src/Unix/video_vosf.h

/*
 *  video_vosf.h - Video/graphics emulation, video on SEGV signals support
 *
 *  Basilisk II (C) 1997-2005 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 must be #include'd only in video_x.cpp
#ifdef ENABLE_VOSF

#include "sigsegv.h"
#include "vm_alloc.h"
#ifdef _WIN32
#include "util_windows.h"
#endif

// Glue for SDL and X11 support
#ifdef USE_SDL_VIDEO
#define MONITOR_INIT                    SDL_monitor_desc &monitor
#define VIDEO_DRV_WIN_INIT              driver_window *drv
#define VIDEO_DRV_DGA_INIT              driver_fullscreen *drv
#define VIDEO_DRV_LOCK_PIXELS   if (SDL_MUSTLOCK(drv->s)) SDL_LockSurface(drv->s)
#define VIDEO_DRV_UNLOCK_PIXELS if (SDL_MUSTLOCK(drv->s)) SDL_UnlockSurface(drv->s)
#define VIDEO_DRV_DEPTH                 drv->s->format->BitsPerPixel
#define VIDEO_DRV_WIDTH                 drv->s->w
#define VIDEO_DRV_HEIGHT                drv->s->h
#define VIDEO_DRV_ROW_BYTES             drv->s->pitch
#else
#ifdef SHEEPSHAVER
#define MONITOR_INIT                    /* nothing */
#define VIDEO_DRV_WIN_INIT              /* nothing */
#define VIDEO_DRV_DGA_INIT              /* nothing */
#define VIDEO_DRV_WINDOW                the_win
#define VIDEO_DRV_GC                    the_gc
#define VIDEO_DRV_IMAGE                 img
#define VIDEO_DRV_HAVE_SHM              have_shm
#else
#define MONITOR_INIT                    X11_monitor_desc &monitor
#define VIDEO_DRV_WIN_INIT              driver_window *drv
#define VIDEO_DRV_DGA_INIT              driver_dga *drv
#define VIDEO_DRV_WINDOW                drv->w
#define VIDEO_DRV_GC                    drv->gc
#define VIDEO_DRV_IMAGE                 drv->img
#define VIDEO_DRV_HAVE_SHM              drv->have_shm
#endif
#define VIDEO_DRV_LOCK_PIXELS   /* nothing */
#define VIDEO_DRV_UNLOCK_PIXELS /* nothing */
#define VIDEO_DRV_DEPTH                 VIDEO_DRV_IMAGE->depth
#define VIDEO_DRV_WIDTH                 VIDEO_DRV_IMAGE->width
#define VIDEO_DRV_HEIGHT                VIDEO_DRV_IMAGE->height
#define VIDEO_DRV_ROW_BYTES             VIDEO_DRV_IMAGE->bytes_per_line
#endif

// Variables for Video on SEGV support
static uint8 *the_host_buffer;  // Host frame buffer in VOSF mode

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

struct ScreenInfo {
    uintptr memStart;                   // Start address aligned to page boundary
    uint32 memLength;                   // Length of the memory addressed by the screen pages
    
    uintptr 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
        bool very_dirty;                        // Flag: set if the frame buffer was completely modified (e.g. colormap changes)
    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; \
        mainBuffer.very_dirty = false; \
} while (0)

#define PFLAG_SET_VERY_DIRTY do { \
        mainBuffer.very_dirty = true; \
} 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
}

#ifdef HAVE_SPINLOCKS
static spinlock_t vosf_lock = SPIN_LOCK_UNLOCKED;                               // Mutex to protect frame buffer (dirtyPages in fact)
#define LOCK_VOSF spin_lock(&vosf_lock)
#define UNLOCK_VOSF spin_unlock(&vosf_lock)
#elif defined(_WIN32)
static mutex_t vosf_lock;                                                                               // Mutex to protect frame buffer (dirtyPages in fact)
#define LOCK_VOSF vosf_lock.lock();
#define UNLOCK_VOSF vosf_lock.unlock();
#elif defined(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;
}

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


/*
 *  Check if VOSF acceleration is profitable on this platform
 */

const int VOSF_PROFITABLE_TRIES = 3;                    // Make 3 attempts for full screen update
const int VOSF_PROFITABLE_THRESHOLD = 16667;    // 60 Hz

static bool video_vosf_profitable(void)
{
        int64 durations[VOSF_PROFITABLE_TRIES];
        int mean_duration = 0;

        for (int i = 0; i < VOSF_PROFITABLE_TRIES; i++) {
                uint64 start = GetTicks_usec();
                for (int p = 0; p < mainBuffer.pageCount; p++) {
                        uint8 *addr = (uint8 *)(mainBuffer.memStart + (p * mainBuffer.pageSize));
                        addr[0] = 0; // Trigger Screen_fault_handler()
                }
                int64 duration = GetTicks_usec() - start;
                mean_duration += duration;
                durations[i] = duration;

