aboutsummaryrefslogtreecommitdiffhomepage
path: root/tests/EmptyPathTest.cpp
blob: b126076fcb55c5788ab6f058a6ceec9f73d473e9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "Test.h"
#include "SkPath.h"
#include "SkCanvas.h"

static void appendStr(SkString* str, const SkPaint& paint) {
    str->appendf(" style[%d] cap[%d] join[%d] antialias[%d]",
                 paint.getStyle(), paint.getStrokeCap(),
                 paint.getStrokeJoin(), paint.isAntiAlias());
}

static void appendStr(SkString* str, const SkPath& path) {
    str->appendf(" filltype[%d] ptcount[%d]",
                 path.getFillType(), path.countPoints());
}

#define DIMENSION   32

static void drawAndTest(skiatest::Reporter* reporter, const SkPath& path,
                        const SkPaint& paint, bool shouldDraw) {
    SkBitmap bm;
    // explicitly specify a trim rowbytes, so we have no padding on each row
    bm.setConfig(SkBitmap::kARGB_8888_Config, DIMENSION, DIMENSION, DIMENSION*4);
    bm.allocPixels();
    bm.eraseColor(0);

    SkCanvas canvas(bm);
    SkPaint p(paint);
    p.setColor(SK_ColorWHITE);

    canvas.drawPath(path, p);

    size_t count = DIMENSION * DIMENSION;
    const SkPMColor* ptr = bm.getAddr32(0, 0);

    SkPMColor andValue = ~0;
    SkPMColor orValue = 0;
    for (size_t i = 0; i < count; ++i) {
        SkPMColor c = ptr[i];
        andValue &= c;
        orValue |= c;
    }

    // success means we drew everywhere or nowhere (depending on shouldDraw)
    bool success = shouldDraw ? (~0U == andValue) : (0 == orValue);

    if (!success) {
        SkString str;
        if (shouldDraw) {
            str.set("Path expected to draw everywhere, but didn't. ");
        } else {
            str.set("Path expected to draw nowhere, but did. ");
        }
        appendStr(&str, paint);
        appendStr(&str, path);
        reporter->report(str.c_str(), skiatest::Reporter::kFailed);

// uncomment this if you want to step in to see the failure
//        canvas.drawPath(path, p);
    }
}

static void iter_paint(skiatest::Reporter* reporter, const SkPath& path, bool shouldDraw) {
    static const SkPaint::Cap gCaps[] = {
        SkPaint::kButt_Cap,
        SkPaint::kRound_Cap,
        SkPaint::kSquare_Cap
    };
    static const SkPaint::Join gJoins[] = {
        SkPaint::kMiter_Join,
        SkPaint::kRound_Join,
        SkPaint::kBevel_Join
    };
    static const SkPaint::Style gStyles[] = {
        SkPaint::kFill_Style,
        SkPaint::kStroke_Style,
        SkPaint::kStrokeAndFill_Style
    };
    for (size_t cap = 0; cap < SK_ARRAY_COUNT(gCaps); ++cap) {
        for (size_t join = 0; join < SK_ARRAY_COUNT(gJoins); ++join) {
            for (size_t style = 0; style < SK_ARRAY_COUNT(gStyles); ++style) {
                SkPaint paint;
                paint.setStrokeWidth(SkIntToScalar(10));

                paint.setStrokeCap(gCaps[cap]);
                paint.setStrokeJoin(gJoins[join]);
                paint.setStyle(gStyles[style]);

                paint.setAntiAlias(false);
                drawAndTest(reporter, path, paint, shouldDraw);
                paint.setAntiAlias(true);
                drawAndTest(reporter, path, paint, shouldDraw);
            }
        }
    }
}

#define CX  (SkIntToScalar(DIMENSION) / 2)
#define CY  (SkIntToScalar(DIMENSION) / 2)

static void make_empty(SkPath* path) {}
static void make_M(SkPath* path) { path->moveTo(CX, CY); }
static void make_MM(SkPath* path) { path->moveTo(CX, CY); path->moveTo(CX, CY); }
static void make_MZM(SkPath* path) { path->moveTo(CX, CY); path->close(); path->moveTo(CX, CY); }
static void make_L(SkPath* path) { path->moveTo(CX, CY); path->lineTo(CX, CY); }
static void make_Q(SkPath* path) { path->moveTo(CX, CY); path->quadTo(CX, CY, CX, CY); }
static void make_C(SkPath* path) { path->moveTo(CX, CY); path->cubicTo(CX, CY, CX, CY, CX, CY); }

/*  Two invariants are tested: How does an empty/degenerate path draw?
 *  - if the path is drawn inverse, it should draw everywhere
 *  - if the path is drawn non-inverse, it should draw nowhere
 *
 *  Things to iterate on:
 *  - path (empty, degenerate line/quad/cubic w/ and w/o close
 *  - paint style
 *  - path filltype
 *  - path stroke variants (e.g. caps, joins, width)
 */
static void test_emptydrawing(skiatest::Reporter* reporter) {
    static void (*gMakeProc[])(SkPath*) = {
        make_empty, make_M, make_MM, make_MZM, make_L, make_Q, make_C
    };
    static SkPath::FillType gFills[] = {
        SkPath::kWinding_FillType,
        SkPath::kEvenOdd_FillType,
        SkPath::kInverseWinding_FillType,
        SkPath::kInverseEvenOdd_FillType
    };
    for (int doClose = 0; doClose < 2; ++doClose) {
        for  (size_t i = 0; i < SK_ARRAY_COUNT(gMakeProc); ++i) {
            SkPath path;
            gMakeProc[i](&path);
            if (doClose) {
                path.close();
            }
            for (size_t fill = 0; fill < SK_ARRAY_COUNT(gFills); ++fill) {
                path.setFillType(gFills[fill]);
                bool shouldDraw = path.isInverseFillType();
                iter_paint(reporter, path, shouldDraw);
            }
        }
    }
}

static void TestEmptyPath(skiatest::Reporter* reporter) {
    test_emptydrawing(reporter);
}

#include "TestClassDef.h"
DEFINE_TESTCLASS("EmptyPath", TestEmptyPathClass, TestEmptyPath)