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 "SkAvoidXfermode.h"
9 #include "SkColorPriv.h"
10 #include "SkFlattenableBuffers.h"
11 #include "SkString.h"
12
SkAvoidXfermode(SkColor opColor,U8CPU tolerance,Mode mode)13 SkAvoidXfermode::SkAvoidXfermode(SkColor opColor, U8CPU tolerance, Mode mode) {
14 if (tolerance > 255) {
15 tolerance = 255;
16 }
17
18 fOpColor = opColor;
19 fDistMul = (256 << 14) / (tolerance + 1);
20 fMode = mode;
21 }
22
SkAvoidXfermode(SkFlattenableReadBuffer & buffer)23 SkAvoidXfermode::SkAvoidXfermode(SkFlattenableReadBuffer& buffer)
24 : INHERITED(buffer) {
25 fOpColor = buffer.readColor();
26 fDistMul = buffer.readUInt();
27 fMode = (Mode)buffer.readUInt();
28 }
29
flatten(SkFlattenableWriteBuffer & buffer) const30 void SkAvoidXfermode::flatten(SkFlattenableWriteBuffer& buffer) const {
31 this->INHERITED::flatten(buffer);
32
33 buffer.writeColor(fOpColor);
34 buffer.writeUInt(fDistMul);
35 buffer.writeUInt(fMode);
36 }
37
38 // returns 0..31
color_dist16(uint16_t c,unsigned r,unsigned g,unsigned b)39 static unsigned color_dist16(uint16_t c, unsigned r, unsigned g, unsigned b) {
40 SkASSERT(r <= SK_R16_MASK);
41 SkASSERT(g <= SK_G16_MASK);
42 SkASSERT(b <= SK_B16_MASK);
43
44 unsigned dr = SkAbs32(SkGetPackedR16(c) - r);
45 unsigned dg = SkAbs32(SkGetPackedG16(c) - g) >> (SK_G16_BITS - SK_R16_BITS);
46 unsigned db = SkAbs32(SkGetPackedB16(c) - b);
47
48 return SkMax32(dr, SkMax32(dg, db));
49 }
50
51 // returns 0..15
color_dist4444(uint16_t c,unsigned r,unsigned g,unsigned b)52 static unsigned color_dist4444(uint16_t c, unsigned r, unsigned g, unsigned b) {
53 SkASSERT(r <= 0xF);
54 SkASSERT(g <= 0xF);
55 SkASSERT(b <= 0xF);
56
57 unsigned dr = SkAbs32(SkGetPackedR4444(c) - r);
58 unsigned dg = SkAbs32(SkGetPackedG4444(c) - g);
59 unsigned db = SkAbs32(SkGetPackedB4444(c) - b);
60
61 return SkMax32(dr, SkMax32(dg, db));
62 }
63
64 // returns 0..255
color_dist32(SkPMColor c,U8CPU r,U8CPU g,U8CPU b)65 static unsigned color_dist32(SkPMColor c, U8CPU r, U8CPU g, U8CPU b) {
66 SkASSERT(r <= 0xFF);
67 SkASSERT(g <= 0xFF);
68 SkASSERT(b <= 0xFF);
69
70 unsigned dr = SkAbs32(SkGetPackedR32(c) - r);
71 unsigned dg = SkAbs32(SkGetPackedG32(c) - g);
72 unsigned db = SkAbs32(SkGetPackedB32(c) - b);
73
74 return SkMax32(dr, SkMax32(dg, db));
75 }
76
scale_dist_14(int dist,uint32_t mul,uint32_t sub)77 static int scale_dist_14(int dist, uint32_t mul, uint32_t sub) {
78 int tmp = dist * mul - sub;
79 int result = (tmp + (1 << 13)) >> 14;
80
81 return result;
82 }
83
Accurate255To256(unsigned x)84 static inline unsigned Accurate255To256(unsigned x) {
85 return x + (x >> 7);
86 }
87
xfer32(SkPMColor dst[],const SkPMColor src[],int count,const SkAlpha aa[]) const88 void SkAvoidXfermode::xfer32(SkPMColor dst[], const SkPMColor src[], int count,
89 const SkAlpha aa[]) const {
90 unsigned opR = SkColorGetR(fOpColor);
91 unsigned opG = SkColorGetG(fOpColor);
92 unsigned opB = SkColorGetB(fOpColor);
93 uint32_t mul = fDistMul;
94 uint32_t sub = (fDistMul - (1 << 14)) << 8;
95
96 int MAX, mask;
97
98 if (kTargetColor_Mode == fMode) {
99 mask = -1;
100 MAX = 255;
101 } else {
102 mask = 0;
103 MAX = 0;
104 }
105
106 for (int i = 0; i < count; i++) {
107 int d = color_dist32(dst[i], opR, opG, opB);
108 // now reverse d if we need to
109 d = MAX + (d ^ mask) - mask;
110 SkASSERT((unsigned)d <= 255);
111 d = Accurate255To256(d);
112
113 d = scale_dist_14(d, mul, sub);