                PFLAG_CLEAR_ALL;
                mainBuffer.dirty = false;
                if (vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ) != 0)
                        return false;
        }

        mean_duration /= VOSF_PROFITABLE_TRIES;
        D(bug("Triggered %d screen faults in %ld usec on average\n", mainBuffer.pageCount, mean_duration));
        return (mean_duration < (VOSF_PROFITABLE_THRESHOLD * (frame_skip ? frame_skip : 1)));
}


/*
 *  Initialize the VOSF system (mainBuffer structure, SIGSEGV handler)
 */

static bool video_vosf_init(MONITOR_INIT)
{
        VIDEO_MODE_INIT_MONITOR;

        const uintptr page_size = vm_get_page_size();
        const uintptr page_mask = page_size - 1;
        
        // Round up frame buffer base to page boundary
        mainBuffer.memStart = (((uintptr) the_buffer) + page_mask) & ~page_mask;
        
        // The frame buffer size shall already be aligned to page boundary (use page_extend)
        mainBuffer.memLength = the_buffer_size;
        
        mainBuffer.pageSize = page_size;
        mainBuffer.pageBits = log_base_2(mainBuffer.pageSize);
        mainBuffer.pageCount =  (mainBuffer.memLength + page_mask)/mainBuffer.pageSize;
        
        // The "2" more bytes requested are a safety net to insure the
        // loops in the update routines will terminate.
        // See "How can we deal with array overrun conditions ?" hereunder for further details.
        mainBuffer.dirtyPages = (char *) malloc(mainBuffer.pageCount + 2);
        if (mainBuffer.dirtyPages == NULL)
                return false;
                
        PFLAG_CLEAR_ALL;
        PFLAG_CLEAR(mainBuffer.pageCount);
        PFLAG_SET(mainBuffer.pageCount+1);
        
        // Allocate and fill in pageInfo with start and end (inclusive) row in number of bytes
        mainBuffer.pageInfo = (ScreenPageInfo *) malloc(mainBuffer.pageCount * sizeof(ScreenPageInfo));
        if (mainBuffer.pageInfo == NULL)
                return false;
        
        uint32 a = 0;
        for (unsigned i = 0; i < mainBuffer.pageCount; i++) {
                unsigned y1 = a / VIDEO_MODE_ROW_BYTES;
                if (y1 >= VIDEO_MODE_Y)
                        y1 = VIDEO_MODE_Y - 1;

                unsigned y2 = (a + mainBuffer.pageSize) / VIDEO_MODE_ROW_BYTES;
                if (y2 >= VIDEO_MODE_Y)
                        y2 = VIDEO_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;
        
        // The frame buffer is sane, i.e. there is no write to it yet
        mainBuffer.dirty = false;
        return true;
}


/*
 * Deinitialize VOSF system
 */

static void video_vosf_exit(void)
{
        if (mainBuffer.pageInfo) {
                free(mainBuffer.pageInfo);
                mainBuffer.pageInfo = NULL;
        }
        if (mainBuffer.dirtyPages) {
                free(mainBuffer.dirtyPages);
                mainBuffer.dirtyPages = NULL;
        }
}


/*
 * Screen fault handler
 */

bool Screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t 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 to. It will be made
         * read-only back in one of the screen update_*() functions.
         */
        if (((uintptr)addr - mainBuffer.memStart) < mainBuffer.memLength) {
                const int page  = ((uintptr)addr - mainBuffer.memStart) >> mainBuffer.pageBits;
                LOCK_VOSF;
                PFLAG_SET(page);
                vm_protect((char *)(addr & -mainBuffer.pageSize), 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 */
        return false;
}


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

/*      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 void update_display_window_vosf(VIDEO_DRV_WIN_INIT)
{
        VIDEO_MODE_INIT;

        int page = 0;
        for (;;) {
                const unsigned 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;

                // Update the_host_buffer
                VIDEO_DRV_LOCK_PIXELS;
                const int src_bytes_per_row = VIDEO_MODE_ROW_BYTES;
                const int dst_bytes_per_row = VIDEO_DRV_ROW_BYTES;
                int i1 = y1 * src_bytes_per_row, i2 = y1 * dst_bytes_per_row, j;
                for (j = y1; j <= y2; j++) {
                        Screen_blit(the_host_buffer + i2, the_buffer + i1, src_bytes_per_row);
                        i1 += src_bytes_per_row;
                        i2 += dst_bytes_per_row;
                }
                VIDEO_DRV_UNLOCK_PIXELS;

