xref: /aosp_15_r20/external/skia/docs/examples/Matrix_mapXY_2.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_mapXY_2, 256, 256, false, 4) {
draw(SkCanvas * canvas)5 void draw(SkCanvas* canvas) {
6     SkMatrix matrix;
7     SkPoint bitmapBounds[4], perspect[4] = {{50, 10}, {180, 40}, {236, 176}, {30, 206}};
8     SkRect::Make(source.bounds()).toQuad(bitmapBounds);
9     matrix.setPolyToPoly(bitmapBounds, perspect, 4);
10     SkPaint paint;
11     paint.setAntiAlias(true);
12     paint.setStrokeWidth(3);
13     for (int x : { 0, source.width() } ) {
14         for (int y : { 0, source.height() } ) {
15             canvas->drawPoint(matrix.mapXY(x, y), paint);
16         }
17     }
18     canvas->concat(matrix);
19     canvas->drawImage(image, 0, 0);
20 }
21 }  // END FIDDLE
22