src/Unix/video_vosf.h

/*
 *  video_vosf.h - Video/graphics emulation, video on SEGV signals support
 *
 *  Basilisk II (C) 1997-2001 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_VOSF_H
#define VIDEO_VOSF_H

// Note: this file is #include'd in video_x.cpp
#ifdef ENABLE_VOSF

#include <fcntl.h>
#include <sys/mman.h>
#include "sigsegv.h"
#include "vm_alloc.h"

#ifdef ENABLE_MON
# include "mon.h"
#endif

// Variables for Video on SEGV support
static uint8 *the_host_buffer;                                          // Host frame buffer in VOSF mode
static uint32 the_buffer_size;                                          // Size of allocated the_buffer

struct ScreenPageInfo {
    int top, bottom;                    // Mapping between this virtual page and Mac scanlines
};

struct ScreenInfo {
    uintptr memBase;                    // Real start address 
    uintptr memStart;                   // Start address aligned to page boundary
    uintptr memEnd;                             // Address of one-past-the-end of the screen
    uint32 memLength;                   // Length of the memory addressed by the screen pages
    
    uint32 pageSize;                    // Size of a page
    int pageBits;                               // Shift count to get the page number
    uint32 pageCount;                   // Number of pages allocated to the screen
    
        bool dirty;                                     // Flag: set if the frame buffer was touched
    char * dirtyPages;                  // Table of flags set if page was altered
    ScreenPageInfo * pageInfo;  // Table of mappings page -> Mac scanlines
};

static ScreenInfo mainBuffer;

#define PFLAG_SET_VALUE                 0x00
#define PFLAG_CLEAR_VALUE               0x01
#define PFLAG_SET_VALUE_4               0x00000000
#define PFLAG_CLEAR_VALUE_4             0x01010101
#define PFLAG_SET(page)                 mainBuffer.dirtyPages[page] = PFLAG_SET_VALUE
#define PFLAG_CLEAR(page)               mainBuffer.dirtyPages[page] = PFLAG_CLEAR_VALUE
#define PFLAG_ISSET(page)               (mainBuffer.dirtyPages[page] == PFLAG_SET_VALUE)
#define PFLAG_ISCLEAR(page)             (mainBuffer.dirtyPages[page] != PFLAG_SET_VALUE)

#ifdef UNALIGNED_PROFITABLE
# define PFLAG_ISSET_4(page)    (*((uint32 *)(mainBuffer.dirtyPages + (page))) == PFLAG_SET_VALUE_4)
# define PFLAG_ISCLEAR_4(page)  (*((uint32 *)(mainBuffer.dirtyPages + (page))) == PFLAG_CLEAR_VALUE_4)
#else
# define PFLAG_ISSET_4(page) \
                PFLAG_ISSET(page  ) && PFLAG_ISSET(page+1) \
        &&      PFLAG_ISSET(page+2) && PFLAG_ISSET(page+3)
# define PFLAG_ISCLEAR_4(page) \
                PFLAG_ISCLEAR(page  ) && PFLAG_ISCLEAR(page+1) \
        &&      PFLAG_ISCLEAR(page+2) && PFLAG_ISCLEAR(page+3)
#endif

// Set the selected page range [ first_page, last_page [ into the SET state
#define PFLAG_SET_RANGE(first_page, last_page) \
        memset(mainBuffer.dirtyPages + (first_page), PFLAG_SET_VALUE, \
                (last_page) - (first_page))

// Set the selected page range [ first_page, last_page [ into the CLEAR state
#define PFLAG_CLEAR_RANGE(first_page, last_page) \
        memset(mainBuffer.dirtyPages + (first_page), PFLAG_CLEAR_VALUE, \
                (last_page) - (first_page))

#define PFLAG_SET_ALL do { \
        PFLAG_SET_RANGE(0, mainBuffer.pageCount); \
        mainBuffer.dirty = true; \
} while (0)

#define PFLAG_CLEAR_ALL do { \
        PFLAG_CLEAR_RANGE(0, mainBuffer.pageCount); \
        mainBuffer.dirty = false; \
} while (0)