#ifdef USE_SDL_VIDEO
                SDL_UpdateRect(drv->s, 0, y1, VIDEO_MODE_X, height);
#else
                if (VIDEO_DRV_HAVE_SHM)
                        XShmPutImage(x_display, VIDEO_DRV_WINDOW, VIDEO_DRV_GC, VIDEO_DRV_IMAGE, 0, y1, 0, y1, VIDEO_MODE_X, height, 0);
                else
                        XPutImage(x_display, VIDEO_DRV_WINDOW, VIDEO_DRV_GC, VIDEO_DRV_IMAGE, 0, y1, 0, y1, VIDEO_MODE_X, height);
#endif
        }
        mainBuffer.dirty = false;
}


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

#if REAL_ADDRESSING || DIRECT_ADDRESSING
static void update_display_dga_vosf(VIDEO_DRV_DGA_INIT)
{
        VIDEO_MODE_INIT;

        // Compute number of bytes per row, take care to virtual screens
        const int src_bytes_per_row = VIDEO_MODE_ROW_BYTES;
        const int dst_bytes_per_row = TrivialBytesPerRow(VIDEO_MODE_X, DepthModeForPixelDepth(VIDEO_DRV_DEPTH));
        const int scr_bytes_per_row = VIDEO_DRV_ROW_BYTES;
        assert(dst_bytes_per_row <= scr_bytes_per_row);
        const int scr_bytes_left = scr_bytes_per_row - dst_bytes_per_row;

        // Full screen update requested?
        if (mainBuffer.very_dirty) {
                PFLAG_CLEAR_ALL;
                vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ);
                memcpy(the_buffer_copy, the_buffer, VIDEO_MODE_ROW_BYTES * VIDEO_MODE_Y);
                VIDEO_DRV_LOCK_PIXELS;
                int i1 = 0, i2 = 0;
                for (int j = 0;  j < VIDEO_MODE_Y; j++) {
                        Screen_blit(the_host_buffer + i2, the_buffer + i1, src_bytes_per_row);
                        i1 += src_bytes_per_row;
                        i2 += scr_bytes_per_row;
                }
#ifdef USE_SDL_VIDEO
                SDL_UpdateRect(drv->s, 0, 0, VIDEO_MODE_X, VIDEO_MODE_Y);
#endif
                VIDEO_DRV_UNLOCK_PIXELS;
                return;
        }

        // Setup partial blitter (use 64-pixel wide chunks)
        const int n_pixels = 64;
        const int n_chunks = VIDEO_MODE_X / n_pixels;
        const int src_chunk_size = src_bytes_per_row / n_chunks;
        const int dst_chunk_size = dst_bytes_per_row / n_chunks;
        const int src_chunk_size_left = src_bytes_per_row - (n_chunks * src_chunk_size);
        const int dst_chunk_size_left = dst_bytes_per_row - (n_chunks * dst_chunk_size);

        int page = 0, last_scanline = -1;
        for (;;) {
                const unsigned 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);

                // Optimized for scanlines, don't process overlapping lines again
                int y1 = mainBuffer.pageInfo[first_page].top;
                int y2 = mainBuffer.pageInfo[page - 1].bottom;
                if (y1 <= last_scanline && ++y1 >= VIDEO_MODE_Y)
                        continue;
                if (y2 <= last_scanline && ++y2 >= VIDEO_MODE_Y)
                        continue;
                last_scanline = y2;

                // Update the_host_buffer and copy of the_buffer, one line at a time
                int i1 = y1 * src_bytes_per_row;
                int i2 = y1 * scr_bytes_per_row;
                VIDEO_DRV_LOCK_PIXELS;
                for (int j = y1; j <= y2; j++) {
                        for (int i = 0; i < n_chunks; i++) {
                                if (memcmp(the_buffer_copy + i1, the_buffer + i1, src_chunk_size) != 0) {
                                        memcpy(the_buffer_copy + i1, the_buffer + i1, src_chunk_size);
                                        Screen_blit(the_host_buffer + i2, the_buffer + i1, src_chunk_size);
#ifdef USE_SDL_VIDEO
                                        SDL_UpdateRect(drv->s, i * n_pixels, j, n_pixels, 1);
#endif
                                }
                                i1 += src_chunk_size;
                                i2 += dst_chunk_size;
                        }
                        if (src_chunk_size_left && dst_chunk_size_left) {
                                if (memcmp(the_buffer_copy + i1, the_buffer + i1, src_chunk_size_left) != 0) {
                                        memcpy(the_buffer_copy + i1, the_buffer + i1, src_chunk_size_left);
                                        Screen_blit(the_host_buffer + i2, the_buffer + i1, src_chunk_size_left);
                                }
                                i1 += src_chunk_size_left;
                                i2 += dst_chunk_size_left;
                        }
                        i2 += scr_bytes_left;
                }
                VIDEO_DRV_UNLOCK_PIXELS;
        }
        mainBuffer.dirty = false;
}
#endif

