src/video/SDL_video.c
author Sam Lantinga <slouken@libsdl.org>
Tue, 31 Jul 2001 00:11:41 +0000
changeset 125 0ae324925dd7
parent 75 b0ae59d0f3ee
child 167 cb384ef627f6
permissions -rw-r--r--
Fix build when GL_CLIENT_PIXEL_STORE_BIT is not defined
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Library General Public
     7     License as published by the Free Software Foundation; either
     8     version 2 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Library General Public License for more details.
    14 
    15     You should have received a copy of the GNU Library General Public
    16     License along with this library; if not, write to the Free
    17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    18 
    19     Sam Lantinga
    20     slouken@devolution.com
    21 */
    22 
    23 #ifdef SAVE_RCSID
    24 static char rcsid =
    25  "@(#) $Id$";
    26 #endif
    27 
    28 /* The high-level video driver subsystem */
    29 
    30 #include <stdio.h>
    31 #include <stdlib.h>
    32 #include <string.h>
    33 
    34 #include "SDL.h"
    35 #include "SDL_error.h"
    36 #include "SDL_video.h"
    37 #include "SDL_events.h"
    38 #include "SDL_mutex.h"
    39 #include "SDL_sysvideo.h"
    40 #include "SDL_sysevents.h"
    41 #include "SDL_blit.h"
    42 #include "SDL_pixels_c.h"
    43 #include "SDL_events_c.h"
    44 #include "SDL_cursor_c.h"
    45 
    46 /* Available video drivers */
    47 static VideoBootStrap *bootstrap[] = {
    48 #ifdef ENABLE_X11
    49 	&X11_bootstrap,
    50 #endif
    51 #ifdef ENABLE_DGA
    52 	&DGA_bootstrap,
    53 #endif
    54 #ifdef ENABLE_NANOX
    55 	&NX_bootstrap,
    56 #endif
    57 #ifdef ENABLE_FBCON
    58 	&FBCON_bootstrap,
    59 #endif
    60 #ifdef ENABLE_PS2GS
    61 	&PS2GS_bootstrap,
    62 #endif
    63 #ifdef ENABLE_GGI
    64 	&GGI_bootstrap,
    65 #endif
    66 #ifdef ENABLE_VGL
    67 	&VGL_bootstrap,
    68 #endif
    69 #ifdef ENABLE_SVGALIB
    70 	&SVGALIB_bootstrap,
    71 #endif
    72 #ifdef ENABLE_AALIB
    73     &AALIB_bootstrap,
    74 #endif
    75 #ifdef ENABLE_DIRECTX
    76 	&DIRECTX_bootstrap,
    77 #endif
    78 #ifdef ENABLE_WINDIB
    79 	&WINDIB_bootstrap,
    80 #endif
    81 #ifdef ENABLE_BWINDOW
    82 	&BWINDOW_bootstrap,
    83 #endif
    84 #ifdef ENABLE_TOOLBOX
    85 	&TOOLBOX_bootstrap,
    86 #endif
    87 #ifdef ENABLE_DRAWSPROCKET
    88 	&DSp_bootstrap,
    89 #endif
    90 #ifdef ENABLE_QUARTZ
    91 	&QZ_bootstrap,
    92 #endif
    93 #ifdef ENABLE_CYBERGRAPHICS
    94 	&CGX_bootstrap,
    95 #endif
    96 #ifdef ENABLE_DUMMYVIDEO
    97 	&DUMMY_bootstrap,
    98 #endif
    99 #ifdef ENABLE_PHOTON
   100 	&ph_bootstrap,
   101 #endif
   102 	NULL
   103 };
   104 SDL_VideoDevice *current_video = NULL;
   105 
   106 /* Various local functions */
   107 int SDL_VideoInit(const char *driver_name, Uint32 flags);
   108 void SDL_VideoQuit(void);
   109 void SDL_GL_UpdateRectsLock(SDL_VideoDevice* this, int numrects, SDL_Rect* rects);
   110 
   111 static SDL_GrabMode SDL_WM_GrabInputOff(void);
   112 #ifdef HAVE_OPENGL
   113 static int lock_count = 0;
   114 #endif
   115 
   116 
   117 /*
   118  * Initialize the video and event subsystems -- determine native pixel format
   119  */
   120 int SDL_VideoInit (const char *driver_name, Uint32 flags)
   121 {
   122 	SDL_VideoDevice *video;
   123 	int index;
   124 	int i;
   125 	SDL_PixelFormat vformat;
   126 	Uint32 video_flags;
   127 
   128 	/* Toggle the event thread flags, based on OS requirements */