// Set the following macro definition to 1 if your system
// provides a really fast strchr() implementation
//#define HAVE_FAST_STRCHR 0

static inline int find_next_page_set(int page)
{
#if HAVE_FAST_STRCHR
        char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_SET_VALUE);
        return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
#else
        while (PFLAG_ISCLEAR_4(page))
                page += 4;
        while (PFLAG_ISCLEAR(page))
                page++;
        return page;
#endif
}

static inline int find_next_page_clear(int page)
{
#if HAVE_FAST_STRCHR
        char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_CLEAR_VALUE);
        return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
#else
        while (PFLAG_ISSET_4(page))
                page += 4;
        while (PFLAG_ISSET(page))
                page++;
        return page;
#endif
}

static int zero_fd = -1;

#ifdef HAVE_PTHREADS
static pthread_mutex_t vosf_lock = PTHREAD_MUTEX_INITIALIZER;   // Mutex to protect frame buffer (dirtyPages in fact)
#define LOCK_VOSF pthread_mutex_lock(&vosf_lock);
#define UNLOCK_VOSF pthread_mutex_unlock(&vosf_lock);
#else
#define LOCK_VOSF
#define UNLOCK_VOSF
#endif

static int log_base_2(uint32 x)
{
        uint32 mask = 0x80000000;
        int l = 31;
        while (l >= 0 && (x & mask) == 0) {
                mask >>= 1;
                l--;
        }
        return l;
}


/*
 *  Initialize mainBuffer structure
 */

static bool video_init_buffer(void)
{
        if (use_vosf) {
                const uint32 page_size  = getpagesize();
                const uint32 page_mask  = page_size - 1;
                
                mainBuffer.memBase      = (uintptr) the_buffer;
                // Align the frame buffer on page boundary
                mainBuffer.memStart             = (uintptr)((((unsigned long) the_buffer) + page_mask) & ~page_mask);
                mainBuffer.memLength    = the_buffer_size;
                mainBuffer.memEnd       = mainBuffer.memStart + mainBuffer.memLength;

                mainBuffer.pageSize     = page_size;
                mainBuffer.pageCount    = (mainBuffer.memLength + page_mask)/mainBuffer.pageSize;
                mainBuffer.pageBits     = log_base_2(mainBuffer.pageSize);

                if (mainBuffer.dirtyPages) {
                        free(mainBuffer.dirtyPages);
                        mainBuffer.dirtyPages = NULL;
                }

                mainBuffer.dirtyPages = (char *) malloc(mainBuffer.pageCount + 2);

                if (mainBuffer.pageInfo) {
                        free(mainBuffer.pageInfo);
                        mainBuffer.pageInfo = NULL;
                }

                mainBuffer.pageInfo = (ScreenPageInfo *) malloc(mainBuffer.pageCount * sizeof(ScreenPageInfo));

                if ((mainBuffer.dirtyPages == 0) || (mainBuffer.pageInfo == 0))
                        return false;
                
                mainBuffer.dirty = false;

                PFLAG_CLEAR_ALL;
                // Safety net to insure the loops in the update routines will terminate
                // See a discussion in <video_vosf.h> for further details
                PFLAG_CLEAR(mainBuffer.pageCount);
                PFLAG_SET(mainBuffer.pageCount+1);

                uint32 a = 0;
                for (int i = 0; i < mainBuffer.pageCount; i++) {
                        int y1 = a / VideoMonitor.mode.bytes_per_row;
                        if (y1 >= VideoMonitor.mode.y)
                                y1 = VideoMonitor.mode.y - 1;

                        int y2 = (a + mainBuffer.pageSize) / VideoMonitor.mode.bytes_per_row;
                        if (y2 >= VideoMonitor.mode.y)
                                y2 = VideoMonitor.mode.y - 1;

                        mainBuffer.pageInfo[i].top = y1;
                        mainBuffer.pageInfo[i].bottom = y2;

                        a += mainBuffer.pageSize;
                        if (a > mainBuffer.memLength)
                                a = mainBuffer.memLength;
                }
                
                // We can now write-protect the frame buffer
                if (vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ) != 0)
                        return false;
        }
        return true;
}


/*
 *  Page-aligned memory allocation
 */

// Extend size to page boundary
static uint32 page_extend(uint32 size)
{
        const uint32 page_size = getpagesize();
        const uint32 page_mask = page_size - 1;
        return (size + page_mask) & ~page_mask;
}

// Screen fault handler
static bool screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction)
{
        D(bug("screen_fault_handler: ADDR=0x%08X from IP=0x%08X\n", fault_address, fault_instruction));
        const uintptr addr = (uintptr)fault_address;
        
