skia2/docs/examples/Matrix_invert.cpp

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// Copyright 2019 Google LLC.
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
#include "fiddle/examples.h"
// HASH=0e03cd9f154603ed4b21ca56d69dae44
REG_FIDDLE(Matrix_invert, 256, 128, false, 0) {
void draw(SkCanvas* canvas) {
const SkPoint src[] = { { 10, 120}, {120, 120}, {120, 10}, { 10, 10} };
const SkPoint dst[] = { {150, 120}, {200, 100}, {240, 30}, { 130, 40} };
SkPaint paint;
paint.setAntiAlias(true);
SkMatrix matrix;
matrix.setPolyToPoly(src, dst, 4);
canvas->drawPoints(SkCanvas::kPolygon_PointMode, 4, src, paint);
canvas->drawPoints(SkCanvas::kPolygon_PointMode, 4, dst, paint);
paint.setColor(SK_ColorBLUE);
paint.setStrokeWidth(3);
paint.setStrokeCap(SkPaint::kRound_Cap);
canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, dst, paint);
if (matrix.invert(&matrix)) {
canvas->concat(matrix);
canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, dst, paint);
}
}
} // END FIDDLE