1 /*
2 * Copyright 2015 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 "SkBlendMode.h"
10 #include "SkCanvas.h"
11 #include "SkColor.h"
12 #include "SkColorSpace.h"
13 #include "SkImageInfo.h"
14 #include "SkPaint.h"
15 #include "SkPoint.h"
16 #include "SkRect.h"
17 #include "SkRefCnt.h"
18 #include "SkSurface.h"
19 #include "SkTypes.h"
20 #include "Test.h"
21
22 #include "GrBackendSurface.h"
23 #include "GrContext.h"
24 #include "GrContextFactory.h"
25 #include "GrContextPriv.h"
26 #include "GrResourceProvider.h"
27 #include "GrTexture.h"
28 #include "GrTypes.h"
29
30 #include <vector>
31
32 struct Results { int diffs, diffs_0x00, diffs_0xff, diffs_by_1; };
33
acceptable(const Results & r)34 static bool acceptable(const Results& r) {
35 #if 0
36 SkDebugf("%d diffs, %d at 0x00, %d at 0xff, %d off by 1, all out of 65536\n",
37 r.diffs, r.diffs_0x00, r.diffs_0xff, r.diffs_by_1);
38 #endif
39 return r.diffs_by_1 == r.diffs // never off by more than 1
40 && r.diffs_0x00 == 0 // transparent must stay transparent
41 && r.diffs_0xff == 0; // opaque must stay opaque
42 }
43
44 template <typename Fn>
test(Fn && multiply)45 static Results test(Fn&& multiply) {
46 Results r = { 0,0,0,0 };
47 for (int x = 0; x < 256; x++) {
48 for (int y = 0; y < 256; y++) {
49 int p = multiply(x, y),
50 ideal = (x*y+127)/255;
51 if (p != ideal) {
52 r.diffs++;
53 if (x == 0x00 || y == 0x00) { r.diffs_0x00++; }
54 if (x == 0xff || y == 0xff) { r.diffs_0xff++; }
55 if (SkTAbs(ideal - p) == 1) { r.diffs_by_1++; }
56 }
57 }}
58 return r;
59 }
60
DEF_TEST(Blend_byte_multiply,r)61 DEF_TEST(Blend_byte_multiply, r) {
62 // These are all temptingly close but fundamentally broken.
63 int (*broken[])(int, int) = {
64 [](int x, int y) { return (x*y)>>8; },
65 [](int x, int y) { return (x*y+128)>>8; },
66 [](int x, int y) { y += y>>7; return (x*y)>>8; },
67 };
68 for (auto multiply : broken) { REPORTER_ASSERT(r, !acceptable(test(multiply))); }
69
70 // These are fine to use, but not perfect.
71 int (*fine[])(int, int) = {
72 [](int x, int y) { return (x*y+x)>>8; },
73 [](int x, int y) { return (x*y+y)>>8; },
74 [](int x, int y) { return (x*y+255)>>8; },
75 [](int x, int y) { y += y>>7; return (x*y+128)>>8; },
76 };
77 for (auto multiply : fine) { REPORTER_ASSERT(r, acceptable(test(multiply))); }
78
79 // These are pefect.
80 int (*perfect[])(int, int) = {
81 [](int x, int y) { return (x*y+127)/255; }, // Duh.
82 [](int x, int y) { int p = (x*y+128); return (p+(p>>8))>>8; },
83 [](int x, int y) { return ((x*y+128)*257)>>16; },
84 };
85 for (auto multiply : perfect) { REPORTER_ASSERT(r, test(multiply).diffs == 0); }
86 }
87
88 namespace {
create_gpu_surface_backend_texture_as_render_target(GrContext * context,int sampleCnt,int width,int height,SkColorType colorType,GrPixelConfig config,GrSurfaceOrigin origin,sk_sp<GrTexture> * backingSurface)89 static sk_sp<SkSurface> create_gpu_surface_backend_texture_as_render_target(
90 GrContext* context, int sampleCnt, int width, int height, SkColorType colorType,
91 GrPixelConfig config, GrSurfaceOrigin origin,
92 sk_sp<GrTexture>* backingSurface) {
93 GrSurfaceDesc backingDesc;
94 backingDesc.fFlags = kRenderTarget_GrSurfaceFlag;
95 backingDesc.fWidth = width;
96 backingDesc.fHeight = height;
97 backingDesc.fConfig = config;
98 backingDesc.fSampleCnt = sampleCnt;
99
100 auto resourceProvider = context->contextPriv().resourceProvider();
101
102 *backingSurface = resourceProvider->createTexture(backingDesc, SkBudgeted::kNo);
103 if (!(*backingSurface)) {
104 return nullptr;
105 }
106
107 GrBackendTexture backendTex = (*backingSurface)->getBackendTexture();
108
109 sk_sp<SkSurface> surface =
110 SkSurface::MakeFromBackendTextureAsRenderTarget(context, backendTex, origin,
111 sampleCnt, colorType, nullptr, nullptr);
112
113 return surface;
114 }
115 }
116
117 // Tests blending to a surface with no texture available.
