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

/*
 *  Page-aligned memory allocation
 */

// Align on page boundaries
static uintptr align_on_page_boundary(uintptr size)
{
        const uint32 page_size = getpagesize();
        const uint32 page_mask = page_size - 1;
        return (size + page_mask) & ~page_mask;
}

// Allocate memory on page boundary
static void * allocate_framebuffer(uint32 size, uint8 * hint = 0)
{
        // Remind that the system can allocate at 0x00000000...
        return mmap((caddr_t)hint, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, zero_fd, 0);
}


/*
 *      Screen fault handler
 */

const uintptr INVALID_PC = (uintptr)-1;

static inline void do_handle_screen_fault(uintptr addr, uintptr pc = INVALID_PC)
{
        /* 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 - 1));
                LOCK_VOSF;
                PFLAG_SET(page);
                mprotect(page_ad, mainBuffer.pageSize, PROT_READ | PROT_WRITE);
                mainBuffer.dirty = true;
                UNLOCK_VOSF;
                return;
        }
        
        /* 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 (pc != INVALID_PC)
                fprintf(stderr, " [IP=0x%08X]", pc);
        fprintf(stderr, "\n");
        
        signal(SIGSEGV, SIG_DFL);
}

#if defined(HAVE_SIGINFO_T)

static void Screen_fault_handler(int, siginfo_t * sip, void *)
{
        D(bug("Screen_fault_handler: ADDR=0x%08X\n", sip->si_addr));
        do_handle_screen_fault((uintptr)sip->si_addr);
}

#elif defined(HAVE_SIGCONTEXT_SUBTERFUGE)

# if defined(__i386__) && defined(__linux__)
static void Screen_fault_handler(int, struct sigcontext scs)
{
        D(bug("Screen_fault_handler: ADDR=0x%08X from IP=0x%08X\n", scs.cr2, scs.eip));
        do_handle_screen_fault((uintptr)scs.cr2, (uintptr)scs.eip);
}

# elif defined(__m68k__) && defined(__NetBSD__)

# include <m68k/frame.h>
static void Screen_fault_handler(int, int code, struct sigcontext *scp)
{
        D(bug("Screen_fault_handler: ADDR=0x%08X\n", code));
        struct sigstate {
                int ss_flags;
                struct frame ss_frame;
        };
        struct sigstate *state = (struct sigstate *)scp->sc_ap;
        uintptr fault_addr;
        switch (state->ss_frame.f_format) {
                case 7:         // 68040 access error
                        // "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown
                        fault_addr = state->ss_frame.f_fmt7.f_fa;
                        break;
                default:
                        fault_addr = (uintptr)code;
                        break;
        }
        do_handle_screen_fault(fault_addr);
}

# else
#  error "No suitable subterfuge for Video on SEGV signals"
# endif
#else
# error "Can't do Video on SEGV signals"
#endif


/*
 *      Screen fault handler initialization
 */

#if defined(HAVE_SIGINFO_T)
static bool Screen_fault_handler_init()
{
        // Setup SIGSEGV handler to process writes to frame buffer
        sigemptyset(&vosf_sa.sa_mask);
        vosf_sa.sa_sigaction = Screen_fault_handler;
        vosf_sa.sa_flags = SA_SIGINFO;
        return (sigaction(SIGSEGV, &vosf_sa, NULL) == 0);
}
#elif defined(HAVE_SIGCONTEXT_SUBTERFUGE)
static bool Screen_fault_handler_init()
{
        // Setup SIGSEGV handler to process writes to frame buffer
        sigemptyset(&vosf_sa.sa_mask);
        vosf_sa.sa_handler = (void (*)(int)) Screen_fault_handler;
#if !EMULATED_68K && defined(__NetBSD__)
        sigaddset(&vosf_sa.sa_mask, SIGALRM);
        vosf_sa.sa_flags = SA_ONSTACK;
#else
        vosf_sa.sa_flags = 0;
#endif
        return (sigaction(SIGSEGV, &vosf_sa, NULL) == 0);
}
#endif


/*
 *      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;
                mprotect((caddr_t)(mainBuffer.memStart + offset), length, PROT_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.bytes_per_row;
                const int bytes_per_pixel = VideoMonitor.bytes_per_row / VideoMonitor.x;
                int i, j;
                