   129 #if defined(MUST_THREAD_EVENTS)
   130 	flags |= SDL_INIT_EVENTTHREAD;
   131 #elif defined(CANT_THREAD_EVENTS)
   132 	if ( (flags & SDL_INIT_EVENTTHREAD) == SDL_INIT_EVENTTHREAD ) {
   133 		SDL_SetError("OS doesn't support threaded events");
   134 		return(-1);
   135 	}
   136 #endif
   137 
   138 	/* Check to make sure we don't overwrite 'current_video' */
   139 	if ( current_video != NULL ) {
   140 		SDL_VideoQuit();
   141 	}
   142 
   143 	/* Select the proper video driver */
   144 	index = 0;
   145 	video = NULL;
   146 	if ( driver_name != NULL ) {
   147 #if 0	/* This will be replaced with a better driver selection API */
   148 		if ( strrchr(driver_name, ':') != NULL ) {
   149 			index = atoi(strrchr(driver_name, ':')+1);
   150 		}
   151 #endif
   152 		for ( i=0; bootstrap[i]; ++i ) {
   153 			if ( strncmp(bootstrap[i]->name, driver_name,
   154 			             strlen(bootstrap[i]->name)) == 0 ) {
   155 				if ( bootstrap[i]->available() ) {
   156 					video = bootstrap[i]->create(index);
   157 					break;
   158 				}
   159 			}
   160 		}
   161 	} else {
   162 		for ( i=0; bootstrap[i]; ++i ) {
   163 			if ( bootstrap[i]->available() ) {
   164 				video = bootstrap[i]->create(index);
   165 				if ( video != NULL ) {
   166 					break;
   167 				}
   168 			}
   169 		}
   170 	}
   171 	if ( video == NULL ) {
   172 		SDL_SetError("No available video device");
   173 		return(-1);
   174 	}
   175 	current_video = video;
   176 	current_video->name = bootstrap[i]->name;
   177 
   178 	/* Do some basic variable initialization */
   179 	video->screen = NULL;
   180 	video->shadow = NULL;
   181 	video->visible = NULL;
   182 	video->physpal = NULL;
   183 	video->gammacols = NULL;
   184 	video->gamma = NULL;
   185 	video->wm_title = NULL;
   186 	video->wm_icon  = NULL;
   187 	video->offset_x = 0;
   188 	video->offset_y = 0;
   189 	memset(&video->info, 0, (sizeof video->info));
   190 
   191 	/* Set some very sane GL defaults */
   192 	video->gl_config.driver_loaded = 0;
   193 	video->gl_config.dll_handle = NULL;
   194 	video->gl_config.red_size = 5;
   195 #if 1 /* This seems to work on more video cards, as a default */
   196 	video->gl_config.green_size = 5;
   197 #else
   198 	video->gl_config.green_size = 6;
   199 #endif
   200 	video->gl_config.blue_size = 5;
   201 	video->gl_config.alpha_size = 0;
   202 	video->gl_config.buffer_size = 0;
   203 	video->gl_config.depth_size = 16;
   204 	video->gl_config.stencil_size = 0;
   205 	video->gl_config.double_buffer = 1;
   206 	video->gl_config.accum_red_size = 0;
   207 	video->gl_config.accum_green_size = 0;
   208 	video->gl_config.accum_blue_size = 0;
   209 	video->gl_config.accum_alpha_size = 0;
   210 	
   211 	/* Initialize the video subsystem */
   212 	memset(&vformat, 0, sizeof(vformat));
   213 	if ( video->VideoInit(video, &vformat) < 0 ) {
   214 		SDL_VideoQuit();
   215 		return(-1);
   216 	}
   217 
   218 	/* Create a zero sized video surface of the appropriate format */
   219 	video_flags = SDL_SWSURFACE;
   220 	SDL_VideoSurface = SDL_CreateRGBSurface(video_flags, 0, 0,
   221 				vformat.BitsPerPixel,
   222 				vformat.Rmask, vformat.Gmask, vformat.Bmask, 0);
   223 	if ( SDL_VideoSurface == NULL ) {
   224 		SDL_VideoQuit();
   225 		return(-1);
   226 	}
   227 	SDL_PublicSurface = NULL;	/* Until SDL_SetVideoMode() */
   228 
   229 #if 0 /* Don't change the current palette - may be used by other programs.
