xref: /third_party/skia/gm/scaledstrokes.cpp (revision cb93a386) 
1/*
2 * Copyright 2015 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "gm/gm.h"
9#include "include/core/SkCanvas.h"
10#include "include/core/SkPaint.h"
11#include "include/core/SkPathBuilder.h"
12#include "include/core/SkRect.h"
13#include "include/core/SkScalar.h"
14#include "include/core/SkSize.h"
15#include "include/core/SkString.h"
16
17class ScaledStrokesGM : public skiagm::GM {
18public:
19    ScaledStrokesGM() {}
20
21protected:
22
23    SkString onShortName() override {
24        return SkString("scaledstrokes");
25    }
26
27    SkISize onISize() override {
28        return SkISize::Make(640, 320);
29    }
30
31    static void draw_path(SkScalar size, SkCanvas* canvas, SkPaint paint) {
32        SkScalar c = 0.551915024494f * size;
33        SkPathBuilder path;
34        path.moveTo(0.0f, size);
35        path.cubicTo(c, size, size, c, size, 0.0f);
36        path.cubicTo(size, -c, c, -size, 0.0f, -size);
37        path.cubicTo(-c, -size, -size, -c, -size, 0.0f);
38        path.cubicTo(-size, c, -c, size, 0.0f, size);
39        canvas->drawPath(path.detach(), paint);
40    }
41
42    void onDraw(SkCanvas* canvas) override {
43        SkPaint paint;
44        SkPath path;
45        paint.setStyle(SkPaint::Style::kStroke_Style);
46        canvas->translate(5.0f, 5.0f);
47        const SkScalar size = 60.0f;
48        for (int i = 0; i < 2; i++) {
49            paint.setAntiAlias(i == 1);
50            for (int j = 0; j < 4; j++) {
51                SkScalar scale = 4.0f - j;
52                paint.setStrokeWidth(4.0f / scale);
53                canvas->save();
54                canvas->translate(size / 2.0f, size / 2.0f);
55                canvas->scale(scale, scale);
56                draw_path(size / 2.0f / scale, canvas, paint);
57                canvas->restore();
58
59                canvas->save();
60                canvas->translate(size / 2.0f, 80.0f + size / 2.0f);
61                canvas->scale(scale, scale);
62                canvas->drawCircle(0.0f, 0.0f, size / 2.0f / scale, paint);
63                canvas->restore();
64
65                canvas->save();
66                canvas->translate(0.0f, 160.0f);
67                canvas->scale(scale, scale);
68                canvas->drawRect(SkRect::MakeXYWH(0.0f, 0.0f, size / scale, size / scale), paint);
69                canvas->restore();
70
71                canvas->save();
72                canvas->translate(0.0f, 240.0f);
73                canvas->scale(scale, scale);
74                canvas->drawLine(0.0f, 0.0f, size / scale, size / scale, paint);
75                canvas->restore();
76
77                canvas->translate(80.0f, 0.0f);
78            }
79        }
80
81    }
82
83private:
84    using INHERITED = GM;
85};
86
87DEF_GM( return new ScaledStrokesGM; )
88