1
2 /*
3 * Copyright 2009 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10 #include "SkColorPriv.h"
11
12 /*
13 Filter_32_opaque
14
15 There is no hard-n-fast rule that the filtering must produce
16 exact results for the color components, but if the 4 incoming colors are
17 all opaque, then the output color must also be opaque. Subsequent parts of
18 the drawing pipeline may rely on this (e.g. which blitrow proc to use).
19 */
20
Filter_32_opaque(unsigned x,unsigned y,SkPMColor a00,SkPMColor a01,SkPMColor a10,SkPMColor a11,SkPMColor * dstColor)21 static inline void Filter_32_opaque(unsigned x, unsigned y,
22 SkPMColor a00, SkPMColor a01,
23 SkPMColor a10, SkPMColor a11,
24 SkPMColor* dstColor) {
25 SkASSERT((unsigned)x <= 0xF);
26 SkASSERT((unsigned)y <= 0xF);
27
28 int xy = x * y;
29 const uint32_t mask = 0xFF00FF;
30
31 int scale = 256 - 16*y - 16*x + xy;
32 uint32_t lo = (a00 & mask) * scale;
33 uint32_t hi = ((a00 >> 8) & mask) * scale;
34
35 scale = 16*x - xy;
36 lo += (a01 & mask) * scale;
37 hi += ((a01 >> 8) & mask) * scale;
38
39 scale = 16*y - xy;
40 lo += (a10 & mask) * scale;
41 hi += ((a10 >> 8) & mask) * scale;
42
43 lo += (a11 & mask) * xy;
44 hi += ((a11 >> 8) & mask) * xy;
45
46 *dstColor = ((lo >> 8) & mask) | (hi & ~mask);
47 }
48
Filter_32_alpha(unsigned x,unsigned y,SkPMColor a00,SkPMColor a01,SkPMColor a10,SkPMColor a11,SkPMColor * dstColor,unsigned alphaScale)49 static inline void Filter_32_alpha(unsigned x, unsigned y,
50 SkPMColor a00, SkPMColor a01,
51 SkPMColor a10, SkPMColor a11,
52 SkPMColor* dstColor,
53 unsigned alphaScale) {
54 SkASSERT((unsigned)x <= 0xF);
55 SkASSERT((unsigned)y <= 0xF);
56 SkASSERT(alphaScale <= 256);
57
58 int xy = x * y;
59 const uint32_t mask = 0xFF00FF;
60
61 int scale = 256 - 16*y - 16*x + xy;
62 uint32_t lo = (a00 & mask) * scale;
63 uint32_t hi = ((a00 >> 8) & mask) * scale;
64
65 scale = 16*x - xy;
66 lo += (a01 & mask) * scale;
67 hi += ((a01 >> 8) & mask) * scale;
68
69 scale = 16*y - xy;
70 lo += (a10 & mask) * scale;
71 hi += ((a10 >> 8) & mask) * scale;
72
73 lo += (a11 & mask) * xy;
74 hi += ((a11 >> 8) & mask) * xy;
75
76 lo = ((lo >> 8) & mask) * alphaScale;
77 hi = ((hi >> 8) & mask) * alphaScale;
78
79 *dstColor = ((lo >> 8) & mask) | (hi & ~mask);
80 }
81
82 // Two color version, where we filter only along 1 axis
Filter_32_opaque(unsigned t,SkPMColor color0,SkPMColor color1,SkPMColor * dstColor)83 static inline void Filter_32_opaque(unsigned t,
84 SkPMColor color0,
85 SkPMColor color1,
86 SkPMColor* dstColor) {
87 SkASSERT((unsigned)t <= 0xF);
88
89 const uint32_t mask = 0xFF00FF;
90
91 int scale = 256 - 16*t;
92 uint32_t lo = (color0 & mask) * scale;
93 uint32_t hi = ((color0 >> 8) & mask) * scale;
94
95 scale = 16*t;
96 lo += (color1 & mask) * scale;
97 hi += ((color1 >> 8) & mask) * scale;
98
99 *dstColor = ((lo >> 8) & mask) | (hi & ~mask);
100 }
101
102 // Two color version, where we filter only along 1 axis
Filter_32_alpha(unsigned t,SkPMColor color0,SkPMColor color1,SkPMColor * dstColor,unsigned alphaScale)103 static inline void Filter_32_alpha(unsigned t,
104 SkPMColor color0,
105 SkPMColor color1,
106 SkPMColor* dstColor,
107 unsigned alphaScale) {
108 SkASSERT((unsigned)t <= 0xF);
109 SkASSERT(alphaScale <= 256);
110
111 const uint32_t mask = 0xFF00FF;
112
113 int scale = 256 - 16*t;
114 uint32_t lo = (color0 & mask) * scale;
115 uint32_t hi = ((color0 >> 8) & mask) * scale;
116
117 scale = 16*t;
118 lo += (color1 & mask) * scale;
119 hi += ((color1 >> 8) & mask) * scale;
120
121 lo = ((lo >> 8) & mask) * alphaScale;
122 hi = ((hi >> 8) & mask) * alphaScale;
123
124 *dstColor = ((lo >> 8) & mask) | (hi & ~mask);
125 }
126