src/include/video.h

/*
 *  video.h - Video/graphics emulation
 *
 *  Basilisk II (C) 1997-2002 Christian Bauer
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef VIDEO_H
#define VIDEO_H

#include <vector>

#ifndef NO_STD_NAMESPACE
using std::vector;
#endif

/*
   Some of the terminology here is completely frelled. In Basilisk II, a
   "video mode" refers to a combination of resolution and color depth, and
   this information is stored in a video_mode structure. In Apple
   documentation, a "mode" historically refers to the color depth only
   (because old Macs had fixed-frequency monitors and could not change the
   resolution). These "modes" are assigned a number (0x80, 0x81, etc.),
   which we here call "Apple mode". When Macs learned how to deal with
   multiscan monitors, Apple introduced another type of "mode", also having
   numbers starting from 0x80 but refrerring to the resolution and/or video
   timing of the display (it's possible to have two modes with the same
   dimension but different refresh rates). We call this a "resolution ID". 
   The combination of "Apple mode" and "ID" corresponds to a Basilisk II
   "video mode". To make the confusion worse, the video driver control call
   that sets the color depth is called "SetMode" while the one that sets
   both depth and resolution is "SwitchMode"...
*/

// Color depth codes
enum video_depth {
        VDEPTH_1BIT,  // 2 colors
        VDEPTH_2BIT,  // 4 colors
        VDEPTH_4BIT,  // 16 colors
        VDEPTH_8BIT,  // 256 colors
        VDEPTH_16BIT, // "Thousands"
        VDEPTH_32BIT  // "Millions"
};

// For compatibility reasons with older (pre-Display Manager) versions of
// MacOS, the Apple modes must start at 0x80 and be contiguous. Therefore
// we construct an array to map the depth codes to the corresponding Apple
// mode. This array is initialized by video_init_depth_list() which must
// be called by the platform-dependant VideoInit() routine after filling
// the VideoModes array.
extern uint16 apple_mode_for_depth[6];

inline uint16 DepthToAppleMode(video_depth depth)
{
        return apple_mode_for_depth[depth];
}

inline bool IsDirectMode(video_depth depth)
{
        return depth == VDEPTH_16BIT || depth == VDEPTH_32BIT;
}

// Return the depth code that corresponds to the specified bits-per-pixel value
inline video_depth DepthModeForPixelDepth(int depth)
{
        switch (depth) {
                case 1: return VDEPTH_1BIT;
                case 2: return VDEPTH_2BIT;
                case 4: return VDEPTH_4BIT;
                case 8: return VDEPTH_8BIT;
                case 15: case 16: return VDEPTH_16BIT;
                case 24: case 32: return VDEPTH_32BIT;
                default: return VDEPTH_1BIT;
        }
}

// Return a bytes-per-row value (assuming no padding) for the specified depth and pixel width
inline uint32 TrivialBytesPerRow(uint32 width, video_depth depth)
{
        switch (depth) {
                case VDEPTH_1BIT: return width / 8;
                case VDEPTH_2BIT: return width / 4;
                case VDEPTH_4BIT: return width / 2;
                case VDEPTH_8BIT: return width;
                case VDEPTH_16BIT: return width * 2;
                case VDEPTH_32BIT: return width * 4;
                default: return width;
        }
}

/*
   You are not completely free in your selection of depth/resolution
   combinations:
     1) the lowest supported color depth must be available in all
        resolutions
     2) if one resolution provides a certain color depth, it must also
        provide all lower supported depths

   For example, it is possible to have this set of modes:
     640x480 @ 8 bit
     640x480 @ 32 bit
     800x600 @ 8 bit
     800x600 @ 32 bit
     1024x768 @ 8 bit

   But this is not possible (violates rule 1):
     640x480 @ 8 bit
     800x600 @ 8 bit
     1024x768 @ 1 bit

   And neither is this (violates rule 2, 640x480 @ 16 bit is missing):
     640x480 @ 8 bit
     640x480 @ 32 bit
     800x600 @ 8 bit
     800x600 @ 16 bit
     1024x768 @ 8 bit
*/

// Description of a video mode
struct video_mode {
        uint32 x;                               // X size of screen (pixels)
        uint32 y;                               // Y size of screen (pixels)
        uint32 resolution_id;   // Resolution ID (should be >= 0x80 and uniquely identify the sets of modes with the same X/Y size)
        uint32 bytes_per_row;   // Bytes per row of frame buffer
        video_depth depth;              // Color depth (see definitions above)
};

inline bool IsDirectMode(const video_mode &mode)
{
        return IsDirectMode(mode.depth);
}

// List of all supported video modes
extern vector<video_mode> VideoModes;

// Description for one (possibly virtual) monitor
struct monitor_desc {
        uint32 mac_frame_base;  // Mac frame buffer address
        video_mode mode;                // Currently selected video mode description
};

// Description of the main (and currently the only) monitor, set by VideoInit()
extern monitor_desc VideoMonitor;

extern int16 VideoDriverOpen(uint32 pb, uint32 dce);
extern int16 VideoDriverControl(uint32 pb, uint32 dce);
extern int16 VideoDriverStatus(uint32 pb, uint32 dce);

// System specific and internal functions/data
extern bool VideoInit(bool classic);
extern void VideoExit(void);

extern void VideoQuitFullScreen(void);

extern void VideoInterrupt(void);
extern void VideoRefresh(void);

// Called by the video driver to switch the video mode
extern void video_switch_to_mode(const video_mode &mode);

// Called by the video driver to set the color palette (in indexed modes)
// or gamma table (in direct modes)
extern void video_set_palette(uint8 *pal, int num);

// Check whether a mode with the specified depth exists
extern bool video_has_depth(video_depth depth);

// Get bytes-per-row value for specified resolution/depth
extern uint32 video_bytes_per_row(video_depth depth, uint32 id);

// Initialize apple_mode_for_depth[] array from VideoModes list
extern void video_init_depth_list(void);

#endif
Revision:	1.13
Committed:	2002-01-15T14:58:41Z (22 years, 7 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
#	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