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