1 /*
2 * Copyright 2016 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 "Test.h"
9 #include "SkColor.h"
10 #include "SkHalf.h"
11 #include "SkOpts.h"
12 #include "SkPixmap.h"
13 #include "SkPM4f.h"
14 #include "SkRandom.h"
15
eq_within_half_float(float a,float b)16 static bool eq_within_half_float(float a, float b) {
17 const float kTolerance = 1.0f / (1 << (8 + 10));
18
19 SkHalf ha = SkFloatToHalf(a);
20 SkHalf hb = SkFloatToHalf(b);
21 float a2 = SkHalfToFloat(ha);
22 float b2 = SkHalfToFloat(hb);
23 return fabsf(a2 - b2) <= kTolerance;
24 }
25
eq_within_half_float(const SkPM4f & a,const SkPM4f & b)26 static bool eq_within_half_float(const SkPM4f& a, const SkPM4f& b) {
27 for (int i = 0; i < 4; ++i) {
28 if (!eq_within_half_float(a.fVec[i], b.fVec[i])) {
29 return false;
30 }
31 }
32 return true;
33 }
34
DEF_TEST(color_half_float,reporter)35 DEF_TEST(color_half_float, reporter) {
36 const int w = 100;
37 const int h = 100;
38
39 SkImageInfo info = SkImageInfo::Make(w, h, kRGBA_F16_SkColorType, kPremul_SkAlphaType);
40
41 SkAutoPixmapStorage pm;
42 pm.alloc(info);
43 REPORTER_ASSERT(reporter, pm.getSafeSize() == SkToSizeT(w * h * sizeof(uint64_t)));
44
45 SkColor4f c4 { 0.5f, 1, 0.5f, 0.25f };
46 pm.erase(c4);
47
48 SkPM4f origpm4 = c4.premul();
49 for (int y = 0; y < pm.height(); ++y) {
50 for (int x = 0; x < pm.width(); ++x) {
51 SkPM4f pm4 = SkPM4f::FromF16(pm.addrF16(x, y));
52 REPORTER_ASSERT(reporter, eq_within_half_float(origpm4, pm4));
53 }
54 }
55 }
56
DEF_TEST(float_to_half,reporter)57 DEF_TEST(float_to_half, reporter) {
58 const float fs[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0 };
59 const uint16_t hs[] = { 0x3c00, 0x4000, 0x4200, 0x4400, 0x4500, 0x4600, 0x4700 };
60
61 uint16_t hscratch[7];
62 SkOpts::float_to_half(hscratch, fs, 7);
63 REPORTER_ASSERT(reporter, 0 == memcmp(hscratch, hs, sizeof(hs)));
64
65 float fscratch[7];
66 SkOpts::half_to_float(fscratch, hs, 7);
67 REPORTER_ASSERT(reporter, 0 == memcmp(fscratch, fs, sizeof(fs)));
68 }
69
u(float f)70 static uint32_t u(float f) {
71 uint32_t x;
72 memcpy(&x, &f, 4);
73 return x;
74 }
75
DEF_TEST(HalfToFloat_01,r)76 DEF_TEST(HalfToFloat_01, r) {
77 for (uint16_t h = 0; h < 0x8000; h++) {
78 float f = SkHalfToFloat(h);
79 if (f >= 0 && f <= 1) {
80 float got = SkHalfToFloat_01(h)[0];
81 if (got != f) {
82 SkDebugf("0x%04x -> 0x%08x (%g), want 0x%08x (%g)\n",
83 h,
84 u(got), got,
85 u(f), f);
86 }
87 REPORTER_ASSERT(r, SkHalfToFloat_01(h)[0] == f);
88 REPORTER_ASSERT(r, SkFloatToHalf_01(SkHalfToFloat_01(h)) == h);
89 }
90 }
91 }
92
DEF_TEST(FloatToHalf_01,r)93 DEF_TEST(FloatToHalf_01, r) {
94 #if 0
95 for (uint32_t bits = 0; bits < 0x80000000; bits++) {
96 #else
97 SkRandom rand;
98 for (int i = 0; i < 1000000; i++) {
99 uint32_t bits = rand.nextU();
100 #endif
101 float f;
102 memcpy(&f, &bits, 4);
103 if (f >= 0 && f <= 1) {
104 uint16_t h1 = (uint16_t)SkFloatToHalf_01(Sk4f(f,0,0,0)),
105 h2 = SkFloatToHalf(f);
106 bool ok = (h1 == h2 || h1 == h2-1);
107 REPORTER_ASSERT(r, ok);
108 if (!ok) {
109 SkDebugf("%08x (%d) -> %04x (%d), want %04x (%d)\n",
110 bits, bits>>23, h1, h1>>10, h2, h2>>10);
111 break;
112 }
113 }
114 }
115 }
116