   230        * The application can't do anything with the display surface until
   231        * a video mode has been set anyway. :)
   232        */
   233 	/* If we have a palettized surface, create a default palette */
   234 	if ( SDL_VideoSurface->format->palette ) {
   235 	        SDL_PixelFormat *vf = SDL_VideoSurface->format;
   236 		SDL_DitherColors(vf->palette->colors, vf->BitsPerPixel);
   237 		video->SetColors(video,
   238 				 0, vf->palette->ncolors, vf->palette->colors);
   239 	}
   240 #endif
   241 	video->info.vfmt = SDL_VideoSurface->format;
   242 
   243 	/* Start the event loop */
   244 	if ( SDL_StartEventLoop(flags) < 0 ) {
   245 		SDL_VideoQuit();
   246 		return(-1);
   247 	}
   248 	SDL_CursorInit(flags & SDL_INIT_EVENTTHREAD);
   249 
   250 	/* We're ready to go! */
   251 	return(0);
   252 }
   253 
   254 char *SDL_VideoDriverName(char *namebuf, int maxlen)
   255 {
   256 	if ( current_video != NULL ) {
   257 		strncpy(namebuf, current_video->name, maxlen-1);
   258 		namebuf[maxlen-1] = '\0';
   259 		return(namebuf);
   260 	}
   261 	return(NULL);
   262 }
   263 
   264 /*
   265  * Get the current display surface
   266  */
   267 SDL_Surface *SDL_GetVideoSurface(void)
   268 {
   269 	SDL_Surface *visible;
   270 
   271 	visible = NULL;
   272 	if ( current_video ) {
   273 		visible = current_video->visible;
   274 	}
   275 	return(visible);
   276 }
   277 
   278 /*
   279  * Get the current information about the video hardware
   280  */
   281 const SDL_VideoInfo *SDL_GetVideoInfo(void)
   282 {
   283 	const SDL_VideoInfo *info;
   284 
   285 	info = NULL;
   286 	if ( current_video ) {
   287 		info = &current_video->info;
   288 	}
   289 	return(info);
   290 }
   291 
   292 /*
   293  * Return a pointer to an array of available screen dimensions for the
   294  * given format, sorted largest to smallest.  Returns NULL if there are
   295  * no dimensions available for a particular format, or (SDL_Rect **)-1
   296  * if any dimension is okay for the given format.  If 'format' is NULL,
   297  * the mode list will be for the format given by SDL_GetVideoInfo()->vfmt
   298  */
   299 SDL_Rect ** SDL_ListModes (SDL_PixelFormat *format, Uint32 flags)
   300 {
   301 	SDL_VideoDevice *video = current_video;
   302 	SDL_VideoDevice *this  = current_video;
   303 	SDL_Rect **modes;
   304 
   305 	modes = NULL;
   306 	if ( SDL_VideoSurface ) {
   307 		if ( format == NULL ) {
   308 			format = SDL_VideoSurface->format;
   309 		}
   310 		modes = video->ListModes(this, format, flags);
   311 	}
   312 	return(modes);
   313 }
   314 
   315 /*
   316  * Check to see if a particular video mode is supported.
   317  * It returns 0 if the requested mode is not supported under any bit depth,
   318  * or returns the bits-per-pixel of the closest available mode with the
   319  * given width and height.  If this bits-per-pixel is different from the
   320  * one used when setting the video mode, SDL_SetVideoMode() will succeed,
   321  * but will emulate the requested bits-per-pixel with a shadow surface.
