gm/localmatriximageshader.cpp

   1 /*
   2  * Copyright 2015 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 "SkSurface.h"
  11
  12 static sk_sp<SkImage> make_image(SkCanvas* rootCanvas, SkColor color) {
  13     SkImageInfo info = SkImageInfo::MakeN32Premul(100, 100);
  14     auto surface(rootCanvas->makeSurface(info));
  15     if (!surface) {
  16         surface = SkSurface::MakeRaster(info);
  17     }
  18
  19     SkPaint paint;
  20     paint.setAntiAlias(true);
  21     paint.setColor(color);
  22     surface->getCanvas()->drawIRect(SkIRect::MakeXYWH(25, 25, 50, 50), paint);
  23     return surface->makeImageSnapshot();
  24 }
  25
  26 DEF_SIMPLE_GM(localmatriximageshader, canvas, 250, 250) {
  27     sk_sp<SkImage> redImage = make_image(canvas, SK_ColorRED);
  28     SkMatrix translate = SkMatrix::MakeTrans(100.0f, 0.0f);
  29     SkMatrix rotate;
  30     rotate.setRotate(45.0f);
  31     sk_sp<SkShader> redImageShader = redImage->makeShader(&translate);
  32     sk_sp<SkShader> redLocalMatrixShader = redImageShader->makeWithLocalMatrix(rotate);
  33
  34     // Rotate about the origin will happen first.
  35     SkPaint paint;
  36     paint.setShader(redLocalMatrixShader);
  37     canvas->drawIRect(SkIRect::MakeWH(250, 250), paint);
  38
  39     sk_sp<SkImage> blueImage = make_image(canvas, SK_ColorBLUE);
  40     sk_sp<SkShader> blueImageShader = blueImage->makeShader(&rotate);
  41     sk_sp<SkShader> blueLocalMatrixShader = blueImageShader->makeWithLocalMatrix(translate);
  42
  43     // Translate will happen first.
  44     paint.setShader(blueLocalMatrixShader);
  45     canvas->drawIRect(SkIRect::MakeWH(250, 250), paint);
  46
  47     canvas->translate(100.0f, 0.0f);
  48
  49     // Use isAImage() and confirm that the shaders will draw exactly the same (to the right by 100).
  50     SkShader::TileMode mode[2];
  51     SkMatrix matrix;
  52     SkImage* image = redLocalMatrixShader->isAImage(&matrix, mode);
  53     paint.setShader(image->makeShader(mode[0], mode[1], &matrix));
  54     canvas->drawIRect(SkIRect::MakeWH(250, 250), paint);
  55     image = blueLocalMatrixShader->isAImage(&matrix, mode);
  56     paint.setShader(image->makeShader(mode[0], mode[1], &matrix));
  57     canvas->drawIRect(SkIRect::MakeWH(250, 250), paint);
  58 }