1/*
2 * Copyright 2012 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 "Test.h"
9
10// This test is specific to the GPU backend.
11#if SK_SUPPORT_GPU
12
13#include "GrContext.h"
14#include "SkGpuDevice.h"
15
16// This was made indivisible by 4 to ensure we test setting GL_PACK_ALIGNMENT properly.
17static const int X_SIZE = 13;
18static const int Y_SIZE = 13;
19
20static void validate_alpha_data(skiatest::Reporter* reporter, int w, int h, const uint8_t* actual,
21                                size_t actualRowBytes, const uint8_t* expected, SkString extraMsg) {
22    for (int y = 0; y < h; ++y) {
23        for (int x = 0; x < w; ++x) {
24            uint8_t a = actual[y * actualRowBytes + x];
25            uint8_t e = expected[y * w + x];
26            if (e != a) {
27                ERRORF(reporter,
28                       "Failed alpha readback. Expected: 0x%02x, Got: 0x%02x at (%d,%d), %s",
29                       e, a, x, y, extraMsg.c_str());
30                return;
31            }
32        }
33    }
34}
35
36DEF_GPUTEST_FOR_RENDERING_CONTEXTS(ReadWriteAlpha, reporter, context) {
37    unsigned char alphaData[X_SIZE * Y_SIZE];
38
39    bool match;
40    static const size_t kRowBytes[] = {0, X_SIZE, X_SIZE + 1, 2 * X_SIZE - 1};
41    for (int rt = 0; rt < 2; ++rt) {
42        GrSurfaceDesc desc;
43        // let Skia know we will be using this texture as a render target
44        desc.fFlags     = rt ? kRenderTarget_GrSurfaceFlag : kNone_GrSurfaceFlags;
45        // it is a single channel texture
46        desc.fConfig    = kAlpha_8_GrPixelConfig;
47        desc.fWidth     = X_SIZE;
48        desc.fHeight    = Y_SIZE;
49
50        // We are initializing the texture with zeros here
51        memset(alphaData, 0, X_SIZE * Y_SIZE);
52        SkAutoTUnref<GrTexture> texture(
53            context->textureProvider()->createTexture(desc, SkBudgeted::kNo , alphaData, 0));
54        if (!texture) {
55            if (!rt) {
56                ERRORF(reporter, "Could not create alpha texture.");
57            }
58            continue;
59        }
60
61        // create a distinctive texture
62        for (int y = 0; y < Y_SIZE; ++y) {
63            for (int x = 0; x < X_SIZE; ++x) {
64                alphaData[y * X_SIZE + x] = y*X_SIZE+x;
65            }
66        }
67
68        for (auto rowBytes : kRowBytes) {
69            // upload the texture (do per-rowbytes iteration because we may overwrite below).
70            texture->writePixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig,
71                                 alphaData, 0);
72
73            size_t nonZeroRowBytes = rowBytes ? rowBytes : X_SIZE;
74            SkAutoTDeleteArray<uint8_t> readback(new uint8_t[nonZeroRowBytes * Y_SIZE]);
75            // clear readback to something non-zero so we can detect readback failures
76            memset(readback.get(), 0x1, nonZeroRowBytes * Y_SIZE);
77
78            // read the texture back
79            texture->readPixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig,
80                                readback.get(), rowBytes);
81
82            // make sure the original & read back versions match
83            SkString msg;
84            msg.printf("rt:%d, rb:%d", rt, SkToU32(rowBytes));
85            validate_alpha_data(reporter, X_SIZE, Y_SIZE, readback.get(), nonZeroRowBytes,
86                                alphaData, msg);
87
88            // Now try writing on the single channel texture (if we could create as a RT).
