1 /*
2 * Copyright 2011 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 "SkRandom.h"
9 #include "Test.h"
10 #include "gradients/SkClampRange.h"
11
12 static skiatest::Reporter* gReporter;
13 #define R_ASSERT(cond) if (!(cond)) { \
14 SkDebugf("%d: %s\n", __LINE__, #cond); \
15 REPORTER_ASSERT(gReporter, cond); \
16 }
17
18 // Arbitrary sentinel values outside [0, 0xFFFF].
19 static const int kV0 = -42, kV1 = -53, kRamp = -64;
20
check_value(int64_t bigfx,int expected)21 static void check_value(int64_t bigfx, int expected) {
22 if (bigfx < 0) {
23 R_ASSERT(expected == kV0);
24 } else if (bigfx > kFracMax_SkGradFixed) {
25 R_ASSERT(expected == kV1);
26 } else if (bigfx == kFracMax_SkGradFixed) {
27 // Either one is fine (and we do see both).
28 R_ASSERT(expected == kV1 || expected == kRamp);
29 } else {
30 R_ASSERT(expected == kRamp);
31 }
32 }
33
slow_check(const SkClampRange & range,const SkGradFixed fx,SkGradFixed dx,int count)34 static void slow_check(const SkClampRange& range,
35 const SkGradFixed fx, SkGradFixed dx, int count) {
36 SkASSERT(range.fCount0 + range.fCount1 + range.fCount2 == count);
37
38 // If dx is large, fx will overflow if updated naively. So we use more bits.
39 int64_t bigfx = fx;
40
41 for (int i = 0; i < range.fCount0; i++) {
42 check_value(bigfx, range.fV0);
43 bigfx += dx;
44 }
45
46 for (int i = 0; i < range.fCount1; i++) {
47 check_value(bigfx, kRamp);
48 bigfx += dx;
49 }
50
51 for (int i = 0; i < range.fCount2; i++) {
52 check_value(bigfx, range.fV1);
53 bigfx += dx;
54 }
55 }
56
57
test_range(SkFixed fx,SkFixed dx,int count)58 static void test_range(SkFixed fx, SkFixed dx, int count) {
59 const SkGradFixed gfx = SkFixedToGradFixed(fx);
60 const SkGradFixed gdx = SkFixedToGradFixed(dx);
61
62 SkClampRange range;
63 range.init(gfx, gdx, count, kV0, kV1);
64 slow_check(range, gfx, gdx, count);
65 }
66
67 #define ff(x) SkIntToFixed(x)
68
DEF_TEST(ClampRange,reporter)69 DEF_TEST(ClampRange, reporter) {
70 gReporter = reporter;
71
72 test_range(0, 0, 20);
73 test_range(0xFFFF, 0, 20);
74 test_range(-ff(2), 0, 20);
75 test_range( ff(2), 0, 20);
76
77 test_range(-10, 1, 20);
78 test_range(10, -1, 20);
79 test_range(-10, 3, 20);
80 test_range(10, -3, 20);
81
82 test_range(ff(1), ff(16384), 100);
83 test_range(ff(-1), ff(-16384), 100);
84 test_range(ff(1)/2, ff(16384), 100);
85 test_range(ff(1)/2, ff(-16384), 100);
86
87 SkRandom rand;
88
89 // test non-overflow cases
90 for (int i = 0; i < 1000000; i++) {
91 SkFixed fx = rand.nextS() >> 1;
92 SkFixed sx = rand.nextS() >> 1;
93 int count = rand.nextU() % 1000 + 1;
94 SkFixed dx = (sx - fx) / count;
95 test_range(fx, dx, count);
96 }
97
98 // TODO(reed): skia:2481, fix whatever bug this is, then uncomment
99 /*
100 // test overflow cases
101 for (int i = 0; i < 100000; i++) {
102 SkFixed fx = rand.nextS();
103 SkFixed dx = rand.nextS();
104 int count = rand.nextU() % 1000 + 1;
105 test_range(fx, dx, count);
106 }
107 */
108 }
109