skia2/tests/PathOpsLineIntersectionTest.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 "SkIntersections.h"
#include "SkPathOpsLine.h"
#include "Test.h"

// FIXME: add tests for intersecting, non-intersecting, degenerate, coincident
static const SkDLine tests[][2] = {
#if 0  // FIXME: these fail because one line is too short and appears quasi-coincident
    {{{{158.000000, 926.000000}, {1108.00000, 926.000000}}},
            {{{1108.00000, 926.000000}, {1108.00000, 925.999634}}}},
    {{{{1108,926}, {1108,925.9996337890625}}}, {{{158,926}, {1108,926}}}},
#endif
    {{{{192, 4}, {243, 4}}}, {{{246, 4}, {189, 4}}}},
    {{{{246, 4}, {189, 4}}}, {{{192, 4}, {243, 4}}}},
    {{{{5, 0}, {0, 5}}}, {{{5, 4}, {1, 4}}}},
    {{{{0, 0}, {1, 0}}}, {{{1, 0}, {0, 0}}}},
    {{{{0, 0}, {0, 0}}}, {{{0, 0}, {1, 0}}}},
    {{{{0, 1}, {0, 1}}}, {{{0, 0}, {0, 2}}}},
    {{{{0, 0}, {1, 0}}}, {{{0, 0}, {2, 0}}}},
    {{{{1, 1}, {2, 2}}}, {{{0, 0}, {3, 3}}}},
    {{{{166.86950047022856, 112.69654129527828}, {166.86948801592692, 112.69655741235339}}},
     {{{166.86960700313026, 112.6965477747386}, {166.86925794355412, 112.69656471103423}}}}
};

static const size_t tests_count = SK_ARRAY_COUNT(tests);

static const SkDLine noIntersect[][2] = {
    {{{{0, 0}, {1, 0}}}, {{{3, 0}, {2, 0}}}},
    {{{{0, 0}, {0, 0}}}, {{{1, 0}, {2, 0}}}},
    {{{{0, 1}, {0, 1}}}, {{{0, 3}, {0, 2}}}},
    {{{{0, 0}, {1, 0}}}, {{{2, 0}, {3, 0}}}},
    {{{{1, 1}, {2, 2}}}, {{{4, 4}, {3, 3}}}},
};

static const size_t noIntersect_count = SK_ARRAY_COUNT(noIntersect);

static const SkDLine coincidentTests[][2] = {
    {{{{235.681549, 531.000000}, {280.318420, 321.000000}}},
            {{{286.695129, 291.000000}, {229.304855, 561.000000}}}},
};

static const size_t coincidentTests_count = SK_ARRAY_COUNT(coincidentTests);

static void check_results(skiatest::Reporter* reporter, const SkDLine& line1, const SkDLine& line2,
                          const SkIntersections& ts) {
    for (int i = 0; i < ts.used(); ++i) {
        SkDPoint result1 = line1.xyAtT(ts[0][i]);
        SkDPoint result2 = line2.xyAtT(ts[1][i]);
        if (!result1.approximatelyEqual(result2)) {
            REPORTER_ASSERT(reporter, ts.used() != 1);
            result2 = line2.xyAtT(ts[1][i ^ 1]);
            REPORTER_ASSERT(reporter, result1.approximatelyEqual(result2));
            REPORTER_ASSERT(reporter, result1.approximatelyEqual(ts.pt(i).asSkPoint()));
        }
    }
}

