Add GM to repro crbug.com/472795

This CL also adds a new parameter to SkBitmapSource which gives the user control of the filter quality.

BUG=472795

Review URL: https://codereview.chromium.org/1072603002

4 files changed, 110 insertions, 8 deletions

diff --git a/gm/bitmapsource2.cpp b/gm/bitmapsource2.cpp
new file mode 100644
index 0000000000..bc4acf717c
--- /dev/null
+++ b/gm/bitmapsource2.cpp
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm.h"
+#include "SkBitmapSource.h"
+
+namespace skiagm {
+
+// This GM reproduces the issue in crbug.com/472795. The SkBitmapSource image
+// is shifted for high quality mode between cpu and gpu.
+class BitmapSourceGM : public GM {
+public:
+    BitmapSourceGM(const char* suffix, SkFilterQuality filter) : fSuffix(suffix), fFilter(filter) {
+        this->setBGColor(0xFFFFFFFF);
+    }
+
+protected:
+    SkString onShortName() override {
+        SkString name("bitmapsrc2_");
+        name.append(fSuffix);
+        return name;
+    }
+
+    SkISize onISize() override { return SkISize::Make(256, 256); }
+
+    // Create a bitmap with high frequency vertical stripes
+    void onOnceBeforeDraw() override {
+        static const SkPMColor gColors[] = {
+            SK_ColorRED,     SK_ColorGRAY,
+            SK_ColorGREEN,   SK_ColorGRAY,
+            SK_ColorBLUE,    SK_ColorGRAY,
+            SK_ColorCYAN,    SK_ColorGRAY,
+            SK_ColorMAGENTA, SK_ColorGRAY,
+            SK_ColorYELLOW,  SK_ColorGRAY,
+            SK_ColorWHITE,   SK_ColorGRAY,
+        };
+
+        fBM.allocN32Pixels(kImageSize, kImageSize, true);
+
+        SkCanvas canvas(fBM);
+
+        int curColor = 0;
+
+        for (int x = 0; x < kImageSize; x += 3) {
+            SkRect r = SkRect::MakeXYWH(SkIntToScalar(x), SkIntToScalar(0), 
+                                        SkIntToScalar(3), SkIntToScalar(kImageSize));
+            SkPaint p;
+            p.setColor(gColors[curColor]);
+            canvas.drawRect(r, p);
+
+            curColor = (curColor+1) % SK_ARRAY_COUNT(gColors);
+        }
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        SkRect srcRect = SkRect::MakeLTRB(0, 0,
+                                          SkIntToScalar(kImageSize), SkIntToScalar(kImageSize));
+        SkRect dstRect = SkRect::MakeLTRB(0.75f, 0.75f, 225.75f, 225.75f);
+
+        SkAutoTUnref<SkImageFilter> filter(SkBitmapSource::Create(fBM, srcRect, dstRect, fFilter));
+
+        SkPaint p;
+        p.setImageFilter(filter);
+
+        canvas->saveLayer(NULL, &p);
+        canvas->restore();
+    }
+
+private:
+    static const int kImageSize = 503;
+
+    SkString fSuffix;
+    SkFilterQuality fFilter;
+    SkBitmap fBM;
+
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return SkNEW_ARGS(BitmapSourceGM, ("none", kNone_SkFilterQuality) );   )
+DEF_GM( return SkNEW_ARGS(BitmapSourceGM, ("low",  kLow_SkFilterQuality) );    )
+DEF_GM( return SkNEW_ARGS(BitmapSourceGM, ("med",  kMedium_SkFilterQuality) ); )
+DEF_GM( return SkNEW_ARGS(BitmapSourceGM, ("high", kHigh_SkFilterQuality) );   )
+
+}
diff --git a/gyp/gmslides.gypi b/gyp/gmslides.gypi
index 09615fd2ba..dc8062e9d9 100644
--- a/gyp/gmslides.gypi
+++ b/gyp/gmslides.gypi
@@ -38,6 +38,7 @@
         '../gm/bitmapscroll.cpp',
         '../gm/bitmapshader.cpp',
         '../gm/bitmapsource.cpp',
+        '../gm/bitmapsource2.cpp',
         '../gm/bleed.cpp',
         '../gm/blurcircles.cpp',
         '../gm/blurs.cpp',
diff --git a/include/effects/SkBitmapSource.h b/include/effects/SkBitmapSource.h
index cd43e8f61f..55b5bedabe 100644
--- a/include/effects/SkBitmapSource.h
+++ b/include/effects/SkBitmapSource.h
@@ -16,9 +16,10 @@ public:
     static SkBitmapSource* Create(const SkBitmap& bitmap) {
         return SkNEW_ARGS(SkBitmapSource, (bitmap));
     }
-    static SkBitmapSource* Create(const SkBitmap& bitmap, const SkRect& srcRect,
-                                  const SkRect& dstRect) {
-        return SkNEW_ARGS(SkBitmapSource, (bitmap, srcRect, dstRect));
+    static SkBitmapSource* Create(const SkBitmap& bitmap,
+                                  const SkRect& srcRect, const SkRect& dstRect,
+                                  SkFilterQuality filterQuality = kHigh_SkFilterQuality) {
+        return SkNEW_ARGS(SkBitmapSource, (bitmap, srcRect, dstRect, filterQuality));
     }
     void computeFastBounds(const SkRect& src, SkRect* dst) const override;
 
