX <= 201; ++lineX) {
                for (int lineY = 199; lineY <= 201; ++lineY) {
                    SkPath path;
                    path.setFillType(SkPathFillType::kWinding);
                    path.addCircle(250, 250, 150);

                    SkPath path2;
                    path2.setFillType(SkPathFillType::kWinding);
                    path2.moveTo(moveX, moveY);  // 200, 300 works... But not 200, 301!!
                    path2.lineTo(lineX, lineY);  // 200, 200 works... But not 199, 200!!
                    path2.lineTo(300, 300);
                    path2.close();

                    SkPath opResult;
                    Op(path, path2, kDifference_SkPathOp, &opResult);

                    SkPath winding;
                    REPORTER_ASSERT(reporter, AsWinding(opResult, &winding));
                    REPORTER_ASSERT(reporter, winding.getFillType() == SkPathFillType::kWinding);

                    SkPath difference;
                    Op(winding, opResult, kXOR_SkPathOp, &difference);
                    REPORTER_ASSERT(reporter, difference.isEmpty());
                }
            }
        }
    }
}

void bug12040_5(skiatest::Reporter* reporter) {
    for (int moveX = 199; moveX <= 201; ++moveX) {
        for (int moveY = 299; moveY <= 301; ++moveY) {
            for (int lineX = 199; lineX <= 201; ++lineX) {
                for (int lineY = 199; lineY <= 201; ++lineY) {
                    SkPath path;
                    path.setFillType(SkPathFillType::kWinding);
                    path.addRect(100, 100, 400, 400);

                    SkPath path2;
                    path2.setFillType(SkPathFillType::kWinding);
                    path2.moveTo(moveX, moveY);
                    path2.lineTo(lineX, lineY);  // 200, 200 works... But not 199, 200!!
                    path2.lineTo(300, 300);
                    path2.close();

                    SkPath opResult;
                    Op(path, path2, kDifference_SkPathOp, &opResult);

                    SkPath winding;
                    REPORTER_ASSERT(reporter, AsWinding(opResult, &winding));
                    REPORTER_ASSERT(reporter, winding.getFillType() == SkPathFillType::kWinding);

                    SkPath difference;
                    Op(winding, opResult, kXOR_SkPathOp, &difference);
                    REPORTER_ASSERT(reporter, difference.isEmpty());
                }
            }
        }
    }
}

void bug13496_1(skiatest::Reporter* reporter) {
    std::string originalPathStr =
            "M5.93 -3.12C5.93 -5.03 4.73 -6.06 3.5 -6.06C2.67 -6.06 1.98 -5.59 1.76 -5.34L1.67 "
            "-5.93L0.75 -5.93L0.75 2.23L1.87 2.04L1.87 -0.12C2.12 -0.03 2.62 0.07 3.18 0.07C4.57 "
            "0.07 5.93 -1.06 5.93 -3.12ZM4.81 -3.09C4.81 -1.51 4.18 -0.85 3.17 -0.85C2.57 -0.85 "
            "2.15 -0.98 1.87 -1.12L1.87 -4.15C2.34 -4.73 2.75 -5.09 3.42 -5.09C4.31 -5.09 4.81 "
            "-4.46 4.81 -3.09Z";

    SkPath path;
    SkParsePath::FromSVGString(originalPathStr.c_str(), &path);

    SkPath simplifiedPath;
    Simplify(path, &simplifiedPath);

    SkPath windingPath;
    REPORTER_ASSERT(reporter, AsWinding(simplifiedPath, &windingPath));
    REPORTER_ASSERT(reporter, windingPath.getFillType() == SkPathFillType::kWinding);

    SkPath difference;
    Op(windingPath, simplifiedPath, kXOR_SkPathOp, &difference);
    REPORTER_ASSERT(reporter, difference.isEmpty());
}

void bug13496_2(skiatest::Reporter* reporter) {
    std::string originalPathStr =
            "M4 0"
            "L0 0"
            "L0 5"
            "L4 4"
            "Z"
            "M3 3"
            "L1 3"
            "L1 1"
            "L3 1"
            "Z";

    SkPath path;
    SkParsePath::FromSVGString(originalPathStr.c_str(), &path);

    SkPath simplifiedPath;
    Simplify(path, &simplifiedPath);