   322  */
   323 static Uint8 SDL_closest_depths[4][8] = {
   324 	/* 8 bit closest depth ordering */
   325 	{ 0, 8, 16, 15, 32, 24, 0, 0 },
   326 	/* 15,16 bit closest depth ordering */
   327 	{ 0, 16, 15, 32, 24, 8, 0, 0 },
   328 	/* 24 bit closest depth ordering */
   329 	{ 0, 24, 32, 16, 15, 8, 0, 0 },
   330 	/* 32 bit closest depth ordering */
   331 	{ 0, 32, 16, 15, 24, 8, 0, 0 }
   332 };
   333 
   334 int SDL_VideoModeOK (int width, int height, int bpp, Uint32 flags) 
   335 {
   336 	int table, b, i;
   337 	int supported;
   338 	SDL_PixelFormat format;
   339 	SDL_Rect **sizes;
   340 
   341 	/* Currently 1 and 4 bpp are not supported */
   342 	if ( bpp < 8 || bpp > 32 ) {
   343 		return(0);
   344 	}
   345 	if ( (width == 0) || (height == 0) ) {
   346 		return(0);
   347 	}
   348 
   349 	/* Search through the list valid of modes */
   350 	memset(&format, 0, sizeof(format));
   351 	supported = 0;
   352 	table = ((bpp+7)/8)-1;
   353 	SDL_closest_depths[table][0] = bpp;
   354 	SDL_closest_depths[table][7] = 0;
   355 	for ( b = 0; !supported && SDL_closest_depths[table][b]; ++b ) {
   356 		format.BitsPerPixel = SDL_closest_depths[table][b];
   357 		sizes = SDL_ListModes(&format, flags);
   358 		if ( sizes == (SDL_Rect **)0 ) {
   359 			/* No sizes supported at this bit-depth */
   360 			continue;
   361 		} else 
   362 #ifdef macintosh /* MPW optimization bug? */
   363 		if ( (sizes == (SDL_Rect **)0xFFFFFFFF) ||
   364 #else
   365 		if ( (sizes == (SDL_Rect **)-1) ||
   366 #endif
   367 		     current_video->handles_any_size ) {
   368 			/* Any size supported at this bit-depth */
   369 			supported = 1;
   370 			continue;
   371 		} else
   372 		for ( i=0; sizes[i]; ++i ) {
   373 			if ((sizes[i]->w == width) && (sizes[i]->h == height)) {
   374 				supported = 1;
   375 				break;
   376 			}
   377 		}
   378 	}
   379 	if ( supported ) {
   380 		--b;
   381 		return(SDL_closest_depths[table][b]);
   382 	} else {
   383 		return(0);
   384 	}
   385 }
   386 
   387 /*
   388  * Get the closest non-emulated video mode to the one requested
   389  */
   390 static int SDL_GetVideoMode (int *w, int *h, int *BitsPerPixel, Uint32 flags)
   391 {
   392 	int table, b, i;
   393 	int supported;
   394 	int native_bpp;
   395 	SDL_PixelFormat format;
   396 	SDL_Rect **sizes;
   397 
   398 	/* Try the original video mode, get the closest depth */
   399 	native_bpp = SDL_VideoModeOK(*w, *h, *BitsPerPixel, flags);
   400 	if ( native_bpp == *BitsPerPixel ) {
   401 		return(1);
   402 	}
   403 	if ( native_bpp > 0 ) {
   404 		*BitsPerPixel = native_bpp;
   405 		return(1);
   406 	}
   407 
   408 	/* No exact size match at any depth, look for closest match */
   409 	memset(&format, 0, sizeof(format));
   410 	supported = 0;
   411 	table = ((*BitsPerPixel+7)/8)-1;
   412 	SDL_closest_depths[table][0] = *BitsPerPixel;
   413 	SDL_closest_depths[table][7] = SDL_VideoSurface->format->BitsPerPixel;
   414 	for ( b = 0; !supported && SDL_closest_depths[table][b]; ++b ) {
   415 		format.BitsPerPixel = SDL_closest_depths[table][b];
   416 		sizes = SDL_ListModes(&format, flags);
   417 		if ( sizes == (SDL_Rect **)0 ) {
   418 			/* No sizes supported at this bit-depth */
   419 			continue;
   420 		}
   421 		for ( i=0; sizes[i]; ++i ) {
   422 			if ((sizes[i]->w < *w) || (sizes[i]->h < *h)) {
   423 				if ( i > 0 ) {
   424 					--i;
   425 					*w = sizes[i]->w;
   426 					*h = sizes[i]->h;
   427 					*BitsPerPixel = SDL_closest_depths[table][b];
   428 					supported = 1;
   429 				} else {
   430 					/* Largest mode too small... */;