#endif /* ENABLE_VOSF */

#endif /* VIDEO_VOSF_H */
Revision:	1.52
Committed:	2005-05-12T14:39:56Z (19 years, 1 month ago) by gbeauche
Content type:	text/plain
Branch:	MAIN
Changes since 1.51:	+14 -8 lines
Log Message:	Fix SDL/DGA build. Drop useless "inline" for updates. Overlapping scanlines optimization.
#	Content
1	/*
2	* video_vosf.h - Video/graphics emulation, video on SEGV signals support
3	*
4	* Basilisk II (C) 1997-2005 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_VOSF_H
22	#define VIDEO_VOSF_H
23
24	// Note: this file must be #include'd only in video_x.cpp
25	#ifdef ENABLE_VOSF
26
27	#include "sigsegv.h"
28	#include "vm_alloc.h"
29	#ifdef _WIN32
30	#include "util_windows.h"
31	#endif
32
33	// Glue for SDL and X11 support
34	#ifdef USE_SDL_VIDEO
35	#define MONITOR_INIT SDL_monitor_desc &monitor
36	#define VIDEO_DRV_WIN_INIT driver_window *drv
37	#define VIDEO_DRV_DGA_INIT driver_fullscreen *drv
38	#define VIDEO_DRV_LOCK_PIXELS if (SDL_MUSTLOCK(drv->s)) SDL_LockSurface(drv->s)
39	#define VIDEO_DRV_UNLOCK_PIXELS if (SDL_MUSTLOCK(drv->s)) SDL_UnlockSurface(drv->s)
40	#define VIDEO_DRV_DEPTH drv->s->format->BitsPerPixel
41	#define VIDEO_DRV_WIDTH drv->s->w
42	#define VIDEO_DRV_HEIGHT drv->s->h
43	#define VIDEO_DRV_ROW_BYTES drv->s->pitch
44	#else
45	#ifdef SHEEPSHAVER
46	#define MONITOR_INIT /* nothing */
47	#define VIDEO_DRV_WIN_INIT /* nothing */
48	#define VIDEO_DRV_DGA_INIT /* nothing */
49	#define VIDEO_DRV_WINDOW the_win
50	#define VIDEO_DRV_GC the_gc
51	#define VIDEO_DRV_IMAGE img
52	#define VIDEO_DRV_HAVE_SHM have_shm
53	#else
54	#define MONITOR_INIT X11_monitor_desc &monitor
55	#define VIDEO_DRV_WIN_INIT driver_window *drv
56	#define VIDEO_DRV_DGA_INIT driver_dga *drv
57	#define VIDEO_DRV_WINDOW drv->w
58	#define VIDEO_DRV_GC drv->gc
59	#define VIDEO_DRV_IMAGE drv->img
60	#define VIDEO_DRV_HAVE_SHM drv->have_shm
61	#endif
62	#define VIDEO_DRV_LOCK_PIXELS /* nothing */
63	#define VIDEO_DRV_UNLOCK_PIXELS /* nothing */
64	#define VIDEO_DRV_DEPTH VIDEO_DRV_IMAGE->depth
65	#define VIDEO_DRV_WIDTH VIDEO_DRV_IMAGE->width
66	#define VIDEO_DRV_HEIGHT VIDEO_DRV_IMAGE->height
67	#define VIDEO_DRV_ROW_BYTES VIDEO_DRV_IMAGE->bytes_per_line
68	#endif
69
70	// Variables for Video on SEGV support
71	static uint8 *the_host_buffer; // Host frame buffer in VOSF mode
72
73	struct ScreenPageInfo {
74	int top, bottom; // Mapping between this virtual page and Mac scanlines
75	};
76
77	struct ScreenInfo {
78	uintptr memStart; // Start address aligned to page boundary
79	uint32 memLength; // Length of the memory addressed by the screen pages
80
81	uintptr pageSize; // Size of a page
82	int pageBits; // Shift count to get the page number
83	uint32 pageCount; // Number of pages allocated to the screen
84
85	bool dirty; // Flag: set if the frame buffer was touched
86	bool very_dirty; // Flag: set if the frame buffer was completely modified (e.g. colormap changes)
87	char * dirtyPages; // Table of flags set if page was altered
88	ScreenPageInfo * pageInfo; // Table of mappings page -> Mac scanlines
89	};
90
91	static ScreenInfo mainBuffer;
92
93	#define PFLAG_SET_VALUE 0x00
94	#define PFLAG_CLEAR_VALUE 0x01
95	#define PFLAG_SET_VALUE_4 0x00000000
96	#define PFLAG_CLEAR_VALUE_4 0x01010101
97	#define PFLAG_SET(page) mainBuffer.dirtyPages[page] = PFLAG_SET_VALUE
98	#define PFLAG_CLEAR(page) mainBuffer.dirtyPages[page] = PFLAG_CLEAR_VALUE
99	#define PFLAG_ISSET(page) (mainBuffer.dirtyPages[page] == PFLAG_SET_VALUE)
100	#define PFLAG_ISCLEAR(page) (mainBuffer.dirtyPages[page] != PFLAG_SET_VALUE)
101
102	#ifdef UNALIGNED_PROFITABLE
103	# define PFLAG_ISSET_4(page) (((uint32 )(mainBuffer.dirtyPages + (page))) == PFLAG_SET_VALUE_4)
