Revert of remove unused SkAvoidXfermode

samplecode/SampleAvoid.cpp

Index: samplecode/SampleAvoid.cpp
diff --git a/samplecode/SampleAvoid.cpp b/samplecode/SampleAvoid.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..aa7ca0e8ef4a19d6fa730edcd85b6791387254c7
--- /dev/null
+++ b/samplecode/SampleAvoid.cpp
@@ -0,0 +1,105 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "SampleCode.h"
+#include "SkView.h"
+#include "SkCanvas.h"
+#include "SkGradientShader.h"
+#include "SkAvoidXfermode.h"
+
+///////////////////////////////////////////////////////////////////////////////
+
+class AvoidView : public SampleView {
+    SkShader* fShader;
+
+    enum {
+        W = 480,
+        H = 320
+    };
+public:
+    AvoidView() {
+        SkColor colors[] = { SK_ColorRED, SK_ColorYELLOW, SK_ColorGREEN, SK_ColorCYAN, SK_ColorBLUE };
+
+#if 0
+        SkPoint pts[] = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) };
+        fShader = SkGradientShader::CreateLinear(pts, colors, NULL,
+                                                 SK_ARRAY_COUNT(colors),
+                                                 SkShader::kMirror_TileMode);
+#else
+        SkPoint pts[] = { { SkIntToScalar(W)/2, SkIntToScalar(H)/2 } };
+        fShader = SkGradientShader::CreateRadial(pts[0], SkIntToScalar(H)/5,
+                                                 colors, NULL,
+                                                 SK_ARRAY_COUNT(colors),
+                                                 SkShader::kMirror_TileMode);
+#endif
+    }
+
+    virtual ~AvoidView() {
+        fShader->unref();
+    }
+
+protected:
+    virtual bool onQuery(SkEvent* evt) {
+        if (SampleCode::TitleQ(*evt)) {
+            SampleCode::TitleR(evt, "AvoidXfermode");
+            return true;
+        }
+        return this->INHERITED::onQuery(evt);
+    }
+
+    virtual void onDrawContent(SkCanvas* canvas) {
+        SkPaint paint;
+        SkRect r = { 0, 0, SkIntToScalar(W), SkIntToScalar(H) };
+
+        canvas->translate(r.width() / 6, r.height() / 6);
+
+        paint.setShader(fShader);
+        canvas->drawRect(r, paint);
+
+        static const struct {
+            int                     fTolerance;
+            SkAvoidXfermode::Mode   fMode;
+            float                   fDX, fDY;
+        } gData[] = {
+            { 16,       SkAvoidXfermode::kAvoidColor_Mode, 0, 0 },
+            { 255-16,   SkAvoidXfermode::kAvoidColor_Mode, 1, 0 },
+            { 16,       SkAvoidXfermode::kTargetColor_Mode, 0, 1 },
+            { 255-16,   SkAvoidXfermode::kTargetColor_Mode, 1, 1 },
+        };
+
+        paint.setShader(NULL);
+        paint.setColor(SK_ColorMAGENTA);
+
+        SkPaint frameP;
+        frameP.setStyle(SkPaint::kStroke_Style);
+
+        for (size_t i = 0; i < SK_ARRAY_COUNT(gData); i++) {
+            SkAutoTUnref<SkAvoidXfermode> mode(SkAvoidXfermode::Create(
+                SK_ColorGREEN, gData[i].fTolerance, gData[i].fMode));
+            paint.setXfermode(mode);
+            int div = 3;
+            SkRect rr = { 0, 0, r.width()/div, r.height()/div };
+            rr.offset(r.width()/4 - rr.width()/2, r.height()/4 - rr.height()/2);
+            rr.offset(r.width() * gData[i].fDX/2, r.height() * gData[i].fDY/2);
+            canvas->drawRect(rr, paint);
+            paint.setXfermode(NULL);
+
+            canvas->drawRect(rr, frameP);
+        }
+    }
+
+private:
+    typedef SampleView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() {
+    return new AvoidView;
+}
+
+static SkViewRegister reg(MyFactory);