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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 "SampleCode.h"
      9 #include "SkView.h"
     10 #include "SkBitmap.h"
     11 #include "SkCanvas.h"
     12 #include "SkColorPriv.h"
     13 #include "SkShader.h"
     14 
     15 static const SkBlendMode gModes[] = {
     16     SkBlendMode::kClear,
     17     SkBlendMode::kSrc,
     18     SkBlendMode::kDst,
     19     SkBlendMode::kSrcOver,
     20     SkBlendMode::kDstOver,
     21     SkBlendMode::kSrcIn,
     22     SkBlendMode::kDstIn,
     23     SkBlendMode::kSrcOut,
     24     SkBlendMode::kDstOut,
     25     SkBlendMode::kSrcATop,
     26     SkBlendMode::kDstATop,
     27     SkBlendMode::kXor,
     28 };
     29 
     30 const int gWidth = 64;
     31 const int gHeight = 64;
     32 const SkScalar W = SkIntToScalar(gWidth);
     33 const SkScalar H = SkIntToScalar(gHeight);
     34 
     35 static SkScalar drawCell(SkCanvas* canvas, SkBlendMode mode, SkAlpha a0, SkAlpha a1) {
     36     SkPaint paint;
     37     paint.setAntiAlias(true);
     38 
     39     SkRect r = SkRect::MakeWH(W, H);
     40     r.inset(W/10, H/10);
     41 
     42     paint.setColor(SK_ColorBLUE);
     43     paint.setAlpha(a0);
     44     canvas->drawOval(r, paint);
     45 
     46     paint.setColor(SK_ColorRED);
     47     paint.setAlpha(a1);
     48     paint.setBlendMode(mode);
     49     for (int angle = 0; angle < 24; ++angle) {
     50         SkScalar x = SkScalarCos(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gWidth;
     51         SkScalar y = SkScalarSin(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gHeight;
     52         paint.setStrokeWidth(SK_Scalar1 * angle * 2 / 24);
     53         canvas->drawLine(W/2, H/2, W/2 + x, H/2 + y, paint);
     54     }
     55 
     56     return H;
     57 }
     58 
     59 static sk_sp<SkShader> make_bg_shader() {
     60     SkBitmap bm;
     61     bm.allocN32Pixels(2, 2);
     62     *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = 0xFFFFFFFF;
     63     *bm.getAddr32(1, 0) = *bm.getAddr32(0, 1) = SkPackARGB32(0xFF, 0xCC, 0xCC, 0xCC);
     64 
     65     SkMatrix m;
     66     m.setScale(SkIntToScalar(6), SkIntToScalar(6));
     67 
     68     return SkShader::MakeBitmapShader(bm, SkShader::kRepeat_TileMode,
     69                                       SkShader::kRepeat_TileMode, &m);
     70 }
     71 
     72 class HairModesView : public SampleView {
     73     SkPaint fBGPaint;
     74 public:
     75     HairModesView() {
     76         fBGPaint.setShader(make_bg_shader());
     77     }
     78 
     79 protected:
     80     // overrides from SkEventSink
     81     virtual bool onQuery(SkEvent* evt) {
     82         if (SampleCode::TitleQ(*evt)) {
     83             SampleCode::TitleR(evt, "HairlineModes");
     84             return true;
     85         }
     86         return this->INHERITED::onQuery(evt);
     87     }
     88 
     89     virtual void onDrawContent(SkCanvas* canvas) {
     90         const SkRect bounds = SkRect::MakeWH(W, H);
     91         static const SkAlpha gAlphaValue[] = { 0xFF, 0x88, 0x88 };
     92 
     93         canvas->translate(SkIntToScalar(4), SkIntToScalar(4));
     94 
     95         for (int alpha = 0; alpha < 4; ++alpha) {
     96             canvas->save();
     97             canvas->save();
     98             for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); ++i) {
     99                 if (6 == i) {
    100                     canvas->restore();
    101                     canvas->translate(W * 5, 0);
    102                     canvas->save();
    103                 }
    104                 canvas->drawRect(bounds, fBGPaint);
    105                 canvas->saveLayer(&bounds, nullptr);
    106                 SkScalar dy = drawCell(canvas, gModes[i],
    107                                        gAlphaValue[alpha & 1],
    108                                        gAlphaValue[alpha & 2]);
    109                 canvas->restore();
    110 
    111                 canvas->translate(0, dy * 5 / 4);
    112             }
    113             canvas->restore();
    114             canvas->restore();
    115             canvas->translate(W * 5 / 4, 0);
    116         }
    117     }
    118 
    119 private:
    120     typedef SampleView INHERITED;
    121 };
    122 
    123 ///////////////////////////////////////////////////////////////////////////////
    124 
    125 static SkView* MyFactory() { return new HairModesView; }
    126 static SkViewRegister reg(MyFactory);
    127