Revert of Simplify SkGpuBlurUtils::GaussianBlur method

src/effects/SkGpuBlurUtils.cpp

Index: src/effects/SkGpuBlurUtils.cpp
diff --git a/src/effects/SkGpuBlurUtils.cpp b/src/effects/SkGpuBlurUtils.cpp
index 1cb2d1dd125692b5e348491aa6eb81254b119761..c3681faca55f0b0a96d22a1835f882d2ff324070 100644
--- a/src/effects/SkGpuBlurUtils.cpp
+++ b/src/effects/SkGpuBlurUtils.cpp
@@ -165,6 +165,7 @@
 
 GrTexture* GaussianBlur(GrContext* context,
                         GrTexture* srcTexture,
+                        bool canClobberSrc,
                         bool gammaCorrect,
                         const SkRect& dstBounds,
                         const SkRect* srcBounds,
@@ -204,38 +205,11 @@
              kSBGRA_8888_GrPixelConfig == srcTexture->config() ||
              kAlpha_8_GrPixelConfig == srcTexture->config());
 
-    const int width = SkScalarFloorToInt(dstBounds.width());
-    const int height = SkScalarFloorToInt(dstBounds.height());
-    const GrPixelConfig config = srcTexture->config();
-
-    const SkSurfaceProps props(gammaCorrect ? SkSurfaceProps::kGammaCorrect_Flag : 0,
-                               SkSurfaceProps::kLegacyFontHost_InitType);
-
-    // For really small blurs (certainly no wider than 5x5 on desktop gpus) it is faster to just
-    // launch a single non separable kernel vs two launches
-    if (sigmaX > 0.0f && sigmaY > 0.0f &&
-            (2 * radiusX + 1) * (2 * radiusY + 1) <= MAX_KERNEL_SIZE) {
-        // We shouldn't be scaling because this is a small size blur
-        SkASSERT((1 == scaleFactorX) && (1 == scaleFactorY));
-
-        sk_sp<GrDrawContext> dstDrawContext(context->newDrawContext(SkBackingFit::kApprox,
-                                                                    width, height, config,
-                                                                    0, kDefault_GrSurfaceOrigin,
-                                                                    &props));
-        if (!dstDrawContext) {
-            return nullptr;
-        }
-        convolve_gaussian_2d(dstDrawContext.get(), clip, localDstBounds, srcOffset,
-                             srcTexture, radiusX, radiusY, sigmaX, sigmaY, srcBounds);
-
-        return dstDrawContext->asTexture().release();
-    } 
-
     GrSurfaceDesc desc;
     desc.fFlags = kRenderTarget_GrSurfaceFlag;
-    desc.fWidth = width;
-    desc.fHeight = height;
-    desc.fConfig = config;
+    desc.fWidth = SkScalarFloorToInt(dstBounds.width());
+    desc.fHeight = SkScalarFloorToInt(dstBounds.height());
+    desc.fConfig = srcTexture->config();
 
     GrTexture* dstTexture;
     GrTexture* tempTexture;
@@ -243,10 +217,14 @@
 
     temp1.reset(context->textureProvider()->createApproxTexture(desc));
     dstTexture = temp1.get();
-    temp2.reset(context->textureProvider()->createApproxTexture(desc));
-    tempTexture = temp2.get();
-
-    if (!dstTexture || !tempTexture) {
+    if (canClobberSrc) {
+        tempTexture = srcTexture;
+    } else {
+        temp2.reset(context->textureProvider()->createApproxTexture(desc));
+        tempTexture = temp2.get();
+    }
+
+    if (nullptr == dstTexture || nullptr == tempTexture) {
         return nullptr;
     }
 