104	# define PFLAG_ISCLEAR_4(page) (((uint32 )(mainBuffer.dirtyPages + (page))) == PFLAG_CLEAR_VALUE_4)
105	#else
106	# define PFLAG_ISSET_4(page) \
107	PFLAG_ISSET(page ) && PFLAG_ISSET(page+1) \
108	&& PFLAG_ISSET(page+2) && PFLAG_ISSET(page+3)
109	# define PFLAG_ISCLEAR_4(page) \
110	PFLAG_ISCLEAR(page ) && PFLAG_ISCLEAR(page+1) \
111	&& PFLAG_ISCLEAR(page+2) && PFLAG_ISCLEAR(page+3)
112	#endif
113
114	// Set the selected page range [ first_page, last_page [ into the SET state
115	#define PFLAG_SET_RANGE(first_page, last_page) \
116	memset(mainBuffer.dirtyPages + (first_page), PFLAG_SET_VALUE, \
117	(last_page) - (first_page))
118
119	// Set the selected page range [ first_page, last_page [ into the CLEAR state
120	#define PFLAG_CLEAR_RANGE(first_page, last_page) \
121	memset(mainBuffer.dirtyPages + (first_page), PFLAG_CLEAR_VALUE, \
122	(last_page) - (first_page))
123
124	#define PFLAG_SET_ALL do { \
125	PFLAG_SET_RANGE(0, mainBuffer.pageCount); \
126	mainBuffer.dirty = true; \
127	} while (0)
128
129	#define PFLAG_CLEAR_ALL do { \
130	PFLAG_CLEAR_RANGE(0, mainBuffer.pageCount); \
131	mainBuffer.dirty = false; \
132	mainBuffer.very_dirty = false; \
133	} while (0)
134
135	#define PFLAG_SET_VERY_DIRTY do { \
136	mainBuffer.very_dirty = true; \
137	} while (0)
138
139	// Set the following macro definition to 1 if your system
140	// provides a really fast strchr() implementation
141	//#define HAVE_FAST_STRCHR 0
142
143	static inline int find_next_page_set(int page)
144	{
145	#if HAVE_FAST_STRCHR
146	char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_SET_VALUE);
147	return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
148	#else
149	while (PFLAG_ISCLEAR_4(page))
150	page += 4;
151	while (PFLAG_ISCLEAR(page))
152	page++;
153	return page;
154	#endif
155	}
156
157	static inline int find_next_page_clear(int page)
158	{
159	#if HAVE_FAST_STRCHR
160	char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_CLEAR_VALUE);
161	return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
162	#else
163	while (PFLAG_ISSET_4(page))
164	page += 4;
165	while (PFLAG_ISSET(page))
166	page++;
167	return page;
168	#endif
169	}
170
171	#ifdef HAVE_SPINLOCKS
172	static spinlock_t vosf_lock = SPIN_LOCK_UNLOCKED; // Mutex to protect frame buffer (dirtyPages in fact)
173	#define LOCK_VOSF spin_lock(&vosf_lock)
174	#define UNLOCK_VOSF spin_unlock(&vosf_lock)
175	#elif defined(_WIN32)
176	static mutex_t vosf_lock; // Mutex to protect frame buffer (dirtyPages in fact)
177	#define LOCK_VOSF vosf_lock.lock();
178	#define UNLOCK_VOSF vosf_lock.unlock();
179	#elif defined(HAVE_PTHREADS)
180	static pthread_mutex_t vosf_lock = PTHREAD_MUTEX_INITIALIZER; // Mutex to protect frame buffer (dirtyPages in fact)
181	#define LOCK_VOSF pthread_mutex_lock(&vosf_lock);
182	#define UNLOCK_VOSF pthread_mutex_unlock(&vosf_lock);
183	#else
184	#define LOCK_VOSF
185	#define UNLOCK_VOSF
186	#endif
187
188	static int log_base_2(uint32 x)
189	{
190	uint32 mask = 0x80000000;
191	int l = 31;
192	while (l >= 0 && (x & mask) == 0) {
193	mask >>= 1;
194	l--;
195	}
196	return l;
197	}
198
199	// Extend size to page boundary
200	static uint32 page_extend(uint32 size)
201	{
202	const uint32 page_size = vm_get_page_size();
203	const uint32 page_mask = page_size - 1;
204	return (size + page_mask) & ~page_mask;
205	}
206
207
208	/*
209	* Check if VOSF acceleration is profitable on this platform
210	*/
211
212	const int VOSF_PROFITABLE_TRIES = 3; // Make 3 attempts for full screen update
213	const int VOSF_PROFITABLE_THRESHOLD = 16667; // 60 Hz
214
215	static bool video_vosf_profitable(void)
216	{
217	int64 durations[VOSF_PROFITABLE_TRIES];