        /* Someone attempted to write to the frame buffer. Make it writeable
         * now so that the data could actually be written. It will be made
         * read-only back in one of the screen update_*() functions.
         */
        if ((addr >= mainBuffer.memStart) && (addr < mainBuffer.memEnd)) {
                const int page  = (addr - mainBuffer.memStart) >> mainBuffer.pageBits;
                caddr_t page_ad = (caddr_t)(addr & -mainBuffer.pageSize);
                LOCK_VOSF;
                PFLAG_SET(page);
                vm_protect((char *)page_ad, mainBuffer.pageSize, VM_PAGE_READ | VM_PAGE_WRITE);
                mainBuffer.dirty = true;
                UNLOCK_VOSF;
                return true;
        }
        
        /* Otherwise, we don't know how to handle the fault, let it crash */
        fprintf(stderr, "do_handle_screen_fault: unhandled address 0x%08X", addr);
        if (fault_instruction != SIGSEGV_INVALID_PC)
                fprintf(stderr, " [IP=0x%08X]", fault_instruction);
        fprintf(stderr, "\n");
#if EMULATED_68K
        uaecptr nextpc;
        extern void m68k_dumpstate(uaecptr *nextpc);
        m68k_dumpstate(&nextpc);
#endif
#ifdef ENABLE_MON
        char *arg[4] = {"mon", "-m", "-r", NULL};
        mon(3, arg);
        QuitEmulator();
#endif
        return false;
}

/*
 *      Update display for Windowed mode and VOSF
 */

// From video_blit.cpp
extern void (*Screen_blit)(uint8 * dest, const uint8 * source, uint32 length);
extern bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order);

/*      How can we deal with array overrun conditions ?
        
        The state of the framebuffer pages that have been touched are maintained
        in the dirtyPages[] table. That table is (pageCount + 2) bytes long.

Terminology
        
        "Last Page" denotes the pageCount-nth page, i.e. dirtyPages[pageCount - 1].
        "CLEAR Page Guard" refers to the page following the Last Page but is always
        in the CLEAR state. "SET Page Guard" refers to the page following the CLEAR
        Page Guard but is always in the SET state.

Rough process
        
        The update routines must determine which pages have to be blitted to the
        screen. This job consists in finding the first_page that was touched.
        i.e. find the next page that is SET. Then, finding how many pages were
        touched starting from first_page. i.e. find the next page that is CLEAR.

There are two cases to check:

        - Last Page is CLEAR: find_next_page_set() will reach the SET Page Guard
        but it is beyond the valid pageCount value. Therefore, we exit from the
        update routine.
        
        - Last Page is SET: first_page equals (pageCount - 1) and
        find_next_page_clear() will reach the CLEAR Page Guard. We blit the last
        page to the screen. On the next iteration, page equals pageCount and
        find_next_page_set() will reach the SET Page Guard. We still safely exit
        from the update routine because the SET Page Guard position is greater
        than pageCount.
*/

static inline void update_display_window_vosf(void)
{
        int page = 0;
        for (;;) {
                const int first_page = find_next_page_set(page);
                if (first_page >= mainBuffer.pageCount)
                        break;

                page = find_next_page_clear(first_page);
                PFLAG_CLEAR_RANGE(first_page, page);

                // Make the dirty pages read-only again
                const int32 offset  = first_page << mainBuffer.pageBits;
                const uint32 length = (page - first_page) << mainBuffer.pageBits;
                vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
                
                // There is at least one line to update
                const int y1 = mainBuffer.pageInfo[first_page].top;
                const int y2 = mainBuffer.pageInfo[page - 1].bottom;
                const int height = y2 - y1 + 1;
                
                const int bytes_per_row = VideoMonitor.mode.bytes_per_row;
                const int bytes_per_pixel = VideoMonitor.mode.bytes_per_row / VideoMonitor.mode.x;
                int i = y1 * bytes_per_row, j;
                
                if (VideoMonitor.mode.depth == VDEPTH_1BIT) {

                        // Update the_host_buffer and copy of the_buffer
                        for (j = y1; j <= y2; j++) {
                                Screen_blit(the_host_buffer + i, the_buffer + i, VideoMonitor.mode.x >> 3);
                                i += bytes_per_row;
                        }

                } else {

                        // Update the_host_buffer and copy of the_buffer
                        for (j = y1; j <= y2; j++) {
                                Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * VideoMonitor.mode.x);
                                i += bytes_per_row;
                        }
                }

                if (have_shm)
                        XShmPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.mode.x, height, 0);
                else
                        XPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.mode.x, height);
        }

        mainBuffer.dirty = false;
}


/*
 *      Update display for DGA mode and VOSF
 *      (only in Direct Addressing mode)
 */

