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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 SkCanvas* create_canvas(int w, int h) {
     16     SkBitmap bm;
     17     bm.setConfig(SkBitmap::kARGB_8888_Config, w, h);
     18     bm.allocPixels();
     19     bm.eraseColor(0);
     20     return new SkCanvas(bm);
     21 }
     22 
     23 static const SkBitmap& extract_bitmap(SkCanvas* canvas) {
     24     return canvas->getDevice()->accessBitmap(false);
     25 }
     26 
     27 static const struct {
     28     SkXfermode::Mode  fMode;
     29     const char*         fLabel;
     30 } gModes[] = {
     31     { SkXfermode::kClear_Mode,    "Clear"     },
     32     { SkXfermode::kSrc_Mode,      "Src"       },
     33     { SkXfermode::kDst_Mode,      "Dst"       },
     34     { SkXfermode::kSrcOver_Mode,  "SrcOver"   },
     35     { SkXfermode::kDstOver_Mode,  "DstOver"   },
     36     { SkXfermode::kSrcIn_Mode,    "SrcIn"     },
     37     { SkXfermode::kDstIn_Mode,    "DstIn"     },
     38     { SkXfermode::kSrcOut_Mode,   "SrcOut"    },
     39     { SkXfermode::kDstOut_Mode,   "DstOut"    },
     40     { SkXfermode::kSrcATop_Mode,  "SrcATop"   },
     41     { SkXfermode::kDstATop_Mode,  "DstATop"   },
     42     { SkXfermode::kXor_Mode,      "Xor"       },
     43 };
     44 
     45 const int gWidth = 64;
     46 const int gHeight = 64;
     47 const SkScalar W = SkIntToScalar(gWidth);
     48 const SkScalar H = SkIntToScalar(gHeight);
     49 
     50 static SkScalar drawCell(SkCanvas* canvas, SkXfermode* mode,
     51                          SkAlpha a0, SkAlpha a1) {
     52 
     53     SkPaint paint;
     54     paint.setAntiAlias(true);
     55 
     56     SkRect r = SkRect::MakeWH(W, H);
     57     r.inset(W/10, H/10);
     58 
     59     paint.setColor(SK_ColorBLUE);
     60     paint.setAlpha(a0);
     61     canvas->drawOval(r, paint);
     62 
     63     paint.setColor(SK_ColorRED);
     64     paint.setAlpha(a1);
     65     paint.setXfermode(mode);
     66 
     67     SkScalar offset = SK_Scalar1 / 3;
     68     SkRect rect = SkRect::MakeXYWH(W / 4 + offset,
     69                                    H / 4 + offset,
     70                                    W / 2, H / 2);
     71     canvas->drawRect(rect, paint);
     72 
     73     return H;
     74 }
     75 
     76 static SkShader* make_bg_shader() {
     77     SkBitmap bm;
     78     bm.setConfig(SkBitmap::kARGB_8888_Config, 2, 2);
     79     bm.allocPixels();
     80     *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = 0xFFFFFFFF;
     81     *bm.getAddr32(1, 0) = *bm.getAddr32(0, 1) = SkPackARGB32(0xFF, 0xCC,
     82                                                              0xCC, 0xCC);
     83 
     84     SkShader* s = SkShader::CreateBitmapShader(bm,
     85                                                SkShader::kRepeat_TileMode,
     86                                                SkShader::kRepeat_TileMode);
     87 
     88     SkMatrix m;
     89     m.setScale(SkIntToScalar(6), SkIntToScalar(6));
     90     s->setLocalMatrix(m);
     91     return s;
     92 }
     93 
     94 class AARectsModesView : public SampleView {
     95     SkPaint fBGPaint;
     96 public:
     97     AARectsModesView () {
     98         fBGPaint.setShader(make_bg_shader())->unref();
     99     }
    100 
    101 protected:
    102     // overrides from SkEventSink
    103     virtual bool onQuery(SkEvent* evt) {
    104         if (SampleCode::TitleQ(*evt)) {
    105             SampleCode::TitleR(evt, "AARectsModes");
    106             return true;
    107         }
    108         return this->INHERITED::onQuery(evt);
    109     }
    110 
    111     virtual void onDrawContent(SkCanvas* canvas) {
    112         const SkRect bounds = SkRect::MakeWH(W, H);
    113         static const SkAlpha gAlphaValue[] = { 0xFF, 0x88, 0x88 };
    114 
    115         canvas->translate(SkIntToScalar(4), SkIntToScalar(4));
    116 
    117         for (int alpha = 0; alpha < 4; ++alpha) {
    118             canvas->save();
    119             canvas->save();
    120             for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); ++i) {
    121                 if (6 == i) {
    122                     canvas->restore();
    123                     canvas->translate(W * 5, 0);
    124                     canvas->save();
    125                 }
    126                 SkXfermode* mode = SkXfermode::Create(gModes[i].fMode);
    127 
    128                 canvas->drawRect(bounds, fBGPaint);
    129                 canvas->saveLayer(&bounds, NULL);
    130                 SkScalar dy = drawCell(canvas, mode,
    131                                        gAlphaValue[alpha & 1],
    132                                        gAlphaValue[alpha & 2]);
    133                 canvas->restore();
    134 
    135                 canvas->translate(0, dy * 5 / 4);
    136                 SkSafeUnref(mode);
    137             }
    138             canvas->restore();
    139             canvas->restore();
    140             canvas->translate(W * 5 / 4, 0);
    141         }
    142     }
    143 
    144 private:
    145     typedef SampleView INHERITED;
    146 };
    147 
    148 ///////////////////////////////////////////////////////////////////////////////
    149 
    150 static SkView* MyFactory() { return new AARectsModesView; }
    151 static SkViewRegister reg(MyFactory);
    152 
    153