skia2/tests/PathOpsQuadLineIntersectionThreadedTest.cpp

/*
 * Copyright 2012 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "PathOpsExtendedTest.h"
#include "SkIntersections.h"
#include "SkPathOpsLine.h"
#include "SkPathOpsQuad.h"
#include "SkReduceOrder.h"

static int doIntersect(SkIntersections& intersections, const SkDQuad& quad, const SkDLine& line,
                       bool& flipped) {
    int result;
    flipped = false;
    if (line[0].fX == line[1].fX) {
        double top = line[0].fY;
        double bottom = line[1].fY;
        flipped = top > bottom;
        if (flipped) {
            SkTSwap<double>(top, bottom);
        }
        result = intersections.vertical(quad, top, bottom, line[0].fX, flipped);
    } else if (line[0].fY == line[1].fY) {
        double left = line[0].fX;
        double right = line[1].fX;
        flipped = left > right;
        if (flipped) {
            SkTSwap<double>(left, right);
        }
        result = intersections.horizontal(quad, left, right, line[0].fY, flipped);
    } else {
        intersections.intersect(quad, line);
        result = intersections.used();
    }
    return result;
}

static void testLineIntersect(skiatest::Reporter* reporter, const SkDQuad& quad,
                              const SkDLine& line, const double x, const double y) {
    char pathStr[1024];
    sk_bzero(pathStr, sizeof(pathStr));
    char* str = pathStr;
    str += sprintf(str, "    path.moveTo(%1.9g, %1.9g);\n", quad[0].fX, quad[0].fY);
    str += sprintf(str, "    path.quadTo(%1.9g, %1.9g, %1.9g, %1.9g);\n", quad[1].fX, quad[1].fY, quad[2].fX, quad[2].fY);
    str += sprintf(str, "    path.moveTo(%1.9g, %1.9g);\n", line[0].fX, line[0].fY);
    str += sprintf(str, "    path.lineTo(%1.9g, %1.9g);\n", line[1].fX, line[1].fY);

    SkIntersections intersections;
    bool flipped = false;
    int result = doIntersect(intersections, quad, line, flipped);
    bool found = false;
    for (int index = 0; index < result; ++index) {
        double quadT = intersections[0][index];
        SkDPoint quadXY = quad.xyAtT(quadT);
        double lineT = intersections[1][index];
        SkDPoint lineXY = line.xyAtT(lineT);
        if (quadXY.approximatelyEqual(lineXY)) {
            found = true;
        }
    }
    REPORTER_ASSERT(reporter, found);
}


// find a point on a quad by choosing a t from 0 to 1
// create a vertical span above and below the point
// verify that intersecting the vertical span and the quad returns t
// verify that a vertical span starting at quad[0] intersects at t=0
// verify that a vertical span starting at quad[2] intersects at t=1
static THREAD_TYPE testQuadLineIntersectMain(void* data)
{
    State4& state = *(State4*) data;
    REPORTER_ASSERT(state.reporter, data);
    do {
        int ax = state.a & 0x03;
        int ay = state.a >> 2;
        int bx = state.b & 0x03;
        int by = state.b >> 2;
        int cx = state.c & 0x03;
        int cy = state.c >> 2;
        SkDQuad quad = {{{ax, ay}, {bx, by}, {cx, cy}}};
        SkReduceOrder reducer;
        int order = reducer.reduce(quad, SkReduceOrder::kFill_Style);
        if (order < 3) {
            continue;  // skip degenerates
        }
        for (int tIndex = 0; tIndex <= 4; ++tIndex) {
            SkDPoint xy = quad.xyAtT(tIndex / 4.0);
            for (int h = -2; h <= 2; ++h) {
                for (int v = -2; v <= 2; ++v) {
                    if (h == v && abs(h) != 1) {
                        continue;
                    }
                    double x = xy.fX;
                    double y = xy.fY;
                    SkDLine line = {{{x - h, y - v}, {x, y}}};
                    testLineIntersect(state.reporter, quad, line, x, y);
                    SkDLine line2 = {{{x, y}, {x + h, y + v}}};
                    testLineIntersect(state.reporter, quad, line2, x, y);
                    SkDLine line3 = {{{x - h, y - v}, {x + h, y + v}}};
                    testLineIntersect(state.reporter, quad, line3, x, y);
                    state.testsRun += 3;
                }
            }
        }
    } while (runNextTestSet(state));
    THREAD_RETURN
}

static void TestQuadLineIntersectionThreaded(skiatest::Reporter* reporter)
{
    int testsRun = 0;
    if (gShowTestProgress) SkDebugf("%s\n", __FUNCTION__);
    const char testStr[] = "testQuadLineIntersect";
    initializeTests(reporter, testStr, sizeof(testStr));
    for (int a = 0; a < 16; ++a) {
        for (int b = 0 ; b < 16; ++b) {
            for (int c = 0 ; c < 16; ++c) {
                testsRun += dispatchTest4(testQuadLineIntersectMain, a, b, c, 0);
            }
            if (!gAllowExtendedTest) goto finish;
            if (gShowTestProgress) SkDebugf(".");
        }
        if (gShowTestProgress) SkDebugf("%d", a);
    }
finish:
    testsRun += waitForCompletion();
    if (gShowTestProgress) SkDebugf("\n%s tests=%d\n", __FUNCTION__, testsRun);
}

#include "TestClassDef.h"
DEFINE_TESTCLASS("PathOpsQuadLineIntersectionThreaded", QuadLineIntersectionThreadedTestClass, \
        TestQuadLineIntersectionThreaded)