#if REAL_ADDRESSING || DIRECT_ADDRESSING
static inline void update_display_dga_vosf(void)
{
        int page = 0;
        for (;;) {
                const int first_page = find_next_page_set(page);
                if (first_page >= mainBuffer.pageCount)
                        break;

                page = find_next_page_clear(first_page);
                PFLAG_CLEAR_RANGE(first_page, page);

                // Make the dirty pages read-only again
                const int32 offset  = first_page << mainBuffer.pageBits;
                const uint32 length = (page - first_page) << mainBuffer.pageBits;
                vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
                
                // I am sure that y2 >= y1 and depth != 1
                const int y1 = mainBuffer.pageInfo[first_page].top;
                const int y2 = mainBuffer.pageInfo[page - 1].bottom;
                
                const int bytes_per_row = VideoMonitor.mode.bytes_per_row;
                const int bytes_per_pixel = VideoMonitor.mode.bytes_per_row / VideoMonitor.mode.x;
                int i, j;
                
                // Check for first column from left and first column
                // from right that have changed
                int x1 = VideoMonitor.mode.x * bytes_per_pixel - 1;
                for (j = y1; j <= y2; j++) {
                        uint8 * const p1 = &the_buffer[j * bytes_per_row];
                        uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
                        for (i = 0; i < x1; i++) {
                                if (p1[i] != p2[i]) {
                                        x1 = i;
                                        break;
                                }
                        }
                }
                x1 /= bytes_per_pixel;
                
                int x2 = x1 * bytes_per_pixel;
                for (j = y2; j >= y1; j--) {
                        uint8 * const p1 = &the_buffer[j * bytes_per_row];
                        uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
                        for (i = VideoMonitor.mode.x * bytes_per_pixel - 1; i > x2; i--) {
                                if (p1[i] != p2[i]) {
                                        x2 = i;
                                        break;
                                }
                        }
                }
                x2 /= bytes_per_pixel;
                
                // Update the_host_buffer and copy of the_buffer
                // There should be at least one pixel to copy
                const int width = x2 - x1 + 1;
                i = y1 * bytes_per_row + x1 * bytes_per_pixel;
                for (j = y1; j <= y2; j++) {
                        Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width);
                        memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width);
                        i += bytes_per_row;
                }
        }
        mainBuffer.dirty = false;
}
#endif

