Explicit tile bounds for SkPictureShader

gm/pictureshadertile.cpp

Index: gm/pictureshadertile.cpp
diff --git a/gm/pictureshadertile.cpp b/gm/pictureshadertile.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..9343da3649536e6fb118de81e02b41440035c3d1
--- /dev/null
+++ b/gm/pictureshadertile.cpp
@@ -0,0 +1,147 @@
+/*
+ * 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 "SkPaint.h"
+#include "SkPicture.h"
+#include "SkPictureRecorder.h"
+#include "SkShader.h"
+
+static const SkScalar kPictureSize = SK_Scalar1;
+static const SkScalar kFillSize = 100;
+static const unsigned kRowSize = 6;
+
+static const struct {
+    SkScalar x, y, w, h;
+    SkScalar offsetX, offsetY;
+} tiles[] = {
+    {      0,      0,    1,    1,      0,    0 },
+    {   0.5f,   0.5f,    1,    1,      0,    0 },
+    {  -0.5f,  -0.5f,    1,    1,      0,    0 },
+
+    {      0,      0, 1.5f, 1.5f,      0,    0 },
+    {   0.5f,   0.5f, 1.5f, 1.5f,      0,    0 },
+    {  -0.5f,  -0.5f, 1.5f, 1.5f,      0,    0 },
+
+    {      0,      0, 0.5f, 0.5f,      0,    0 },
+    { -0.25f, -0.25f, 0.5f, 0.5f,      0,    0 },
+    {  0.25f,  0.25f, 0.5f, 0.5f,      0,    0 },
+
+    {      0,      0,    1,    1,   0.5f, 0.5f },
+    {   0.5f,   0.5f,    1,    1,   0.5f, 0.5f },
+    {  -0.5f,  -0.5f,    1,    1,   0.5f, 0.5f },
+
+    {      0,      0, 1.5f, 1.5f,   0.5f, 0.5f },
+    {   0.5f,   0.5f, 1.5f, 1.5f,   0.5f, 0.5f },
+    {  -0.5f,  -0.5f, 1.5f, 1.5f,   0.5f, 0.5f },
+
+    {      0,      0, 1.5f,    1,      0,    0 },
+    {   0.5f,   0.5f, 1.5f,    1,      0,    0 },
+    {  -0.5f,  -0.5f, 1.5f,    1,      0,    0 },
+
+    {      0,      0, 0.5f,    1,      0,    0 },
+    { -0.25f, -0.25f, 0.5f,    1,      0,    0 },
+    {  0.25f,  0.25f, 0.5f,    1,      0,    0 },
+
+    {      0,      0,    1, 1.5f,      0,    0 },
+    {   0.5f,   0.5f,    1, 1.5f,      0,    0 },
+    {  -0.5f,  -0.5f,    1, 1.5f,      0,    0 },
+
+    {      0,      0,    1, 0.5f,      0,    0 },
+    { -0.25f, -0.25f,    1, 0.5f,      0,    0 },
+    {  0.25f,  0.25f,    1, 0.5f,      0,    0 },
+};
+
+class PictureShaderTileGM : public skiagm::GM {
+public:
+    PictureShaderTileGM() {
+        SkPictureRecorder recorder;
+        SkCanvas* pictureCanvas = recorder.beginRecording(SkScalarCeilToInt(kPictureSize),
+                                                          SkScalarCeilToInt(kPictureSize),
+                                                          NULL, 0);
+        drawScene(pictureCanvas, kPictureSize);
+        SkAutoTUnref<SkPicture> picture(recorder.endRecording());
+
+        for (unsigned i = 0; i < SK_ARRAY_COUNT(tiles); ++i) {
+            SkRect tile = SkRect::MakeXYWH(tiles[i].x * kPictureSize,
+                                           tiles[i].y * kPictureSize,
+                                           tiles[i].w * kPictureSize,
+                                           tiles[i].h * kPictureSize);
+            SkMatrix localMatrix;
+            localMatrix.setTranslate(tiles[i].offsetX * kPictureSize,
+                                     tiles[i].offsetY * kPictureSize);
+            localMatrix.postScale(kFillSize / (2 * kPictureSize),
+                                  kFillSize / (2 * kPictureSize));
+            fShaders[i].reset(SkShader::CreatePictureShader(picture,
+                              SkShader::kRepeat_TileMode,
+                              SkShader::kRepeat_TileMode,
+                              &localMatrix,
+                              &tile));
+        }
+    }
+
+protected:
+    virtual uint32_t onGetFlags() const SK_OVERRIDE {
+        return kSkipTiled_Flag;
+    }
+
+    virtual SkString onShortName() SK_OVERRIDE {
+        return SkString("pictureshadertile");
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE {
+        return SkISize::Make(800, 600);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        canvas->clear(SK_ColorBLACK);
+
+        SkPaint paint;
+        paint.setStyle(SkPaint::kFill_Style);
+
+        for (unsigned i = 0; i < SK_ARRAY_COUNT(fShaders); ++i) {
+            paint.setShader(fShaders[i]);
+
+            canvas->save();
+            canvas->translate((i % kRowSize) * kFillSize * 1.1f,
+                              (i / kRowSize) * kFillSize * 1.1f);
+            canvas->drawRect(SkRect::MakeWH(kFillSize, kFillSize), paint);
+            canvas->restore();
+        }
+    }
+
+private:
+    void drawScene(SkCanvas* canvas, SkScalar pictureSize) {
+        canvas->clear(SK_ColorWHITE);
+
+        SkPaint paint;
+        paint.setColor(SK_ColorGREEN);
+        paint.setStyle(SkPaint::kFill_Style);
+        paint.setAntiAlias(true);
+
+        canvas->drawCircle(pictureSize / 4, pictureSize / 4, pictureSize / 4, paint);
+        canvas->drawRect(SkRect::MakeXYWH(pictureSize / 2, pictureSize / 2,
+                                          pictureSize / 2, pictureSize / 2), paint);
+
+        paint.setColor(SK_ColorRED);
+        canvas->drawLine(pictureSize / 2, pictureSize * 1 / 3,
+                         pictureSize / 2, pictureSize * 2 / 3, paint);
+        canvas->drawLine(pictureSize * 1 / 3, pictureSize / 2,
+                         pictureSize * 2 / 3, pictureSize / 2, paint);
+
+        paint.setColor(SK_ColorBLACK);
+        paint.setStyle(SkPaint::kStroke_Style);
+        canvas->drawRect(SkRect::MakeWH(pictureSize, pictureSize), paint);
+    }
+
+    SkAutoTUnref<SkShader> fShaders[SK_ARRAY_COUNT(tiles)];
+
+    typedef GM INHERITED;
+};
+
+DEF_GM( return SkNEW(PictureShaderTileGM); )