Add a GM for image filters applied to stroked primitives.

BUG=skia:3194

Review URL: https://codereview.chromium.org/1323573004

gm/imagefiltersstroked.cpp

@@ -0,0 +1,112 @@
+/*
+ * 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 "sk_tool_utils.h"
+#include "SkBlurImageFilter.h"
+#include "SkColor.h"
+#include "SkDropShadowImageFilter.h"
+#include "SkOffsetImageFilter.h"
+#include "SkScalar.h"
+#include "gm.h"
+
+#define RESIZE_FACTOR_X SkIntToScalar(2)
+#define RESIZE_FACTOR_Y SkIntToScalar(5)
+
+namespace skiagm {
+
+class ImageFiltersStrokedGM : public GM {
+public:
+    ImageFiltersStrokedGM() {
+        this->setBGColor(0x00000000);
+    }
+
+protected:
+
+    SkString onShortName() override {
+        return SkString("imagefiltersstroked");
+    }
+
+    SkISize onISize() override {
+        return SkISize::Make(860, 500);
+    }
+
+    static void draw_circle(SkCanvas* canvas, const SkRect& r, const SkPaint& paint) {
+        canvas->drawCircle(r.centerX(), r.centerY(),
+                           r.width() * 2 / 5, paint);
+    }
+
+    static void draw_line(SkCanvas* canvas, const SkRect& r, const SkPaint& paint) {
+        canvas->drawLine(r.fLeft, r.fBottom, r.fRight, r.fTop, paint);
+    }
+
+    static void draw_rect(SkCanvas* canvas, const SkRect& r, const SkPaint& paint) {
+        canvas->drawRect(r, paint);
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        void (*drawProc[])(SkCanvas*, const SkRect&, const SkPaint&) = {
+            draw_line, draw_rect, draw_circle,
+        };
+
+        canvas->clear(SK_ColorBLACK);
+
+        SkMatrix resizeMatrix;
+        resizeMatrix.setScale(RESIZE_FACTOR_X, RESIZE_FACTOR_Y);
+
+        SkImageFilter* filters[] = {
+            SkBlurImageFilter::Create(5, 5),
+            SkDropShadowImageFilter::Create(10, 10, 3, 3, SK_ColorGREEN,
+                SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode),
+            SkOffsetImageFilter::Create(-16, 32),
+            SkImageFilter::CreateMatrixFilter(resizeMatrix, kNone_SkFilterQuality),
+        };
+
+        SkRect r = SkRect::MakeWH(64, 64);
+        SkScalar margin = 32;
+        SkPaint paint;
+        paint.setColor(SK_ColorWHITE);
+        paint.setAntiAlias(true);
+        paint.setStrokeWidth(10);
+        paint.setStyle(SkPaint::kStroke_Style);
+        paint.setTextSize(48);
+        paint.setTextAlign(SkPaint::kCenter_Align);
+
+        for (size_t i = 0; i < SK_ARRAY_COUNT(drawProc); ++i) {
+            canvas->translate(0, margin);
+            canvas->save();
+            for (size_t j = 0; j < SK_ARRAY_COUNT(filters); ++j) {
+                canvas->translate(margin, 0);
+                canvas->save();
+                if (2 == j) {
+                    canvas->translate(16, -32);
+                } else if (3 == j) {
+                    canvas->scale(SkScalarInvert(RESIZE_FACTOR_X),
+                                  SkScalarInvert(RESIZE_FACTOR_Y));
+                }
+                paint.setImageFilter(filters[j]);
+                drawProc[i](canvas, r, paint);
+                canvas->restore();
+                canvas->translate(r.width() + margin, 0);
+            }
+            canvas->restore();
+            canvas->translate(0, r.height());
+        }
+
+        for (size_t i = 0; i < SK_ARRAY_COUNT(filters); ++i) {
+            SkSafeUnref(filters[i]);
+        }
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM(return new ImageFiltersStrokedGM;)
+
+}