    SkPath windingPath;
    REPORTER_ASSERT(reporter, AsWinding(simplifiedPath, &windingPath));
    REPORTER_ASSERT(reporter, windingPath.getFillType() == SkPathFillType::kWinding);

    SkPath difference;
    Op(windingPath, simplifiedPath, kXOR_SkPathOp, &difference);
    REPORTER_ASSERT(reporter, difference.isEmpty());
}

void bug13496_3(skiatest::Reporter* reporter) {
    std::string originalPathStr =
            "M4 0"
            "L0 0"
            "L0 4"
            "L4 4"
            "Z"
            "M3 3"
            "L1 3"
            "L1 1"
            "L3 1"
            "Z";

    SkPath path;
    SkParsePath::FromSVGString(originalPathStr.c_str(), &path);

    SkPath simplifiedPath;
    Simplify(path, &simplifiedPath);

    SkPath windingPath;
    REPORTER_ASSERT(reporter, AsWinding(simplifiedPath, &windingPath));
    REPORTER_ASSERT(reporter, windingPath.getFillType() == SkPathFillType::kWinding);

    SkPath difference;
    Op(windingPath, simplifiedPath, kXOR_SkPathOp, &difference);
    REPORTER_ASSERT(reporter, difference.isEmpty());
}

DEF_TEST(PathOpsAsWinding, reporter) {
    SkPath test, result;
    test.addRect({1, 2, 3, 4});
    // if test is winding
    REPORTER_ASSERT(reporter, AsWinding(test, &result));
    REPORTER_ASSERT(reporter, test == result);
    // if test is empty
    test.reset();
    test.setFillType(SkPathFillType::kEvenOdd);
    REPORTER_ASSERT(reporter, AsWinding(test, &result));
    REPORTER_ASSERT(reporter, result.isEmpty());
    REPORTER_ASSERT(reporter, result.getFillType() == SkPathFillType::kWinding);
    // if test is convex
    test.addCircle(5, 5, 10);
    REPORTER_ASSERT(reporter, AsWinding(test, &result));
    REPORTER_ASSERT(reporter, result.isConvex());
    test.setFillType(SkPathFillType::kWinding);
    REPORTER_ASSERT(reporter, test == result);
    // if test has infinity
    test.reset();
    test.addRect({1, 2, 3, SK_ScalarInfinity});
    test.setFillType(SkPathFillType::kEvenOdd);
    REPORTER_ASSERT(reporter, !AsWinding(test, &result));
    // if test has only one contour
    test.reset();
    SkPoint ell[] = {{0, 0}, {4, 0}, {4, 1}, {1, 1}, {1, 4}, {0, 4}};
    test.addPoly(ell, std::size(ell), true);
    test.setFillType(SkPathFillType::kEvenOdd);
    REPORTER_ASSERT(reporter, AsWinding(test, &result));
    REPORTER_ASSERT(reporter, !result.isConvex());
    test.setFillType(SkPathFillType::kWinding);
    REPORTER_ASSERT(reporter, test == result);
    // test two contours that do not overlap or share bounds
    test.addRect({5, 2, 6, 3});
    test.setFillType(SkPathFillType::kEvenOdd);
    REPORTER_ASSERT(reporter, AsWinding(test, &result));
    REPORTER_ASSERT(reporter, !result.isConvex());
    test.setFillType(SkPathFillType::kWinding);
    REPORTER_ASSERT(reporter, test == result);
    // test two contours that do not overlap but share bounds
    test.reset();
    test.addPoly(ell, std::size(ell), true);
    test.addRect({2, 2, 3, 3});
    test.setFillType(SkPathFillType::kEvenOdd);
    REPORTER_ASSERT(reporter, AsWinding(test, &result));
    REPORTER_ASSERT(reporter, !result.isConvex());
    test.setFillType(SkPathFillType::kWinding);
    REPORTER_ASSERT(reporter, test == result);
    // test two contours that partially overlap
    test.reset();
    test.addRect({0, 0, 3, 3});
    test.addRect({1, 1, 4, 4});
    test.setFillType(SkPathFillType::kEvenOdd);
    REPORTER_ASSERT(reporter, AsWinding(test, &result));
    REPORTER_ASSERT(reporter, !result.isConvex());
    test.setFillType(SkPathFillType::kWinding);
    REPORTER_ASSERT(reporter, test == result);
    // test that result may be input
    SkPath copy = test;
    test.setFillType(SkPathFillType::kEvenOdd);
    REPORTER_ASSERT(reporter, AsWinding(test, &test));
    REPORTER_ASSERT(reporter, !test.isConvex());
    REPORTER_ASSERT(reporter, test == copy);
    // test a in b, b in a, cw/ccw
    constexpr SkRect rectA = {0, 0, 3, 3};
