Implement an SkPicture image filter source. This is required for the external-SVG reference feature…

gm/picturesource.cpp

+/*
+ * Copyright 2013 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 "SkPictureSource.h"
+
+// This GM exercises the SkPictureSource ImageFilter class.
+
+class PictureSourceGM : public skiagm::GM {
+public:
+    PictureSourceGM() {
+    }
+
+protected:
+    virtual SkString onShortName() SK_OVERRIDE {
+        return SkString("picturesource");
+    }
+
+    void makePicture() {
+        SkCanvas* canvas = fPicture.beginRecording(100, 100);
+        canvas->clear(0x00000000);
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        paint.setColor(0xFFFFFFFF);
+        paint.setTextSize(SkIntToScalar(96));
+        const char* str = "e";
+        canvas->drawText(str, strlen(str), SkIntToScalar(20), SkIntToScalar(70), paint);
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE { return SkISize::Make(500, 150); }
+
+    virtual void onOnceBeforeDraw() SK_OVERRIDE {
+        this->makePicture();
+    }
+
+    static void fillRectFiltered(SkCanvas* canvas, const SkRect& clipRect, SkImageFilter* filter) {
+        SkPaint paint;
+        paint.setImageFilter(filter);
+        canvas->save();
+        canvas->clipRect(clipRect);
+        canvas->drawPaint(paint);
+        canvas->restore();
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        canvas->clear(0x00000000);
+        {
+            SkRect srcRect = SkRect::MakeXYWH(20, 20, 30, 30);
+            SkRect emptyRect = SkRect::MakeXYWH(20, 20, 0, 0);
+            SkRect bounds = SkRect::MakeXYWH(0, 0, 100, 100);
+            SkAutoTUnref<SkImageFilter> pictureSource(new SkPictureSource(fPicture));
+            SkAutoTUnref<SkImageFilter> pictureSourceSrcRect(new SkPictureSource(fPicture, srcRect));
+            SkAutoTUnref<SkImageFilter> pictureSourceEmptyRect(new SkPictureSource(fPicture, emptyRect));
+
+            // Draw the picture unscaled.
+            fillRectFiltered(canvas, bounds, pictureSource);
+            canvas->translate(SkIntToScalar(100), 0);
+
+            // Draw an unscaled subset of the source picture.
+            fillRectFiltered(canvas, bounds, pictureSourceSrcRect);
+            canvas->translate(SkIntToScalar(100), 0);
+
+            // Draw the picture to an empty rect (should draw nothing).
+            fillRectFiltered(canvas, bounds, pictureSourceEmptyRect);
+            canvas->translate(SkIntToScalar(100), 0);
+        }
+    }
+
+private:
+    SkPicture fPicture;
+    typedef GM INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return new PictureSourceGM; )