add inital gm for colorfilters

gm/colorfilters.cpp

Index: gm/colorfilters.cpp
diff --git a/gm/colorfilters.cpp b/gm/colorfilters.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..4246d6968ade479f8348c6fa2fe66386766a3218
--- /dev/null
+++ b/gm/colorfilters.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 "SkCanvas.h"
+#include "SkColorFilter.h"
+#include "SkGradientShader.h"
+
+static SkShader* make_shader(const SkRect& bounds) {
+    const SkPoint pts[] = {
+        { bounds.left(), bounds.top() },
+        { bounds.right(), bounds.bottom() },
+    };
+    const SkColor colors[] = {
+        SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorBLACK,
+        SK_ColorCYAN, SK_ColorMAGENTA, SK_ColorYELLOW,
+    };
+    return SkGradientShader::CreateLinear(pts,
+                                          colors, NULL, SK_ARRAY_COUNT(colors),
+                                          SkShader::kClamp_TileMode);
+}
+
+typedef void (*InstallPaint)(SkPaint*, uint32_t, uint32_t);
+
+static void install_nothing(SkPaint* paint, uint32_t, uint32_t) {
+    paint->setColorFilter(NULL);
+}
+
+static void install_lighting(SkPaint* paint, uint32_t mul, uint32_t add) {
+    paint->setColorFilter(SkColorFilter::CreateLightingFilter(mul, add))->unref();
+}
+
+class ColorFiltersGM : public skiagm::GM {
+public:
+    ColorFiltersGM() {
+        fName.set("lightingcolorfilter");

[tfarina, 2014/02/06 16:31:33]

is this equivalent to:

ColorFiltersGM() : fName("lightingcolorfilter") {} ?

+    }
+
+protected:
+    virtual SkString onShortName() {
+        return fName;
+    }
+
+    virtual SkISize onISize() {
+        return SkISize::Make(640, 480);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        SkPaint paint;
+        SkRect r;
+        r.setWH(600, 50);
+        paint.setShader(make_shader(r))->unref();
+
+        const struct {
+            InstallPaint    fProc;
+            uint32_t        fData0, fData1;
+        } rec[] = {
+            { install_nothing, 0, 0 },
+            { install_lighting, 0xFF0000, 0 },
+            { install_lighting, 0x00FF00, 0 },
+            { install_lighting, 0x0000FF, 0 },
+            { install_lighting, 0x000000, 0xFF0000 },
+            { install_lighting, 0x000000, 0x00FF00 },
+            { install_lighting, 0x000000, 0x0000FF },
+        };
+
+        canvas->translate(10, 10);
+        for (size_t i = 0; i < SK_ARRAY_COUNT(rec); ++i) {
+            rec[i].fProc(&paint, rec[i].fData0, rec[i].fData1);
+            canvas->drawRect(r, paint);
+            canvas->translate(0, r.height() + 10);
+        }
+    }
+
+private:
+    SkString fName;
+    typedef GM INHERITED;
+};
+
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return SkNEW(ColorFiltersGM); )
+