xref: /aosp_15_r20/external/skia/docs/examples/Path_IsCubicDegenerate.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1*c8dee2aaSAndroid Build Coastguard Worker // Copyright 2019 Google LLC.
2*c8dee2aaSAndroid Build Coastguard Worker // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3*c8dee2aaSAndroid Build Coastguard Worker #include "tools/fiddle/examples.h"
4*c8dee2aaSAndroid Build Coastguard Worker REG_FIDDLE(Path_IsCubicDegenerate, 256, 256, true, 0) {
draw(SkCanvas * canvas)5*c8dee2aaSAndroid Build Coastguard Worker void draw(SkCanvas* canvas) {
6*c8dee2aaSAndroid Build Coastguard Worker     SkPoint points[] = {{1, 0}, {0, 0}, {0, 0}, {0, 0}};
7*c8dee2aaSAndroid Build Coastguard Worker     SkScalar step = 1;
8*c8dee2aaSAndroid Build Coastguard Worker     SkScalar prior, length = 0, degenerate = 0;
9*c8dee2aaSAndroid Build Coastguard Worker     do {
10*c8dee2aaSAndroid Build Coastguard Worker         prior = points[0].fX;
11*c8dee2aaSAndroid Build Coastguard Worker         step /= 2;
12*c8dee2aaSAndroid Build Coastguard Worker         if (SkPath::IsCubicDegenerate(points[0], points[1], points[2], points[3], false)) {
13*c8dee2aaSAndroid Build Coastguard Worker             degenerate = prior;
14*c8dee2aaSAndroid Build Coastguard Worker             points[0].fX += step;
15*c8dee2aaSAndroid Build Coastguard Worker         } else {
16*c8dee2aaSAndroid Build Coastguard Worker             length = prior;
17*c8dee2aaSAndroid Build Coastguard Worker             points[0].fX -= step;
18*c8dee2aaSAndroid Build Coastguard Worker         }
19*c8dee2aaSAndroid Build Coastguard Worker     } while (prior != points[0].fX);
20*c8dee2aaSAndroid Build Coastguard Worker     SkDebugf("%1.8g is degenerate\n", degenerate);
21*c8dee2aaSAndroid Build Coastguard Worker     SkDebugf("%1.8g is length\n", length);
22*c8dee2aaSAndroid Build Coastguard Worker }
23*c8dee2aaSAndroid Build Coastguard Worker }  // END FIDDLE
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