    constexpr SkRect rectB = {1, 1, 2, 2};
    const std::initializer_list<SkPoint> revBccw = {{1, 2}, {2, 2}, {2, 1}, {1, 1}};
    const std::initializer_list<SkPoint> revBcw  = {{2, 1}, {2, 2}, {1, 2}, {1, 1}};
    for (bool aFirst : {false, true}) {
        for (auto dirA : {SkPathDirection::kCW, SkPathDirection::kCCW}) {
            for (auto dirB : {SkPathDirection::kCW, SkPathDirection::kCCW}) {
                test.reset();
                test.setFillType(SkPathFillType::kEvenOdd);
                if (aFirst) {
                    test.addRect(rectA, dirA);
                    test.addRect(rectB, dirB);
                } else {
                    test.addRect(rectB, dirB);
                    test.addRect(rectA, dirA);
                }
                SkPath original = test;
                REPORTER_ASSERT(reporter, AsWinding(test, &result));
                REPORTER_ASSERT(reporter, result.getFillType() == SkPathFillType::kWinding);
                test.reset();
                if (aFirst) {
                    test.addRect(rectA, dirA);
                }
                if (dirA != dirB) {
                    test.addRect(rectB, dirB);
                } else {
                    test.addPoly(SkPathDirection::kCW == dirA ? revBccw : revBcw, true);
                }
                if (!aFirst) {
                    test.addRect(rectA, dirA);
                }
                REPORTER_ASSERT(reporter, test == result);
                // test that result may be input
                REPORTER_ASSERT(reporter, AsWinding(original, &original));
                REPORTER_ASSERT(reporter, original.getFillType() == SkPathFillType::kWinding);
                REPORTER_ASSERT(reporter, original == result);
            }
        }
    }
    // Test curve types with donuts. Create a donut with outer and hole in all directions.
    // After converting to winding, all donuts should have a hole in the middle.
    for (bool aFirst : {false, true}) {
        for (auto dirA : {SkPathDirection::kCW, SkPathDirection::kCCW}) {
            for (auto dirB : {SkPathDirection::kCW, SkPathDirection::kCCW}) {
                for (auto curveA : { SkPath::kLine_Verb, SkPath::kQuad_Verb,
                                     SkPath::kConic_Verb, SkPath::kCubic_Verb } ) {
                    SkPath pathA = build_squircle(curveA, rectA, dirA);
                    for (auto curveB : { SkPath::kLine_Verb, SkPath::kQuad_Verb,
                                     SkPath::kConic_Verb, SkPath::kCubic_Verb } ) {
                        test = aFirst ? pathA : SkPath();
                        test.addPath(build_squircle(curveB, rectB, dirB));
                        if (!aFirst) {
                            test.addPath(pathA);
                        }
                        test.setFillType(SkPathFillType::kEvenOdd);
                        REPORTER_ASSERT(reporter, AsWinding(test, &result));
                       REPORTER_ASSERT(reporter, result.getFillType() == SkPathFillType::kWinding);
                        for (SkScalar x = rectA.fLeft - 1; x <= rectA.fRight + 1; ++x) {
                            for (SkScalar y = rectA.fTop - 1; y <= rectA.fBottom + 1; ++y) {
                                bool evenOddContains = test.contains(x, y);
                                bool windingContains = result.contains(x, y);
                                REPORTER_ASSERT(reporter, evenOddContains == windingContains);
                            }
                        }
                    }
                }
            }
        }
    }
    // test https://bugs.chromium.org/p/skia/issues/detail?id=12040
    bug12040_1(reporter);
    bug12040_2(reporter);
    bug12040_3(reporter);
    bug12040_4(reporter);
    bug12040_5(reporter);
    // test https://bugs.chromium.org/p/skia/issues/detail?id=13496
    bug13496_1(reporter);
    bug13496_2(reporter);
    bug13496_3(reporter);
}