                // Check for first column from left and first column
                // from right that have changed
                int x1, x2, width;
                if (depth == 1) {

                        x1 = VideoMonitor.x - 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>>3); i++) {
                                        if (p1[i] != p2[i]) {
                                                x1 = i << 3;
                                                break;
                                        }
                                }
                        }

                        x2 = x1;
                        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.x>>3) - 1; i > (x2>>3); i--) {
                                        if (p1[i] != p2[i]) {
                                                x2 = (i << 3) + 7;
                                                break;
                                        }
                                }
                        }
                        width = x2 - x1 + 1;

                        // Update the_host_buffer and copy of the_buffer
                        i = y1 * bytes_per_row + (x1 >> 3);
                        for (j = y1; j <= y2; j++) {
                                Screen_blit(the_host_buffer + i, the_buffer + i, width >> 3);
                                memcpy(the_buffer_copy + i, the_buffer + i, width >> 3);
                                i += bytes_per_row;
                        }

                } else {

                        x1 = VideoMonitor.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;
                
                        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.x * bytes_per_pixel - 1; i > x2; i--) {
                                        if (p1[i] != p2[i]) {
                                                x2 = i;
                                                break;
                                        }
                                }
                        }
                        x2 /= bytes_per_pixel;
                        width = x2 - x1 + 1;

                        // Update the_host_buffer and copy of the_buffer
                        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;
                        }
                }
                
                if (have_shm)
                        XShmPutImage(x_display, the_win, the_gc, img, x1, y1, x1, y1, width, height, 0);
                else
                        XPutImage(x_display, the_win, the_gc, img, x1, y1, x1, y1, width, 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;
                mprotect((caddr_t)(mainBuffer.memStart + offset), length, PROT_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.bytes_per_row;
                const int bytes_per_pixel = VideoMonitor.bytes_per_row / VideoMonitor.x;
                int i, j;
                
