GrTestUtils.h revision 3f655f34a234aceaa0c2947ce999a2127c729dea 
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#ifndef GrTestUtils_DEFINED
9#define GrTestUtils_DEFINED
10
11#include "SkTypes.h"
12
13#ifdef GR_TEST_UTILS
14
15#include "GrColor.h"
16#include "SkRandom.h"
17
18class SkMatrix;
19struct SkRect;
20
21namespace GrTest {
22/**
23 * A helper for use in Test functions.
24 */
25const SkMatrix& TestMatrix(SkRandom*);
26const SkRect& TestRect(SkRandom*);
27
28}
29
30static inline GrColor GrRandomColor(SkRandom* random) {
31    // There are only a few cases of random colors which interest us
32    enum ColorMode {
33        kAllOnes_ColorMode,
34        kAllZeros_ColorMode,
35        kAlphaOne_ColorMode,
36        kRandom_ColorMode,
37        kLast_ColorMode = kRandom_ColorMode
38    };
39
40    ColorMode colorMode = ColorMode(random->nextULessThan(kLast_ColorMode + 1));
41    GrColor color;
42    switch (colorMode) {
43        case kAllOnes_ColorMode:
44            color = GrColorPackRGBA(0xFF, 0xFF, 0xFF, 0xFF);
45            break;
46        case kAllZeros_ColorMode:
47            color = GrColorPackRGBA(0, 0, 0, 0);
48            break;
49        case kAlphaOne_ColorMode:
50            color = GrColorPackRGBA(random->nextULessThan(256),
51                                    random->nextULessThan(256),
52                                    random->nextULessThan(256),
53                                    0xFF);
54            break;
55        case kRandom_ColorMode: {
56                uint8_t alpha = random->nextULessThan(256);
57                color = GrColorPackRGBA(random->nextRangeU(0, alpha),
58                                        random->nextRangeU(0, alpha),
59                                        random->nextRangeU(0, alpha),
60                                        alpha);
61            break;
62        }
63    }
64    GrColorIsPMAssert(color);
65    return color;
66}
67
68static inline uint8_t GrRandomCoverage(SkRandom* random) {
69    enum CoverageMode {
70        kZero_CoverageMode,
71        kAllOnes_CoverageMode,
72        kRandom_CoverageMode,
73        kLast_CoverageMode = kRandom_CoverageMode
74    };
75
76    CoverageMode colorMode = CoverageMode(random->nextULessThan(kLast_CoverageMode + 1));
77    uint8_t coverage;
78    switch (colorMode) {
79        case kZero_CoverageMode:
80            coverage = 0;
81        case kAllOnes_CoverageMode:
82            coverage = 0xff;
83            break;
84        case kRandom_CoverageMode:
85            coverage = random->nextULessThan(256);
86            break;
87    }
88    return coverage;
89}
90
91#endif
92#endif
93