Convert readSurfacePixels to use a draw context instead of a texture

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2165523003

Review-Url: https://codereview.chromium.org/2165523003

4 files changed, 17 insertions, 20 deletions

diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index 4a2b2b0228..4cb90c658e 100644
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -437,21 +437,20 @@ bool GrContext::readSurfacePixels(GrSurface* src,
     SkAutoTUnref<GrSurface> surfaceToRead(SkRef(src));
     bool didTempDraw = false;
     if (GrGpu::kNoDraw_DrawPreference != drawPreference) {
-        if (tempDrawInfo.fUseExactScratch) {
+        if (SkBackingFit::kExact == tempDrawInfo.fTempSurfaceFit) {
             // We only respect this when the entire src is being read. Otherwise we can trigger too
             // many odd ball texture sizes and trash the cache.
             if (width != src->width() || height != src->height()) {
-                tempDrawInfo.fUseExactScratch = false;
+                tempDrawInfo.fTempSurfaceFit= SkBackingFit::kApprox;
             }
         }
-        SkAutoTUnref<GrTexture> temp;
-        if (tempDrawInfo.fUseExactScratch) {
-            temp.reset(this->textureProvider()->createTexture(tempDrawInfo.fTempSurfaceDesc,
-                                                              SkBudgeted::kYes));
-        } else {
-            temp.reset(this->textureProvider()->createApproxTexture(tempDrawInfo.fTempSurfaceDesc));
-        }
-        if (temp) {
+        sk_sp<GrDrawContext> tempDC = this->newDrawContext(tempDrawInfo.fTempSurfaceFit,
+                                                           tempDrawInfo.fTempSurfaceDesc.fWidth,
+                                                           tempDrawInfo.fTempSurfaceDesc.fHeight,
+                                                           tempDrawInfo.fTempSurfaceDesc.fConfig,
+                                                           tempDrawInfo.fTempSurfaceDesc.fSampleCnt,
+                                                           tempDrawInfo.fTempSurfaceDesc.fOrigin);
+        if (tempDC) {
             SkMatrix textureMatrix;
             textureMatrix.setTranslate(SkIntToScalar(left), SkIntToScalar(top));
             textureMatrix.postIDiv(src->width(), src->height());
@@ -464,10 +463,10 @@ bool GrContext::readSurfacePixels(GrSurface* src,
                 } else if (GrGpu::kCallerPrefersDraw_DrawPreference == drawPreference) {
                     // We only wanted to do the draw in order to perform the unpremul so don't
                     // bother.
-                    temp.reset(nullptr);
+                    tempDC.reset(nullptr);
                 }
             }
-            if (!fp && temp) {
+            if (!fp && tempDC) {
                 fp = GrConfigConversionEffect::Make(src->asTexture(), tempDrawInfo.fSwizzle,
                                                     GrConfigConversionEffect::kNone_PMConversion,
                                                     textureMatrix);
@@ -478,10 +477,8 @@ bool GrContext::readSurfacePixels(GrSurface* src,
                 paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
                 paint.setAllowSRGBInputs(true);
                 SkRect rect = SkRect::MakeWH(SkIntToScalar(width), SkIntToScalar(height));
-                sk_sp<GrDrawContext> drawContext(
-                                            this->drawContext(sk_ref_sp(temp->asRenderTarget())));
-                drawContext->drawRect(GrNoClip(), paint, SkMatrix::I(), rect, nullptr);
-                surfaceToRead.reset(SkRef(temp.get()));
+                tempDC->drawRect(GrNoClip(), paint, SkMatrix::I(), rect, nullptr);
+                surfaceToRead.reset(tempDC->asTexture().release());
                 left = 0;
                 top = 0;
                 didTempDraw = true;
diff --git a/src/gpu/GrGpu.h b/src/gpu/GrGpu.h
index dce41fd4c2..37427b5739 100644
--- a/src/gpu/GrGpu.h
+++ b/src/gpu/GrGpu.h
@@ -170,7 +170,7 @@ public:
         GrSurfaceDesc   fTempSurfaceDesc;
         /** Indicates whether there is a performance advantage to using an exact match texture
             (in terms of width and height) for the intermediate texture instead of approximate. */
-        bool            fUseExactScratch;
+        SkBackingFit    fTempSurfaceFit;
         /** Swizzle to apply during the draw. This is used to compensate for either feature or
             performance limitations in the underlying 3D API. */
         GrSwizzle       fSwizzle;
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 8b9242cd05..ae38ed8779 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -2328,8 +2328,8 @@ bool GrGLGpu::onGetReadPixelsInfo(GrSurface* srcSurface, int width, int height,
     tempDrawInfo->fTempSurfaceDesc.fHeight = height;
     tempDrawInfo->fTempSurfaceDesc.fSampleCnt = 0;
     tempDrawInfo->fTempSurfaceDesc.fOrigin = kTopLeft_GrSurfaceOrigin; // no CPU y-flip for TL.
-    tempDrawInfo->fUseExactScratch = this->glCaps().partialFBOReadIsSlow();
-
+    tempDrawInfo->fTempSurfaceFit = this->glCaps().partialFBOReadIsSlow() ? SkBackingFit::kExact
+                                                                          : SkBackingFit::kApprox;
     // For now assume no swizzling, we may change that below.
     tempDrawInfo->fSwizzle = GrSwizzle::RGBA();
 
diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index e779bac99b..a09a805e3c 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -1388,7 +1388,7 @@ bool GrVkGpu::onGetReadPixelsInfo(GrSurface* srcSurface, int width, int height,
     tempDrawInfo->fTempSurfaceDesc.fHeight = height;
     tempDrawInfo->fTempSurfaceDesc.fSampleCnt = 0;
     tempDrawInfo->fTempSurfaceDesc.fOrigin = kTopLeft_GrSurfaceOrigin; // no CPU y-flip for TL.
-    tempDrawInfo->fUseExactScratch = false;
+    tempDrawInfo->fTempSurfaceFit = SkBackingFit::kApprox;
 
     // For now assume no swizzling, we may change that below.
     tempDrawInfo->fSwizzle = GrSwizzle::RGBA();