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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 "SkCanvas.h"
     11 #include "SkDevice.h"
     12 #include "SkColorPriv.h"
     13 #include "SkShader.h"
     14 
     15 static const struct {
     16     SkXfermode::Mode  fMode;
     17     const char*         fLabel;
     18 } gModes[] = {
     19     { SkXfermode::kClear_Mode,    "Clear"     },
     20     { SkXfermode::kSrc_Mode,      "Src"       },
     21     { SkXfermode::kDst_Mode,      "Dst"       },
     22     { SkXfermode::kSrcOver_Mode,  "SrcOver"   },
     23     { SkXfermode::kDstOver_Mode,  "DstOver"   },
     24     { SkXfermode::kSrcIn_Mode,    "SrcIn"     },
     25     { SkXfermode::kDstIn_Mode,    "DstIn"     },
     26     { SkXfermode::kSrcOut_Mode,   "SrcOut"    },
     27     { SkXfermode::kDstOut_Mode,   "DstOut"    },
     28     { SkXfermode::kSrcATop_Mode,  "SrcATop"   },
     29     { SkXfermode::kDstATop_Mode,  "DstATop"   },
     30     { SkXfermode::kXor_Mode,      "Xor"       },
     31 };
     32 
     33 const int gWidth = 64;
     34 const int gHeight = 64;
     35 const SkScalar W = SkIntToScalar(gWidth);
     36 const SkScalar H = SkIntToScalar(gHeight);
     37 
     38 static SkScalar drawCell(SkCanvas* canvas, SkXfermode* mode,
     39                          SkAlpha a0, SkAlpha a1) {
     40 
     41     SkPaint paint;
     42     paint.setAntiAlias(true);
     43 
     44     SkRect r = SkRect::MakeWH(W, H);
     45     r.inset(W/10, H/10);
     46 
     47     paint.setColor(SK_ColorBLUE);
     48     paint.setAlpha(a0);
     49     canvas->drawOval(r, paint);
     50 
     51     paint.setColor(SK_ColorRED);
     52     paint.setAlpha(a1);
     53     paint.setXfermode(mode);
     54 
     55     SkScalar offset = SK_Scalar1 / 3;
     56     SkRect rect = SkRect::MakeXYWH(W / 4 + offset,
     57                                    H / 4 + offset,
     58                                    W / 2, H / 2);
     59     canvas->drawRect(rect, paint);
     60 
     61     return H;
     62 }
     63 
     64 static SkShader* make_bg_shader() {
     65     SkBitmap bm;
     66     bm.allocN32Pixels(2, 2);
     67     *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = 0xFFFFFFFF;
     68     *bm.getAddr32(1, 0) = *bm.getAddr32(0, 1) = SkPackARGB32(0xFF, 0xCC,
     69                                                              0xCC, 0xCC);
     70 
     71     SkMatrix m;
     72     m.setScale(SkIntToScalar(6), SkIntToScalar(6));
     73 
     74     return SkShader::CreateBitmapShader(bm,
     75                                         SkShader::kRepeat_TileMode,
     76                                         SkShader::kRepeat_TileMode,
     77                                         &m);
     78 }
     79 
     80 class AARectsModesView : public SampleView {
     81     SkPaint fBGPaint;
     82 public:
     83     AARectsModesView () {
     84         fBGPaint.setShader(make_bg_shader())->unref();
     85     }
     86 
     87 protected:
     88     // overrides from SkEventSink
     89     virtual bool onQuery(SkEvent* evt) {
     90         if (SampleCode::TitleQ(*evt)) {
     91             SampleCode::TitleR(evt, "AARectsModes");
     92             return true;
     93         }
     94         return this->INHERITED::onQuery(evt);
     95     }
     96 
     97     virtual void onDrawContent(SkCanvas* canvas) {
     98         const SkRect bounds = SkRect::MakeWH(W, H);
     99         static const SkAlpha gAlphaValue[] = { 0xFF, 0x88, 0x88 };
    100 
    101         canvas->translate(SkIntToScalar(4), SkIntToScalar(4));
    102 
    103         for (int alpha = 0; alpha < 4; ++alpha) {
    104             canvas->save();
    105             canvas->save();
    106             for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); ++i) {
    107                 if (6 == i) {
    108                     canvas->restore();
    109                     canvas->translate(W * 5, 0);
    110                     canvas->save();
    111                 }
    112                 SkXfermode* mode = SkXfermode::Create(gModes[i].fMode);
    113 
    114                 canvas->drawRect(bounds, fBGPaint);
    115                 canvas->saveLayer(&bounds, NULL);
    116                 SkScalar dy = drawCell(canvas, mode,
    117                                        gAlphaValue[alpha & 1],
    118                                        gAlphaValue[alpha & 2]);
    119                 canvas->restore();
    120 
    121                 canvas->translate(0, dy * 5 / 4);
    122                 SkSafeUnref(mode);
    123             }
    124             canvas->restore();
    125             canvas->restore();
    126             canvas->translate(W * 5 / 4, 0);
    127         }
    128     }
    129 
    130 private:
    131     typedef SampleView INHERITED;
    132 };
    133 
    134 ///////////////////////////////////////////////////////////////////////////////
    135 
    136 static SkView* MyFactory() { return new AARectsModesView; }
    137 static SkViewRegister reg(MyFactory);
    138