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 "SkCanvas.h"
9 #include "SkSurface.h"
10 #include "Test.h"
11 #include "sk_tool_utils.h"
12
13 #if SK_SUPPORT_GPU
14 #include "GrContext.h"
15 #endif
16
pack_unpremul_rgba(SkColor c)17 static uint32_t pack_unpremul_rgba(SkColor c) {
18 uint32_t packed;
19 uint8_t* byte = reinterpret_cast<uint8_t*>(&packed);
20 byte[0] = SkColorGetR(c);
21 byte[1] = SkColorGetG(c);
22 byte[2] = SkColorGetB(c);
23 byte[3] = SkColorGetA(c);
24 return packed;
25 }
26
pack_unpremul_bgra(SkColor c)27 static uint32_t pack_unpremul_bgra(SkColor c) {
28 uint32_t packed;
29 uint8_t* byte = reinterpret_cast<uint8_t*>(&packed);
30 byte[0] = SkColorGetB(c);
31 byte[1] = SkColorGetG(c);
32 byte[2] = SkColorGetR(c);
33 byte[3] = SkColorGetA(c);
34 return packed;
35 }
36
37 typedef uint32_t (*PackUnpremulProc)(SkColor);
38
39 const struct {
40 SkColorType fColorType;
41 PackUnpremulProc fPackProc;
42 } gUnpremul[] = {
43 { kRGBA_8888_SkColorType, pack_unpremul_rgba },
44 { kBGRA_8888_SkColorType, pack_unpremul_bgra },
45 };
46
fill_canvas(SkCanvas * canvas,SkColorType colorType,PackUnpremulProc proc)47 static void fill_canvas(SkCanvas* canvas, SkColorType colorType, PackUnpremulProc proc) {
48 // Don't strictly need a bitmap, but its a handy way to allocate the pixels
49 SkBitmap bmp;
50 bmp.allocN32Pixels(256, 256);
51
52 for (int a = 0; a < 256; ++a) {
53 uint32_t* pixels = bmp.getAddr32(0, a);
54 for (int r = 0; r < 256; ++r) {
55 pixels[r] = proc(SkColorSetARGB(a, r, 0, 0));
56 }
57 }
58
59 const SkImageInfo info = SkImageInfo::Make(bmp.width(), bmp.height(),
60 colorType, kUnpremul_SkAlphaType);
61 canvas->writePixels(info, bmp.getPixels(), bmp.rowBytes(), 0, 0);
62 }
63
test_premul_alpha_roundtrip(skiatest::Reporter * reporter,SkSurface * surf)64 static void test_premul_alpha_roundtrip(skiatest::Reporter* reporter, SkSurface* surf) {
65 SkCanvas* canvas = surf->getCanvas();
66 for (size_t upmaIdx = 0; upmaIdx < SK_ARRAY_COUNT(gUnpremul); ++upmaIdx) {
67 fill_canvas(canvas, gUnpremul[upmaIdx].fColorType, gUnpremul[upmaIdx].fPackProc);
68
69 const SkImageInfo info = SkImageInfo::Make(256, 256, gUnpremul[upmaIdx].fColorType,
70 kUnpremul_SkAlphaType);
71 SkBitmap readBmp1;
72 readBmp1.allocPixels(info);
73 SkBitmap readBmp2;
74 readBmp2.allocPixels(info);
75
76 readBmp1.eraseColor(0);
77 readBmp2.eraseColor(0);
78
79 canvas->readPixels(&readBmp1, 0, 0);
80 sk_tool_utils::write_pixels(canvas, readBmp1, 0, 0, gUnpremul[upmaIdx].fColorType,
81 kUnpremul_SkAlphaType);
82 canvas->readPixels(&readBmp2, 0, 0);
83
84 bool success = true;
85 for (int y = 0; y < 256 && success; ++y) {
86 const uint32_t* pixels1 = readBmp1.getAddr32(0, y);
87 const uint32_t* pixels2 = readBmp2.getAddr32(0, y);
88 for (int x = 0; x < 256 && success; ++x) {
89 // We see sporadic failures here. May help to see where it goes wrong.
90 if (pixels1[x] != pixels2[x]) {
91 SkDebugf("%x != %x, x = %d, y = %d\n", pixels1[x], pixels2[x], x, y);
92 }
93 REPORTER_ASSERT(reporter, success = pixels1[x] == pixels2[x]);
94 }
95 }
96 }
97 }
98
DEF_TEST(PremulAlphaRoundTrip,reporter)99 DEF_TEST(PremulAlphaRoundTrip, reporter) {
100 const SkImageInfo info = SkImageInfo::MakeN32Premul(256, 256);
101
102 sk_sp<SkSurface> surf(SkSurface::MakeRaster(info));
103
104 test_premul_alpha_roundtrip(reporter, surf.get());
105 }
106 #if SK_SUPPORT_GPU
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(PremulAlphaRoundTrip_Gpu,reporter,ctxInfo)107 DEF_GPUTEST_FOR_RENDERING_CONTEXTS(PremulAlphaRoundTrip_Gpu, reporter, ctxInfo) {
108 const SkImageInfo info = SkImageInfo::MakeN32Premul(256, 256);
109
110 sk_sp<SkSurface> surf(SkSurface::MakeRenderTarget(ctxInfo.grContext(),
111 SkBudgeted::kNo,
112 info));
113 test_premul_alpha_roundtrip(reporter, surf.get());
114 }
115 #endif
116