                // Check for first column from left and first column
                // from right that have changed
                int x1 = VideoMonitor.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.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:	1.13
Committed:	2001-01-28T14:05:19Z (23 years, 9 months ago) by gbeauche
Content type:	text/plain
Branch:	MAIN
Changes since 1.12:	+13 -198 lines
Log Message:	Mainly changes to the VOSF code: - improved blitters selection - improved blitters performance if UNALIGNED_PROFITABLE is set - cleaned up 8 bpp blitters
#	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			/*
28			* Page-aligned memory allocation
29			*/
30
31			// Align on page boundaries
32	gbeauche	1.4	static uintptr align_on_page_boundary(uintptr size)
33	gbeauche	1.1	{
34			const uint32 page_size = getpagesize();
35			const uint32 page_mask = page_size - 1;
36			return (size + page_mask) & ~page_mask;
37			}
38
39			// Allocate memory on page boundary
40			static void * allocate_framebuffer(uint32 size, uint8 * hint = 0)
41			{
42			// Remind that the system can allocate at 0x00000000...
43			return mmap((caddr_t)hint, size, PROT_READ \| PROT_WRITE, MAP_PRIVATE, zero_fd, 0);
44			}
45
46
47			/*
48			* Screen fault handler
49			*/
50
51	gbeauche	1.11	const uintptr INVALID_PC = (uintptr)-1;
52
53			static inline void do_handle_screen_fault(uintptr addr, uintptr pc = INVALID_PC)
54	gbeauche	1.1	{
55	gbeauche	1.11	/* Someone attempted to write to the frame buffer. Make it writeable
56			* now so that the data could actually be written. It will be made
57			* read-only back in one of the screen update_*() functions.
58			*/
59			if ((addr >= mainBuffer.memStart) && (addr < mainBuffer.memEnd)) {
60			const int page = (addr - mainBuffer.memStart) >> mainBuffer.pageBits;
61			caddr_t page_ad = (caddr_t)(addr & ~(mainBuffer.pageSize - 1));
62			LOCK_VOSF;
63			PFLAG_SET(page);
64			mprotect(page_ad, mainBuffer.pageSize, PROT_READ \| PROT_WRITE);
65	gbeauche	1.13	mainBuffer.dirty = true;
66	gbeauche	1.11	UNLOCK_VOSF;
67			return;
68	gbeauche	1.1	}
69
70	gbeauche	1.11	/* Otherwise, we don't know how to handle the fault, let it crash */
71			fprintf(stderr, "do_handle_screen_fault: unhandled address 0x%08X", addr);
72			if (pc != INVALID_PC)
73			fprintf(stderr, " [IP=0x%08X]", pc);
74			fprintf(stderr, "\n");
75
76			signal(SIGSEGV, SIG_DFL);
77	gbeauche	1.1	}
78
79			#if defined(HAVE_SIGINFO_T)
80	cebix	1.6
81	gbeauche	1.1	static void Screen_fault_handler(int, siginfo_t * sip, void *)
82			{
83			D(bug("Screen_fault_handler: ADDR=0x%08X\n", sip->si_addr));
84	gbeauche	1.4	do_handle_screen_fault((uintptr)sip->si_addr);
85	gbeauche	1.1	}
86	cebix	1.6
87	gbeauche	1.1	#elif defined(HAVE_SIGCONTEXT_SUBTERFUGE)
88	cebix	1.6
89	gbeauche	1.1	# if defined(__i386__) && defined(__linux__)
90			static void Screen_fault_handler(int, struct sigcontext scs)
91			{
92			D(bug("Screen_fault_handler: ADDR=0x%08X from IP=0x%08X\n", scs.cr2, scs.eip));
93	gbeauche	1.11	do_handle_screen_fault((uintptr)scs.cr2, (uintptr)scs.eip);
94	gbeauche	1.1	}
95	cebix	1.6
96			# elif defined(__m68k__) && defined(__NetBSD__)
97
98			# include <m68k/frame.h>
99			static void Screen_fault_handler(int, int code, struct sigcontext *scp)
100			{
101			D(bug("Screen_fault_handler: ADDR=0x%08X\n", code));
102			struct sigstate {
103			int ss_flags;
104			struct frame ss_frame;
105			};
106			struct sigstate state = (struct sigstate )scp->sc_ap;
107			uintptr fault_addr;
108			switch (state->ss_frame.f_format) {
109			case 7: // 68040 access error
110			// "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown
111			fault_addr = state->ss_frame.f_fmt7.f_fa;
112			break;
113			default:
114			fault_addr = (uintptr)code;
115			break;
116			}
117			do_handle_screen_fault(fault_addr);
118			}
119
120	gbeauche	1.1	# else
121			# error "No suitable subterfuge for Video on SEGV signals"
122			# endif
123			#else
124			# error "Can't do Video on SEGV signals"
125			#endif
126
127
128			/*
129			* Screen fault handler initialization
130			*/
131
132			#if defined(HAVE_SIGINFO_T)
133			static bool Screen_fault_handler_init()
134			{
135			// Setup SIGSEGV handler to process writes to frame buffer
136			sigemptyset(&vosf_sa.sa_mask);
137			vosf_sa.sa_sigaction = Screen_fault_handler;
