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 "gm.h" 9 #include "SkCanvas.h" 10 #include "SkColorPriv.h" 11 #include "SkShader.h" 12 13 #include "SkArithmeticMode.h" 14 #include "SkGradientShader.h" 15 #define WW 100 16 #define HH 32 17 18 static SkBitmap make_bm() { 19 SkBitmap bm; 20 bm.setConfig(SkBitmap::kARGB_8888_Config, WW, HH); 21 bm.allocPixels(); 22 bm.eraseColor(SK_ColorTRANSPARENT); 23 return bm; 24 } 25 26 static SkBitmap make_src() { 27 SkBitmap bm = make_bm(); 28 SkCanvas canvas(bm); 29 SkPaint paint; 30 SkPoint pts[] = { {0, 0}, {SkIntToScalar(WW), SkIntToScalar(HH)} }; 31 SkColor colors[] = { 32 SK_ColorBLACK, SK_ColorGREEN, SK_ColorCYAN, 33 SK_ColorRED, SK_ColorMAGENTA, SK_ColorWHITE 34 }; 35 SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors), 36 SkShader::kClamp_TileMode); 37 paint.setShader(s)->unref(); 38 canvas.drawPaint(paint); 39 return bm; 40 } 41 42 static SkBitmap make_dst() { 43 SkBitmap bm = make_bm(); 44 SkCanvas canvas(bm); 45 SkPaint paint; 46 SkPoint pts[] = { {0, SkIntToScalar(HH)}, {SkIntToScalar(WW), 0} }; 47 SkColor colors[] = { 48 SK_ColorBLUE, SK_ColorYELLOW, SK_ColorBLACK, SK_ColorGREEN, SK_ColorGRAY 49 }; 50 SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors), 51 SkShader::kClamp_TileMode); 52 paint.setShader(s)->unref(); 53 canvas.drawPaint(paint); 54 return bm; 55 } 56 57 static SkBitmap make_arith(const SkBitmap& src, const SkBitmap& dst, 58 const SkScalar k[]) { 59 SkBitmap bm = make_bm(); 60 SkCanvas canvas(bm); 61 SkPaint paint; 62 canvas.drawBitmap(dst, 0, 0, NULL); 63 SkXfermode* xfer = SkArithmeticMode::Create(k[0], k[1], k[2], k[3]); 64 paint.setXfermode(xfer)->unref(); 65 canvas.drawBitmap(src, 0, 0, &paint); 66 return bm; 67 } 68 69 static void show_k_text(SkCanvas* canvas, SkScalar x, SkScalar y, const SkScalar k[]) { 70 SkPaint paint; 71 paint.setTextSize(SkIntToScalar(24)); 72 paint.setAntiAlias(true); 73 for (int i = 0; i < 4; ++i) { 74 SkString str; 75 str.appendScalar(k[i]); 76 SkScalar width = paint.measureText(str.c_str(), str.size()); 77 canvas->drawText(str.c_str(), str.size(), x, y + paint.getTextSize(), paint); 78 x += width + SkIntToScalar(10); 79 } 80 } 81 82 class ArithmodeGM : public skiagm::GM { 83 public: 84 ArithmodeGM () {} 85 86 protected: 87 88 virtual SkString onShortName() { 89 return SkString("arithmode"); 90 } 91 92 virtual SkISize onISize() { return SkISize::Make(640, 480); } 93 94 virtual void onDraw(SkCanvas* canvas) { 95 SkBitmap src = make_src(); 96 SkBitmap dst = make_dst(); 97 98 const SkScalar one = SK_Scalar1; 99 static const SkScalar K[] = { 100 0, 0, 0, 0, 101 0, 0, 0, one, 102 0, one, 0, 0, 103 0, 0, one, 0, 104 0, one, one, 0, 105 0, one, -one, 0, 106 0, one/2, one/2, 0, 107 0, one/2, one/2, one/4, 108 0, one/2, one/2, -one/4, 109 one/4, one/2, one/2, 0, 110 -one/4, one/2, one/2, 0, 111 }; 112 113 const SkScalar* k = K; 114 const SkScalar* stop = k + SK_ARRAY_COUNT(K); 115 SkScalar y = 0; 116 SkScalar gap = SkIntToScalar(src.width() + 20); 117 while (k < stop) { 118 SkScalar x = 0; 119 SkBitmap res = make_arith(src, dst, k); 120 canvas->drawBitmap(src, x, y, NULL); 121 x += gap; 122 canvas->drawBitmap(dst, x, y, NULL); 123 x += gap; 124 canvas->drawBitmap(res, x, y, NULL); 125 x += gap; 126 show_k_text(canvas, x, y, k); 127 k += 4; 128 y += SkIntToScalar(src.height() + 12); 129 } 130 } 131 132 private: 133 typedef GM INHERITED; 134 }; 135 136 /////////////////////////////////////////////////////////////////////////////// 137 138 static skiagm::GM* MyFactory(void*) { return new ArithmodeGM; } 139 static skiagm::GMRegistry reg(MyFactory); 140