Implement edge AA for concave polys in the tesselated path renderer.

Review URL:  http://codereview.appspot.com/4571072/



git-svn-id: http://skia.googlecode.com/svn/trunk@1600 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 146 insertions, 0 deletions

diff --git a/samplecode/SampleConcavePaths.cpp b/samplecode/SampleConcavePaths.cpp
new file mode 100644
index 0000000000..e084af220d
--- /dev/null
+++ b/samplecode/SampleConcavePaths.cpp
@@ -0,0 +1,146 @@
+
+#include "SampleCode.h"
+#include "SkView.h"
+#include "SkCanvas.h"
+#include "SkGradientShader.h"
+#include "SkGraphics.h"
+#include "SkImageDecoder.h"
+#include "SkPath.h"
+#include "SkRegion.h"
+#include "SkShader.h"
+#include "SkUtils.h"
+#include "SkXfermode.h"
+#include "SkColorPriv.h"
+#include "SkColorFilter.h"
+#include "SkParsePath.h"
+#include "SkTime.h"
+#include "SkTypeface.h"
+
+#include "SkGeometry.h"
+
+class ConcavePathView : public SampleView {
+public:
+	ConcavePathView() {}
+    
+protected:
+    // overrides from SkEventSink
+    virtual bool onQuery(SkEvent* evt) {
+        if (SampleCode::TitleQ(*evt)) {
+            SampleCode::TitleR(evt, "ConcavePaths");
+            return true;
+        }
+        return this->INHERITED::onQuery(evt);
+    }
+    
+    virtual void onDrawContent(SkCanvas* canvas) {        
+        SkPaint paint;
+        
+        paint.setAntiAlias(true);
+        paint.setStyle(SkPaint::kFill_Style);
+
+        // Concave test
+        if (1) {
+            SkPath path;
+            canvas->translate(0, 0);
+            path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(30), SkIntToScalar(30));
+            path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+            canvas->drawPath(path, paint);
+        }
+        // Reverse concave test
+        if (1) {
+            SkPath path;
+            canvas->save();
+            canvas->translate(100, 0);
+            path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+            path.lineTo(SkIntToScalar(30), SkIntToScalar(30));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+            canvas->drawPath(path, paint);
+            canvas->restore();
+        }
+        // Bowtie (intersection)
+        if (1) {
+            SkPath path;
+            canvas->save();
+            canvas->translate(200, 0);
+            path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+            canvas->drawPath(path, paint);
+            canvas->restore();
+        }
+        // "fake" bowtie (concave, but no intersection)
+        if (1) {
+            SkPath path;
+            canvas->save();
+            canvas->translate(300, 0);
+            path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(50), SkIntToScalar(40));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+            path.lineTo(SkIntToScalar(50), SkIntToScalar(60));
+            path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+            canvas->drawPath(path, paint);
+            canvas->restore();
+        }
+        // Fish test (intersection/concave)
+        if (1) {
+            SkPath path;
+            canvas->save();
+            canvas->translate(0, 100);
+            path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+            path.lineTo(SkIntToScalar(70), SkIntToScalar(50));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+            path.lineTo(SkIntToScalar(0), SkIntToScalar(50));
+            canvas->drawPath(path, paint);
+            canvas->restore();
+        }
+        // Collinear test
+        if (1) {
+            SkPath path;
+            canvas->save();
+            canvas->translate(100, 100);
+            path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(50), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(50), SkIntToScalar(80));
+            canvas->drawPath(path, paint);
+            canvas->restore();
+        }
+        // Hole test
+        if (1) {
+            SkPath path;
+            canvas->save();
+            canvas->translate(200, 100);
+            path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+            path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+            path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+            path.moveTo(SkIntToScalar(30), SkIntToScalar(30));
+            path.lineTo(SkIntToScalar(30), SkIntToScalar(70));
+            path.lineTo(SkIntToScalar(70), SkIntToScalar(70));
+            path.lineTo(SkIntToScalar(70), SkIntToScalar(30));
+            canvas->drawPath(path, paint);
+            canvas->restore();
+        }
+    }
+    
+    virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y) {
+        this->inval(NULL);
+        return this->INHERITED::onFindClickHandler(x, y);
+    }
+    
+private:
+    typedef SampleView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() { return new ConcavePathView; }
+static SkViewRegister reg(MyFactory);
+