   431 				}
   432 				break;
   433 			}
   434 		}
   435 		if ( (i > 0) && ! sizes[i] ) {
   436 			/* The smallest mode was larger than requested, OK */
   437 			--i;
   438 			*w = sizes[i]->w;
   439 			*h = sizes[i]->h;
   440 			*BitsPerPixel = SDL_closest_depths[table][b];
   441 			supported = 1;
   442 		}
   443 	}
   444 	if ( ! supported ) {
   445 		SDL_SetError("No video mode large enough for %dx%d", *w, *h);
   446 	}
   447 	return(supported);
   448 }
   449 
   450 /* This should probably go somewhere else -- like SDL_surface.c */
   451 static void SDL_ClearSurface(SDL_Surface *surface)
   452 {
   453 	Uint32 black;
   454 
   455 	black = SDL_MapRGB(surface->format, 0, 0, 0);
   456 	SDL_FillRect(surface, NULL, black);
   457 	if ((surface->flags&SDL_HWSURFACE) && (surface->flags&SDL_DOUBLEBUF)) {
   458 		SDL_Flip(surface);
   459 		SDL_FillRect(surface, NULL, black);
   460 	}
   461 	SDL_Flip(surface);
   462 }
   463 
   464 /*
   465  * Create a shadow surface suitable for fooling the app. :-)
   466  */
   467 static void SDL_CreateShadowSurface(int depth)
   468 {
   469 	Uint32 Rmask, Gmask, Bmask;
   470 
   471 	/* Allocate the shadow surface */
   472 	if ( depth == (SDL_VideoSurface->format)->BitsPerPixel ) {
   473 		Rmask = (SDL_VideoSurface->format)->Rmask;
   474 		Gmask = (SDL_VideoSurface->format)->Gmask;
   475 		Bmask = (SDL_VideoSurface->format)->Bmask;
   476 	} else {
   477 		Rmask = Gmask = Bmask = 0;
   478 	}
   479 	SDL_ShadowSurface = SDL_CreateRGBSurface(SDL_SWSURFACE,
   480 				SDL_VideoSurface->w, SDL_VideoSurface->h,
   481 						depth, Rmask, Gmask, Bmask, 0);
   482 	if ( SDL_ShadowSurface == NULL ) {
   483 		return;
   484 	}
   485 
   486 	/* 8-bit shadow surfaces report that they have exclusive palette */
   487 	if ( SDL_ShadowSurface->format->palette ) {
   488 		SDL_ShadowSurface->flags |= SDL_HWPALETTE;
   489 		if ( depth == (SDL_VideoSurface->format)->BitsPerPixel ) {
   490 			memcpy(SDL_ShadowSurface->format->palette->colors,
   491 				SDL_VideoSurface->format->palette->colors,
   492 				SDL_VideoSurface->format->palette->ncolors*
   493 							sizeof(SDL_Color));
   494 		} else {
   495 			SDL_DitherColors(
   496 			SDL_ShadowSurface->format->palette->colors, depth);
   497 		}
   498 	}
   499 
   500 	/* If the video surface is resizable, the shadow should say so */
   501 	if ( (SDL_VideoSurface->flags & SDL_RESIZABLE) == SDL_RESIZABLE ) {
   502 		SDL_ShadowSurface->flags |= SDL_RESIZABLE;
   503 	}
   504 	/* If the video surface has no frame, the shadow should say so */
   505 	if ( (SDL_VideoSurface->flags & SDL_NOFRAME) == SDL_NOFRAME ) {
   506 		SDL_ShadowSurface->flags |= SDL_NOFRAME;
   507 	}
   508 	/* If the video surface is fullscreen, the shadow should say so */
   509 	if ( (SDL_VideoSurface->flags & SDL_FULLSCREEN) == SDL_FULLSCREEN ) {
   510 		SDL_ShadowSurface->flags |= SDL_FULLSCREEN;
   511 	}
   512 	/* If the video surface is flippable, the shadow should say so */
   513 	if ( (SDL_VideoSurface->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF ) {
   514 		SDL_ShadowSurface->flags |= SDL_DOUBLEBUF;
   515 	}
   516 	return;
   517 }
   518 
   519 /*
   520  * Set the requested video mode, allocating a shadow buffer if necessary.
   521  */
   522 SDL_Surface * SDL_SetVideoMode (int width, int height, int bpp, Uint32 flags)
   523 {
   524 	SDL_VideoDevice *video, *this;
   525 	SDL_Surface *prev_mode, *mode;
   526 	int video_w;
   527 	int video_h;
   528 	int video_bpp;
   529 	int is_opengl;
   530 	SDL_GrabMode saved_grab;
   531 
   532 	/* Start up the video driver, if necessary..