static void testOne(skiatest::Reporter* reporter, const SkDLine& line1, const SkDLine& line2) {
    SkIntersections i;
    int pts = i.intersect(line1, line2);
    REPORTER_ASSERT(reporter, pts);
    REPORTER_ASSERT(reporter, pts == i.used());
    check_results(reporter, line1, line2, i);
    if (line1[0] == line1[1] || line2[0] == line2[1]) {
        return;
    }
    if (line1[0].fY == line1[1].fY) {
        double left = SkTMin(line1[0].fX, line1[1].fX);
        double right = SkTMax(line1[0].fX, line1[1].fX);
        SkIntersections ts;
        ts.horizontal(line2, left, right, line1[0].fY, line1[0].fX != left);
        check_results(reporter, line2, line1, ts);
    }
    if (line2[0].fY == line2[1].fY) {
        double left = SkTMin(line2[0].fX, line2[1].fX);
        double right = SkTMax(line2[0].fX, line2[1].fX);
        SkIntersections ts;
        ts.horizontal(line1, left, right, line2[0].fY, line2[0].fX != left);
        check_results(reporter, line1, line2, ts);
    }
    if (line1[0].fX == line1[1].fX) {
        double top = SkTMin(line1[0].fY, line1[1].fY);
        double bottom = SkTMax(line1[0].fY, line1[1].fY);
        SkIntersections ts;
        ts.vertical(line2, top, bottom, line1[0].fX, line1[0].fY != top);
        check_results(reporter, line2, line1, ts);
    }
    if (line2[0].fX == line2[1].fX) {
        double top = SkTMin(line2[0].fY, line2[1].fY);
        double bottom = SkTMax(line2[0].fY, line2[1].fY);
        SkIntersections ts;
        ts.vertical(line1, top, bottom, line2[0].fX, line2[0].fY != top);
        check_results(reporter, line1, line2, ts);
    }
}

static void testOneCoincident(skiatest::Reporter* reporter, const SkDLine& line1,
                              const SkDLine& line2) {
    SkIntersections ts2;
    int pts2 = ts2.intersect(line1, line2);
    REPORTER_ASSERT(reporter, pts2 == 2);
    REPORTER_ASSERT(reporter, pts2 == ts2.used());
    check_results(reporter, line1, line2, ts2);
#if 0
    SkIntersections ts;
    int pts = ts.intersect(line1, line2);
    REPORTER_ASSERT(reporter, pts == pts2);
    REPORTER_ASSERT(reporter, pts == 2);
    REPORTER_ASSERT(reporter, pts == ts.used());
    check_results(reporter, line1, line2, ts);
#endif
}

static void PathOpsLineIntersectionTest(skiatest::Reporter* reporter) {
    size_t index;
    for (index = 0; index < coincidentTests_count; ++index) {
        const SkDLine& line1 = coincidentTests[index][0];
        const SkDLine& line2 = coincidentTests[index][1];
        testOneCoincident(reporter, line1, line2);
        reporter->bumpTestCount();
    }
    for (index = 0; index < tests_count; ++index) {
        const SkDLine& line1 = tests[index][0];
        const SkDLine& line2 = tests[index][1];
        testOne(reporter, line1, line2);
        reporter->bumpTestCount();
    }
    for (index = 0; index < noIntersect_count; ++index) {
        const SkDLine& line1 = noIntersect[index][0];
        const SkDLine& line2 = noIntersect[index][1];
        SkIntersections ts;
        int pts = ts.intersect(line1, line2);
        REPORTER_ASSERT(reporter, !pts);
        REPORTER_ASSERT(reporter, pts == ts.used());
        reporter->bumpTestCount();
    }
}

static void PathOpsLineIntersectionTestOne(skiatest::Reporter* reporter) {
    int index = 0;
    SkASSERT(index < (int) tests_count);
    const SkDLine& line1 = tests[index][0];
    const SkDLine& line2 = tests[index][1];
    testOne(reporter, line1, line2);
}

static void PathOpsLineIntersectionTestOneCoincident(skiatest::Reporter* reporter) {
    int index = 0;
    SkASSERT(index < (int) coincidentTests_count);
    const SkDLine& line1 = coincidentTests[index][0];
    const SkDLine& line2 = coincidentTests[index][1];
    testOneCoincident(reporter, line1, line2);
}

#include "TestClassDef.h"
DEFINE_TESTCLASS_SHORT(PathOpsLineIntersectionTest)

DEFINE_TESTCLASS_SHORT(PathOpsLineIntersectionTestOne)

DEFINE_TESTCLASS_SHORT(PathOpsLineIntersectionTestOneCoincident)