1 /*
2 * Copyright 2011 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 "include/core/SkCanvas.h"
9 #include "include/core/SkSurface.h"
10 #include "tests/Test.h"
11 #include "tools/ToolUtils.h"
12
13 #include "include/gpu/GrContext.h"
14
pack_unpremul_rgba(SkColor c)15 static uint32_t pack_unpremul_rgba(SkColor c) {
16 uint32_t packed;
17 uint8_t* byte = reinterpret_cast<uint8_t*>(&packed);
18 byte[0] = SkColorGetR(c);
19 byte[1] = SkColorGetG(c);
20 byte[2] = SkColorGetB(c);
21 byte[3] = SkColorGetA(c);
22 return packed;
23 }
24
pack_unpremul_bgra(SkColor c)25 static uint32_t pack_unpremul_bgra(SkColor c) {
26 uint32_t packed;
27 uint8_t* byte = reinterpret_cast<uint8_t*>(&packed);
28 byte[0] = SkColorGetB(c);
29 byte[1] = SkColorGetG(c);
30 byte[2] = SkColorGetR(c);
31 byte[3] = SkColorGetA(c);
32 return packed;
33 }
34
35 typedef uint32_t (*PackUnpremulProc)(SkColor);
36
37 const struct {
38 SkColorType fColorType;
39 PackUnpremulProc fPackProc;
40 } gUnpremul[] = {
41 { kRGBA_8888_SkColorType, pack_unpremul_rgba },
42 { kBGRA_8888_SkColorType, pack_unpremul_bgra },
43 };
44
fill_surface(SkSurface * surf,SkColorType colorType,PackUnpremulProc proc)45 static void fill_surface(SkSurface* surf, SkColorType colorType, PackUnpremulProc proc) {
46 // Don't strictly need a bitmap, but its a handy way to allocate the pixels
47 SkBitmap bmp;
48 bmp.allocN32Pixels(256, 256);
49
50 for (int a = 0; a < 256; ++a) {
51 uint32_t* pixels = bmp.getAddr32(0, a);
52 for (int r = 0; r < 256; ++r) {
53 pixels[r] = proc(SkColorSetARGB(a, r, 0, 0));
54 }
55 }
56
57 const SkImageInfo info = SkImageInfo::Make(bmp.width(), bmp.height(),
58 colorType, kUnpremul_SkAlphaType);
59 surf->writePixels({info, bmp.getPixels(), bmp.rowBytes()}, 0, 0);
60 }
61
test_premul_alpha_roundtrip(skiatest::Reporter * reporter,SkSurface * surf)62 static void test_premul_alpha_roundtrip(skiatest::Reporter* reporter, SkSurface* surf) {
63 for (size_t upmaIdx = 0; upmaIdx < SK_ARRAY_COUNT(gUnpremul); ++upmaIdx) {
64 fill_surface(surf, gUnpremul[upmaIdx].fColorType, gUnpremul[upmaIdx].fPackProc);
65
66 const SkImageInfo info = SkImageInfo::Make(256, 256, gUnpremul[upmaIdx].fColorType,
67 kUnpremul_SkAlphaType);
68 SkBitmap readBmp1;
69 readBmp1.allocPixels(info);
70 SkBitmap readBmp2;
71 readBmp2.allocPixels(info);
72
73 readBmp1.eraseColor(0);
74 readBmp2.eraseColor(0);
75
76 surf->readPixels(readBmp1, 0, 0);
77 surf->writePixels(readBmp1, 0, 0);
78 surf->readPixels(readBmp2, 0, 0);
79
80 bool success = true;
81 for (int y = 0; y < 256 && success; ++y) {
82 const uint32_t* pixels1 = readBmp1.getAddr32(0, y);
83 const uint32_t* pixels2 = readBmp2.getAddr32(0, y);
84 for (int x = 0; x < 256 && success; ++x) {
85 // We see sporadic failures here. May help to see where it goes wrong.
86 if (pixels1[x] != pixels2[x]) {
87 SkDebugf("%x != %x, x = %d, y = %d\n", pixels1[x], pixels2[x], x, y);
88 }
89 REPORTER_ASSERT(reporter, success = pixels1[x] == pixels2[x]);
90 }
91 }
92 }
93 }
94
DEF_TEST(PremulAlphaRoundTrip,reporter)95 DEF_TEST(PremulAlphaRoundTrip, reporter) {
96 const SkImageInfo info = SkImageInfo::MakeN32Premul(256, 256);
97
98 sk_sp<SkSurface> surf(SkSurface::MakeRaster(info));
99
100 test_premul_alpha_roundtrip(reporter, surf.get());
101 }
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(PremulAlphaRoundTrip_Gpu,reporter,ctxInfo)102 DEF_GPUTEST_FOR_RENDERING_CONTEXTS(PremulAlphaRoundTrip_Gpu, reporter, ctxInfo) {
103 const SkImageInfo info = SkImageInfo::MakeN32Premul(256, 256);
104
105 sk_sp<SkSurface> surf(SkSurface::MakeRenderTarget(ctxInfo.grContext(),
106 SkBudgeted::kNo,
107 info));
108 test_premul_alpha_roundtrip(reporter, surf.get());
109 }
110