Example #1
0
static GrTexture* load_yuv_texture(GrContext* ctx, const GrUniqueKey& optionalKey,
                                   const SkBitmap& bm, const GrSurfaceDesc& desc) {
    // Subsets are not supported, the whole pixelRef is loaded when using YUV decoding
    SkPixelRef* pixelRef = bm.pixelRef();
    if ((NULL == pixelRef) || 
        (pixelRef->info().width()  != bm.info().width()) ||
        (pixelRef->info().height() != bm.info().height())) {
        return NULL;
    }

    const bool useCache = optionalKey.isValid();
    SkYUVPlanesCache::Info yuvInfo;
    SkAutoTUnref<SkCachedData> cachedData;
    SkAutoMalloc storage;
    if (useCache) {
        cachedData.reset(SkYUVPlanesCache::FindAndRef(pixelRef->getGenerationID(), &yuvInfo));
    }

    void* planes[3];
    if (cachedData.get()) {
        planes[0] = (void*)cachedData->data();
        planes[1] = (uint8_t*)planes[0] + yuvInfo.fSizeInMemory[0];
        planes[2] = (uint8_t*)planes[1] + yuvInfo.fSizeInMemory[1];
    } else {
        // Fetch yuv plane sizes for memory allocation. Here, width and height can be
        // rounded up to JPEG block size and be larger than the image's width and height.
        if (!pixelRef->getYUV8Planes(yuvInfo.fSize, NULL, NULL, NULL)) {
            return NULL;
        }

        // Allocate the memory for YUV
        size_t totalSize(0);
        for (int i = 0; i < 3; ++i) {
            yuvInfo.fRowBytes[i] = yuvInfo.fSize[i].fWidth;
            yuvInfo.fSizeInMemory[i] = yuvInfo.fRowBytes[i] * yuvInfo.fSize[i].fHeight;
            totalSize += yuvInfo.fSizeInMemory[i];
        }
        if (useCache) {
            cachedData.reset(SkResourceCache::NewCachedData(totalSize));
            planes[0] = cachedData->writable_data();
        } else {
            storage.reset(totalSize);
            planes[0] = storage.get();
        }
        planes[1] = (uint8_t*)planes[0] + yuvInfo.fSizeInMemory[0];
        planes[2] = (uint8_t*)planes[1] + yuvInfo.fSizeInMemory[1];

        // Get the YUV planes and update plane sizes to actual image size
        if (!pixelRef->getYUV8Planes(yuvInfo.fSize, planes, yuvInfo.fRowBytes,
                                     &yuvInfo.fColorSpace)) {
            return NULL;
        }

        if (useCache) {
            // Decoding is done, cache the resulting YUV planes
            SkYUVPlanesCache::Add(pixelRef->getGenerationID(), cachedData, &yuvInfo);
        }
    }

    GrSurfaceDesc yuvDesc;
    yuvDesc.fConfig = kAlpha_8_GrPixelConfig;
    SkAutoTUnref<GrTexture> yuvTextures[3];
    for (int i = 0; i < 3; ++i) {
        yuvDesc.fWidth  = yuvInfo.fSize[i].fWidth;
        yuvDesc.fHeight = yuvInfo.fSize[i].fHeight;
        bool needsExactTexture =
            (yuvDesc.fWidth  != yuvInfo.fSize[0].fWidth) ||
            (yuvDesc.fHeight != yuvInfo.fSize[0].fHeight);
        if (needsExactTexture) {
            yuvTextures[i].reset(ctx->textureProvider()->createTexture(yuvDesc, true));
        } else {
            yuvTextures[i].reset(ctx->textureProvider()->createApproxTexture(yuvDesc));
        }
        if (!yuvTextures[i] ||
            !yuvTextures[i]->writePixels(0, 0, yuvDesc.fWidth, yuvDesc.fHeight,
                                         yuvDesc.fConfig, planes[i], yuvInfo.fRowBytes[i])) {
            return NULL;
        }
    }

    GrSurfaceDesc rtDesc = desc;
    rtDesc.fFlags = rtDesc.fFlags | kRenderTarget_GrSurfaceFlag;

    GrTexture* result = create_texture_for_bmp(ctx, optionalKey, rtDesc, pixelRef, NULL, 0);
    if (!result) {
        return NULL;
    }

    GrRenderTarget* renderTarget = result->asRenderTarget();
    SkASSERT(renderTarget);

    GrPaint paint;
    SkAutoTUnref<GrFragmentProcessor>
        yuvToRgbProcessor(GrYUVtoRGBEffect::Create(paint.getProcessorDataManager(), yuvTextures[0],
                                                   yuvTextures[1], yuvTextures[2],
                                                   yuvInfo.fSize, yuvInfo.fColorSpace));
    paint.addColorProcessor(yuvToRgbProcessor);
    SkRect r = SkRect::MakeWH(SkIntToScalar(yuvInfo.fSize[0].fWidth),
                              SkIntToScalar(yuvInfo.fSize[0].fHeight));

    GrDrawContext* drawContext = ctx->drawContext();
    if (!drawContext) {
        return NULL;
    }

    drawContext->drawRect(renderTarget, GrClip::WideOpen(), paint, SkMatrix::I(), r);

    return result;
}