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root/cebix/BasiliskII/src/Unix/video_blit.h
Revision: 1.2
Committed: 2000-09-23T06:51:46Z (24 years, 1 month ago) by gbeauche
Content type: text/plain
Branch: MAIN
Changes since 1.1: +8 -0 lines
Log Message:
- added a condition if (depth <= 8) before copying more than two bytes

File Contents

# Content
1 /*
2 * video_blit.h - Video/graphics emulation, blitters
3 *
4 * Basilisk II (C) 1997-2000 Christian Bauer
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 #ifndef FB_BLIT_1
22 # error "Undefined 16-bit word blit function"
23 #endif
24
25 #ifndef FB_BLIT_2
26 # error "Undefined 32-bit word blit function"
27 #endif
28
29 #ifndef FB_DEPTH
30 # error "Undefined screen depth"
31 #endif
32
33 static void FB_FUNC_NAME(uint8 * dest, const uint8 * source, uint32 length)
34 {
35 #if FB_DEPTH <= 8
36 // Align source and dest to 16-bit word boundaries
37 if (FB_DEPTH <= 8 && ((unsigned long) source) & 1) {
38 *dest++ = *source++;
39 length -= 1;
40 }
41 #endif
42
43 // source and dest are mutually aligned
44 uint16 * swp = ((uint16 *)source);
45 uint16 * dwp = ((uint16 *) dest );
46
47 #if FB_DEPTH <= 8
48 if (length >= 2) {
49 #endif
50
51 #if FB_DEPTH <= 16
52 // Align source and dest to 32-bit word boundaries
53 if (((unsigned long) source) & 2) {
54 const uint16 val = *swp++;
55 FB_BLIT_1(*dwp++, val);
56 length -= 2;
57 }
58 #endif
59
60 // Blit 4-byte words
61 if (length >= 4) {
62 const int remainder = (length / 4) % 8;
63 uint32 * slp = (uint32 *)swp + remainder;
64 uint32 * dlp = (uint32 *)dwp + remainder;
65
66 int n = ((length / 4) + 7) / 8;
67 switch (remainder) {
68 case 0: do {
69 slp += 8; dlp += 8;
70 FB_BLIT_2(dlp[-8], slp[-8]);
71 case 7: FB_BLIT_2(dlp[-7], slp[-7]);
72 case 6: FB_BLIT_2(dlp[-6], slp[-6]);
73 case 5: FB_BLIT_2(dlp[-5], slp[-5]);
74 case 4: FB_BLIT_2(dlp[-4], slp[-4]);
75 case 3: FB_BLIT_2(dlp[-3], slp[-3]);
76 case 2: FB_BLIT_2(dlp[-2], slp[-2]);
77 case 1: FB_BLIT_2(dlp[-1], slp[-1]);
78 } while (--n > 0);
79 }
80 }
81
82 #if FB_DEPTH <= 16
83 // There might remain one word to blit
84 if (length & 2) {
85 uint16 * const s = (uint16 *)(((uint8 *)swp) + length - 2);
86 uint16 * const d = (uint16 *)(((uint8 *)dwp) + length - 2);
87 FB_BLIT_1(*d, *s);
88 }
89 #endif
90
91 #if FB_DEPTH <= 8
92 }
93 #endif
94 }
95
96 #undef FB_FUNC_NAME
97
98 #ifdef FB_BLIT_1
99 #undef FB_BLIT_1
100 #endif
101
102 #ifdef FB_BLIT_2
103 #undef FB_BLIT_2
104 #endif
105
106 #ifdef FB_DEPTH
107 #undef FB_DEPTH
108 #endif