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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, SkAlpha a0, SkAlpha a1) {
     51 
     52     SkPaint paint;
     53     paint.setAntiAlias(true);
     54 
     55     SkRect r = SkRect::MakeWH(W, H);
     56     r.inset(W/10, H/10);
     57 
     58     paint.setColor(SK_ColorBLUE);
     59     paint.setAlpha(a0);
     60     canvas->drawOval(r, paint);
     61 
     62     paint.setColor(SK_ColorRED);
     63     paint.setAlpha(a1);
     64     paint.setXfermode(mode);
     65     for (int angle = 0; angle < 24; ++angle) {
     66         SkScalar x = SkScalarCos(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gWidth;
     67         SkScalar y = SkScalarSin(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gHeight;
     68         paint.setStrokeWidth(SK_Scalar1 * angle * 2 / 24);
     69         canvas->drawLine(W/2, H/2, W/2 + x, H/2 + y, paint);
     70     }
     71 
     72     return H;
     73 }
     74 
     75 static SkShader* make_bg_shader() {
     76     SkBitmap bm;
     77     bm.setConfig(SkBitmap::kARGB_8888_Config, 2, 2);
     78     bm.allocPixels();
     79     *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = 0xFFFFFFFF;
     80     *bm.getAddr32(1, 0) = *bm.getAddr32(0, 1) = SkPackARGB32(0xFF, 0xCC, 0xCC, 0xCC);
     81 
     82     SkShader* s = SkShader::CreateBitmapShader(bm,
     83                                                SkShader::kRepeat_TileMode,
     84                                                SkShader::kRepeat_TileMode);
     85 
     86     SkMatrix m;
     87     m.setScale(SkIntToScalar(6), SkIntToScalar(6));
     88     s->setLocalMatrix(m);
     89     return s;
     90 }
     91 
     92 class HairModesView : public SampleView {
     93     SkPaint fBGPaint;
     94 public:
     95 	HairModesView() {
     96         fBGPaint.setShader(make_bg_shader())->unref();
     97     }
     98 
     99 protected:
    100     // overrides from SkEventSink
    101     virtual bool onQuery(SkEvent* evt) {
    102         if (SampleCode::TitleQ(*evt)) {
    103             SampleCode::TitleR(evt, "HairlineModes");
    104             return true;
    105         }
    106         return this->INHERITED::onQuery(evt);
    107     }
    108 
    109     virtual void onDrawContent(SkCanvas* canvas) {
    110         const SkRect bounds = SkRect::MakeWH(W, H);
    111         static const SkAlpha gAlphaValue[] = { 0xFF, 0x88, 0x88 };
    112 
    113         canvas->translate(SkIntToScalar(4), SkIntToScalar(4));
    114 
    115         for (int alpha = 0; alpha < 4; ++alpha) {
    116             canvas->save();
    117             canvas->save();
    118             for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); ++i) {
    119                 if (6 == i) {
    120                     canvas->restore();
    121                     canvas->translate(W * 5, 0);
    122                     canvas->save();
    123                 }
    124                 SkXfermode* mode = SkXfermode::Create(gModes[i].fMode);
    125 
    126                 canvas->drawRect(bounds, fBGPaint);
    127                 canvas->saveLayer(&bounds, NULL);
    128                 SkScalar dy = drawCell(canvas, mode,
    129                                        gAlphaValue[alpha & 1],
    130                                        gAlphaValue[alpha & 2]);
    131                 canvas->restore();
    132 
    133                 canvas->translate(0, dy * 5 / 4);
    134                 SkSafeUnref(mode);
    135             }
    136             canvas->restore();
    137             canvas->restore();
    138             canvas->translate(W * 5 / 4, 0);
    139         }
    140     }
    141 
    142 private:
    143     typedef SampleView INHERITED;
    144 };
    145 
    146 ///////////////////////////////////////////////////////////////////////////////
    147 
    148 static SkView* MyFactory() { return new HairModesView; }
    149 static SkViewRegister reg(MyFactory);
    150 
    151