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// HASH=5de2de0f00354e59074a9bb1a42d5a63
5REG_FIDDLE(Miter_Limit, 384, 170, false, 0) {
6void draw(SkCanvas* canvas) {
7    SkPoint pts[] = {{ 10, 50 }, { 110, 80 }, { 10, 110 }};
8    SkVector v[] = { pts[0] - pts[1], pts[2] - pts[1] };
9    SkScalar angle1 = SkScalarATan2(v[0].fY, v[0].fX);
10    SkScalar angle2 = SkScalarATan2(v[1].fY, v[1].fX);
11    const SkScalar strokeWidth = 20;
12    SkScalar miterLimit = 1 / SkScalarSin((angle2 - angle1) / 2);
13    SkScalar miterLength = strokeWidth * miterLimit;
14    SkPath path;
15    path.moveTo(pts[0]);
16    path.lineTo(pts[1]);
17    path.lineTo(pts[2]);
18    SkPaint paint;  // set to default kMiter_Join
19    paint.setAntiAlias(true);
20    paint.setStyle(SkPaint::kStroke_Style);
21    paint.setStrokeMiter(miterLimit);
22    paint.setStrokeWidth(strokeWidth);
23    canvas->drawPath(path, paint);
24    paint.setStrokeWidth(1);
25    canvas->drawLine(pts[1].fX - miterLength / 2, pts[1].fY + 50,
26                     pts[1].fX + miterLength / 2, pts[1].fY + 50, paint);
27    canvas->translate(200, 0);
28    miterLimit *= 0.99f;
29    paint.setStrokeMiter(miterLimit);
30    paint.setStrokeWidth(strokeWidth);
31    canvas->drawPath(path, paint);
32    paint.setStrokeWidth(1);
33    canvas->drawLine(pts[1].fX - miterLength / 2, pts[1].fY + 50,
34                     pts[1].fX + miterLength / 2, pts[1].fY + 50, paint);
35}
36}  // END FIDDLE
37