#endif /* ENABLE_VOSF */

#endif /* VIDEO_VOSF_H */
Revision:	1.19
Committed:	2001-06-28T21:20:00Z (23 years, 5 months ago) by cebix
Content type:	text/plain
Branch:	MAIN
Changes since 1.18:	+212 -1 lines
Log Message:	video_x.cpp supports resolution switching in windowed mode: the available resolutions are 512x384, 640x480, 800x600, 1024x768 and 1280x1024 (the prefs editor has to be updated to reflect this). The resolution selected in the prefs editor is used as the default, but it can be changed in the Monitors control panel. So far only tested with direct addressing.
#	User	Rev	Content
1	gbeauche	1.1	/*
2			* video_vosf.h - Video/graphics emulation, video on SEGV signals support
3			*
4	gbeauche	1.13	* Basilisk II (C) 1997-2001 Christian Bauer
5	gbeauche	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_VOSF_H
22			#define VIDEO_VOSF_H
23
24			// Note: this file is #include'd in video_x.cpp
25			#ifdef ENABLE_VOSF
26
27	cebix	1.19	#include <fcntl.h>
28			#include <sys/mman.h>
29			#include "sigsegv.h"
30			#include "vm_alloc.h"
31
32			#ifdef ENABLE_MON
33			# include "mon.h"
34			#endif
35
36			// Variables for Video on SEGV support
37			static uint8 *the_host_buffer; // Host frame buffer in VOSF mode
38			static uint32 the_buffer_size; // Size of allocated the_buffer
39
40			struct ScreenPageInfo {
41			int top, bottom; // Mapping between this virtual page and Mac scanlines
42			};
43
44			struct ScreenInfo {
45			uintptr memBase; // Real start address
46			uintptr memStart; // Start address aligned to page boundary
47			uintptr memEnd; // Address of one-past-the-end of the screen
48			uint32 memLength; // Length of the memory addressed by the screen pages
49
50			uint32 pageSize; // Size of a page
51			int pageBits; // Shift count to get the page number
52			uint32 pageCount; // Number of pages allocated to the screen
53
54			bool dirty; // Flag: set if the frame buffer was touched
55			char * dirtyPages; // Table of flags set if page was altered
56			ScreenPageInfo * pageInfo; // Table of mappings page -> Mac scanlines
57			};
58
59			static ScreenInfo mainBuffer;
60
61			#define PFLAG_SET_VALUE 0x00
62			#define PFLAG_CLEAR_VALUE 0x01
63			#define PFLAG_SET_VALUE_4 0x00000000
64			#define PFLAG_CLEAR_VALUE_4 0x01010101
65			#define PFLAG_SET(page) mainBuffer.dirtyPages[page] = PFLAG_SET_VALUE
66			#define PFLAG_CLEAR(page) mainBuffer.dirtyPages[page] = PFLAG_CLEAR_VALUE
67			#define PFLAG_ISSET(page) (mainBuffer.dirtyPages[page] == PFLAG_SET_VALUE)
68			#define PFLAG_ISCLEAR(page) (mainBuffer.dirtyPages[page] != PFLAG_SET_VALUE)
69
70			#ifdef UNALIGNED_PROFITABLE
71			# define PFLAG_ISSET_4(page) (((uint32 )(mainBuffer.dirtyPages + (page))) == PFLAG_SET_VALUE_4)
72			# define PFLAG_ISCLEAR_4(page) (((uint32 )(mainBuffer.dirtyPages + (page))) == PFLAG_CLEAR_VALUE_4)
73			#else
74			# define PFLAG_ISSET_4(page) \
75			PFLAG_ISSET(page ) && PFLAG_ISSET(page+1) \
76			&& PFLAG_ISSET(page+2) && PFLAG_ISSET(page+3)
77			# define PFLAG_ISCLEAR_4(page) \
78			PFLAG_ISCLEAR(page ) && PFLAG_ISCLEAR(page+1) \
79			&& PFLAG_ISCLEAR(page+2) && PFLAG_ISCLEAR(page+3)
80			#endif
81
82			// Set the selected page range [ first_page, last_page [ into the SET state
83			#define PFLAG_SET_RANGE(first_page, last_page) \
84			memset(mainBuffer.dirtyPages + (first_page), PFLAG_SET_VALUE, \
85			(last_page) - (first_page))
86
87			// Set the selected page range [ first_page, last_page [ into the CLEAR state
88			#define PFLAG_CLEAR_RANGE(first_page, last_page) \
89			memset(mainBuffer.dirtyPages + (first_page), PFLAG_CLEAR_VALUE, \
90			(last_page) - (first_page))
91
92			#define PFLAG_SET_ALL do { \
93			PFLAG_SET_RANGE(0, mainBuffer.pageCount); \
94			mainBuffer.dirty = true; \
95			} while (0)
96
97			#define PFLAG_CLEAR_ALL do { \
98			PFLAG_CLEAR_RANGE(0, mainBuffer.pageCount); \
99			mainBuffer.dirty = false; \
100			} while (0)
101
102			// Set the following macro definition to 1 if your system
103			// provides a really fast strchr() implementation
104			//#define HAVE_FAST_STRCHR 0