@@ -263,13 +241,13 @@
             matrix.mapRect(&domain, *srcBounds);
             domain.inset((i < scaleFactorX) ? SK_ScalarHalf / srcTexture->width() : 0.0f,
                          (i < scaleFactorY) ? SK_ScalarHalf / srcTexture->height() : 0.0f);
-            sk_sp<const GrFragmentProcessor> fp(GrTextureDomainEffect::Create(
-                                                        srcTexture,
-                                                        matrix,
-                                                        domain,
-                                                        GrTextureDomain::kDecal_Mode,
-                                                        GrTextureParams::kBilerp_FilterMode));
-            paint.addColorFragmentProcessor(fp.get());
+            SkAutoTUnref<const GrFragmentProcessor> fp(GrTextureDomainEffect::Create(
+                srcTexture,
+                matrix,
+                domain,
+                GrTextureDomain::kDecal_Mode,
+                GrTextureParams::kBilerp_FilterMode));
+            paint.addColorFragmentProcessor(fp);
             srcRect.offset(-srcOffset);
             srcOffset.set(0, 0);
         } else {
@@ -294,77 +272,100 @@
         localSrcBounds = srcRect;
     }
 
+    SkSurfaceProps props(gammaCorrect ? SkSurfaceProps::kGammaCorrect_Flag : 0,
+                         SkSurfaceProps::kLegacyFontHost_InitType);
+
+    // For really small blurs (certainly no wider than 5x5 on desktop gpus) it is faster to just
+    // launch a single non separable kernel vs two launches
     srcRect = localDstBounds;
-
-    scale_rect(&srcRect, 1.0f / scaleFactorX, 1.0f / scaleFactorY);
-    srcRect.roundOut(&srcRect);
-    SkIRect srcIRect = srcRect.roundOut();
-    if (sigmaX > 0.0f) {
-        if (scaleFactorX > 1) {
-            // TODO: if we pass in the source draw context we don't need this here
-            if (!srcDrawContext) {
-                srcDrawContext = context->drawContext(sk_ref_sp(srcTexture->asRenderTarget()));
-                if (!srcDrawContext) {
-                    return nullptr;
-                }
-            }
-
-            // Clear out a radius to the right of the srcRect to prevent the
-            // X convolution from reading garbage.
-            clearRect = SkIRect::MakeXYWH(srcIRect.fRight, srcIRect.fTop,
-                                          radiusX, srcIRect.height());
-            srcDrawContext->clear(&clearRect, 0x0, false);
-        }
+    if (sigmaX > 0.0f && sigmaY > 0.0f &&
+            (2 * radiusX + 1) * (2 * radiusY + 1) <= MAX_KERNEL_SIZE) {
+        // We shouldn't be scaling because this is a small size blur
+        SkASSERT((1 == scaleFactorX) && (1 == scaleFactorY));
 
         sk_sp<GrDrawContext> dstDrawContext(
             context->drawContext(sk_ref_sp(dstTexture->asRenderTarget()), &props));
         if (!dstDrawContext) {
             return nullptr;
         }
-        convolve_gaussian(dstDrawContext.get(), clip, srcRect,
-                          srcTexture, Gr1DKernelEffect::kX_Direction, radiusX, sigmaX,
-                          srcBounds, srcOffset);
+        convolve_gaussian_2d(dstDrawContext.get(), clip, srcRect, srcOffset,
+                             srcTexture, radiusX, radiusY, sigmaX, sigmaY, srcBounds);
+
         srcDrawContext.swap(dstDrawContext);
+        srcRect.offsetTo(0, 0);
         srcTexture = dstTexture;
-        srcRect.offsetTo(0, 0);
         SkTSwap(dstTexture, tempTexture);
-        localSrcBounds = srcRect;
-        srcOffset.set(0, 0);
-    }
-
-    if (sigmaY > 0.0f) {
-        if (scaleFactorY > 1 || sigmaX > 0.0f) {
-            // TODO: if we pass in the source draw context we don't need this here
-            if (!srcDrawContext) {
-                srcDrawContext = context->drawContext(sk_ref_sp(srcTexture->asRenderTarget()));
+
+    } else {
+        scale_rect(&srcRect, 1.0f / scaleFactorX, 1.0f / scaleFactorY);
+        srcRect.roundOut(&srcRect);
+        const SkIRect srcIRect = srcRect.roundOut();
+        if (sigmaX > 0.0f) {
+            if (scaleFactorX > 1) {
+                // TODO: if we pass in the source draw context we don't need this here
                 if (!srcDrawContext) {
-                    return nullptr;
+                    srcDrawContext = context->drawContext(sk_ref_sp(srcTexture->asRenderTarget()));
+                    if (!srcDrawContext) {
+                        return nullptr;
+                    }
                 }
+
+                // Clear out a radius to the right of the srcRect to prevent the
+                // X convolution from reading garbage.
+                clearRect = SkIRect::MakeXYWH(srcIRect.fRight, srcIRect.fTop,
+                                              radiusX, srcIRect.height());
+                srcDrawContext->clear(&clearRect, 0x0, false);
             }
 