@@ -27,7 +28,9 @@ public:
 
 protected:
     explicit SkBitmapSource(const SkBitmap& bitmap);
-    SkBitmapSource(const SkBitmap& bitmap, const SkRect& srcRect, const SkRect& dstRect);
+    SkBitmapSource(const SkBitmap& bitmap,
+                   const SkRect& srcRect, const SkRect& dstRect,
+                   SkFilterQuality filterQuality);
     void flatten(SkWriteBuffer&) const override;
 
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
@@ -36,6 +39,8 @@ protected:
 private:
     SkBitmap fBitmap;
     SkRect   fSrcRect, fDstRect;
+    SkFilterQuality fFilterQuality;
+
     typedef SkImageFilter INHERITED;
 };
 
diff --git a/src/effects/SkBitmapSource.cpp b/src/effects/SkBitmapSource.cpp
index 87c6053cc4..ee8b798936 100644
--- a/src/effects/SkBitmapSource.cpp
+++ b/src/effects/SkBitmapSource.cpp
@@ -18,13 +18,18 @@ SkBitmapSource::SkBitmapSource(const SkBitmap& bitmap)
   , fSrcRect(SkRect::MakeWH(SkIntToScalar(bitmap.width()),
                             SkIntToScalar(bitmap.height())))
   , fDstRect(fSrcRect)
-{}
+  , fFilterQuality(kHigh_SkFilterQuality) {
+}
 
-SkBitmapSource::SkBitmapSource(const SkBitmap& bitmap, const SkRect& srcRect, const SkRect& dstRect)
+SkBitmapSource::SkBitmapSource(const SkBitmap& bitmap, 
+                               const SkRect& srcRect, const SkRect& dstRect,
+                               SkFilterQuality filterQuality)
   : INHERITED(0, 0)
   , fBitmap(bitmap)
   , fSrcRect(srcRect)
-  , fDstRect(dstRect) {}
+  , fDstRect(dstRect)
+  , fFilterQuality(filterQuality) {
+}
 
 SkFlattenable* SkBitmapSource::CreateProc(SkReadBuffer& buffer) {
     SkRect src, dst;
@@ -71,12 +76,13 @@ bool SkBitmapSource::onFilterImage(Proxy* proxy, const SkBitmap&, const Context&
     // None filtering when it's translate-only
     paint.setFilterQuality(
         fSrcRect.width() == dstRect.width() && fSrcRect.height() == dstRect.height() ?
-               kNone_SkFilterQuality : kHigh_SkFilterQuality);
+               kNone_SkFilterQuality : fFilterQuality);
     canvas.drawBitmapRectToRect(fBitmap, &fSrcRect, dstRect, &paint);
 
     *result = device.get()->accessBitmap(false);
     offset->fX = dstIRect.fLeft;
     offset->fY = dstIRect.fTop;
+
     return true;
 }