105
106			static inline int find_next_page_set(int page)
107			{
108			#if HAVE_FAST_STRCHR
109			char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_SET_VALUE);
110			return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
111			#else
112			while (PFLAG_ISCLEAR_4(page))
113			page += 4;
114			while (PFLAG_ISCLEAR(page))
115			page++;
116			return page;
117			#endif
118			}
119
120			static inline int find_next_page_clear(int page)
121			{
122			#if HAVE_FAST_STRCHR
123			char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_CLEAR_VALUE);
124			return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
125			#else
126			while (PFLAG_ISSET_4(page))
127			page += 4;
128			while (PFLAG_ISSET(page))
129			page++;
130			return page;
131			#endif
132			}
133
134			static int zero_fd = -1;
135
136			#ifdef HAVE_PTHREADS
137			static pthread_mutex_t vosf_lock = PTHREAD_MUTEX_INITIALIZER; // Mutex to protect frame buffer (dirtyPages in fact)
138			#define LOCK_VOSF pthread_mutex_lock(&vosf_lock);
139			#define UNLOCK_VOSF pthread_mutex_unlock(&vosf_lock);
140			#else
141			#define LOCK_VOSF
142			#define UNLOCK_VOSF
143			#endif
144
145			static int log_base_2(uint32 x)
146			{
147			uint32 mask = 0x80000000;
148			int l = 31;
149			while (l >= 0 && (x & mask) == 0) {
150			mask >>= 1;
151			l--;
152			}
153			return l;
154			}
155
156
157			/*
158			* Initialize mainBuffer structure
159			*/
160
161			static bool video_init_buffer(void)
162			{
163			if (use_vosf) {
164			const uint32 page_size = getpagesize();
165			const uint32 page_mask = page_size - 1;
166
167			mainBuffer.memBase = (uintptr) the_buffer;
168			// Align the frame buffer on page boundary
169			mainBuffer.memStart = (uintptr)((((unsigned long) the_buffer) + page_mask) & ~page_mask);
170			mainBuffer.memLength = the_buffer_size;
171			mainBuffer.memEnd = mainBuffer.memStart + mainBuffer.memLength;
172
173			mainBuffer.pageSize = page_size;
174			mainBuffer.pageCount = (mainBuffer.memLength + page_mask)/mainBuffer.pageSize;
175			mainBuffer.pageBits = log_base_2(mainBuffer.pageSize);
176
177			if (mainBuffer.dirtyPages) {
178			free(mainBuffer.dirtyPages);
179			mainBuffer.dirtyPages = NULL;
180			}
181
182			mainBuffer.dirtyPages = (char *) malloc(mainBuffer.pageCount + 2);
183
184			if (mainBuffer.pageInfo) {
185			free(mainBuffer.pageInfo);
186			mainBuffer.pageInfo = NULL;
187			}
188
189			mainBuffer.pageInfo = (ScreenPageInfo ) malloc(mainBuffer.pageCount sizeof(ScreenPageInfo));
190
191			if ((mainBuffer.dirtyPages == 0) \|\| (mainBuffer.pageInfo == 0))
192			return false;
193
194			mainBuffer.dirty = false;
195
196			PFLAG_CLEAR_ALL;
197			// Safety net to insure the loops in the update routines will terminate
198			// See a discussion in <video_vosf.h> for further details
199			PFLAG_CLEAR(mainBuffer.pageCount);
200			PFLAG_SET(mainBuffer.pageCount+1);
201
202			uint32 a = 0;
203			for (int i = 0; i < mainBuffer.pageCount; i++) {
204			int y1 = a / VideoMonitor.mode.bytes_per_row;
205			if (y1 >= VideoMonitor.mode.y)
206			y1 = VideoMonitor.mode.y - 1;
207
208			int y2 = (a + mainBuffer.pageSize) / VideoMonitor.mode.bytes_per_row;
209			if (y2 >= VideoMonitor.mode.y)
210			y2 = VideoMonitor.mode.y - 1;
211
212			mainBuffer.pageInfo[i].top = y1;
213			mainBuffer.pageInfo[i].bottom = y2;
214
215			a += mainBuffer.pageSize;
216			if (a > mainBuffer.memLength)
217			a = mainBuffer.memLength;
218			}
219
220			// We can now write-protect the frame buffer
221			if (vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ) != 0)
222			return false;
223			}
224			return true;
225			}
226
227
228	gbeauche	1.1	/*
229			* Page-aligned memory allocation
230			*/
231
232	gbeauche	1.17	// Extend size to page boundary
233			static uint32 page_extend(uint32 size)
234	gbeauche	1.1	{
235			const uint32 page_size = getpagesize();
236			const uint32 page_mask = page_size - 1;
237			return (size + page_mask) & ~page_mask;
238			}
239
240	gbeauche	1.16	// Screen fault handler