218	int mean_duration = 0;
219
220	for (int i = 0; i < VOSF_PROFITABLE_TRIES; i++) {
221	uint64 start = GetTicks_usec();
222	for (int p = 0; p < mainBuffer.pageCount; p++) {
223	uint8 addr = (uint8 )(mainBuffer.memStart + (p * mainBuffer.pageSize));
224	addr[0] = 0; // Trigger Screen_fault_handler()
225	}
226	int64 duration = GetTicks_usec() - start;
227	mean_duration += duration;
228	durations[i] = duration;
229
230	PFLAG_CLEAR_ALL;
231	mainBuffer.dirty = false;
232	if (vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ) != 0)
233	return false;
234	}
235
236	mean_duration /= VOSF_PROFITABLE_TRIES;
237	D(bug("Triggered %d screen faults in %ld usec on average\n", mainBuffer.pageCount, mean_duration));
238	return (mean_duration < (VOSF_PROFITABLE_THRESHOLD * (frame_skip ? frame_skip : 1)));
239	}
240
241
242	/*
243	* Initialize the VOSF system (mainBuffer structure, SIGSEGV handler)
244	*/
245
246	static bool video_vosf_init(MONITOR_INIT)
247	{
248	VIDEO_MODE_INIT_MONITOR;
249
250	const uintptr page_size = vm_get_page_size();
251	const uintptr page_mask = page_size - 1;
252
253	// Round up frame buffer base to page boundary
254	mainBuffer.memStart = (((uintptr) the_buffer) + page_mask) & ~page_mask;
255
256	// The frame buffer size shall already be aligned to page boundary (use page_extend)
257	mainBuffer.memLength = the_buffer_size;
258
259	mainBuffer.pageSize = page_size;
260	mainBuffer.pageBits = log_base_2(mainBuffer.pageSize);
261	mainBuffer.pageCount = (mainBuffer.memLength + page_mask)/mainBuffer.pageSize;
262
263	// The "2" more bytes requested are a safety net to insure the
264	// loops in the update routines will terminate.
265	// See "How can we deal with array overrun conditions ?" hereunder for further details.
266	mainBuffer.dirtyPages = (char *) malloc(mainBuffer.pageCount + 2);
267	if (mainBuffer.dirtyPages == NULL)
268	return false;
269
270	PFLAG_CLEAR_ALL;
271	PFLAG_CLEAR(mainBuffer.pageCount);
272	PFLAG_SET(mainBuffer.pageCount+1);
273
274	// Allocate and fill in pageInfo with start and end (inclusive) row in number of bytes
275	mainBuffer.pageInfo = (ScreenPageInfo ) malloc(mainBuffer.pageCount sizeof(ScreenPageInfo));
276	if (mainBuffer.pageInfo == NULL)
277	return false;
278
279	uint32 a = 0;
280	for (unsigned i = 0; i < mainBuffer.pageCount; i++) {
281	unsigned y1 = a / VIDEO_MODE_ROW_BYTES;
282	if (y1 >= VIDEO_MODE_Y)
283	y1 = VIDEO_MODE_Y - 1;
284
285	unsigned y2 = (a + mainBuffer.pageSize) / VIDEO_MODE_ROW_BYTES;
286	if (y2 >= VIDEO_MODE_Y)
287	y2 = VIDEO_MODE_Y - 1;
288
289	mainBuffer.pageInfo[i].top = y1;
290	mainBuffer.pageInfo[i].bottom = y2;
291
292	a += mainBuffer.pageSize;
293	if (a > mainBuffer.memLength)
294	a = mainBuffer.memLength;
295	}
296
297	// We can now write-protect the frame buffer
298	if (vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ) != 0)
299	return false;
300
301	// The frame buffer is sane, i.e. there is no write to it yet
302	mainBuffer.dirty = false;
303	return true;
304	}
305
306
307	/*
308	* Deinitialize VOSF system
309	*/
310
311	static void video_vosf_exit(void)
312	{
313	if (mainBuffer.pageInfo) {
314	free(mainBuffer.pageInfo);
315	mainBuffer.pageInfo = NULL;
316	}
317	if (mainBuffer.dirtyPages) {
318	free(mainBuffer.dirtyPages);
319	mainBuffer.dirtyPages = NULL;
320	}
321	}
322
323
324	/*
325	* Screen fault handler
326	*/
327
328	bool Screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction)
329	{
330	const uintptr addr = (uintptr)fault_address;
331
332	/* Someone attempted to write to the frame buffer. Make it writeable
333	* now so that the data could actually be written to. It will be made
334	* read-only back in one of the screen update_*() functions.
