Improve debugger's visualization of transparent textures

src/utils/debugger/SkDrawCommand.cpp

 
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkDrawCommand.h"
@@ skipping 112 matching lines @@
     if (input.width() > input.height()) {
         yScale *= input.height() / (float) input.width();
     } else {
         xScale *= input.width() / (float) input.height();
     }
 
     SkRect dst = SkRect::MakeXYWH(SK_Scalar1, SK_Scalar1,
                                   xScale * input.width(),
                                   yScale * input.height());
 
+    static const int kNumBlocks = 8;
+
     canvas->clear(0xFFFFFFFF);
+    SkISize block = {
+        canvas->imageInfo().width()/kNumBlocks,
+        canvas->imageInfo().height()/kNumBlocks
+    };
+    for (int y = 0; y < kNumBlocks; ++y) {
+        for (int x = 0; x < kNumBlocks; ++x) {
+            SkPaint paint;
+            paint.setColor((x+y)%2 ? SK_ColorLTGRAY : SK_ColorDKGRAY);
+            SkRect r = SkRect::MakeXYWH(SkIntToScalar(x*block.width()),
+                                        SkIntToScalar(y*block.height()),
+                                        SkIntToScalar(block.width()),
+                                        SkIntToScalar(block.height()));
+            canvas->drawRect(r, paint);
+        }
+    }
+
     canvas->drawBitmapRect(input, dst, nullptr);
 
     if (srcRect) {
         SkRect r = SkRect::MakeLTRB(srcRect->fLeft * xScale + SK_Scalar1,
                                     srcRect->fTop * yScale + SK_Scalar1,
                                     srcRect->fRight * xScale + SK_Scalar1,
                                     srcRect->fBottom * yScale + SK_Scalar1);
         SkPaint p;
         p.setColor(SK_ColorRED);
         p.setStyle(SkPaint::kStroke_Style);
@@ skipping 813 matching lines @@
 
 void SkSetMatrixCommand::setUserMatrix(const SkMatrix& userMatrix) {
     fUserMatrix = userMatrix;
 }
 
 void SkSetMatrixCommand::execute(SkCanvas* canvas) const {
     SkMatrix temp = SkMatrix::Concat(fUserMatrix, fMatrix);
     canvas->setMatrix(temp);
 }