1 /*
2 * Copyright 2005, Stephan Aßmus <superstippi@gmx.de>. All rights reserved.
3 * Distributed under the terms of the MIT License.
4 *
5 * DrawingMode implementing B_OP_ALPHA in "Constant Overlay" mode on B_RGBA32.
6 *
7 */
8
9 #ifndef DRAWING_MODE_ALPHA_CO_H
10 #define DRAWING_MODE_ALPHA_CO_H
11
12 #include "DrawingMode.h"
13
14 // BLEND_ALPHA_CO
15 #define BLEND_ALPHA_CO(d, r, g, b, a) \
16 { \
17 BLEND16(d, r, g, b, a); \
18 }
19
20 // ASSIGN_ALPHA_CO
21 #define ASSIGN_ALPHA_CO(d, r, g, b) \
22 { \
23 d[0] = (b); \
24 d[1] = (g); \
25 d[2] = (r); \
26 d[3] = 255; \
27 }
28
29 // blend_pixel_alpha_co
30 void
blend_pixel_alpha_co(int x,int y,const color_type & c,uint8 cover,agg_buffer * buffer,const PatternHandler * pattern)31 blend_pixel_alpha_co(int x, int y, const color_type& c, uint8 cover,
32 agg_buffer* buffer, const PatternHandler* pattern)
33 {
34 uint8* p = buffer->row_ptr(y) + (x << 2);
35 rgb_color color = pattern->ColorAt(x, y);
36 uint16 alpha = pattern->HighColor().alpha * cover;
37 if (alpha == 255 * 255) {
38 ASSIGN_ALPHA_CO(p, color.red, color.green, color.blue);
39 } else {
40 BLEND_ALPHA_CO(p, color.red, color.green, color.blue, alpha);
41 }
42 }
43
44 // blend_hline_alpha_co
45 void
blend_hline_alpha_co(int x,int y,unsigned len,const color_type & c,uint8 cover,agg_buffer * buffer,const PatternHandler * pattern)46 blend_hline_alpha_co(int x, int y, unsigned len,
47 const color_type& c, uint8 cover,
48 agg_buffer* buffer, const PatternHandler* pattern)
49 {
50 rgb_color color = pattern->HighColor();
51 uint16 alpha = color.alpha * cover;
52 if (alpha == 255*255) {
53 // cache the low and high color as 32bit values
54 // high color
55 uint32 vh;
56 uint8* p8 = (uint8*)&vh;
57 p8[0] = color.blue;
58 p8[1] = color.green;
59 p8[2] = color.red;
60 p8[3] = 255;
61 // low color
62 color = pattern->LowColor();
63 uint32 vl;
64 p8 = (uint8*)&vl;
65 p8[0] = color.blue;
66 p8[1] = color.green;
67 p8[2] = color.red;
68 p8[3] = 255;
69 // row offset as 32bit pointer
70 uint32* p32 = (uint32*)(buffer->row_ptr(y)) + x;
71 do {
72 if (pattern->IsHighColor(x, y))
73 *p32 = vh;
74 else
75 *p32 = vl;
76 p32++;
77 x++;
78 } while(--len);
79 } else {
80 uint8* p = buffer->row_ptr(y) + (x << 2);
81 do {
82 rgb_color color = pattern->ColorAt(x, y);
83 BLEND_ALPHA_CO(p, color.red, color.green, color.blue, alpha);
84 x++;
85 p += 4;
86 } while(--len);
87 }
88 }
89
90 // blend_solid_hspan_alpha_co
91 void
blend_solid_hspan_alpha_co(int x,int y,unsigned len,const color_type & c,const uint8 * covers,agg_buffer * buffer,const PatternHandler * pattern)92 blend_solid_hspan_alpha_co(int x, int y, unsigned len,
93 const color_type& c, const uint8* covers,
94 agg_buffer* buffer, const PatternHandler* pattern)
95 {
96 uint8* p = buffer->row_ptr(y) + (x << 2);
97 uint8 hAlpha = pattern->HighColor().alpha;
98 do {
99 rgb_color color = pattern->ColorAt(x, y);
100 uint16 alpha = hAlpha * *covers;
101 if (alpha) {
102 if (alpha == 255 * 255) {
103 ASSIGN_ALPHA_CO(p, color.red, color.green, color.blue);
104 } else {
105 BLEND_ALPHA_CO(p, color.red, color.green, color.blue, alpha);
106 }
107 }
108 covers++;
109 p += 4;
110 x++;
111 } while(--len);
112 }
113
114
115
116 // blend_solid_vspan_alpha_co
117 void
blend_solid_vspan_alpha_co(int x,int y,unsigned len,const color_type & c,const uint8 * covers,agg_buffer * buffer,const PatternHandler * pattern)118 blend_solid_vspan_alpha_co(int x, int y, unsigned len,
119 const color_type& c, const uint8* covers,
120 agg_buffer* buffer, const PatternHandler* pattern)
121 {
122 uint8* p = buffer->row_ptr(y) + (x << 2);
123 uint8 hAlpha = pattern->HighColor().alpha;
124 do {
125 rgb_color color = pattern->ColorAt(x, y);
126 uint16 alpha = hAlpha * *covers;
127 if (alpha) {
128 if (alpha == 255 * 255) {
129 ASSIGN_ALPHA_CO(p, color.red, color.green, color.blue);
130 } else {
131 BLEND_ALPHA_CO(p, color.red, color.green, color.blue, alpha);
132 }
133 }
134 covers++;
135 p += buffer->stride();
136 y++;
137 } while(--len);
138 }
139
140
141 // blend_color_hspan_alpha_co
142 void
blend_color_hspan_alpha_co(int x,int y,unsigned len,const color_type * colors,const uint8 * covers,uint8 cover,agg_buffer * buffer,const PatternHandler * pattern)143 blend_color_hspan_alpha_co(int x, int y, unsigned len,
144 const color_type* colors,
145 const uint8* covers, uint8 cover,
146 agg_buffer* buffer, const PatternHandler* pattern)
147 {
148 uint8* p = buffer->row_ptr(y) + (x << 2);
149 uint8 hAlpha = pattern->HighColor().alpha;
150 if (covers) {
151 // non-solid opacity
152 do {
153 uint16 alpha = hAlpha * colors->a * *covers / 255;
154 if (alpha) {
155 if (alpha == 255*255) {
156 ASSIGN_ALPHA_CO(p, colors->r, colors->g, colors->b);
157 } else {
158 BLEND_ALPHA_CO(p, colors->r, colors->g, colors->b, alpha);
159 }
160 }
161 covers++;
162 p += 4;
163 ++colors;
164 } while(--len);
165 } else {
166 // solid full opcacity
167 uint16 alpha = hAlpha * colors->a * cover / 255;
168 if (alpha == 255 * 255) {
169 do {
170 ASSIGN_ALPHA_CO(p, colors->r, colors->g, colors->b);
171 p += 4;
172 ++colors;
173 } while(--len);
174 // solid partial opacity
175 } else if (alpha) {
176 do {
177 BLEND_ALPHA_CO(p, colors->r, colors->g, colors->b, alpha);
178 p += 4;
179 ++colors;
180 } while(--len);
181 }
182 }
183 }
184
185 #endif // DRAWING_MODE_ALPHA_CO_H
186
187