xref: /aosp_15_r20/external/skia/docs/examples/Matrix_decomposeScale.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_decomposeScale, 256, 256, true, 0) {
draw(SkCanvas * canvas)5 void draw(SkCanvas* canvas) {
6     SkMatrix matrix;
7     matrix.setRotate(90 * SK_Scalar1);
8     matrix.postScale(1.f / 4, 1.f / 2);
9     matrix.dump();
10     SkSize scale = {SK_ScalarNaN, SK_ScalarNaN};
11     SkMatrix remaining;
12     remaining.reset();
13     bool success = matrix.decomposeScale(&scale, &remaining);
14     SkDebugf("success: %s  ", success ? "true" : "false");
15     SkDebugf("scale: %g, %g\n", scale.width(), scale.height());
16     remaining.dump();
17     SkMatrix scaleMatrix = SkMatrix::Scale(scale.width(), scale.height());
18     SkMatrix combined = SkMatrix::Concat(scaleMatrix, remaining);
19     combined.dump();
20 }
21 }  // END FIDDLE
22