Fix the way we patch up the matrix for scaled images that aren't

clamp/clamp

BUG=skia:2904
TBR=reed

Review URL: https://codereview.chromium.org/675823002

1 files changed, 88 insertions, 0 deletions

diff --git a/gm/tiledscaledbitmap.cpp b/gm/tiledscaledbitmap.cpp
new file mode 100644
index 0000000000..3ea110c44f
--- /dev/null
+++ b/gm/tiledscaledbitmap.cpp
@@ -0,0 +1,88 @@
+
+/*
+ * Copyright 2014 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 "Resources.h"
+#include "SkBitmap.h"
+#include "SkImageDecoder.h"
+#include "SkPaint.h"
+#include "SkShader.h"
+#include "SkStream.h"
+
+
+ /***
+  *
+  * This GM reproduces Skia bug 2904, in which a tiled bitmap shader was failing to draw correctly
+  * when fractional image scaling was ignored by the high quality bitmap scaler.
+  *
+  ***/
+
+namespace skiagm {
+
+class TiledScaledBitmapGM : public GM {
+public:
+
+    TiledScaledBitmapGM() {
+    }
+
+protected:
+    virtual SkString onShortName() {
+        return SkString("tiledscaledbitmap");
+    }
+
+    virtual SkISize onISize() {
+        return SkISize::Make(1016, 616);
+    }
+
+    virtual uint32_t onGetFlags() const SK_OVERRIDE {
+        return kSkipTiled_Flag;
+    }
+
+    static SkBitmap make_bm(int width, int height) { 
+        SkBitmap bm;
+        bm.allocN32Pixels(width, height);
+        bm.eraseColor(SK_ColorTRANSPARENT);
+        SkCanvas canvas(bm);
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        canvas.drawCircle(width/2.f, height/2.f, width/4.f, paint);
+        return bm; 
+    }
+
+    virtual void onOnceBeforeDraw() SK_OVERRIDE {
+        fBitmap = make_bm(360, 288);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        SkPaint paint;
+
+        paint.setAntiAlias(true);
+        paint.setFilterLevel(SkPaint::kHigh_FilterLevel);
+
+        SkMatrix mat;
+        mat.setScale(121.f/360.f, 93.f/288.f);
+        mat.postTranslate(-72, -72);
+
+        SkShader *shader = SkShader::CreateBitmapShader(fBitmap, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, &mat);
+        paint.setShader(shader);
+
+        SkSafeUnref(shader);
+        canvas->drawRectCoords(8,8,1008, 608, paint);
+    }
+
+private:
+    SkBitmap fBitmap;
+
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM(return SkNEW(TiledScaledBitmapGM);)
+
+}