138	cebix	1.5	vosf_sa.sa_flags = SA_SIGINFO;
139	gbeauche	1.1	return (sigaction(SIGSEGV, &vosf_sa, NULL) == 0);
140			}
141			#elif defined(HAVE_SIGCONTEXT_SUBTERFUGE)
142			static bool Screen_fault_handler_init()
143			{
144			// Setup SIGSEGV handler to process writes to frame buffer
145			sigemptyset(&vosf_sa.sa_mask);
146			vosf_sa.sa_handler = (void (*)(int)) Screen_fault_handler;
147	cebix	1.7	#if !EMULATED_68K && defined(__NetBSD__)
148			sigaddset(&vosf_sa.sa_mask, SIGALRM);
149			vosf_sa.sa_flags = SA_ONSTACK;
150			#else
151	gbeauche	1.1	vosf_sa.sa_flags = 0;
152	cebix	1.7	#endif
153	gbeauche	1.1	return (sigaction(SIGSEGV, &vosf_sa, NULL) == 0);
154			}
155			#endif
156
157
158			/*
159			* Update display for Windowed mode and VOSF
160			*/
161
162	gbeauche	1.13	// From video_blit.cpp
163			extern void (Screen_blit)(uint8 dest, const uint8 * source, uint32 length);
164			extern bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order);
165
166	gbeauche	1.12	/* How can we deal with array overrun conditions ?
167
168			The state of the framebuffer pages that have been touched are maintained
169			in the dirtyPages[] table. That table is (pageCount + 2) bytes long.
170
171			Terminology
172
173			"Last Page" denotes the pageCount-nth page, i.e. dirtyPages[pageCount - 1].
174			"CLEAR Page Guard" refers to the page following the Last Page but is always
175			in the CLEAR state. "SET Page Guard" refers to the page following the CLEAR
176			Page Guard but is always in the SET state.
177
178			Rough process
179
180	gbeauche	1.13	The update routines must determine which pages have to be blitted to the
181	gbeauche	1.12	screen. This job consists in finding the first_page that was touched.
182			i.e. find the next page that is SET. Then, finding how many pages were
183			touched starting from first_page. i.e. find the next page that is CLEAR.
184
185	gbeauche	1.13	There are two cases to check:
186	gbeauche	1.12
187			- Last Page is CLEAR: find_next_page_set() will reach the SET Page Guard
188			but it is beyond the valid pageCount value. Therefore, we exit from the
189			update routine.
190
191			- Last Page is SET: first_page equals (pageCount - 1) and
192			find_next_page_clear() will reach the CLEAR Page Guard. We blit the last
193			page to the screen. On the next iteration, page equals pageCount and
194			find_next_page_set() will reach the SET Page Guard. We still safely exit
195			from the update routine because the SET Page Guard position is greater
196			than pageCount.
197			*/
198
199	gbeauche	1.1	static inline void update_display_window_vosf(void)
200			{
201			int page = 0;
202			for (;;) {
203	gbeauche	1.11	const int first_page = find_next_page_set(page);
204			if (first_page >= mainBuffer.pageCount)
205	gbeauche	1.1	break;
206	gbeauche	1.11
207			page = find_next_page_clear(first_page);
208			PFLAG_CLEAR_RANGE(first_page, page);
209	cebix	1.7
210	gbeauche	1.1	// Make the dirty pages read-only again
211			const int32 offset = first_page << mainBuffer.pageBits;
212			const uint32 length = (page - first_page) << mainBuffer.pageBits;
213			mprotect((caddr_t)(mainBuffer.memStart + offset), length, PROT_READ);
214
215			// There is at least one line to update
216			const int y1 = mainBuffer.pageInfo[first_page].top;
217			const int y2 = mainBuffer.pageInfo[page - 1].bottom;
218			const int height = y2 - y1 + 1;
219
220			const int bytes_per_row = VideoMonitor.bytes_per_row;
221			const int bytes_per_pixel = VideoMonitor.bytes_per_row / VideoMonitor.x;
222			int i, j;
223
224			// Check for first column from left and first column
225			// from right that have changed
226	cebix	1.6	int x1, x2, width;
227			if (depth == 1) {
228
229			x1 = VideoMonitor.x - 1;
230			for (j = y1; j <= y2; j++) {
231			uint8 * const p1 = &the_buffer[j * bytes_per_row];
232			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
233			for (i = 0; i < (x1>>3); i++) {
234			if (p1[i] != p2[i]) {
235			x1 = i << 3;
236			break;
237			}
238	gbeauche	1.1	}
239			}
240	cebix	1.6
241			x2 = x1;
242			for (j = y2; j >= y1; j--) {
243			uint8 * const p1 = &the_buffer[j * bytes_per_row];
244			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
245			for (i = (VideoMonitor.x>>3) - 1; i > (x2>>3); i--) {
246			if (p1[i] != p2[i]) {
247	cebix	1.7	x2 = (i << 3) + 7;