241			static bool screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction)
242	gbeauche	1.1	{
243	gbeauche	1.16	D(bug("screen_fault_handler: ADDR=0x%08X from IP=0x%08X\n", fault_address, fault_instruction));
244			const uintptr addr = (uintptr)fault_address;
245
246	gbeauche	1.11	/* Someone attempted to write to the frame buffer. Make it writeable
247			* now so that the data could actually be written. It will be made
248			* read-only back in one of the screen update_*() functions.
249			*/
250			if ((addr >= mainBuffer.memStart) && (addr < mainBuffer.memEnd)) {
251			const int page = (addr - mainBuffer.memStart) >> mainBuffer.pageBits;
252	gbeauche	1.17	caddr_t page_ad = (caddr_t)(addr & -mainBuffer.pageSize);
253	gbeauche	1.11	LOCK_VOSF;
254			PFLAG_SET(page);
255	gbeauche	1.17	vm_protect((char *)page_ad, mainBuffer.pageSize, VM_PAGE_READ \| VM_PAGE_WRITE);
256	gbeauche	1.13	mainBuffer.dirty = true;
257	gbeauche	1.11	UNLOCK_VOSF;
258	gbeauche	1.16	return true;
259	gbeauche	1.1	}
260
261	gbeauche	1.11	/* Otherwise, we don't know how to handle the fault, let it crash */
262			fprintf(stderr, "do_handle_screen_fault: unhandled address 0x%08X", addr);
263	gbeauche	1.16	if (fault_instruction != SIGSEGV_INVALID_PC)
264			fprintf(stderr, " [IP=0x%08X]", fault_instruction);
265	gbeauche	1.11	fprintf(stderr, "\n");
266	cebix	1.19	#if EMULATED_68K
267			uaecptr nextpc;
268			extern void m68k_dumpstate(uaecptr *nextpc);
269			m68k_dumpstate(&nextpc);
270			#endif
271			#ifdef ENABLE_MON
272			char *arg[4] = {"mon", "-m", "-r", NULL};
273			mon(3, arg);
274			QuitEmulator();
275			#endif
276	gbeauche	1.16	return false;
277	gbeauche	1.1	}
278
279			/*
280			* Update display for Windowed mode and VOSF
281			*/
282
283	gbeauche	1.13	// From video_blit.cpp
284			extern void (Screen_blit)(uint8 dest, const uint8 * source, uint32 length);
285			extern bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order);
286
287	gbeauche	1.12	/* How can we deal with array overrun conditions ?
288
289			The state of the framebuffer pages that have been touched are maintained
290			in the dirtyPages[] table. That table is (pageCount + 2) bytes long.
291
292			Terminology
293
294			"Last Page" denotes the pageCount-nth page, i.e. dirtyPages[pageCount - 1].
295			"CLEAR Page Guard" refers to the page following the Last Page but is always
296			in the CLEAR state. "SET Page Guard" refers to the page following the CLEAR
297			Page Guard but is always in the SET state.
298
299			Rough process
300
301	gbeauche	1.13	The update routines must determine which pages have to be blitted to the
302	gbeauche	1.12	screen. This job consists in finding the first_page that was touched.
303			i.e. find the next page that is SET. Then, finding how many pages were
304			touched starting from first_page. i.e. find the next page that is CLEAR.
305
306	gbeauche	1.13	There are two cases to check:
307	gbeauche	1.12
308			- Last Page is CLEAR: find_next_page_set() will reach the SET Page Guard
309			but it is beyond the valid pageCount value. Therefore, we exit from the
310			update routine.
311
312			- Last Page is SET: first_page equals (pageCount - 1) and
313			find_next_page_clear() will reach the CLEAR Page Guard. We blit the last
314			page to the screen. On the next iteration, page equals pageCount and
315			find_next_page_set() will reach the SET Page Guard. We still safely exit
316			from the update routine because the SET Page Guard position is greater
317			than pageCount.
318			*/
319
320	gbeauche	1.1	static inline void update_display_window_vosf(void)
321			{
322			int page = 0;
323			for (;;) {
324	gbeauche	1.11	const int first_page = find_next_page_set(page);
325			if (first_page >= mainBuffer.pageCount)
326	gbeauche	1.1	break;
327	gbeauche	1.11
328			page = find_next_page_clear(first_page);
329			PFLAG_CLEAR_RANGE(first_page, page);
330	cebix	1.7
331	gbeauche	1.1	// Make the dirty pages read-only again
332			const int32 offset = first_page << mainBuffer.pageBits;
333			const uint32 length = (page - first_page) << mainBuffer.pageBits;
