xref: /aosp_15_r20/external/skia/docs/examples/Matrix_mapRectToQuad.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
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  REG_FIDDLE(Matrix_mapRectToQuad, 256, 192, false, 0) {
draw(SkCanvas * canvas)5  void draw(SkCanvas* canvas) {
6      SkPaint paint;
7      paint.setAntiAlias(true);
8      SkMatrix matrix;
9      matrix.setRotate(60, 128, 128);
10      SkRect rect = {50, 50, 150, 150};
11      SkPoint pts[4];
12      matrix.mapRectToQuad(pts, rect);
13      for (int i = 0; i < 4; ++i) {
14          canvas->drawCircle(pts[i].fX, pts[i].fY, 3, paint);
15      }
16      canvas->concat(matrix);
17      paint.setStyle(SkPaint::kStroke_Style);
18      canvas->drawRect(rect, paint);
19  }
20  }  // END FIDDLE
21