1 2/* 3 * Copyright 2014 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9#include "gm.h" 10#include "SkGradientShader.h" 11#include "SkPatchUtils.h" 12 13static SkShader* make_shader() { 14 const SkColor colors[] = { 15 SK_ColorRED, SK_ColorCYAN, SK_ColorGREEN, SK_ColorWHITE, SK_ColorMAGENTA, SK_ColorBLUE, 16 SK_ColorYELLOW, 17 }; 18 const SkPoint pts[] = { { 100.f / 4.f, 0.f }, { 3.f * 100.f / 4.f, 100.f } }; 19 20 return SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors), 21 SkShader::kMirror_TileMode); 22} 23 24static void draw_control_points(SkCanvas* canvas, const SkPoint cubics[12]) { 25 //draw control points 26 SkPaint paint; 27 SkPoint bottom[SkPatchUtils::kNumPtsCubic]; 28 SkPatchUtils::getBottomCubic(cubics, bottom); 29 SkPoint top[SkPatchUtils::kNumPtsCubic]; 30 SkPatchUtils::getTopCubic(cubics, top); 31 SkPoint left[SkPatchUtils::kNumPtsCubic]; 32 SkPatchUtils::getLeftCubic(cubics, left); 33 SkPoint right[SkPatchUtils::kNumPtsCubic]; 34 SkPatchUtils::getRightCubic(cubics, right); 35 36 paint.setColor(SK_ColorBLACK); 37 paint.setStrokeWidth(0.5f); 38 SkPoint corners[4] = { bottom[0], bottom[3], top[0], top[3] }; 39 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, bottom, paint); 40 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, bottom + 1, paint); 41 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, top, paint); 42 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, left, paint); 43 canvas->drawPoints(SkCanvas::kLines_PointMode, 4, right, paint); 44 45 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, top + 1, paint); 46 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, left + 1, paint); 47 canvas->drawPoints(SkCanvas::kLines_PointMode, 2, right + 1, paint); 48 49 paint.setStrokeWidth(2); 50 51 paint.setColor(SK_ColorRED); 52 canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, corners, paint); 53 54 paint.setColor(SK_ColorBLUE); 55 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, bottom + 1, paint); 56 57 paint.setColor(SK_ColorCYAN); 58 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, top + 1, paint); 59 60 paint.setColor(SK_ColorYELLOW); 61 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, left + 1, paint); 62 63 paint.setColor(SK_ColorGREEN); 64 canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, right + 1, paint); 65} 66 67namespace skiagm { 68/** 69 * This GM draws a cubics coons patch using the specialized call SkCanvas::drawPatch. 70 */ 71class SkPatchGM : public GM { 72 73public: 74 SkPatchGM() { 75 this->setBGColor(0xFFFFFFFF); 76 } 77 78protected: 79 SkString onShortName() override { 80 return SkString("patch_primitive"); 81 } 82 83 SkISize onISize() override { 84 return SkISize::Make(800, 800); 85 } 86 87 void onDraw(SkCanvas* canvas) override { 88 89 SkPaint paint; 90 91 // The order of the colors and points is clockwise starting at upper-left corner. 92 const SkPoint cubics[SkPatchUtils::kNumCtrlPts] = { 93 //top points 94 {100,100},{150,50},{250,150}, {300,100}, 95 //right points 96 {250, 150},{350,250}, 97 //bottom points 98 {300,300},{250,250},{150,350},{100,300}, 99 //left points 100 {50,250},{150,150} 101 }; 102 103 const SkColor colors[SkPatchUtils::kNumCorners] = { 104 SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorCYAN 105 }; 106 const SkPoint texCoords[SkPatchUtils::kNumCorners] = { 107 {0.0f, 0.0f}, {100.0f, 0.0f}, {100.0f,100.0f}, {0.0f, 100.0f}} 108 ; 109 110 const SkXfermode::Mode modes[] = { 111 SkXfermode::kSrc_Mode, 112 SkXfermode::kDst_Mode, 113 SkXfermode::kModulate_Mode, 114 }; 115 116 SkAutoTUnref<SkShader> shader(make_shader()); 117 118 canvas->save(); 119 for (int y = 0; y < 3; y++) { 120 SkAutoTUnref<SkXfermode> xfer(SkXfermode::Create(modes[y])); 121 122 for (int x = 0; x < 4; x++) { 123 canvas->save(); 124 canvas->translate(x * 350.0f, y * 350.0f); 125 switch (x) { 126 case 0: 127 canvas->drawPatch(cubics, NULL, NULL, xfer, paint); 128 break; 129 case 1: 130 canvas->drawPatch(cubics, colors, NULL, xfer, paint); 131 break; 132 case 2: 133 paint.setShader(shader); 134 canvas->drawPatch(cubics, NULL, texCoords, xfer, paint); 135 paint.setShader(NULL); 136 break; 137 case 3: 138 paint.setShader(shader); 139 canvas->drawPatch(cubics, colors, texCoords, xfer, paint); 140 paint.setShader(NULL); 141 break; 142 default: 143 break; 144 } 145 146 draw_control_points(canvas, cubics); 147 canvas->restore(); 148 } 149 } 150 canvas->restore(); 151 } 152 153private: 154 typedef GM INHERITED; 155}; 156 157DEF_GM(return SkNEW(SkPatchGM); ) 158 159} 160