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root/cebix/BasiliskII/src/include/video.h
Revision: 1.12
Committed: 2001-07-03T19:20:47Z (23 years, 4 months ago) by cebix
Content type: text/plain
Branch: MAIN
Changes since 1.11: +18 -11 lines
Log Message:
- improved compatibility of multiple depth/resolution handling with versions
  of MacOS before 7.6:
   - Apple mode IDs are now allocated contiguously from 0x80 (the video_*.cpp
     module must call video_init_depth_list() after adding all modes)
   - if the video driver didn't receive a GetVideoParameters call, it patches
     ScrnBase and the main GDevice upon a video mode switch (otherwise MacOS
     will continue to use the old frame buffer base)
   - the rowBytes values in the video parameters slot resources are correct
     for all bit depths

File Contents

# Content
1 /*
2 * video.h - Video/graphics emulation
3 *
4 * Basilisk II (C) 1997-2001 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 VIDEO_H
22 #define VIDEO_H
23
24 #include <vector>
25
26 #ifndef NO_STD_NAMESPACE
27 using std::vector;
28 #endif
29
30 /*
31 Some of the terminology here is completely frelled. In Basilisk II, a
32 "video mode" refers to a combination of resolution and color depth, and
33 this information is stored in a video_mode structure. In Apple
34 documentation, a "mode" historically refers to the color depth only
35 (because old Macs had fixed-frequency monitors and could not change the
36 resolution). These "modes" are assigned a number (0x80, 0x81, etc.),
37 which we here call "Apple mode". When Macs learned how to deal with
38 multiscan monitors, Apple introduced another type of "mode", also having
39 numbers starting from 0x80 but refrerring to the resolution and/or video
40 timing of the display (it's possible to have two modes with the same
41 dimension but different refresh rates). We call this a "resolution ID".
42 The combination of "Apple mode" and "ID" corresponds to a Basilisk II
43 "video mode". To make the confusion worse, the video driver control call
44 that sets the color depth is called "SetMode" while the one that sets
45 both depth and resolution is "SwitchMode"...
46 */
47
48 // Color depth codes
49 enum video_depth {
50 VDEPTH_1BIT, // 2 colors
51 VDEPTH_2BIT, // 4 colors
52 VDEPTH_4BIT, // 16 colors
53 VDEPTH_8BIT, // 256 colors
54 VDEPTH_16BIT, // "Thousands"
55 VDEPTH_32BIT // "Millions"
56 };
57
58 // For compatibility reasons with older (pre-Display Manager) versions of
59 // MacOS, the Apple modes must start at 0x80 and be contiguous. Therefore
60 // we construct an array to map the depth codes to the corresponding Apple
61 // mode. This array is initialized by video_init_depth_list() which must
62 // be called by the platform-dependant VideoInit() routine after filling
63 // the VideoModes array.
64 extern uint16 apple_mode_for_depth[6];
65
66 inline uint16 DepthToAppleMode(video_depth depth)
67 {
68 return apple_mode_for_depth[depth];
69 }
70
71 inline bool IsDirectMode(video_depth depth)
72 {
73 return depth == VDEPTH_16BIT || depth == VDEPTH_32BIT;
74 }
75
76 // Return the depth code that corresponds to the specified bits-per-pixel value
77 inline video_depth DepthModeForPixelDepth(int depth)
78 {
79 switch (depth) {
80 case 1: return VDEPTH_1BIT;
81 case 2: return VDEPTH_2BIT;
82 case 4: return VDEPTH_4BIT;
83 case 8: return VDEPTH_8BIT;
84 case 15: case 16: return VDEPTH_16BIT;
85 case 24: case 32: return VDEPTH_32BIT;
86 default: return VDEPTH_1BIT;
87 }
88 }
89
90 // Return a bytes-per-row value (assuming no padding) for the specified depth and pixel width
91 inline uint32 TrivialBytesPerRow(uint32 width, video_depth depth)
92 {
93 switch (depth) {
94 case VDEPTH_1BIT: return width / 8;
95 case VDEPTH_2BIT: return width / 4;
96 case VDEPTH_4BIT: return width / 2;
97 case VDEPTH_8BIT: return width;
98 case VDEPTH_16BIT: return width * 2;
99 case VDEPTH_32BIT: return width * 4;
100 default: return width;
101 }
102 }
103
104 /*
105 You are not completely free in your selection of depth/resolution
106 combinations:
107 1) the lowest supported color depth must be available in all
108 resolutions
109 2) if one resolution provides a certain color depth, it must also
110 provide all lower supported depths
111
112 For example, it is possible to have this set of modes:
113 640x480 @ 8 bit
114 640x480 @ 32 bit
115 800x600 @ 8 bit
116 800x600 @ 32 bit
117 1024x768 @ 8 bit
118
119 But this is not possible (violates rule 1):
120 640x480 @ 8 bit
121 800x600 @ 8 bit
122 1024x768 @ 1 bit
123
124 And neither is this (violates rule 2, 640x480 @ 16 bit is missing):
125 640x480 @ 8 bit
126 640x480 @ 32 bit
127 800x600 @ 8 bit
128 800x600 @ 16 bit
129 1024x768 @ 8 bit
130 */
131
132 // Description of a video mode
133 struct video_mode {
134 uint32 x; // X size of screen (pixels)
135 uint32 y; // Y size of screen (pixels)
136 uint32 resolution_id; // Resolution ID (should be >= 0x80 and uniquely identify the sets of modes with the same X/Y size)
137 uint32 bytes_per_row; // Bytes per row of frame buffer
138 video_depth depth; // Color depth (see definitions above)
139 };
140
141 inline bool IsDirectMode(const video_mode &mode)
142 {
143 return IsDirectMode(mode.depth);
144 }
145
146 // List of all supported video modes
147 extern vector<video_mode> VideoModes;
148
149 // Description for one (possibly virtual) monitor
150 struct monitor_desc {
151 uint32 mac_frame_base; // Mac frame buffer address
152 video_mode mode; // Currently selected video mode description
153 };
154
155 // Description of the main (and currently the only) monitor, set by VideoInit()
156 extern monitor_desc VideoMonitor;
157
158 extern int16 VideoDriverOpen(uint32 pb, uint32 dce);
159 extern int16 VideoDriverControl(uint32 pb, uint32 dce);
160 extern int16 VideoDriverStatus(uint32 pb, uint32 dce);
161
162 // System specific and internal functions/data
163 extern bool VideoInit(bool classic);
164 extern void VideoExit(void);
165
166 extern void VideoQuitFullScreen(void);
167
168 extern void VideoInterrupt(void);
169 extern void VideoRefresh(void);
170
171 // Called by the video driver to switch the video mode
172 extern void video_switch_to_mode(const video_mode &mode);
173
174 // Called by the video driver to set the color palette (in indexed modes)
175 // or gamma table (in direct modes)
176 extern void video_set_palette(uint8 *pal, int num);
177
178 // Check whether a mode with the specified depth exists
179 extern bool video_has_depth(video_depth depth);
180
181 // Get bytes-per-row value for specified resolution/depth
182 extern uint32 video_bytes_per_row(video_depth depth, uint32 id);
183
184 // Initialize apple_mode_for_depth[] array from VideoModes list
185 extern void video_init_depth_list(void);
186
187 #endif