248	cebix	1.6	break;
249			}
250			}
251			}
252			width = x2 - x1 + 1;
253
254			// Update the_host_buffer and copy of the_buffer
255			i = y1 * bytes_per_row + (x1 >> 3);
256			for (j = y1; j <= y2; j++) {
257	gbeauche	1.13	Screen_blit(the_host_buffer + i, the_buffer + i, width >> 3);
258	cebix	1.6	memcpy(the_buffer_copy + i, the_buffer + i, width >> 3);
259			i += bytes_per_row;
260			}
261
262			} else {
263
264			x1 = VideoMonitor.x * bytes_per_pixel - 1;
265			for (j = y1; j <= y2; j++) {
266			uint8 * const p1 = &the_buffer[j * bytes_per_row];
267			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
268			for (i = 0; i < x1; i++) {
269			if (p1[i] != p2[i]) {
270			x1 = i;
271			break;
272			}
273			}
274			}
275			x1 /= bytes_per_pixel;
276	gbeauche	1.1
277	cebix	1.6	x2 = x1 * bytes_per_pixel;
278			for (j = y2; j >= y1; j--) {
279			uint8 * const p1 = &the_buffer[j * bytes_per_row];
280			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
281			for (i = VideoMonitor.x * bytes_per_pixel - 1; i > x2; i--) {
282			if (p1[i] != p2[i]) {
283			x2 = i;
284			break;
285			}
286	gbeauche	1.1	}
287			}
288	cebix	1.6	x2 /= bytes_per_pixel;
289			width = x2 - x1 + 1;
290
291			// Update the_host_buffer and copy of the_buffer
292			i = y1 * bytes_per_row + x1 * bytes_per_pixel;
293			for (j = y1; j <= y2; j++) {
294	gbeauche	1.13	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width);
295	cebix	1.6	memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width);
296			i += bytes_per_row;
297			}
298	gbeauche	1.1	}
299
300			if (have_shm)
301			XShmPutImage(x_display, the_win, the_gc, img, x1, y1, x1, y1, width, height, 0);
302			else
303			XPutImage(x_display, the_win, the_gc, img, x1, y1, x1, y1, width, height);
304			}
305	gbeauche	1.13	mainBuffer.dirty = false;
306	gbeauche	1.1	}
307
308
309			/*
310			* Update display for DGA mode and VOSF
311			* (only in Direct Addressing mode)
312			*/
313
314			#if REAL_ADDRESSING \|\| DIRECT_ADDRESSING
315			static inline void update_display_dga_vosf(void)
316			{
317			int page = 0;
318			for (;;) {
319	gbeauche	1.11	const int first_page = find_next_page_set(page);
320			if (first_page >= mainBuffer.pageCount)
321	gbeauche	1.1	break;
322	gbeauche	1.11
323			page = find_next_page_clear(first_page);
324			PFLAG_CLEAR_RANGE(first_page, page);
325
326	gbeauche	1.1	// Make the dirty pages read-only again
327			const int32 offset = first_page << mainBuffer.pageBits;
328			const uint32 length = (page - first_page) << mainBuffer.pageBits;
329			mprotect((caddr_t)(mainBuffer.memStart + offset), length, PROT_READ);
330
331			// I am sure that y2 >= y1 and depth != 1
332			const int y1 = mainBuffer.pageInfo[first_page].top;
333			const int y2 = mainBuffer.pageInfo[page - 1].bottom;
334
335			const int bytes_per_row = VideoMonitor.bytes_per_row;
336			const int bytes_per_pixel = VideoMonitor.bytes_per_row / VideoMonitor.x;
337			int i, j;
338
339			// Check for first column from left and first column
340			// from right that have changed
341			int x1 = VideoMonitor.x * bytes_per_pixel - 1;
342			for (j = y1; j <= y2; j++) {
343			uint8 * const p1 = &the_buffer[j * bytes_per_row];
344			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
345			for (i = 0; i < x1; i++) {
346			if (p1[i] != p2[i]) {
347			x1 = i;
348			break;
349			}
350			}
351			}
352			x1 /= bytes_per_pixel;
353
354			int x2 = x1 * bytes_per_pixel;
355			for (j = y2; j >= y1; j--) {
356			uint8 * const p1 = &the_buffer[j * bytes_per_row];
357			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
358			for (i = VideoMonitor.x * bytes_per_pixel - 1; i > x2; i--) {
359			if (p1[i] != p2[i]) {
360			x2 = i;
361			break;
362			}
363			}
364			}
365			x2 /= bytes_per_pixel;
366
367			// Update the_host_buffer and copy of the_buffer
368			// There should be at least one pixel to copy
369			const int width = x2 - x1 + 1;
370			i = y1 * bytes_per_row + x1 * bytes_per_pixel;
371			for (j = y1; j <= y2; j++) {
372	gbeauche	1.13	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width);
373	gbeauche	1.1	memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width);
374			i += bytes_per_row;
375			}
376			}
377	gbeauche	1.13	mainBuffer.dirty = false;
378	gbeauche	1.1	}
379			#endif
380
381			#endif /* ENABLE_VOSF */
382
383			#endif /* VIDEO_VOSF_H */