334	gbeauche	1.17	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
335	gbeauche	1.1
336			// There is at least one line to update
337			const int y1 = mainBuffer.pageInfo[first_page].top;
338			const int y2 = mainBuffer.pageInfo[page - 1].bottom;
339			const int height = y2 - y1 + 1;
340
341	cebix	1.18	const int bytes_per_row = VideoMonitor.mode.bytes_per_row;
342			const int bytes_per_pixel = VideoMonitor.mode.bytes_per_row / VideoMonitor.mode.x;
343	cebix	1.15	int i = y1 * bytes_per_row, j;
344	gbeauche	1.1
345	cebix	1.19	if (VideoMonitor.mode.depth == VDEPTH_1BIT) {
346	cebix	1.6
347			// Update the_host_buffer and copy of the_buffer
348			for (j = y1; j <= y2; j++) {
349	cebix	1.18	Screen_blit(the_host_buffer + i, the_buffer + i, VideoMonitor.mode.x >> 3);
350	cebix	1.6	i += bytes_per_row;
351			}
352
353			} else {
354
355			// Update the_host_buffer and copy of the_buffer
356			for (j = y1; j <= y2; j++) {
357	cebix	1.18	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * VideoMonitor.mode.x);
358	cebix	1.6	i += bytes_per_row;
359			}
360	gbeauche	1.1	}
361	cebix	1.15
362	gbeauche	1.1	if (have_shm)
363	cebix	1.18	XShmPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.mode.x, height, 0);
364	gbeauche	1.1	else
365	cebix	1.18	XPutImage(x_display, the_win, the_gc, img, 0, y1, 0, y1, VideoMonitor.mode.x, height);
366	gbeauche	1.1	}
367	cebix	1.15
368	gbeauche	1.13	mainBuffer.dirty = false;
369	gbeauche	1.1	}
370
371
372			/*
373			* Update display for DGA mode and VOSF
374			* (only in Direct Addressing mode)
375			*/
376
377			#if REAL_ADDRESSING \|\| DIRECT_ADDRESSING
378			static inline void update_display_dga_vosf(void)
379			{
380			int page = 0;
381			for (;;) {
382	gbeauche	1.11	const int first_page = find_next_page_set(page);
383			if (first_page >= mainBuffer.pageCount)
384	gbeauche	1.1	break;
385	gbeauche	1.11
386			page = find_next_page_clear(first_page);
387			PFLAG_CLEAR_RANGE(first_page, page);
388
389	gbeauche	1.1	// Make the dirty pages read-only again
390			const int32 offset = first_page << mainBuffer.pageBits;
391			const uint32 length = (page - first_page) << mainBuffer.pageBits;
392	gbeauche	1.17	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
393	gbeauche	1.1
394			// I am sure that y2 >= y1 and depth != 1
395			const int y1 = mainBuffer.pageInfo[first_page].top;
396			const int y2 = mainBuffer.pageInfo[page - 1].bottom;
397
398	cebix	1.18	const int bytes_per_row = VideoMonitor.mode.bytes_per_row;
399			const int bytes_per_pixel = VideoMonitor.mode.bytes_per_row / VideoMonitor.mode.x;
400	gbeauche	1.1	int i, j;
401
402			// Check for first column from left and first column
403			// from right that have changed
404	cebix	1.18	int x1 = VideoMonitor.mode.x * bytes_per_pixel - 1;
405	gbeauche	1.1	for (j = y1; j <= y2; j++) {
406			uint8 * const p1 = &the_buffer[j * bytes_per_row];
407			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
408			for (i = 0; i < x1; i++) {
409			if (p1[i] != p2[i]) {
410			x1 = i;
411			break;
412			}
413			}
414			}
415			x1 /= bytes_per_pixel;
416
417			int x2 = x1 * bytes_per_pixel;
418			for (j = y2; j >= y1; j--) {
419			uint8 * const p1 = &the_buffer[j * bytes_per_row];
420			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
421	cebix	1.18	for (i = VideoMonitor.mode.x * bytes_per_pixel - 1; i > x2; i--) {
422	gbeauche	1.1	if (p1[i] != p2[i]) {
423			x2 = i;
424			break;
425			}
426			}
427			}
428			x2 /= bytes_per_pixel;
429
430			// Update the_host_buffer and copy of the_buffer
431			// There should be at least one pixel to copy
432			const int width = x2 - x1 + 1;
433			i = y1 * bytes_per_row + x1 * bytes_per_pixel;
434			for (j = y1; j <= y2; j++) {
435	gbeauche	1.13	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width);
436	gbeauche	1.1	memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width);
437			i += bytes_per_row;
438			}
439			}
440	gbeauche	1.13	mainBuffer.dirty = false;
441	gbeauche	1.1	}
442			#endif
443
444			#endif /* ENABLE_VOSF */
445
446			#endif /* VIDEO_VOSF_H */