1 /* 2 * Copyright 2016 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 "Resources.h" 10 11 #include "SkImageDecoder.h" 12 #include "SkPixelXorXfermode.h" 13 #include "SkStream.h" 14 15 class PixelXorXfermodeGM : public skiagm::GM { 16 public: 17 PixelXorXfermodeGM() { } 18 19 protected: 20 SkString onShortName() override { 21 return SkString("pixelxorxfermode"); 22 } 23 24 SkISize onISize() override { return SkISize::Make(512, 512); } 25 26 void onOnceBeforeDraw() override { 27 SkImageDecoder* codec = nullptr; 28 SkString resourcePath = GetResourcePath("mandrill_512.png"); 29 SkFILEStream stream(resourcePath.c_str()); 30 if (stream.isValid()) { 31 codec = SkImageDecoder::Factory(&stream); 32 } 33 if (codec) { 34 stream.rewind(); 35 codec->decode(&stream, &fBM, kN32_SkColorType, SkImageDecoder::kDecodePixels_Mode); 36 delete codec; 37 } else { 38 fBM.allocN32Pixels(1, 1); 39 fBM.eraseARGB(255, 255, 0 , 0); // red == bad 40 } 41 } 42 43 void onDraw(SkCanvas* canvas) override { 44 canvas->drawBitmap(fBM, 0, 0); 45 46 SkRect r = SkRect::MakeIWH(256, 256); 47 48 // Negate the red channel of the dst (via the ancillary color) but leave 49 // the green & blue channels alone 50 SkPaint p1; 51 p1.setColor(SK_ColorBLACK); // noop 52 p1.setXfermode(SkPixelXorXfermode::Create(0x7FFF0000))->unref(); 53 54 canvas->drawRect(r, p1); 55 56 r.offsetTo(256.0f, 0.0f); 57 58 // Negate the dst color via the src color 59 SkPaint p2; 60 p2.setColor(SK_ColorWHITE); 61 p2.setXfermode(SkPixelXorXfermode::Create(SK_ColorBLACK))->unref(); // noop 62 63 canvas->drawRect(r, p2); 64 65 r.offsetTo(0.0f, 256.0f); 66 67 // Just return the original color 68 SkPaint p3; 69 p3.setColor(SK_ColorBLACK); // noop 70 p3.setXfermode(SkPixelXorXfermode::Create(SK_ColorBLACK))->unref(); // noop 71 72 canvas->drawRect(r, p3); 73 74 r.offsetTo(256.0f, 256.0f); 75 76 // Negate the red & green channels (via the ancillary color) but leave 77 // the blue channel alone 78 SkPaint p4; 79 p4.setColor(SK_ColorBLACK); // noop 80 p4.setXfermode(SkPixelXorXfermode::Create(SK_ColorYELLOW))->unref(); 81 82 canvas->drawRect(r, p4); 83 } 84 85 private: 86 SkBitmap fBM; 87 88 typedef GM INHERITED; 89 }; 90 91 ////////////////////////////////////////////////////////////////////////////// 92 93 DEF_GM(return new PixelXorXfermodeGM;) 94