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root/cebix/BasiliskII/src/include/video.h
Revision: 1.13
Committed: 2002-01-15T14:58:41Z (22 years, 9 months ago) by cebix
Content type: text/plain
Branch: MAIN
CVS Tags: snapshot-15012002
Changes since 1.12: +1 -1 lines
Log Message:
- documentation updates
- 2001 -> 2002
- version 0.9 -> 1.0

File Contents

# User Rev Content
1 cebix 1.1 /*
2     * video.h - Video/graphics emulation
3     *
4 cebix 1.13 * Basilisk II (C) 1997-2002 Christian Bauer
5 cebix 1.1 *
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 cebix 1.6 #include <vector>
25    
26 cebix 1.10 #ifndef NO_STD_NAMESPACE
27     using std::vector;
28     #endif
29    
30 cebix 1.9 /*
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 cebix 1.6 // 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 cebix 1.1 };
57    
58 cebix 1.12 // 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 cebix 1.8 inline uint16 DepthToAppleMode(video_depth depth)
67     {
68 cebix 1.12 return apple_mode_for_depth[depth];
69 cebix 1.8 }
70    
71 cebix 1.6 inline bool IsDirectMode(video_depth depth)
72     {
73     return depth == VDEPTH_16BIT || depth == VDEPTH_32BIT;
74     }
75    
76 cebix 1.9 // Return the depth code that corresponds to the specified bits-per-pixel value
77 cebix 1.8 inline video_depth DepthModeForPixelDepth(int depth)
78 cebix 1.6 {
79 cebix 1.8 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 cebix 1.6 }
89 cebix 1.1
90 cebix 1.9 // Return a bytes-per-row value (assuming no padding) for the specified depth and pixel width
91 cebix 1.8 inline uint32 TrivialBytesPerRow(uint32 width, video_depth depth)
92 cebix 1.6 {
93 cebix 1.8 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 cebix 1.10 default: return width;
101 cebix 1.8 }
102 cebix 1.6 }
103    
104 cebix 1.9 /*
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 cebix 1.6 struct video_mode {
134 cebix 1.1 uint32 x; // X size of screen (pixels)
135     uint32 y; // Y size of screen (pixels)
136 cebix 1.6 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 cebix 1.10 extern vector<video_mode> VideoModes;
148 cebix 1.6
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 cebix 1.1 };
154    
155 cebix 1.9 // Description of the main (and currently the only) monitor, set by VideoInit()
156     extern monitor_desc VideoMonitor;
157 cebix 1.1
158 cebix 1.2 extern int16 VideoDriverOpen(uint32 pb, uint32 dce);
159     extern int16 VideoDriverControl(uint32 pb, uint32 dce);
160     extern int16 VideoDriverStatus(uint32 pb, uint32 dce);
161 cebix 1.1
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 cebix 1.4 extern void VideoRefresh(void);
170 cebix 1.1
171 cebix 1.9 // Called by the video driver to switch the video mode
172 cebix 1.7 extern void video_switch_to_mode(const video_mode &mode);
173 cebix 1.9
174     // Called by the video driver to set the color palette (in indexed modes)
175     // or gamma table (in direct modes)
176 cebix 1.11 extern void video_set_palette(uint8 *pal, int num);
177 cebix 1.12
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 cebix 1.1
187     #endif