1 /*
2  * Copyright 2013 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "SkBitmap.h"
9 #include "SkMipMap.h"
10 #include "SkRandom.h"
11 #include "Test.h"
12 
make_bitmap(SkBitmap * bm,int width,int height)13 static void make_bitmap(SkBitmap* bm, int width, int height) {
14     bm->allocN32Pixels(width, height);
15     bm->eraseColor(SK_ColorWHITE);
16 }
17 
DEF_TEST(MipMap,reporter)18 DEF_TEST(MipMap, reporter) {
19     SkBitmap bm;
20     SkRandom rand;
21 
22     for (int i = 0; i < 500; ++i) {
23         // for now, Build needs a min size of 2, otherwise it will return nullptr.
24         // should fix that to support 1 X N, where N > 1 to return non-null.
25         int width = 2 + rand.nextU() % 1000;
26         int height = 2 + rand.nextU() % 1000;
27         make_bitmap(&bm, width, height);
28         SkAutoTUnref<SkMipMap> mm(SkMipMap::Build(bm, nullptr));
29 
30         REPORTER_ASSERT(reporter, mm->countLevels() == SkMipMap::ComputeLevelCount(width, height));
31         REPORTER_ASSERT(reporter, !mm->extractLevel(SkSize::Make(SK_Scalar1, SK_Scalar1),
32                                                     nullptr));
33         REPORTER_ASSERT(reporter, !mm->extractLevel(SkSize::Make(SK_Scalar1 * 2, SK_Scalar1 * 2),
34                                                     nullptr));
35 
36         SkMipMap::Level prevLevel;
37         sk_bzero(&prevLevel, sizeof(prevLevel));
38 
39         SkScalar scale = SK_Scalar1;
40         for (int j = 0; j < 30; ++j) {
41             scale = scale * 2 / 3;
42 
43             SkMipMap::Level level;
44             if (mm->extractLevel(SkSize::Make(scale, scale), &level)) {
45                 REPORTER_ASSERT(reporter, level.fPixmap.addr());
46                 REPORTER_ASSERT(reporter, level.fPixmap.width() > 0);
47                 REPORTER_ASSERT(reporter, level.fPixmap.height() > 0);
48                 REPORTER_ASSERT(reporter, (int)level.fPixmap.rowBytes() >= level.fPixmap.width() * 4);
49 
50                 if (prevLevel.fPixmap.addr()) {
51                     REPORTER_ASSERT(reporter, level.fPixmap.width() <= prevLevel.fPixmap.width());
52                     REPORTER_ASSERT(reporter, level.fPixmap.height() <= prevLevel.fPixmap.height());
53                 }
54                 prevLevel = level;
55             }
56         }
57     }
58 }
59 
test_mipmap_generation(int width,int height,int expectedMipLevelCount,skiatest::Reporter * reporter)60 static void test_mipmap_generation(int width, int height, int expectedMipLevelCount,
61                                    skiatest::Reporter* reporter) {
62     SkBitmap bm;
63     bm.allocN32Pixels(width, height);
64     bm.eraseColor(SK_ColorWHITE);
65     SkAutoTUnref<SkMipMap> mm(SkMipMap::Build(bm, nullptr));
66 
67     const int mipLevelCount = mm->countLevels();
68     REPORTER_ASSERT(reporter, mipLevelCount == expectedMipLevelCount);
69     for (int i = 0; i < mipLevelCount; ++i) {
70         SkMipMap::Level level;
71         REPORTER_ASSERT(reporter, mm->getLevel(i, &level));
72         // Make sure the mipmaps contain valid data and that the sizes are correct
73         REPORTER_ASSERT(reporter, level.fPixmap.addr());
74 
75         // + 1 because SkMipMap does not include the base mipmap level.
76         int twoToTheMipLevel = 1 << (i + 1);
77         int currentWidth = width / twoToTheMipLevel;
78         int currentHeight = height / twoToTheMipLevel;
79         REPORTER_ASSERT(reporter, level.fPixmap.width() == currentWidth);
80         REPORTER_ASSERT(reporter, level.fPixmap.height() == currentHeight);
81     }
82 }
83 
DEF_TEST(MipMap_DirectLevelAccess,reporter)84 DEF_TEST(MipMap_DirectLevelAccess, reporter) {
85     // create mipmap with invalid size
86     {
87         // SkMipMap current requires the dimensions be greater than 2x2
88         SkBitmap bm;
89         bm.allocN32Pixels(1, 1);
90         bm.eraseColor(SK_ColorWHITE);
91         SkAutoTUnref<SkMipMap> mm(SkMipMap::Build(bm, nullptr));
92 
93         REPORTER_ASSERT(reporter, mm == nullptr);
94     }
95 
96     // check small mipmap's count and levels
97     // There should be 5 mipmap levels generated:
98     // 16x16, 8x8, 4x4, 2x2, 1x1
99     test_mipmap_generation(32, 32, 5, reporter);
100 
101     // check large mipmap's count and levels
102     // There should be 9 mipmap levels generated:
103     // 500x500, 250x250, 125x125, 62x62, 31x31, 15x15, 7x7, 3x3, 1x1
104     test_mipmap_generation(1000, 1000, 9, reporter);
105 }
106 
107 struct LevelCountScenario {
108     int fWidth;
109     int fHeight;
110     int fExpectedLevelCount;
111 };
112 
DEF_TEST(MipMap_ComputeLevelCount,reporter)113 DEF_TEST(MipMap_ComputeLevelCount, reporter) {
114     const LevelCountScenario tests[] = {
115         // Test mipmaps with negative sizes
116         {-100, 100, 0},
117         {100, -100, 0},
118         {-100, -100, 0},
119 
120         // Test mipmaps with 0, 1, 2 as dimensions
121         // (SkMipMap::Build requires a min size of 2)
122         //
123         // 0
124         {0, 100, 0},
125         {100, 0, 0},
126         {0, 0, 0},
127         // 1
128         {1, 100, 0},
129         {100, 1, 0},
130         {1, 1, 0},
131         // 2
132         {2, 100, 1},
133         {100, 2, 1},
134         {2, 2, 1},
135 
136         // Test a handful of boundaries such as 63x63 and 64x64
137         {63, 63, 5},
138         {64, 64, 6},
139         {127, 127, 6},
140         {128, 128, 7},
141         {255, 255, 7},
142         {256, 256, 8},
143 
144         // Test different dimensions, such as 256x64
145         {64, 129, 6},
146         {255, 32, 5},
147         {500, 1000, 8}
148     };
149 
150     for (auto& currentTest : tests) {
151         int levelCount = SkMipMap::ComputeLevelCount(currentTest.fWidth, currentTest.fHeight);
152         REPORTER_ASSERT(reporter, currentTest.fExpectedLevelCount == levelCount);
153     }
154 }
155