Fix gpu drawBitmap to work when BM is A8 and we have a shader

src/gpu/SkGpuDevice.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGpuDevice.h"
 
 #include "GrBlurUtils.h"
@@ skipping 1283 matching lines @@
 
     SkRect dstRect = {0, 0, srcRect.width(), srcRect.height() };
     SkRect paintRect;
     SkScalar wInv = SkScalarInvert(SkIntToScalar(texture->width()));
     SkScalar hInv = SkScalarInvert(SkIntToScalar(texture->height()));
     paintRect.setLTRB(SkScalarMul(srcRect.fLeft,   wInv),
                       SkScalarMul(srcRect.fTop,    hInv),
                       SkScalarMul(srcRect.fRight,  wInv),
                       SkScalarMul(srcRect.fBottom, hInv));
 
+    SkMatrix texMatrix;
+    texMatrix.reset();
+    if (kAlpha_8_SkColorType == bitmap.colorType() && paint.getShader()) {
+        // In cases where we are doing an A8 bitmap draw with a shader installed, we cannot use
+        // local coords with the bitmap draw since it may mess up texture look ups for the shader.
+        // Thus we need to pass in the transform matrix directly to the texture processor used for
+        // the bitmap draw.
+        texMatrix.setScale(wInv, hInv);
+    }
+
     SkRect textureDomain = SkRect::MakeEmpty();
 
     // Construct a GrPaint by setting the bitmap texture as the first effect and then configuring
     // the rest from the SkPaint.
     GrPaint grPaint;
     SkAutoTUnref<const GrFragmentProcessor> fp;
 
     if (needsTextureDomain && (SkCanvas::kStrict_SrcRectConstraint == constraint)) {
         // Use a constrained texture domain to avoid color bleeding
         SkScalar left, top, right, bottom;
         if (srcRect.width() > SK_Scalar1) {
             SkScalar border = SK_ScalarHalf / texture->width();
             left = paintRect.left() + border;
             right = paintRect.right() - border;
         } else {
             left = right = SkScalarHalf(paintRect.left() + paintRect.right());
         }
         if (srcRect.height() > SK_Scalar1) {
             SkScalar border = SK_ScalarHalf / texture->height();
             top = paintRect.top() + border;
             bottom = paintRect.bottom() - border;
         } else {
             top = bottom = SkScalarHalf(paintRect.top() + paintRect.bottom());
         }
         textureDomain.setLTRB(left, top, right, bottom);
         if (bicubic) {
-            fp.reset(GrBicubicEffect::Create(texture, SkMatrix::I(), textureDomain));
+            fp.reset(GrBicubicEffect::Create(texture, texMatrix, textureDomain));
         } else {
             fp.reset(GrTextureDomainEffect::Create(texture,
-                                                   SkMatrix::I(),
+                                                   texMatrix,
                                                    textureDomain,
                                                    GrTextureDomain::kClamp_Mode,
                                                    params.filterMode()));
         }
     } else if (bicubic) {
         SkASSERT(GrTextureParams::kNone_FilterMode == params.filterMode());
         SkShader::TileMode tileModes[2] = { params.getTileModeX(), params.getTileModeY() };
-        fp.reset(GrBicubicEffect::Create(texture, SkMatrix::I(), tileModes));
+        fp.reset(GrBicubicEffect::Create(texture, texMatrix, tileModes));
     } else {
-        fp.reset(GrSimpleTextureEffect::Create(texture, SkMatrix::I(), params));
+        fp.reset(GrSimpleTextureEffect::Create(texture, texMatrix, params));
     }
 
+    SkAutoTUnref<const GrFragmentProcessor> shaderFP;
+
     if (kAlpha_8_SkColorType == bitmap.colorType()) {
-        fp.reset(GrFragmentProcessor::MulOutputByInputUnpremulColor(fp));
+        if (const SkShader* shader = paint.getShader()) {
+            shaderFP.reset(shader->asFragmentProcessor(this->context(),
+                                                       viewMatrix,
+                                                       nullptr,
+                                                       paint.getFilterQuality()));
+            if (!shaderFP) {
+                return;
+            }
+            const GrFragmentProcessor* fpSeries[] = { shaderFP.get(), fp.get() };
+            fp.reset(GrFragmentProcessor::RunInSeries(fpSeries, 2));
+        } else {
+            fp.reset(GrFragmentProcessor::MulOutputByInputUnpremulColor(fp));
+        }
     } else {
         fp.reset(GrFragmentProcessor::MulOutputByInputAlpha(fp));
     }
 
     if (!SkPaintToGrPaintReplaceShader(this->context(), paint, fp, &grPaint)) {
         return;
     }
 
-    fDrawContext->drawNonAARectToRect(fRenderTarget, fClip, grPaint, viewMatrix, dstRect,
-                                      paintRect);
+    if (kAlpha_8_SkColorType == bitmap.colorType() && paint.getShader()) {
+        // We don't have local coords in this case and have previously set the transform
+        // matrices directly on the texture processor.
+        fDrawContext->drawRect(fRenderTarget, fClip, grPaint, viewMatrix, dstRect);
+    } else {
+        fDrawContext->drawNonAARectToRect(fRenderTarget, fClip, grPaint, viewMatrix, dstRect,
+                                          paintRect);
+    }
 }
 
 bool SkGpuDevice::filterTexture(GrContext* context, GrTexture* texture,
                                 int width, int height,
                                 const SkImageFilter* filter,
                                 const SkImageFilter::Context& ctx,
                                 SkBitmap* result, SkIPoint* offset) {
     SkASSERT(filter);
 
     SkImageFilter::Proxy proxy(this);
@@ skipping 626 matching lines @@
 #endif
 }
 
 SkImageFilter::Cache* SkGpuDevice::getImageFilterCache() {
     // We always return a transient cache, so it is freed after each
     // filter traversal.
     return SkImageFilter::Cache::Create(kDefaultImageFilterCacheSize);
 }
 
 #endif