335	*/
336	if (((uintptr)addr - mainBuffer.memStart) < mainBuffer.memLength) {
337	const int page = ((uintptr)addr - mainBuffer.memStart) >> mainBuffer.pageBits;
338	LOCK_VOSF;
339	PFLAG_SET(page);
340	vm_protect((char *)(addr & -mainBuffer.pageSize), mainBuffer.pageSize, VM_PAGE_READ \| VM_PAGE_WRITE);
341	mainBuffer.dirty = true;
342	UNLOCK_VOSF;
343	return true;
344	}
345
346	/* Otherwise, we don't know how to handle the fault, let it crash */
347	return false;
348	}
349
350
351	/*
352	* Update display for Windowed mode and VOSF
353	*/
354
355	/* How can we deal with array overrun conditions ?
356
357	The state of the framebuffer pages that have been touched are maintained
358	in the dirtyPages[] table. That table is (pageCount + 2) bytes long.
359
360	Terminology
361
362	"Last Page" denotes the pageCount-nth page, i.e. dirtyPages[pageCount - 1].
363	"CLEAR Page Guard" refers to the page following the Last Page but is always
364	in the CLEAR state. "SET Page Guard" refers to the page following the CLEAR
365	Page Guard but is always in the SET state.
366
367	Rough process
368
369	The update routines must determine which pages have to be blitted to the
370	screen. This job consists in finding the first_page that was touched.
371	i.e. find the next page that is SET. Then, finding how many pages were
372	touched starting from first_page. i.e. find the next page that is CLEAR.
373
374	There are two cases to check:
375
376	- Last Page is CLEAR: find_next_page_set() will reach the SET Page Guard
377	but it is beyond the valid pageCount value. Therefore, we exit from the
378	update routine.
379
380	- Last Page is SET: first_page equals (pageCount - 1) and
381	find_next_page_clear() will reach the CLEAR Page Guard. We blit the last
382	page to the screen. On the next iteration, page equals pageCount and
383	find_next_page_set() will reach the SET Page Guard. We still safely exit
384	from the update routine because the SET Page Guard position is greater
385	than pageCount.
386	*/
387
388	static void update_display_window_vosf(VIDEO_DRV_WIN_INIT)
389	{
390	VIDEO_MODE_INIT;
391
392	int page = 0;
393	for (;;) {
394	const unsigned first_page = find_next_page_set(page);
395	if (first_page >= mainBuffer.pageCount)
396	break;
397
398	page = find_next_page_clear(first_page);
399	PFLAG_CLEAR_RANGE(first_page, page);
400
401	// Make the dirty pages read-only again
402	const int32 offset = first_page << mainBuffer.pageBits;
403	const uint32 length = (page - first_page) << mainBuffer.pageBits;
404	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
405
406	// There is at least one line to update
407	const int y1 = mainBuffer.pageInfo[first_page].top;
408	const int y2 = mainBuffer.pageInfo[page - 1].bottom;
409	const int height = y2 - y1 + 1;
410
411	// Update the_host_buffer
412	VIDEO_DRV_LOCK_PIXELS;
413	const int src_bytes_per_row = VIDEO_MODE_ROW_BYTES;
414	const int dst_bytes_per_row = VIDEO_DRV_ROW_BYTES;
415	int i1 = y1 * src_bytes_per_row, i2 = y1 * dst_bytes_per_row, j;
416	for (j = y1; j <= y2; j++) {
417	Screen_blit(the_host_buffer + i2, the_buffer + i1, src_bytes_per_row);
418	i1 += src_bytes_per_row;
419	i2 += dst_bytes_per_row;
420	}
421	VIDEO_DRV_UNLOCK_PIXELS;
422
423	#ifdef USE_SDL_VIDEO
424	SDL_UpdateRect(drv->s, 0, y1, VIDEO_MODE_X, height);
425	#else
426	if (VIDEO_DRV_HAVE_SHM)
427	XShmPutImage(x_display, VIDEO_DRV_WINDOW, VIDEO_DRV_GC, VIDEO_DRV_IMAGE, 0, y1, 0, y1, VIDEO_MODE_X, height, 0);
428	else
429	XPutImage(x_display, VIDEO_DRV_WINDOW, VIDEO_DRV_GC, VIDEO_DRV_IMAGE, 0, y1, 0, y1, VIDEO_MODE_X, height);
430	#endif
431	}
432	mainBuffer.dirty = false;
433	}
434
435
436	/*
