GrYUVProvider.cpp revision f267c1efe7de7a8e71404afde6cbf93c3808d267 
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 "GrContext.h"
9#include "GrDrawContext.h"
10#include "GrYUVProvider.h"
11#include "effects/GrYUVEffect.h"
12
13#include "SkCachedData.h"
14#include "SkRefCnt.h"
15#include "SkResourceCache.h"
16#include "SkYUVPlanesCache.h"
17
18namespace {
19/**
20 *  Helper class to manage the resources used for storing the YUV planar data. Depending on the
21 *  useCache option, we may find (and lock) the data in our ResourceCache, or we may have allocated
22 *  it in scratch storage.
23 */
24class YUVScoper {
25public:
26    bool init(GrYUVProvider*, SkYUVPlanesCache::Info*, void* planes[3], bool useCache);
27
28private:
29    // we only use one or the other of these
30    SkAutoTUnref<SkCachedData>  fCachedData;
31    SkAutoMalloc                fStorage;
32};
33}
34
35bool YUVScoper::init(GrYUVProvider* provider, SkYUVPlanesCache::Info* yuvInfo, void* planes[3],
36                     bool useCache) {
37    if (useCache) {
38        fCachedData.reset(SkYUVPlanesCache::FindAndRef(provider->onGetID(), yuvInfo));
39    }
40
41    if (fCachedData.get()) {
42        planes[0] = (void*)fCachedData->data();
43        planes[1] = (uint8_t*)planes[0] + yuvInfo->fSizeInMemory[0];
44        planes[2] = (uint8_t*)planes[1] + yuvInfo->fSizeInMemory[1];
45    } else {
46        // Fetch yuv plane sizes for memory allocation. Here, width and height can be
47        // rounded up to JPEG block size and be larger than the image's width and height.
48        if (!provider->onGetYUVSizes(yuvInfo->fSize)) {
49            return false;
50        }
51
52        // Allocate the memory for YUV
53        size_t totalSize(0);
54        for (int i = 0; i < GrYUVProvider::kPlaneCount; ++i) {
55            yuvInfo->fRowBytes[i] = yuvInfo->fSize[i].fWidth; // we assume snug fit: rb == width
56            yuvInfo->fSizeInMemory[i] = yuvInfo->fRowBytes[i] * yuvInfo->fSize[i].fHeight;
57            totalSize += yuvInfo->fSizeInMemory[i];
58        }
59        if (useCache) {
60            fCachedData.reset(SkResourceCache::NewCachedData(totalSize));
61            planes[0] = fCachedData->writable_data();
62        } else {
63            fStorage.reset(totalSize);
64            planes[0] = fStorage.get();
65        }
66        planes[1] = (uint8_t*)planes[0] + yuvInfo->fSizeInMemory[0];
67        planes[2] = (uint8_t*)planes[1] + yuvInfo->fSizeInMemory[1];
68
69        // Get the YUV planes and update plane sizes to actual image size
70        if (!provider->onGetYUVPlanes(yuvInfo->fSize, planes, yuvInfo->fRowBytes,
71                                      &yuvInfo->fColorSpace)) {
72            return false;
73        }
74
75        if (useCache) {
76            // Decoding is done, cache the resulting YUV planes
77            SkYUVPlanesCache::Add(provider->onGetID(), fCachedData, yuvInfo);
78        }
79    }
80    return true;
81}
82
83GrTexture* GrYUVProvider::refAsTexture(GrContext* ctx, const GrSurfaceDesc& desc, bool useCache) {
84    SkYUVPlanesCache::Info yuvInfo;
85    void* planes[3];
86    YUVScoper scoper;
87    if (!scoper.init(this, &yuvInfo, planes, useCache)) {
88        return nullptr;
89    }
90
91    GrSurfaceDesc yuvDesc;
92    yuvDesc.fConfig = kAlpha_8_GrPixelConfig;
93    SkAutoTUnref<GrTexture> yuvTextures[3];
94    for (int i = 0; i < 3; ++i) {
95        yuvDesc.fWidth  = yuvInfo.fSize[i].fWidth;
96        yuvDesc.fHeight = yuvInfo.fSize[i].fHeight;
97        // TODO: why do we need this check?
98        bool needsExactTexture = (yuvDesc.fWidth  != yuvInfo.fSize[0].fWidth) ||
99                                 (yuvDesc.fHeight != yuvInfo.fSize[0].fHeight);
100        if (needsExactTexture) {
101            yuvTextures[i].reset(ctx->textureProvider()->createTexture(yuvDesc, true));
102        } else {
103            yuvTextures[i].reset(ctx->textureProvider()->createApproxTexture(yuvDesc));
104        }
105        if (!yuvTextures[i] ||
106            !yuvTextures[i]->writePixels(0, 0, yuvDesc.fWidth, yuvDesc.fHeight,
107                                         yuvDesc.fConfig, planes[i], yuvInfo.fRowBytes[i])) {
108                return nullptr;
109            }
110    }
111
112    GrSurfaceDesc rtDesc = desc;
113    rtDesc.fFlags = rtDesc.fFlags | kRenderTarget_GrSurfaceFlag;
114
115    SkAutoTUnref<GrTexture> result(ctx->textureProvider()->createTexture(rtDesc, true, nullptr, 0));
116    if (!result) {
117        return nullptr;
118    }
119
120    GrRenderTarget* renderTarget = result->asRenderTarget();
121    SkASSERT(renderTarget);
122
123    GrPaint paint;
124    SkAutoTUnref<const GrFragmentProcessor> yuvToRgbProcessor(
125                                        GrYUVEffect::CreateYUVToRGB(yuvTextures[0],
126                                                                    yuvTextures[1],
127                                                                    yuvTextures[2],
128                                                                    yuvInfo.fSize,
129                                                                    yuvInfo.fColorSpace));
130    paint.addColorFragmentProcessor(yuvToRgbProcessor);
131    paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
132    const SkRect r = SkRect::MakeIWH(yuvInfo.fSize[0].fWidth, yuvInfo.fSize[0].fHeight);
133
134    SkAutoTUnref<GrDrawContext> drawContext(ctx->drawContext(renderTarget));
135    if (!drawContext) {
136        return nullptr;
137    }
138
139    drawContext->drawRect(GrClip::WideOpen(), paint, SkMatrix::I(), r);
140
141    return result.detach();
142}
143
144