114 SkASSERT(d <= 256);
115
116 if (d > 0) {
117 if (NULL != aa) {
118 d = SkAlphaMul(d, Accurate255To256(*aa++));
119 if (0 == d) {
120 continue;
121 }
122 }
123 dst[i] = SkFourByteInterp256(src[i], dst[i], d);
124 }
125 }
126 }
127
SkBlend3216(SkPMColor src,U16CPU dst,unsigned scale)128 static inline U16CPU SkBlend3216(SkPMColor src, U16CPU dst, unsigned scale) {
129 SkASSERT(scale <= 32);
130 scale <<= 3;
131
132 return SkPackRGB16( SkAlphaBlend(SkPacked32ToR16(src), SkGetPackedR16(dst), scale),
133 SkAlphaBlend(SkPacked32ToG16(src), SkGetPackedG16(dst), scale),
134 SkAlphaBlend(SkPacked32ToB16(src), SkGetPackedB16(dst), scale));
135 }
136
xfer16(uint16_t dst[],const SkPMColor src[],int count,const SkAlpha aa[]) const137 void SkAvoidXfermode::xfer16(uint16_t dst[], const SkPMColor src[], int count,
138 const SkAlpha aa[]) const {
139 unsigned opR = SkColorGetR(fOpColor) >> (8 - SK_R16_BITS);
140 unsigned opG = SkColorGetG(fOpColor) >> (8 - SK_G16_BITS);
141 unsigned opB = SkColorGetB(fOpColor) >> (8 - SK_R16_BITS);
142 uint32_t mul = fDistMul;
143 uint32_t sub = (fDistMul - (1 << 14)) << SK_R16_BITS;
144
145 int MAX, mask;
146
147 if (kTargetColor_Mode == fMode) {
148 mask = -1;
149 MAX = 31;
150 } else {
151 mask = 0;
152 MAX = 0;
153 }
154
155 for (int i = 0; i < count; i++) {
156 int d = color_dist16(dst[i], opR, opG, opB);
157 // now reverse d if we need to
158 d = MAX + (d ^ mask) - mask;
159 SkASSERT((unsigned)d <= 31);
160 // convert from 0..31 to 0..32
161 d += d >> 4;
162 d = scale_dist_14(d, mul, sub);
163 SkASSERT(d <= 32);
164
165 if (d > 0) {
166 if (NULL != aa) {
167 d = SkAlphaMul(d, Accurate255To256(*aa++));
168 if (0 == d) {
169 continue;
170 }
171 }
172 dst[i] = SkBlend3216(src[i], dst[i], d);
173 }
174 }
175 }
176
xfer4444(uint16_t dst[],const SkPMColor src[],int count,const SkAlpha aa[]) const177 void SkAvoidXfermode::xfer4444(uint16_t dst[], const SkPMColor src[], int count,
178 const SkAlpha aa[]) const {
179 unsigned opR = SkColorGetR(fOpColor) >> 4;
180 unsigned opG = SkColorGetG(fOpColor) >> 4;
181 unsigned opB = SkColorGetB(fOpColor) >> 4;
182 uint32_t mul = fDistMul;
183 uint32_t sub = (fDistMul - (1 << 14)) << 4;
184
185 int MAX, mask;
186
187 if (kTargetColor_Mode == fMode) {
188 mask = -1;
189 MAX = 15;
190 } else {
191 mask = 0;
192 MAX = 0;
193 }
194
195 for (int i = 0; i < count; i++) {
196 int d = color_dist4444(dst[i], opR, opG, opB);
197 // now reverse d if we need to
198 d = MAX + (d ^ mask) - mask;
199 SkASSERT((unsigned)d <= 15);
200 // convert from 0..15 to 0..16
201 d += d >> 3;
202 d = scale_dist_14(d, mul, sub);
203 SkASSERT(d <= 16);
204
205 if (d > 0) {
206 if (NULL != aa) {
207 d = SkAlphaMul(d, Accurate255To256(*aa++));
208 if (0 == d) {
209 continue;
210 }
211 }
212 dst[i] = SkBlend4444(SkPixel32ToPixel4444(src[i]), dst[i], d);
213 }
214 }
215 }
216
xferA8(SkAlpha dst[],const SkPMColor src[],int count,const SkAlpha aa[]) const217 void SkAvoidXfermode::xferA8(SkAlpha dst[], const SkPMColor src[], int count,
218 const SkAlpha aa[]) const {
219 // override in subclass
220 }
221
222 #ifdef SK_DEVELOPER
toString(SkString * str) const223 void SkAvoidXfermode::toString(SkString* str) const {
224 str->append("SkAvoidXfermode: opColor: ");
225 str->appendHex(fOpColor);
226 str->appendf("distMul: %d ", fDistMul);
227
228 static const char* gModeStrings[] = { "Avoid", "Target" };
229
230 str->appendf("mode: %s", gModeStrings[fMode]);
231 }
232 #endif
233