DEF_GPUTEST_FOR_GL_RENDERING_CONTEXTS(ES2BlendWithNoTexture,reporter,ctxInfo)118 DEF_GPUTEST_FOR_GL_RENDERING_CONTEXTS(ES2BlendWithNoTexture, reporter, ctxInfo) {
119 GrContext* context = ctxInfo.grContext();
120 const int kWidth = 10;
121 const int kHeight = 10;
122 const GrPixelConfig kConfig = kRGBA_8888_GrPixelConfig;
123 const SkColorType kColorType = kRGBA_8888_SkColorType;
124
125 // Build our test cases:
126 struct RectAndSamplePoint {
127 SkRect rect;
128 SkIPoint outPoint;
129 SkIPoint inPoint;
130 } allRectsAndPoints[3] = {
131 {SkRect::MakeXYWH(0, 0, 5, 5), SkIPoint::Make(7, 7), SkIPoint::Make(2, 2)},
132 {SkRect::MakeXYWH(2, 2, 5, 5), SkIPoint::Make(1, 1), SkIPoint::Make(4, 4)},
133 {SkRect::MakeXYWH(5, 5, 5, 5), SkIPoint::Make(2, 2), SkIPoint::Make(7, 7)},
134 };
135
136 struct TestCase {
137 RectAndSamplePoint fRectAndPoints;
138 SkRect fClip;
139 int fSampleCnt;
140 GrSurfaceOrigin fOrigin;
141 };
142 std::vector<TestCase> testCases;
143
144 for (auto origin : { kTopLeft_GrSurfaceOrigin, kBottomLeft_GrSurfaceOrigin}) {
145 for (int sampleCnt : {1, 4}) {
146 for (auto rectAndPoints : allRectsAndPoints) {
147 for (auto clip : {SkRect::MakeXYWH(0, 0, 10, 10), SkRect::MakeXYWH(1, 1, 8, 8)}) {
148 testCases.push_back({rectAndPoints, clip, sampleCnt, origin});
149 }
150 }
151 }
152 }
153
154 // Run each test case:
155 for (auto testCase : testCases) {
156 int sampleCnt = testCase.fSampleCnt;
157 SkRect paintRect = testCase.fRectAndPoints.rect;
158 SkIPoint outPoint = testCase.fRectAndPoints.outPoint;
159 SkIPoint inPoint = testCase.fRectAndPoints.inPoint;
160 GrSurfaceOrigin origin = testCase.fOrigin;
161
162 sk_sp<GrTexture> backingSurface;
163 // BGRA forces a framebuffer blit on ES2.
164 sk_sp<SkSurface> surface = create_gpu_surface_backend_texture_as_render_target(
165 context, sampleCnt, kWidth, kHeight, kColorType, kConfig, origin, &backingSurface);
166
167 if (!surface && sampleCnt > 1) {
168 // Some platforms don't support MSAA.
169 continue;
170 }
171 REPORTER_ASSERT(reporter, !!surface);
172
173 // Fill our canvas with 0xFFFF80
174 SkCanvas* canvas = surface->getCanvas();
175 canvas->clipRect(testCase.fClip, false);
176 SkPaint black_paint;
177 black_paint.setColor(SkColorSetRGB(0xFF, 0xFF, 0x80));
178 canvas->drawRect(SkRect::MakeXYWH(0, 0, kWidth, kHeight), black_paint);
179
180 // Blend 2x2 pixels at 5,5 with 0x80FFFF. Use multiply blend mode as this will trigger
181 // a copy of the destination.
182 SkPaint white_paint;
183 white_paint.setColor(SkColorSetRGB(0x80, 0xFF, 0xFF));
184 white_paint.setBlendMode(SkBlendMode::kMultiply);
185 canvas->drawRect(paintRect, white_paint);
186
187 // Read the result into a bitmap.
188 SkBitmap bitmap;
189 REPORTER_ASSERT(reporter, bitmap.tryAllocPixels(SkImageInfo::Make(
190 kWidth, kHeight, kColorType, kPremul_SkAlphaType)));
191 REPORTER_ASSERT(
192 reporter,
193 surface->readPixels(bitmap.info(), bitmap.getPixels(), bitmap.rowBytes(), 0, 0));
194
195 // Check the in/out pixels.
196 REPORTER_ASSERT(reporter, bitmap.getColor(outPoint.x(), outPoint.y()) ==
197 SkColorSetRGB(0xFF, 0xFF, 0x80));
198 REPORTER_ASSERT(reporter, bitmap.getColor(inPoint.x(), inPoint.y()) ==
199 SkColorSetRGB(0x80, 0xFF, 0x80));
200
201 // Clean up - surface depends on backingSurface and must be released first.
202 surface.reset();
203 backingSurface.reset();
204 }
205 }
206