grab from latest android
git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleDither.cpp b/samplecode/SampleDither.cpp
new file mode 100644
index 0000000..7f7877a
--- /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);
+