437	* Update display for DGA mode and VOSF
438	* (only in Real or Direct Addressing mode)
439	*/
440
441	#if REAL_ADDRESSING \|\| DIRECT_ADDRESSING
442	static void update_display_dga_vosf(VIDEO_DRV_DGA_INIT)
443	{
444	VIDEO_MODE_INIT;
445
446	// Compute number of bytes per row, take care to virtual screens
447	const int src_bytes_per_row = VIDEO_MODE_ROW_BYTES;
448	const int dst_bytes_per_row = TrivialBytesPerRow(VIDEO_MODE_X, DepthModeForPixelDepth(VIDEO_DRV_DEPTH));
449	const int scr_bytes_per_row = VIDEO_DRV_ROW_BYTES;
450	assert(dst_bytes_per_row <= scr_bytes_per_row);
451	const int scr_bytes_left = scr_bytes_per_row - dst_bytes_per_row;
452
453	// Full screen update requested?
454	if (mainBuffer.very_dirty) {
455	PFLAG_CLEAR_ALL;
456	vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ);
457	memcpy(the_buffer_copy, the_buffer, VIDEO_MODE_ROW_BYTES * VIDEO_MODE_Y);
458	VIDEO_DRV_LOCK_PIXELS;
459	int i1 = 0, i2 = 0;
460	for (int j = 0; j < VIDEO_MODE_Y; j++) {
461	Screen_blit(the_host_buffer + i2, the_buffer + i1, src_bytes_per_row);
462	i1 += src_bytes_per_row;
463	i2 += scr_bytes_per_row;
464	}
465	#ifdef USE_SDL_VIDEO
466	SDL_UpdateRect(drv->s, 0, 0, VIDEO_MODE_X, VIDEO_MODE_Y);
467	#endif
468	VIDEO_DRV_UNLOCK_PIXELS;
469	return;
470	}
471
472	// Setup partial blitter (use 64-pixel wide chunks)
473	const int n_pixels = 64;
474	const int n_chunks = VIDEO_MODE_X / n_pixels;
475	const int src_chunk_size = src_bytes_per_row / n_chunks;
476	const int dst_chunk_size = dst_bytes_per_row / n_chunks;
477	const int src_chunk_size_left = src_bytes_per_row - (n_chunks * src_chunk_size);
478	const int dst_chunk_size_left = dst_bytes_per_row - (n_chunks * dst_chunk_size);
479
480	int page = 0, last_scanline = -1;
481	for (;;) {
482	const unsigned first_page = find_next_page_set(page);
483	if (first_page >= mainBuffer.pageCount)
484	break;
485
486	page = find_next_page_clear(first_page);
487	PFLAG_CLEAR_RANGE(first_page, page);
488
489	// Make the dirty pages read-only again
490	const int32 offset = first_page << mainBuffer.pageBits;
491	const uint32 length = (page - first_page) << mainBuffer.pageBits;
492	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
493
494	// Optimized for scanlines, don't process overlapping lines again
495	int y1 = mainBuffer.pageInfo[first_page].top;
496	int y2 = mainBuffer.pageInfo[page - 1].bottom;
497	if (y1 <= last_scanline && ++y1 >= VIDEO_MODE_Y)
498	continue;
499	if (y2 <= last_scanline && ++y2 >= VIDEO_MODE_Y)
500	continue;
501	last_scanline = y2;
502
503	// Update the_host_buffer and copy of the_buffer, one line at a time
504	int i1 = y1 * src_bytes_per_row;
505	int i2 = y1 * scr_bytes_per_row;
506	VIDEO_DRV_LOCK_PIXELS;
507	for (int j = y1; j <= y2; j++) {
508	for (int i = 0; i < n_chunks; i++) {
509	if (memcmp(the_buffer_copy + i1, the_buffer + i1, src_chunk_size) != 0) {
510	memcpy(the_buffer_copy + i1, the_buffer + i1, src_chunk_size);
511	Screen_blit(the_host_buffer + i2, the_buffer + i1, src_chunk_size);
512	#ifdef USE_SDL_VIDEO
513	SDL_UpdateRect(drv->s, i * n_pixels, j, n_pixels, 1);
514	#endif
515	}
516	i1 += src_chunk_size;
517	i2 += dst_chunk_size;
518	}
519	if (src_chunk_size_left && dst_chunk_size_left) {
520	if (memcmp(the_buffer_copy + i1, the_buffer + i1, src_chunk_size_left) != 0) {
521	memcpy(the_buffer_copy + i1, the_buffer + i1, src_chunk_size_left);
522	Screen_blit(the_host_buffer + i2, the_buffer + i1, src_chunk_size_left);
523	}
524	i1 += src_chunk_size_left;
525	i2 += dst_chunk_size_left;
526	}
527	i2 += scr_bytes_left;
528	}
529	VIDEO_DRV_UNLOCK_PIXELS;
530	}
531	mainBuffer.dirty = false;
532	}
533	#endif
534
535	#endif /* ENABLE_VOSF */
536
537	#endif /* VIDEO_VOSF_H */