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_mapHomogeneousPoints, 256, 256, false, 0) {
draw(SkCanvas * canvas)5 void draw(SkCanvas* canvas) {
6 SkPoint3 src[] = {{3, 3, 1}, {8, 2, 2}, {5, 0, 4}, {0, 1, 3},
7 {3, 7, 1}, {8, 6, 2}, {5, 4, 4}, {0, 5, 3}};
8 int lines[] = { 0, 1, 1, 2, 2, 3, 3, 0, 4, 5, 5, 6, 6, 7, 7, 4, 0, 4, 1, 5, 2, 6, 3, 7 };
9 constexpr int count = std::size(src);
10 auto debugster = [=](SkPoint3 src[]) -> void {
11 for (size_t i = 0; i < std::size(lines); i += 2) {
12 const SkPoint3& s = src[lines[i]];
13 const SkPoint3& e = src[lines[i + 1]];
14 SkPaint paint;
15 paint.setARGB(77, 23, 99, 154);
16 canvas->drawLine(s.fX / s.fZ, s.fY / s.fZ, e.fX / e.fZ, e.fY / e.fZ, paint);
17 }
18 };
19 canvas->save();
20 canvas->translate(5, 5);
21 canvas->scale(15, 15);
22 debugster(src);
23 canvas->restore();
24 canvas->translate(128, 128);
25 SkMatrix matrix;
26 matrix.setAll(15, 0, 0, 0, 15, 0, -0.08f, 0.04f, 1);
27 matrix.mapHomogeneousPoints(src, src, count);
28 debugster(src);
29 }
30 } // END FIDDLE
31