This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
/
SDL_blendline.c
258 lines (234 loc) · 7.38 KB
/
SDL_blendline.c
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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997-2009 Sam Lantinga
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Sam Lantinga
slouken@libsdl.org
*/
#include "SDL_config.h"
#include "SDL_draw.h"
static int
SDL_BlendLine_RGB555(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
unsigned inva = 0xff - a;
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_BLEND_RGB555);
break;
case SDL_BLENDMODE_ADD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_ADD_RGB555);
break;
case SDL_BLENDMODE_MOD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_MOD_RGB555);
break;
default:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_RGB555);
break;
}
return 0;
}
static int
SDL_BlendLine_RGB565(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
unsigned inva = 0xff - a;
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_BLEND_RGB565);
break;
case SDL_BLENDMODE_ADD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_ADD_RGB565);
break;
case SDL_BLENDMODE_MOD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_MOD_RGB565);
break;
default:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_RGB565);
break;
}
return 0;
}
static int
SDL_BlendLine_RGB888(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
unsigned inva = 0xff - a;
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_BLEND_RGB888);
break;
case SDL_BLENDMODE_ADD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_ADD_RGB888);
break;
case SDL_BLENDMODE_MOD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_MOD_RGB888);
break;
default:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_RGB888);
break;
}
return 0;
}
static int
SDL_BlendLine_ARGB8888(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
unsigned inva = 0xff - a;
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_BLEND_ARGB8888);
break;
case SDL_BLENDMODE_ADD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_ADD_ARGB8888);
break;
case SDL_BLENDMODE_MOD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_MOD_ARGB8888);
break;
default:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY_ARGB8888);
break;
}
return 0;
}
static int
SDL_BlendLine_RGB(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
SDL_PixelFormat *fmt = dst->format;
unsigned inva = 0xff - a;
switch (fmt->BytesPerPixel) {
case 2:
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY2_BLEND_RGB);
break;
case SDL_BLENDMODE_ADD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY2_ADD_RGB);
break;
case SDL_BLENDMODE_MOD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY2_MOD_RGB);
break;
default:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY2_RGB);
break;
}
return 0;
case 4:
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY4_BLEND_RGB);
break;
case SDL_BLENDMODE_ADD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY4_ADD_RGB);
break;
case SDL_BLENDMODE_MOD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY4_MOD_RGB);
break;
default:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY4_RGB);
break;
}
return 0;
default:
SDL_Unsupported();
return -1;
}
}
static int
SDL_BlendLine_RGBA(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
SDL_PixelFormat *fmt = dst->format;
unsigned inva = 0xff - a;
switch (fmt->BytesPerPixel) {
case 4:
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY4_BLEND_RGBA);
break;
case SDL_BLENDMODE_ADD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY4_ADD_RGBA);
break;
case SDL_BLENDMODE_MOD:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY4_MOD_RGBA);
break;
default:
DRAWLINE(x1, y1, x2, y2, DRAW_SETPIXELXY4_RGBA);
break;
}
return 0;
default:
SDL_Unsupported();
return -1;
}
}
int
SDL_BlendLine(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
SDL_PixelFormat *fmt = dst->format;
/* This function doesn't work on surfaces < 8 bpp */
if (dst->format->BitsPerPixel < 8) {
SDL_SetError("SDL_BlendLine(): Unsupported surface format");
return (-1);
}
/* Perform clipping */
/* FIXME
if (!SDL_IntersectRect(dstrect, &dst->clip_rect, dstrect)) {
return (0);
}
*/
if ((blendMode == SDL_BLENDMODE_BLEND)
|| (blendMode == SDL_BLENDMODE_ADD)) {
r = DRAW_MUL(r, a);
g = DRAW_MUL(g, a);
b = DRAW_MUL(b, a);
}
switch (fmt->BitsPerPixel) {
case 15:
switch (fmt->Rmask) {
case 0x7C00:
return SDL_BlendLine_RGB555(dst, x1, y1, x2, y2, blendMode, r, g,
b, a);
}
break;
case 16:
switch (fmt->Rmask) {
case 0xF800:
return SDL_BlendLine_RGB565(dst, x1, y1, x2, y2, blendMode, r, g,
b, a);
}
break;
case 32:
switch (fmt->Rmask) {
case 0x00FF0000:
if (!fmt->Amask) {
return SDL_BlendLine_RGB888(dst, x1, y1, x2, y2, blendMode, r,
g, b, a);
} else {
return SDL_BlendLine_ARGB8888(dst, x1, y1, x2, y2, blendMode,
r, g, b, a);
}
break;
}
default:
break;
}
if (!fmt->Amask) {
return SDL_BlendLine_RGB(dst, x1, y1, x2, y2, blendMode, r, g, b, a);
} else {
return SDL_BlendLine_RGBA(dst, x1, y1, x2, y2, blendMode, r, g, b, a);
}
}
/* vi: set ts=4 sw=4 expandtab: */