tests/RegionTest.cpp

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "Test.h"
#include "SkRegion.h"
#include "SkRandom.h"

static void test_empties(skiatest::Reporter* reporter) {
    SkRegion valid(SkIRect::MakeWH(10, 10));
    SkRegion empty, empty2;

    REPORTER_ASSERT(reporter, empty.isEmpty());
    REPORTER_ASSERT(reporter, !valid.isEmpty());

    // test intersects
    REPORTER_ASSERT(reporter, !empty.intersects(empty2));
    REPORTER_ASSERT(reporter, !valid.intersects(empty));

    // test contains
    REPORTER_ASSERT(reporter, !empty.contains(empty2));
    REPORTER_ASSERT(reporter, !valid.contains(empty));
    REPORTER_ASSERT(reporter, !empty.contains(valid));
}

enum {
    W = 256,
    H = 256
};

static SkIRect randRect(SkRandom& rand) {
    int x = rand.nextU() % W;
    int y = rand.nextU() % H;
    int w = rand.nextU() % W;
    int h = rand.nextU() % H;
    return SkIRect::MakeXYWH(x, y, w >> 1, h >> 1);
}

static void randRgn(SkRandom& rand, SkRegion* rgn, int n) {
    rgn->setEmpty();
    for (int i = 0; i < n; ++i) {
        rgn->op(randRect(rand), SkRegion::kUnion_Op);
    }
}

static bool slow_contains(const SkRegion& outer, const SkRegion& inner) {
    SkRegion tmp;
    tmp.op(outer, inner, SkRegion::kUnion_Op);
    return outer == tmp;
}

static bool slow_intersects(const SkRegion& outer, const SkRegion& inner) {
    SkRegion tmp;
    return tmp.op(outer, inner, SkRegion::kIntersect_Op);
}

static void contains_proc(skiatest::Reporter* reporter,
                          const SkRegion& a, const SkRegion& b) {
    bool c0 = a.contains(b);
    bool c1 = slow_contains(a, b);
    REPORTER_ASSERT(reporter, c0 == c1);
}

static void intersects_proc(skiatest::Reporter* reporter,
                          const SkRegion& a, const SkRegion& b) {
    bool c0 = a.intersects(b);
    bool c1 = slow_intersects(a, b);
    REPORTER_ASSERT(reporter, c0 == c1);
}

static void test_proc(skiatest::Reporter* reporter,
                      void (*proc)(skiatest::Reporter*,
                                   const SkRegion& a, const SkRegion&)) {
    SkRandom rand;
    for (int i = 0; i < 10000; ++i) {
        SkRegion outer;
        randRgn(rand, &outer, 8);
        SkRegion inner;
        randRgn(rand, &inner, 2);
        proc(reporter, outer, inner);
    }
}

static void rand_rect(SkIRect* rect, SkRandom& rand) {
    int bits = 6;
    int shift = 32 - bits;
    rect->set(rand.nextU() >> shift, rand.nextU() >> shift,
              rand.nextU() >> shift, rand.nextU() >> shift);
    rect->sort();
}

static bool test_rects(const SkIRect rect[], int count) {
    SkRegion rgn0, rgn1;

    for (int i = 0; i < count; i++) {
        rgn0.op(rect[i], SkRegion::kUnion_Op);
    }
    rgn1.setRects(rect, count);

    if (rgn0 != rgn1) {
        SkDebugf("\n");
        for (int i = 0; i < count; i++) {
            SkDebugf(" { %d, %d, %d, %d },\n",
                     rect[i].fLeft, rect[i].fTop,
                     rect[i].fRight, rect[i].fBottom);
        }
        SkDebugf("\n");
        return false;
    }
    return true;
}

static void TestRegion(skiatest::Reporter* reporter) {
    const SkIRect r2[] = {
        { 0, 0, 1, 1 },
        { 2, 2, 3, 3 },
    };
    REPORTER_ASSERT(reporter, test_rects(r2, SK_ARRAY_COUNT(r2)));
    
    const SkIRect rects[] = {
        { 0, 0, 1, 2 },
        { 2, 1, 3, 3 },
        { 4, 0, 5, 1 },
        { 6, 0, 7, 4 },
    };
    REPORTER_ASSERT(reporter, test_rects(rects, SK_ARRAY_COUNT(rects)));

    SkRandom rand;
    for (int i = 0; i < 1000; i++) {
        SkRegion rgn0, rgn1;

        const int N = 8;
        SkIRect rect[N];
        for (int j = 0; j < N; j++) {
            rand_rect(&rect[j], rand);
        }
        REPORTER_ASSERT(reporter, test_rects(rect, N));
    }
    
    test_proc(reporter, contains_proc);
    test_proc(reporter, intersects_proc);
    test_empties(reporter);
}

#include "TestClassDef.h"
DEFINE_TESTCLASS("Region", RegionTestClass, TestRegion)