1/*
2 * Copyright 2013 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.h"
9#include "SkCanvas.h"
10#include "SkPath.h"
11
12namespace skiagm {
13
14// This GM tests a grab-bag of non-closed paths. All these paths look like
15// closed rects, but they don't call path.close(). Depending on the stroke
16// settings these slightly different paths give widely different results.
17class NonClosedPathsGM: public GM {
18public:
19    NonClosedPathsGM() {}
20
21    enum ClosureType {
22        TotallyNonClosed,  // The last point doesn't coincide with the first one in the contour.
23                           // The path looks not closed at all.
24
25        FakeCloseCorner,   // The last point coincides with the first one at a corner.
26                           // The path looks closed, but final rendering has 2 ends with cap.
27
28        FakeCloseMiddle,   // The last point coincides with the first one in the middle of a line.
29                           // The path looks closed, and the final rendering looks closed too.
30
31        kClosureTypeCount
32    };
33
34protected:
35    virtual uint32_t onGetFlags() const SK_OVERRIDE {
36        return kSkipTiled_Flag;
37    }
38
39    virtual SkString onShortName() SK_OVERRIDE {
40        return SkString("nonclosedpaths");
41    }
42
43    // 12 * 18 + 3 cases, every case is 100 * 100 pixels.
44    virtual SkISize onISize() SK_OVERRIDE {
45        return SkISize::Make(1220, 1920);
46    }
47
48    // Use rect-like geometry for non-closed path, for right angles make it
49    // easier to show the visual difference of lineCap and lineJoin.
50    static void MakePath(SkPath* path, ClosureType type) {
51        if (FakeCloseMiddle == type) {
52            path->moveTo(30, 50);
53            path->lineTo(30, 30);
54        } else {
55            path->moveTo(30, 30);
56        }
57        path->lineTo(70, 30);
58        path->lineTo(70, 70);
59        path->lineTo(30, 70);
60        path->lineTo(30, 50);
61        if (FakeCloseCorner == type) {
62            path->lineTo(30, 30);
63        }
64    }
65
66    // Set the location for the current test on the canvas
67    static void SetLocation(SkCanvas* canvas, int counter, int lineNum) {
68        SkScalar x = SK_Scalar1 * 100 * (counter % lineNum) + 10 + SK_Scalar1 / 4;
69        SkScalar y = SK_Scalar1 * 100 * (counter / lineNum) + 10 + 3 * SK_Scalar1 / 4;
70        canvas->translate(x, y);
71    }
72
73    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
74        // Stroke widths are:
75        // 0(may use hairline rendering), 10(common case for stroke-style)
76        // 40 and 50(>= geometry width/height, make the contour filled in fact)
77        static const int kStrokeWidth[] = {0, 10, 40, 50};
78        int numWidths = SK_ARRAY_COUNT(kStrokeWidth);
79
80        static const SkPaint::Style kStyle[] = {
81            SkPaint::kStroke_Style, SkPaint::kStrokeAndFill_Style
82        };
83
84        static const SkPaint::Cap kCap[] = {
85            SkPaint::kButt_Cap, SkPaint::kRound_Cap, SkPaint::kSquare_Cap
86        };
87
88        static const SkPaint::Join kJoin[] = {
89            SkPaint::kMiter_Join, SkPaint::kRound_Join, SkPaint::kBevel_Join
90        };
91
92        static const ClosureType kType[] = {
93            TotallyNonClosed, FakeCloseCorner, FakeCloseMiddle
94        };
95
96        int counter = 0;
97        SkPaint paint;
98        paint.setAntiAlias(true);
99
100        // For stroke style painter and fill-and-stroke style painter
101        for (size_t type = 0; type < kClosureTypeCount; ++type) {
102            for (size_t style = 0; style < SK_ARRAY_COUNT(kStyle); ++style) {
103                for (size_t cap = 0; cap < SK_ARRAY_COUNT(kCap); ++cap) {
104                    for (size_t join = 0; join < SK_ARRAY_COUNT(kJoin); ++join) {
105                        for (int width = 0; width < numWidths; ++width) {
106                            canvas->save();
107                            SetLocation(canvas, counter, SkPaint::kJoinCount * numWidths);
108
109                            SkPath path;
110                            MakePath(&path, kType[type]);
111
112                            paint.setStyle(kStyle[style]);
113                            paint.setStrokeCap(kCap[cap]);
114                            paint.setStrokeJoin(kJoin[join]);
115                            paint.setStrokeWidth(SkIntToScalar(kStrokeWidth[width]));
116
117                            canvas->drawPath(path, paint);
118                            canvas->restore();
119                            ++counter;
120                        }
121                    }
122                }
123            }
124        }
125
126        // For fill style painter
127        paint.setStyle(SkPaint::kFill_Style);
128        for (size_t type = 0; type < kClosureTypeCount; ++type) {
129            canvas->save();
130            SetLocation(canvas, counter, SkPaint::kJoinCount * numWidths);
131
132            SkPath path;
133            MakePath(&path, kType[type]);
134
135            canvas->drawPath(path, paint);
136            canvas->restore();
137            ++counter;
138        }
139    }
140
141private:
142    typedef GM INHERITED;
143};
144
145//////////////////////////////////////////////////////////////////////////////
146
147DEF_GM(return new NonClosedPathsGM;)
148
149}
150