89            if (texture->asRenderTarget()) {
90                SkSurfaceProps props(SkSurfaceProps::kLegacyFontHost_InitType);
91                SkAutoTUnref<SkBaseDevice> device(SkGpuDevice::Create(
92                    texture->asRenderTarget(), &props, SkGpuDevice::kUninit_InitContents));
93                SkCanvas canvas(device);
94
95                SkPaint paint;
96
97                const SkRect rect = SkRect::MakeLTRB(-10, -10, X_SIZE + 10, Y_SIZE + 10);
98
99                paint.setColor(SK_ColorWHITE);
100
101                canvas.drawRect(rect, paint);
102
103                memset(readback.get(), 0x1, nonZeroRowBytes * Y_SIZE);
104                texture->readPixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig, readback.get(),
105                                    rowBytes);
106
107                match = true;
108                for (int y = 0; y < Y_SIZE && match; ++y) {
109                    for (int x = 0; x < X_SIZE && match; ++x) {
110                        uint8_t rbValue = readback.get()[y * nonZeroRowBytes + x];
111                        if (0xFF != rbValue) {
112                            ERRORF(reporter,
113                                   "Failed alpha readback after clear. Expected: 0xFF, Got: 0x%02x"
114                                   " at (%d,%d), rb:%d", rbValue, x, y, SkToU32(rowBytes));
115                            match = false;
116                        }
117                    }
118                }
119            }
120        }
121    }
122
123    static const GrPixelConfig kRGBAConfigs[] {
124        kRGBA_8888_GrPixelConfig,
125        kBGRA_8888_GrPixelConfig,
126        kSRGBA_8888_GrPixelConfig
127    };
128
129    for (int y = 0; y < Y_SIZE; ++y) {
130        for (int x = 0; x < X_SIZE; ++x) {
131            alphaData[y * X_SIZE + x] = y*X_SIZE+x;
132        }
133    }
134
135    // Attempt to read back just alpha from a RGBA/BGRA texture. Once with a texture-only src and
136    // once with a render target.
137    for (auto cfg : kRGBAConfigs) {
138        for (int rt = 0; rt < 2; ++rt) {
139            GrSurfaceDesc desc;
140            desc.fFlags     = rt ? kRenderTarget_GrSurfaceFlag : kNone_GrSurfaceFlags;
141            desc.fConfig    = cfg;
142            desc.fWidth     = X_SIZE;
143            desc.fHeight    = Y_SIZE;
144
145            uint32_t rgbaData[X_SIZE * Y_SIZE];
146            // Make the alpha channel of the rgba texture come from alphaData.
147            for (int y = 0; y < Y_SIZE; ++y) {
148                for (int x = 0; x < X_SIZE; ++x) {
149                    rgbaData[y * X_SIZE + x] = GrColorPackRGBA(6, 7, 8, alphaData[y * X_SIZE + x]);
150                }
151            }
152            SkAutoTUnref<GrTexture> texture(
153                context->textureProvider()->createTexture(desc, SkBudgeted::kNo, rgbaData, 0));
154            if (!texture) {
155                // We always expect to be able to create a RGBA texture
156                if (!rt  && kRGBA_8888_GrPixelConfig == desc.fConfig) {
157                    ERRORF(reporter, "Failed to create RGBA texture.");
158                }
159                continue;
160            }
161
162            for (auto rowBytes : kRowBytes) {
163                size_t nonZeroRowBytes = rowBytes ? rowBytes : X_SIZE;
164
165                SkAutoTDeleteArray<uint8_t> readback(new uint8_t[nonZeroRowBytes * Y_SIZE]);
166                // Clear so we don't accidentally see values from previous iteration.
167                memset(readback.get(), 0x0, nonZeroRowBytes * Y_SIZE);
168
169                // read the texture back
170                texture->readPixels(0, 0, desc.fWidth, desc.fHeight, kAlpha_8_GrPixelConfig,
171                                    readback.get(), rowBytes);
172
173                // make sure the original & read back versions match
174                SkString msg;
175                msg.printf("rt:%d, rb:%d", rt, SkToU32(rowBytes));
176                validate_alpha_data(reporter, X_SIZE, Y_SIZE, readback.get(), nonZeroRowBytes,
177                                    alphaData, msg);
178            }
179        }
180    }
181}
182
183#endif
184