add gm for srcmode (and clearmode) in prep for optimization work



git-svn-id: http://skia.googlecode.com/svn/trunk@6429 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/srcmode.cpp b/gm/srcmode.cpp
new file mode 100644
index 0000000..3aa1b57
--- /dev/null
+++ b/gm/srcmode.cpp
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2012 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"
+
+#define W   SkIntToScalar(100)
+#define H   SkIntToScalar(60)
+
+typedef void (*Proc)(SkCanvas*, const SkPaint&);
+
+static void draw_hair(SkCanvas* canvas, const SkPaint& paint) {
+    SkPaint p(paint);
+    p.setStrokeWidth(0);
+    canvas->drawLine(0, 0, W, H, p);
+}
+
+static void draw_thick(SkCanvas* canvas, const SkPaint& paint) {
+    SkPaint p(paint);
+    p.setStrokeWidth(H/5);
+    canvas->drawLine(0, 0, W, H, p);
+}
+
+static void draw_rect(SkCanvas* canvas, const SkPaint& paint) {
+    canvas->drawRect(SkRect::MakeWH(W, H), paint);
+}
+
+static void draw_oval(SkCanvas* canvas, const SkPaint& paint) {
+    canvas->drawOval(SkRect::MakeWH(W, H), paint);
+}
+
+static void draw_text(SkCanvas* canvas, const SkPaint& paint) {
+    SkPaint p(paint);
+    p.setTextSize(H/4);
+    canvas->drawText("Hamburgefons", 12, 0, H*2/3, p);
+}
+
+class SrcModeGM : public skiagm::GM {
+    SkPath fPath;
+public:
+    SrcModeGM() {
+        this->setBGColor(0xFFDDDDDD);
+    }
+
+protected:
+    virtual SkString onShortName() {
+        return SkString("srcmode");
+    }
+
+    virtual SkISize onISize() {
+        return SkISize::Make(640, 480);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
+
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        paint.setColor(0x80FF0000);
+
+        const Proc procs[] = {
+            draw_hair, draw_thick, draw_rect, draw_oval, draw_text
+        };
+
+        const SkXfermode::Mode modes[] = {
+            SkXfermode::kSrcOver_Mode, SkXfermode::kSrc_Mode, SkXfermode::kClear_Mode
+        };
+
+        for (size_t x = 0; x < SK_ARRAY_COUNT(modes); ++x) {
+            paint.setXfermodeMode(modes[x]);
+            canvas->save();
+            for (size_t y = 0; y < SK_ARRAY_COUNT(procs); ++y) {
+                procs[y](canvas, paint);
+                canvas->translate(0, H * 5 / 4);
+            }
+            canvas->restore();
+            canvas->translate(W * 5 / 4, 0);
+        }
+    }
+
+private:
+    typedef skiagm::GM INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+DEF_GM(return new SrcModeGM;)
+