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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 
      8 #include "Sample.h"
      9 #include "SkBitmap.h"
     10 #include "SkCanvas.h"
     11 #include "SkColorPriv.h"
     12 #include "SkShader.h"
     13 
     14 static const SkBlendMode gModes[] = {
     15     SkBlendMode::kClear,
     16     SkBlendMode::kSrc,
     17     SkBlendMode::kDst,
     18     SkBlendMode::kSrcOver,
     19     SkBlendMode::kDstOver,
     20     SkBlendMode::kSrcIn,
     21     SkBlendMode::kDstIn,
     22     SkBlendMode::kSrcOut,
     23     SkBlendMode::kDstOut,
     24     SkBlendMode::kSrcATop,
     25     SkBlendMode::kDstATop,
     26     SkBlendMode::kXor,
     27 };
     28 
     29 const int gWidth = 64;
     30 const int gHeight = 64;
     31 const SkScalar W = SkIntToScalar(gWidth);
     32 const SkScalar H = SkIntToScalar(gHeight);
     33 
     34 static SkScalar drawCell(SkCanvas* canvas, SkBlendMode mode, SkAlpha a0, SkAlpha a1) {
     35     SkPaint paint;
     36     paint.setAntiAlias(true);
     37 
     38     SkRect r = SkRect::MakeWH(W, H);
     39     r.inset(W/10, H/10);
     40 
     41     paint.setColor(SK_ColorBLUE);
     42     paint.setAlpha(a0);
     43     canvas->drawOval(r, paint);
     44 
     45     paint.setColor(SK_ColorRED);
     46     paint.setAlpha(a1);
     47     paint.setBlendMode(mode);
     48     for (int angle = 0; angle < 24; ++angle) {
     49         SkScalar x = SkScalarCos(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gWidth;
     50         SkScalar y = SkScalarSin(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gHeight;
     51         paint.setStrokeWidth(SK_Scalar1 * angle * 2 / 24);
     52         canvas->drawLine(W/2, H/2, W/2 + x, H/2 + y, paint);
     53     }
     54 
     55     return H;
     56 }
     57 
     58 static sk_sp<SkShader> make_bg_shader() {
     59     SkBitmap bm;
     60     bm.allocN32Pixels(2, 2);
     61     *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = 0xFFFFFFFF;
     62     *bm.getAddr32(1, 0) = *bm.getAddr32(0, 1) = SkPackARGB32(0xFF, 0xCC, 0xCC, 0xCC);
     63 
     64     SkMatrix m;
     65     m.setScale(SkIntToScalar(6), SkIntToScalar(6));
     66 
     67     return SkShader::MakeBitmapShader(bm, SkShader::kRepeat_TileMode,
     68                                       SkShader::kRepeat_TileMode, &m);
     69 }
     70 
     71 class HairModesView : public Sample {
     72     SkPaint fBGPaint;
     73 public:
     74     HairModesView() {
     75         fBGPaint.setShader(make_bg_shader());
     76     }
     77 
     78 protected:
     79     virtual bool onQuery(Sample::Event* evt) {
     80         if (Sample::TitleQ(*evt)) {
     81             Sample::TitleR(evt, "HairlineModes");
     82             return true;
     83         }
     84         return this->INHERITED::onQuery(evt);
     85     }
     86 
     87     virtual void onDrawContent(SkCanvas* canvas) {
     88         const SkRect bounds = SkRect::MakeWH(W, H);
     89         static const SkAlpha gAlphaValue[] = { 0xFF, 0x88, 0x88 };
     90 
     91         canvas->translate(SkIntToScalar(4), SkIntToScalar(4));
     92 
     93         for (int alpha = 0; alpha < 4; ++alpha) {
     94             canvas->save();
     95             canvas->save();
     96             for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); ++i) {
     97                 if (6 == i) {
     98                     canvas->restore();
     99                     canvas->translate(W * 5, 0);
    100                     canvas->save();
    101                 }
    102                 canvas->drawRect(bounds, fBGPaint);
    103                 canvas->saveLayer(&bounds, nullptr);
    104                 SkScalar dy = drawCell(canvas, gModes[i],
    105                                        gAlphaValue[alpha & 1],
    106                                        gAlphaValue[alpha & 2]);
    107                 canvas->restore();
    108 
    109                 canvas->translate(0, dy * 5 / 4);
    110             }
    111             canvas->restore();
    112             canvas->restore();
    113             canvas->translate(W * 5 / 4, 0);
    114         }
    115     }
    116 
    117 private:
    118     typedef Sample INHERITED;
    119 };
    120 
    121 ///////////////////////////////////////////////////////////////////////////////
    122 
    123 DEF_SAMPLE( return new HairModesView(); )
    124