submodule/skia/docs/examples/Pixmap_scalePixels.cpp

   1 // Copyright 2019 Google LLC.
   2 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
   3 #include "tools/fiddle/examples.h"
   4 // HASH=8e3c8a9c1d0d2e9b8bf66e24d274f792
   5 REG_FIDDLE(Pixmap_scalePixels, 256, 256, false, 3) {
   6 void draw(SkCanvas* canvas) {
   7     SkImageInfo info = SkImageInfo::MakeN32Premul(image->width(), image->height());
   8     std::vector<int32_t> srcPixels;
   9     int rowBytes = image->width() * 4;
  10     srcPixels.resize(image->height() * rowBytes);
  11     SkPixmap pixmap(info, (const void*) &srcPixels.front(), rowBytes);
  12     image->readPixels(nullptr, pixmap, 0, 0);
  13     for (int offset : { 32, 64, 96 } ) {
  14         info = SkImageInfo::MakeN32Premul(image->width() + offset, image->height());
  15         rowBytes = info.width() * 4;
  16         std::vector<int32_t> dstPixels;
  17         dstPixels.resize(image->height() * rowBytes);
  18         SkPixmap dstmap(info, &dstPixels.front(), rowBytes);
  19         pixmap.scalePixels(dstmap, SkSamplingOptions(SkFilterMode::kLinear,
  20                                                      SkMipmapMode::kNearest));
  21         SkBitmap bitmap;
  22         bitmap.installPixels(dstmap);
  23         canvas->translate(32, 32);
  24         canvas->drawImage(bitmap.asImage(), 0, 0);
  25     }
  26 }
  27 }  // END FIDDLE