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      1 /*
      2  * Copyright 2011 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 #include "SampleCode.h"
      8 #include "SkView.h"
      9 #include "SkCanvas.h"
     10 #include "SkGradientShader.h"
     11 #include "SkPath.h"
     12 #include "SkRegion.h"
     13 #include "SkShader.h"
     14 #include "SkUtils.h"
     15 #include "Sk1DPathEffect.h"
     16 #include "SkCornerPathEffect.h"
     17 #include "SkPathMeasure.h"
     18 #include "SkRandom.h"
     19 #include "SkColorPriv.h"
     20 #include "SkColorFilter.h"
     21 #include "SkDither.h"
     22 #include "sk_tool_utils.h"
     23 
     24 static void draw_sweep(SkCanvas* c, int width, int height, SkScalar angle) {
     25     SkRect  r;
     26     SkPaint p;
     27 
     28     p.setAntiAlias(true);
     29 //    p.setDither(true);
     30     p.setStrokeWidth(SkIntToScalar(width/10));
     31     p.setStyle(SkPaint::kStroke_Style);
     32 
     33     r.set(0, 0, SkIntToScalar(width), SkIntToScalar(height));
     34 
     35     //    SkColor colors[] = { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN, SK_ColorCYAN };
     36     SkColor colors[] = { 0x4c737373, 0x4c737373, 0xffffd300 };
     37     p.setShader(SkGradientShader::MakeSweep(r.centerX(), r.centerY(),
     38                                             colors, nullptr, SK_ARRAY_COUNT(colors)));
     39 
     40     SkAutoCanvasRestore acr(c, true);
     41     c->rotate(angle, r.centerX(), r.centerY());
     42 
     43     SkRect bounds = r;
     44     r.inset(p.getStrokeWidth(), p.getStrokeWidth());
     45     SkRect innerBounds = r;
     46 
     47     if (true) {
     48         c->drawOval(r, p);
     49     } else {
     50         SkScalar x = r.centerX();
     51         SkScalar y = r.centerY();
     52         SkScalar radius = r.width() / 2;
     53         SkScalar thickness = p.getStrokeWidth();
     54         SkScalar sweep = 360.0f;
     55         SkPath path;
     56 
     57         path.moveTo(x + radius, y);
     58         // outer top
     59         path.lineTo(x + radius + thickness, y);
     60         // outer arc
     61         path.arcTo(bounds, 0, sweep, false);
     62         // inner arc
     63         path.arcTo(innerBounds, sweep, -sweep, false);
     64         path.close();
     65     }
     66 }
     67 
     68 static void make_bm(SkBitmap* bm) {
     69     bm->allocN32Pixels(100, 100);
     70     bm->eraseColor(SK_ColorTRANSPARENT);
     71 
     72     SkCanvas c(*bm);
     73     draw_sweep(&c, bm->width(), bm->height(), 0);
     74 }
     75 
     76 static void pre_dither(const SkBitmap& bm) {
     77     for (int y = 0; y < bm.height(); y++) {
     78         DITHER_4444_SCAN(y);
     79 
     80         SkPMColor* p = bm.getAddr32(0, y);
     81         for (int x = 0; x < bm.width(); x++) {
     82             SkPMColor c = *p;
     83 
     84             unsigned a = SkGetPackedA32(c);
     85             unsigned r = SkGetPackedR32(c);
     86             unsigned g = SkGetPackedG32(c);
     87             unsigned b = SkGetPackedB32(c);
     88 
     89             unsigned d = DITHER_VALUE(x);
     90 
     91             a = SkDITHER_A32To4444(a, d);
     92             r = SkDITHER_R32To4444(r, d);
     93             g = SkDITHER_G32To4444(g, d);
     94             b = SkDITHER_B32To4444(b, d);
     95 
     96             a = SkA4444ToA32(a);
     97             r = SkR4444ToR32(r);
     98             g = SkG4444ToG32(g);
     99             b = SkB4444ToB32(b);
    100 
    101             *p++ = SkPackARGB32(a, r, g, b);
    102         }
    103     }
    104 }
    105 
    106 class DitherView : public SampleView {
    107 public:
    108     SkBitmap    fBM, fBMPreDither, fBM16;
    109     SkScalar fAngle;
    110 
    111     DitherView() {
    112         make_bm(&fBM);
    113         make_bm(&fBMPreDither);
    114         pre_dither(fBMPreDither);
    115         sk_tool_utils::copy_to(&fBM16, kARGB_4444_SkColorType, fBM);
    116 
    117         fAngle = 0;
    118 
    119         this->setBGColor(0xFF181818);
    120     }
    121 
    122 protected:
    123     // overrides from SkEventSink
    124     virtual bool onQuery(SkEvent* evt) {
    125         if (SampleCode::TitleQ(*evt)) {
    126             SampleCode::TitleR(evt, "Dither");
    127             return true;
    128         }
    129         return this->INHERITED::onQuery(evt);
    130     }
    131 
    132     virtual void onDrawContent(SkCanvas* canvas) {
    133         SkPaint paint;
    134         SkScalar x = SkIntToScalar(10);
    135         SkScalar y = SkIntToScalar(10);
    136         const SkScalar DX = SkIntToScalar(fBM.width() + 10);
    137 
    138         paint.setAntiAlias(true);
    139 
    140         if (true) {
    141             canvas->drawBitmap(fBM, x, y, &paint);
    142             x += DX;
    143             paint.setDither(true);
    144             canvas->drawBitmap(fBM, x, y, &paint);
    145 
    146             x += DX;
    147             paint.setDither(false);
    148             canvas->drawBitmap(fBMPreDither, x, y, &paint);
    149 
    150             x += DX;
    151             canvas->drawBitmap(fBM16, x, y, &paint);
    152         }
    153 
    154         canvas->translate(DX, DX*2);
    155         draw_sweep(canvas, fBM.width(), fBM.height(), fAngle);
    156         canvas->translate(DX, 0);
    157         draw_sweep(canvas, fBM.width()>>1, fBM.height()>>1, fAngle);
    158         canvas->translate(DX, 0);
    159         draw_sweep(canvas, fBM.width()>>2, fBM.height()>>2, fAngle);
    160 
    161         fAngle += SK_Scalar1/2;
    162     }
    163 
    164 private:
    165     typedef SampleView INHERITED;
    166 };
    167 
    168 //////////////////////////////////////////////////////////////////////////////
    169 
    170 static SkView* MyFactory() { return new DitherView; }
    171 static SkViewRegister reg(MyFactory);
    172