grab from latest android

git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 198 insertions, 0 deletions

diff --git a/samplecode/SampleDither.cpp b/samplecode/SampleDither.cpp
new file mode 100644
index 0000000000..7f7877ae31
--- /dev/null
+++ b/samplecode/SampleDither.cpp
@@ -0,0 +1,198 @@
+#include "SampleCode.h"
+#include "SkView.h"
+#include "SkCanvas.h"
+#include "SkGradientShader.h"
+#include "SkPath.h"
+#include "SkRegion.h"
+#include "SkShader.h"
+#include "SkUtils.h"
+#include "SkShaderExtras.h"
+#include "Sk1DPathEffect.h"
+#include "SkCornerPathEffect.h"
+#include "SkPathMeasure.h"
+#include "SkRandom.h"
+#include "SkColorPriv.h"
+#include "SkColorFilter.h"
+#include "SkDither.h"
+
+static void draw_sweep(SkCanvas* c, int width, int height, SkScalar angle) {
+    SkRect  r;
+    SkPaint p;
+    
+    p.setAntiAlias(true);
+//    p.setDither(true);
+    p.setStrokeWidth(SkIntToScalar(width/10));
+    p.setStyle(SkPaint::kStroke_Style);
+
+    r.set(0, 0, SkIntToScalar(width), SkIntToScalar(height));
+    
+    //    SkColor colors[] = { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN, SK_ColorCYAN };
+    SkColor colors[] = { 0x4c737373, 0x4c737373, 0xffffd300 };
+    SkShader* s = SkGradientShader::CreateSweep(r.centerX(), r.centerY(),
+                                                colors, NULL, SK_ARRAY_COUNT(colors));
+    p.setShader(s)->unref();
+    
+    SkAutoCanvasRestore acr(c, true);
+
+    c->translate(r.centerX(), r.centerY());
+    c->rotate(angle);
+    c->translate(-r.centerX(), -r.centerY());
+
+    SkRect bounds = r;
+    r.inset(p.getStrokeWidth(), p.getStrokeWidth());
+    SkRect innerBounds = r;
+
+    if (true) {
+        c->drawOval(r, p);
+    } else {
+        SkScalar x = r.centerX();
+        SkScalar y = r.centerY();
+        SkScalar radius = r.width() / 2;
+        SkScalar thickness = p.getStrokeWidth();
+        SkScalar sweep = SkFloatToScalar(360.0f);
+        SkPath path;
+        
+        path.moveTo(x + radius, y);
+        // outer top
+        path.lineTo(x + radius + thickness, y);
+        // outer arc
+        path.arcTo(bounds, 0, sweep, false);
+        // inner arc
+        path.arcTo(innerBounds, sweep, -sweep, false);
+        path.close();
+    }
+}
+
+static void make_bm(SkBitmap* bm)
+{
+    bm->setConfig(SkBitmap::kARGB_8888_Config, 100, 100);
+    bm->allocPixels();
+#if 0
+    bm->eraseColor(SK_ColorBLUE);
+    return;
+#else
+    bm->eraseColor(0);
+#endif
+    
+    SkCanvas c(*bm);    
+    draw_sweep(&c, bm->width(), bm->height(), 0);
+}
+
+static void pre_dither(const SkBitmap& bm)
+{
+    SkAutoLockPixels alp(bm);
+    
+    for (unsigned y = 0; y < bm.height(); y++) {
+        DITHER_4444_SCAN(y);
+        
+        SkPMColor* p = bm.getAddr32(0, y);
+        for (unsigned x = 0; x < bm.width(); x++) {
+            SkPMColor c = *p;
+            
+            unsigned a = SkGetPackedA32(c);
+            unsigned r = SkGetPackedR32(c);
+            unsigned g = SkGetPackedG32(c);
+            unsigned b = SkGetPackedB32(c);
+            
+            unsigned d = DITHER_VALUE(x);
+
+            a = SkDITHER_A32To4444(a, d);
+            r = SkDITHER_R32To4444(r, d);
+            g = SkDITHER_G32To4444(g, d);
+            b = SkDITHER_B32To4444(b, d);
+            
+            a = SkA4444ToA32(a);
+            r = SkR4444ToR32(r);
+            g = SkG4444ToG32(g);
+            b = SkB4444ToB32(b);
+            
+            *p++ = SkPackARGB32(a, r, g, b);
+        }
+    }
+}
+
+class DitherView : public SkView {
+public:
+    SkBitmap    fBM, fBMPreDither, fBM16;
+    SkScalar fAngle;
+
+	DitherView() {
+        make_bm(&fBM);
+        make_bm(&fBMPreDither);
+        pre_dither(fBMPreDither);
+        fBM.copyTo(&fBM16, SkBitmap::kARGB_4444_Config);
+        
+        fAngle = 0;
+    }
+
+protected:
+    // overrides from SkEventSink
+    virtual bool onQuery(SkEvent* evt) {
+        if (SampleCode::TitleQ(*evt)) {
+            SampleCode::TitleR(evt, "Dither");
+            return true;
+        }
+        return this->INHERITED::onQuery(evt);
+    }
+    
+    void drawBG(SkCanvas* canvas) {
+//        canvas->drawColor(0xFFDDDDDD);
+        canvas->drawColor(0xFF181818);
+    }
+    
+    virtual void onDraw(SkCanvas* canvas) {
+        this->drawBG(canvas);
+
+        SkPaint paint;
+        SkScalar x = SkIntToScalar(10);
+        SkScalar y = SkIntToScalar(10);
+        const SkScalar DX = SkIntToScalar(fBM.width() + 10);
+        
+        paint.setAntiAlias(true);
+        
+        if (true) {
+            canvas->drawBitmap(fBM, x, y, &paint);
+            x += DX;
+            paint.setDither(true);
+            canvas->drawBitmap(fBM, x, y, &paint);
+            
+            x += DX;
+            paint.setDither(false);
+            canvas->drawBitmap(fBMPreDither, x, y, &paint);
+            
+            x += DX;
+            canvas->drawBitmap(fBM16, x, y, &paint);
+        }
+        
+        canvas->translate(DX, DX*2);
+        draw_sweep(canvas, fBM.width(), fBM.height(), fAngle);
+        canvas->translate(DX, 0);
+        draw_sweep(canvas, fBM.width()>>1, fBM.height()>>1, fAngle);
+        canvas->translate(DX, 0);
+        draw_sweep(canvas, fBM.width()>>2, fBM.height()>>2, fAngle);
+
+        fAngle += SK_Scalar1/2;
+        this->inval(NULL);
+    }
+
+    virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y) 
+    {
+     //   fSweep += SK_Scalar1;
+        this->inval(NULL);
+        return this->INHERITED::onFindClickHandler(x, y);
+    }
+    
+    virtual bool onClick(Click* click) 
+    {
+        return this->INHERITED::onClick(click);
+    }
+    
+private:
+    typedef SkView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() { return new DitherView; }
+static SkViewRegister reg(MyFactory);
+