1 /*
2 * Copyright 2006 The Android Open Source Project
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 "SkColor.h"
9 #include "SkColorData.h"
10 #include "SkFixed.h"
11
SkPreMultiplyARGB(U8CPU a,U8CPU r,U8CPU g,U8CPU b)12 SkPMColor SkPreMultiplyARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
13 return SkPremultiplyARGBInline(a, r, g, b);
14 }
15
SkPreMultiplyColor(SkColor c)16 SkPMColor SkPreMultiplyColor(SkColor c) {
17 return SkPremultiplyARGBInline(SkColorGetA(c), SkColorGetR(c),
18 SkColorGetG(c), SkColorGetB(c));
19 }
20
21 ///////////////////////////////////////////////////////////////////////////////
22
ByteToScalar(U8CPU x)23 static inline SkScalar ByteToScalar(U8CPU x) {
24 SkASSERT(x <= 255);
25 return SkIntToScalar(x) / 255;
26 }
27
ByteDivToScalar(int numer,U8CPU denom)28 static inline SkScalar ByteDivToScalar(int numer, U8CPU denom) {
29 // cast to keep the answer signed
30 return SkIntToScalar(numer) / (int)denom;
31 }
32
SkRGBToHSV(U8CPU r,U8CPU g,U8CPU b,SkScalar hsv[3])33 void SkRGBToHSV(U8CPU r, U8CPU g, U8CPU b, SkScalar hsv[3]) {
34 SkASSERT(hsv);
35
36 unsigned min = SkMin32(r, SkMin32(g, b));
37 unsigned max = SkMax32(r, SkMax32(g, b));
38 unsigned delta = max - min;
39
40 SkScalar v = ByteToScalar(max);
41 SkASSERT(v >= 0 && v <= SK_Scalar1);
42
43 if (0 == delta) { // we're a shade of gray
44 hsv[0] = 0;
45 hsv[1] = 0;
46 hsv[2] = v;
47 return;
48 }
49
50 SkScalar s = ByteDivToScalar(delta, max);
51 SkASSERT(s >= 0 && s <= SK_Scalar1);
52
53 SkScalar h;
54 if (r == max) {
55 h = ByteDivToScalar(g - b, delta);
56 } else if (g == max) {
57 h = SkIntToScalar(2) + ByteDivToScalar(b - r, delta);
58 } else { // b == max
59 h = SkIntToScalar(4) + ByteDivToScalar(r - g, delta);
60 }
61
62 h *= 60;
63 if (h < 0) {
64 h += SkIntToScalar(360);
65 }
66 SkASSERT(h >= 0 && h < SkIntToScalar(360));
67
68 hsv[0] = h;
69 hsv[1] = s;
70 hsv[2] = v;
71 }
72
SkHSVToColor(U8CPU a,const SkScalar hsv[3])73 SkColor SkHSVToColor(U8CPU a, const SkScalar hsv[3]) {
74 SkASSERT(hsv);
75
76 SkScalar s = SkScalarPin(hsv[1], 0, 1);
77 SkScalar v = SkScalarPin(hsv[2], 0, 1);
78
79 U8CPU v_byte = SkScalarRoundToInt(v * 255);
80
81 if (SkScalarNearlyZero(s)) { // shade of gray
82 return SkColorSetARGB(a, v_byte, v_byte, v_byte);
83 }
84 SkScalar hx = (hsv[0] < 0 || hsv[0] >= SkIntToScalar(360)) ? 0 : hsv[0]/60;
85 SkScalar w = SkScalarFloorToScalar(hx);
86 SkScalar f = hx - w;
87
88 unsigned p = SkScalarRoundToInt((SK_Scalar1 - s) * v * 255);
89 unsigned q = SkScalarRoundToInt((SK_Scalar1 - (s * f)) * v * 255);
90 unsigned t = SkScalarRoundToInt((SK_Scalar1 - (s * (SK_Scalar1 - f))) * v * 255);
91
92 unsigned r, g, b;
93
94 SkASSERT((unsigned)(w) < 6);
95 switch ((unsigned)(w)) {
96 case 0: r = v_byte; g = t; b = p; break;
97 case 1: r = q; g = v_byte; b = p; break;
98 case 2: r = p; g = v_byte; b = t; break;
99 case 3: r = p; g = q; b = v_byte; break;
100 case 4: r = t; g = p; b = v_byte; break;
101 default: r = v_byte; g = p; b = q; break;
102 }
103 return SkColorSetARGB(a, r, g, b);
104 }
105
106 ///////////////////////////////////////////////////////////////////////////////////////////////////
107 #include "SkPM4fPriv.h"
108 #include "SkHalf.h"
109
FromPMColor(SkPMColor c)110 SkPM4f SkPM4f::FromPMColor(SkPMColor c) {
111 return From4f(swizzle_rb_if_bgra(Sk4f_fromL32(c)));
112 }
113
unpremul() const114 SkColor4f SkPM4f::unpremul() const {
115 float alpha = fVec[A];
116 if (0 == alpha) {
117 return { 0, 0, 0, 0 };
118 } else {
119 float invAlpha = 1 / alpha;
120 return { fVec[R] * invAlpha, fVec[G] * invAlpha, fVec[B] * invAlpha, alpha };
121 }
122 }
123
toF16(uint16_t half[4]) const124 void SkPM4f::toF16(uint16_t half[4]) const {
125 for (int i = 0; i < 4; ++i) {
126 half[i] = SkFloatToHalf(fVec[i]);
127 }
128 }
129
toF16() const130 uint64_t SkPM4f::toF16() const {
131 uint64_t value;
132 this->toF16(reinterpret_cast<uint16_t*>(&value));
133 return value;
134 }
135
FromF16(const uint16_t half[4])136 SkPM4f SkPM4f::FromF16(const uint16_t half[4]) {
137 return {{
138 SkHalfToFloat(half[0]),
139 SkHalfToFloat(half[1]),
140 SkHalfToFloat(half[2]),
141 SkHalfToFloat(half[3])
142 }};
143 }
144
145 #ifdef SK_DEBUG
assertIsUnit() const146 void SkPM4f::assertIsUnit() const {
147 auto c4 = Sk4f::Load(fVec);
148 SkASSERT((c4 >= Sk4f(0)).allTrue() && (c4 <= Sk4f(1)).allTrue());
149 }
150 #endif
151
152 ///////////////////////////////////////////////////////////////////////////////////////////////////
153
FromColor(SkColor bgra)154 SkColor4f SkColor4f::FromColor(SkColor bgra) {
155 SkColor4f rgba;
156 swizzle_rb(Sk4f_fromS32(bgra)).store(rgba.vec());
157 return rgba;
158 }
159
toSkColor() const160 SkColor SkColor4f::toSkColor() const {
161 return Sk4f_toS32(swizzle_rb(Sk4f::Load(this->vec())));
162 }
163
Pin(float r,float g,float b,float a)164 SkColor4f SkColor4f::Pin(float r, float g, float b, float a) {
165 SkColor4f c4;
166 Sk4f::Min(Sk4f::Max(Sk4f(r, g, b, a), Sk4f(0)), Sk4f(1)).store(c4.vec());
167 return c4;
168 }
169
premul() const170 SkPM4f SkColor4f::premul() const {
171 auto src = Sk4f::Load(this->pin().vec());
172 float srcAlpha = src[3]; // need the pinned version of our alpha
173 src = src * Sk4f(srcAlpha, srcAlpha, srcAlpha, 1);
174
175 return SkPM4f::From4f(src);
176 }
177