-            // Clear out a radius below the srcRect to prevent the Y
-            // convolution from reading garbage.
-            clearRect = SkIRect::MakeXYWH(srcIRect.fLeft, srcIRect.fBottom,
-                                          srcIRect.width(), radiusY);
-            srcDrawContext->clear(&clearRect, 0x0, false);
-        }
-
-        sk_sp<GrDrawContext> dstDrawContext(
-            context->drawContext(sk_ref_sp(dstTexture->asRenderTarget()), &props));
-        if (!dstDrawContext) {
-            return nullptr;
-        }
-        convolve_gaussian(dstDrawContext.get(), clip, srcRect,
-                          srcTexture, Gr1DKernelEffect::kY_Direction, radiusY, sigmaY,
-                          srcBounds, srcOffset);
-
-        srcDrawContext.swap(dstDrawContext);
-        srcTexture = dstTexture;
-        srcRect.offsetTo(0, 0);
-        SkTSwap(dstTexture, tempTexture);
-    }
-
-    srcIRect = srcRect.roundOut();
+            sk_sp<GrDrawContext> dstDrawContext(
+                context->drawContext(sk_ref_sp(dstTexture->asRenderTarget()), &props));
+            if (!dstDrawContext) {
+                return nullptr;
+            }
+            convolve_gaussian(dstDrawContext.get(), clip, srcRect,
+                              srcTexture, Gr1DKernelEffect::kX_Direction, radiusX, sigmaX,
+                              srcBounds, srcOffset);
+            srcDrawContext.swap(dstDrawContext);
+            srcTexture = dstTexture;
+            srcRect.offsetTo(0, 0);
+            SkTSwap(dstTexture, tempTexture);
+            localSrcBounds = srcRect;
+            srcOffset.set(0, 0);
+        }
+
+        if (sigmaY > 0.0f) {
+            if (scaleFactorY > 1 || sigmaX > 0.0f) {
+                // TODO: if we pass in the source draw context we don't need this here
+                if (!srcDrawContext) {
+                    srcDrawContext = context->drawContext(sk_ref_sp(srcTexture->asRenderTarget()));
+                    if (!srcDrawContext) {
+                        return nullptr;
+                    }
+                }
+
+                // Clear out a radius below the srcRect to prevent the Y
+                // convolution from reading garbage.
+                clearRect = SkIRect::MakeXYWH(srcIRect.fLeft, srcIRect.fBottom,
+                                              srcIRect.width(), radiusY);
+                srcDrawContext->clear(&clearRect, 0x0, false);
+            }
+
+            sk_sp<GrDrawContext> dstDrawContext(
+                context->drawContext(sk_ref_sp(dstTexture->asRenderTarget()), &props));
+            if (!dstDrawContext) {
+                return nullptr;
+            }
+            convolve_gaussian(dstDrawContext.get(), clip, srcRect,
+                              srcTexture, Gr1DKernelEffect::kY_Direction, radiusY, sigmaY,
+                              srcBounds, srcOffset);
+
+            srcDrawContext.swap(dstDrawContext);
+            srcTexture = dstTexture;
+            srcRect.offsetTo(0, 0);
+            SkTSwap(dstTexture, tempTexture);
+        }
+    }
+    const SkIRect srcIRect = srcRect.roundOut();
 
     if (scaleFactorX > 1 || scaleFactorY > 1) {
         SkASSERT(srcDrawContext);