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#include "SampleCode.h"
#include "SkColorPriv.h"
#include "SkGradientShader.h"
#include "SkView.h"
#include "SkCanvas.h"
#include "SkUtils.h"
static SkBitmap make_bitmap() {
SkBitmap bm;
SkColorTable* ctable = new SkColorTable(256);
SkPMColor* c = ctable->lockColors();
for (int i = 0; i < 256; i++) {
c[i] = SkPackARGB32(255 - i, 0, 0, 0);
}
ctable->unlockColors(true);
bm.setConfig(SkBitmap::kIndex8_Config, 256, 256);
bm.allocPixels(ctable);
ctable->unref();
bm.lockPixels();
const float cx = bm.width() * 0.5f;
const float cy = bm.height() * 0.5f;
for (int y = 0; y < bm.height(); y++) {
float dy = y - cy;
dy *= dy;
uint8_t* p = bm.getAddr8(0, y);
for (int x = 0; x < 256; x++) {
float dx = x - cx;
dx *= dx;
float d = (dx + dy) / (cx/2);
int id = (int)d;
if (id > 255) {
id = 255;
}
p[x] = id;
}
}
bm.unlockPixels();
return bm;
}
class ExtractAlphaView : public SkView {
SkBitmap fBM8;
SkBitmap fBM32;
SkBitmap fBM4;
public:
ExtractAlphaView() {
fBM8 = make_bitmap();
fBM8.copyTo(&fBM32, SkBitmap::kARGB_8888_Config);
fBM8.copyTo(&fBM4, SkBitmap::kARGB_4444_Config);
}
protected:
// overrides from SkEventSink
virtual bool onQuery(SkEvent* evt) {
if (SampleCode::TitleQ(*evt)) {
SampleCode::TitleR(evt, "DitherBitmap");
return true;
}
return this->INHERITED::onQuery(evt);
}
void drawBG(SkCanvas* canvas) {
canvas->drawColor(0xFFDDDDDD);
}
virtual void onDraw(SkCanvas* canvas) {
drawBG(canvas);
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
SkMatrix matrix;
matrix.setScale(3.55f, 80.f);
canvas->setMatrix(matrix);
paint.setStrokeWidth(0.0588f);
canvas->drawLine(10, 5, 30, 4.8f, paint);
paint.setStrokeWidth(0.06f);
canvas->drawLine(20, 5, 40, 4.8f, paint);
}
private:
typedef SkView INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
static SkView* MyFactory() { return new ExtractAlphaView; }
static SkViewRegister reg(MyFactory);
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