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
|
/* libs/graphics/sgl/SkColor.cpp
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include "SkColor.h"
#include "SkColorPriv.h"
SkPMColor SkPreMultiplyARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
if (a != 255) {
#if 0
unsigned scale = SkAlpha255To256(a);
r = SkAlphaMul(r, scale);
g = SkAlphaMul(g, scale);
b = SkAlphaMul(b, scale);
#else
r = SkMulDiv255Round(r, a);
g = SkMulDiv255Round(g, a);
b = SkMulDiv255Round(b, a);
#endif
}
return SkPackARGB32(a, r, g, b);
}
SkPMColor SkPreMultiplyColor(SkColor c) {
unsigned a = SkColorGetA(c);
unsigned r = SkColorGetR(c);
unsigned g = SkColorGetG(c);
unsigned b = SkColorGetB(c);
return SkPreMultiplyARGB(a, r, g, b);
}
//////////////////////////////////////////////////////////////////////////////////////////////
static inline SkScalar ByteToScalar(U8CPU x) {
SkASSERT(x <= 255);
return SkIntToScalar(x) / 255;
}
static inline SkScalar ByteDivToScalar(int numer, U8CPU denom) {
// cast to keep the answer signed
return SkIntToScalar(numer) / (int)denom;
}
void SkRGBToHSV(U8CPU r, U8CPU g, U8CPU b, SkScalar hsv[3]) {
SkASSERT(hsv);
unsigned min = SkMin32(r, SkMin32(g, b));
unsigned max = SkMax32(r, SkMax32(g, b));
unsigned delta = max - min;
SkScalar v = ByteToScalar(max);
SkASSERT(v >= 0 && v <= SK_Scalar1);
if (0 == delta) { // we're a shade of gray
hsv[0] = 0;
hsv[1] = 0;
hsv[2] = v;
return;
}
SkScalar s = ByteDivToScalar(delta, max);
SkASSERT(s >= 0 && s <= SK_Scalar1);
SkScalar h;
if (r == max) {
h = ByteDivToScalar(g - b, delta);
} else if (g == max) {
h = SkIntToScalar(2) + ByteDivToScalar(b - r, delta);
} else { // b == max
h = SkIntToScalar(4) + ByteDivToScalar(r - g, delta);
}
h *= 60;
if (h < 0) {
h += SkIntToScalar(360);
}
SkASSERT(h >= 0 && h < SkIntToScalar(360));
hsv[0] = h;
hsv[1] = s;
hsv[2] = v;
}
static inline U8CPU UnitScalarToByte(SkScalar x) {
if (x < 0) {
return 0;
}
if (x >= SK_Scalar1) {
return 255;
}
return SkScalarToFixed(x) >> 8;
}
SkColor SkHSVToColor(U8CPU a, const SkScalar hsv[3]) {
SkASSERT(hsv);
U8CPU s = UnitScalarToByte(hsv[1]);
U8CPU v = UnitScalarToByte(hsv[2]);
if (0 == s) { // shade of gray
return SkColorSetARGB(a, v, v, v);
}
SkFixed hx = (hsv[0] < 0 || hsv[0] >= SkIntToScalar(360)) ? 0 : SkScalarToFixed(hsv[0]/60);
SkFixed f = hx & 0xFFFF;
unsigned v_scale = SkAlpha255To256(v);
unsigned p = SkAlphaMul(255 - s, v_scale);
unsigned q = SkAlphaMul(255 - (s * f >> 16), v_scale);
unsigned t = SkAlphaMul(255 - (s * (SK_Fixed1 - f) >> 16), v_scale);
unsigned r, g, b;
SkASSERT((unsigned)(hx >> 16) < 6);
switch (hx >> 16) {
case 0: r = v; g = t; b = p; break;
case 1: r = q; g = v; b = p; break;
case 2: r = p; g = v; b = t; break;
case 3: r = p; g = q; b = v; break;
case 4: r = t; g = p; b = v; break;
default: r = v; g = p; b = q; break;
}
return SkColorSetARGB(a, r, g, b);
}
|
