Add a GM for image filters applied to stroked primitives.

gm/imagefiltersstroked.cpp

Index: gm/imagefiltersstroked.cpp
diff --git a/gm/imagefiltersstroked.cpp b/gm/imagefiltersstroked.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..4a9058839a5936e4005100ca962e478634d851c2
--- /dev/null
+++ b/gm/imagefiltersstroked.cpp
@@ -0,0 +1,117 @@
+/*
+ * 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);
+    }
+
+    static void draw_text(SkCanvas* canvas, const SkRect& r, const SkPaint& paint) {
+        canvas->drawText("A", 1, r.centerX(), r.centerY(), paint);

[reed1, 2015/08/28 19:41:38]

Cary will bark loudly if we draw fonts just to draw something (as it makes
comparing this GM with other platforms much harder). If you must draw text, see
if you can use his set_portable_typeface helper.

[Stephen White, 2015/08/28 19:46:20]

Removed.

+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        void (*drawProc[])(SkCanvas*, const SkRect&, const SkPaint&) = {
+            draw_line, draw_rect, draw_circle, draw_text,
+        };
+
+        canvas->clear(SK_ColorBLACK);
+
+        SkMatrix resizeMatrix;
+        resizeMatrix.setScale(RESIZE_FACTOR_X, RESIZE_FACTOR_Y);
+
+        SkImageFilter* filters[] = {
+            SkBlurImageFilter::Create(SkIntToScalar(5), SkIntToScalar(5)),
+            SkDropShadowImageFilter::Create(SkIntToScalar(10), SkIntToScalar(10),
+                SkIntToScalar(3), SkIntToScalar(3), SK_ColorGREEN,
+                SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode),
+            SkOffsetImageFilter::Create(SkIntToScalar(-16), SkIntToScalar(32)),
+            SkImageFilter::CreateMatrixFilter(resizeMatrix, kNone_SkFilterQuality),
+        };
+
+        SkRect r = SkRect::MakeWH(SkIntToScalar(64), SkIntToScalar(64));

[reed1, 2015/08/28 19:41:38]

nits: for literals, you don't need SkIntToScalar(), and it makes it harder to
read

[Stephen White, 2015/08/28 19:46:20]

Removed.

+        SkScalar margin = SkIntToScalar(32);
+        SkPaint paint;
+        paint.setColor(SK_ColorWHITE);
+        paint.setAntiAlias(true);
+        paint.setStrokeWidth(SkIntToScalar(10));
+        paint.setStyle(SkPaint::kStroke_Style);
+        paint.setTextSize(SkIntToScalar(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(SkIntToScalar(16), SkIntToScalar(-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;)
+
+}