Merge "Fix PixelCopy readback"

    sk_sp<SkImage> image(SkImage::MakeFromAdoptedTexture(grContext.get(), backendTexture,

            kTopLeft_GrSurfaceOrigin));

    if (image) {

        // Convert imgTransform matrix from right to left handed coordinate system.

        // If we have a matrix transformation in right handed coordinate system

        //|ScaleX, SkewX,  TransX| same transform in left handed is    |ScaleX, SkewX,   TransX  |

        //|SkewY,  ScaleY, TransY|                                     |-SkewY, -ScaleY, 1-TransY|

        //|0,      0,      1     |                                     |0,      0,       1       |

        SkMatrix textureMatrix;

        textureMatrix.setIdentity();

        textureMatrix[SkMatrix::kMScaleX] = imgTransform[Matrix4::kScaleX];

        textureMatrix[SkMatrix::kMScaleY] = -imgTransform[Matrix4::kScaleY];

        textureMatrix[SkMatrix::kMSkewX] = imgTransform[Matrix4::kSkewX];

        textureMatrix[SkMatrix::kMSkewY] = -imgTransform[Matrix4::kSkewY];

        textureMatrix[SkMatrix::kMTransX] = imgTransform[Matrix4::kTranslateX];

        textureMatrix[SkMatrix::kMTransY] = 1-imgTransform[Matrix4::kTranslateY];

        // textureMatrix maps 2D texture coordinates of the form (s, t, 1) with s and t in the

        // inclusive range [0, 1] to the texture (see GLConsumer::getTransformMatrix comments).

        // Convert textureMatrix to translate in real texture dimensions. Texture width and

        // height are affected by the orientation (width and height swapped for 90/270 rotation).

        if (textureMatrix[SkMatrix::kMSkewX] >= 0.5f || textureMatrix[SkMatrix::kMSkewX] <= -0.5f) {

            textureMatrix[SkMatrix::kMTransX] *= imgHeight;

            textureMatrix[SkMatrix::kMTransY] *= imgWidth;

        } else {

            textureMatrix[SkMatrix::kMTransX] *= imgWidth;

            textureMatrix[SkMatrix::kMTransY] *= imgHeight;

        int displayedWidth = imgWidth, displayedHeight = imgHeight;

        // If this is a 90 or 270 degree rotation we need to swap width/height to get the device

        // size.

        if (imgTransform[Matrix4::kSkewX] >= 0.5f || imgTransform[Matrix4::kSkewX] <= -0.5f) {

            std::swap(displayedWidth, displayedHeight);

        }

        // convert to Skia data structures

        SkRect skiaSrcRect = srcRect.toSkRect();

        SkMatrix textureMatrixInv;

        SkRect skiaDestRect = SkRect::MakeWH(bitmap->width(), bitmap->height());

        bool srcNotEmpty = false;

        if (textureMatrix.invert(&textureMatrixInv)) {

        SkRect skiaSrcRect = srcRect.toSkRect();

        if (skiaSrcRect.isEmpty()) {

                skiaSrcRect = SkRect::MakeIWH(imgWidth, imgHeight);

                srcNotEmpty = !skiaSrcRect.isEmpty();

            } else {

                // src and dest rectangles need to be converted into texture coordinates before the

                // rotation matrix is applied (because drawImageRect preconcat its matrix).

                textureMatrixInv.mapRect(&skiaSrcRect);

                srcNotEmpty = skiaSrcRect.intersect(SkRect::MakeIWH(imgWidth, imgHeight));

            }

            textureMatrixInv.mapRect(&skiaDestRect);

            skiaSrcRect = SkRect::MakeIWH(displayedWidth, displayedHeight);

        }

        bool srcNotEmpty = skiaSrcRect.intersect(SkRect::MakeIWH(displayedWidth, displayedHeight));

        if (srcNotEmpty) {

            SkMatrix textureMatrixInv;

            imgTransform.copyTo(textureMatrixInv);

            //TODO: after skia bug https://bugs.chromium.org/p/skia/issues/detail?id=7075 is fixed

            // use bottom left origin and remove flipV and invert transformations.

            SkMatrix flipV;

            flipV.setAll(1, 0, 0, 0, -1, 1, 0, 0, 1);

            textureMatrixInv.preConcat(flipV);

            textureMatrixInv.preScale(1.0f/displayedWidth, 1.0f/displayedHeight);

            textureMatrixInv.postScale(imgWidth, imgHeight);

            SkMatrix textureMatrix;

            if (!textureMatrixInv.invert(&textureMatrix)) {

                textureMatrix = textureMatrixInv;

            }

            textureMatrixInv.mapRect(&skiaSrcRect);

            textureMatrixInv.mapRect(&skiaDestRect);

            // we render in an offscreen buffer to scale and to avoid an issue b/62262733

            // with reading incorrect data from EGLImage backed SkImage (likely a driver bug)

            sk_sp<SkSurface> scaledSurface = SkSurface::MakeRenderTarget(

                    grContext.get(), SkBudgeted::kYes, bitmap->info());

            SkPaint paint;

            paint.setBlendMode(SkBlendMode::kSrc);

            // Apply a filter, which is matching OpenGL pipeline readback behaviour. Filter usage

            // is codified by tests using golden images like DecodeAccuracyTest.

            if (skiaSrcRect.width() != bitmap->width()

                    || skiaSrcRect.height() != bitmap->height()) {

                //TODO: apply filter always, but check if tests will be fine

                paint.setFilterQuality(kLow_SkFilterQuality);

            }

            scaledSurface->getCanvas()->concat(textureMatrix);

            scaledSurface->getCanvas()->drawImageRect(image, skiaSrcRect, skiaDestRect, &paint,

                    SkCanvas::kFast_SrcRectConstraint);