   533 	   WARNING: This is the only function protected this way!
   534 	 */
   535 	if ( ! current_video ) {
   536 		if ( SDL_Init(SDL_INIT_VIDEO|SDL_INIT_NOPARACHUTE) < 0 ) {
   537 			return(NULL);
   538 		}
   539 	}
   540 	this = video = current_video;
   541 
   542 	/* Default to the current video bpp */
   543 	if ( bpp == 0 ) {
   544 		flags |= SDL_ANYFORMAT;
   545 		bpp = SDL_VideoSurface->format->BitsPerPixel;
   546 	}
   547 
   548 	/* Get a good video mode, the closest one possible */
   549 	video_w = width;
   550 	video_h = height;
   551 	video_bpp = bpp;
   552 	if ( ! SDL_GetVideoMode(&video_w, &video_h, &video_bpp, flags) ) {
   553 		return(NULL);
   554 	}
   555 
   556 	/* Check the requested flags */
   557 	/* There's no palette in > 8 bits-per-pixel mode */
   558 	if ( video_bpp > 8 ) {
   559 		flags &= ~SDL_HWPALETTE;
   560 	}
   561 #if 0
   562 	if ( (flags&SDL_FULLSCREEN) != SDL_FULLSCREEN ) {
   563 		/* There's no windowed double-buffering */
   564 		flags &= ~SDL_DOUBLEBUF;
   565 	}
   566 #endif
   567 	if ( (flags&SDL_DOUBLEBUF) == SDL_DOUBLEBUF ) {
   568 		/* Use hardware surfaces when double-buffering */
   569 		flags |= SDL_HWSURFACE;
   570 	}
   571 
   572 	is_opengl = ( ( flags & SDL_OPENGL ) == SDL_OPENGL );
   573 	if ( is_opengl ) {
   574 		/* These flags are for 2D video modes only */
   575 		flags &= ~(SDL_HWSURFACE|SDL_DOUBLEBUF);
   576 	}
   577 
   578 	/* Reset the keyboard here so event callbacks can run */
   579 	SDL_ResetKeyboard();
   580 
   581 	/* Clean up any previous video mode */
   582 	if ( SDL_PublicSurface != NULL ) {
   583 		SDL_PublicSurface = NULL;
   584 	}
   585 	if ( SDL_ShadowSurface != NULL ) {
   586 		SDL_Surface *ready_to_go;
   587 		ready_to_go = SDL_ShadowSurface;
   588 		SDL_ShadowSurface = NULL;
   589 		SDL_FreeSurface(ready_to_go);
   590 	}
   591 	if ( video->physpal ) {
   592 		free(video->physpal->colors);
   593 		free(video->physpal);
   594 		video->physpal = NULL;
   595 	}
   596 	if( video->gammacols) {
   597 	        free(video->gammacols);
   598 		video->gammacols = NULL;
   599 	}
   600 
   601 	/* Save the previous grab state and turn off grab for mode switch */
   602 	saved_grab = SDL_WM_GrabInputOff();
   603 
   604 	/* Try to set the video mode, along with offset and clipping */
   605 	prev_mode = SDL_VideoSurface;
   606 	SDL_LockCursor();
   607 	SDL_VideoSurface = NULL;	/* In case it's freed by driver */
   608 	mode = video->SetVideoMode(this, prev_mode,video_w,video_h,video_bpp,flags);
   609 	if ( mode ) { /* Prevent resize events from mode change */
   610 	    SDL_PrivateResize(mode->w, mode->h);
   611         }
   612 	/*
   613 	 * rcg11292000
   614 	 * If you try to set an SDL_OPENGL surface, and fail to find a
   615 	 * matching  visual, then the next call to SDL_SetVideoMode()
   616 	 * will segfault, since  we no longer point to a dummy surface,
   617 	 * but rather NULL.
   618 	 * Sam 11/29/00
   619 	 * WARNING, we need to make sure that the previous mode hasn't
   620 	 * already been freed by the video driver.  What do we do in
   621 	 * that case?  Should we call SDL_VideoInit() again?
   622 	 */
   623 	SDL_VideoSurface = (mode != NULL) ? mode : prev_mode;
   624 
   625 	if ( (mode != NULL) && (!is_opengl) ) {
   626 		/* Sanity check */
   627 		if ( (mode->w < width) || (mode->h < height) ) {
   628 			SDL_SetError("Video mode smaller than requested");
   629 			return(NULL);
   630 		}
   631 
   632 		/* If we have a palettized surface, create a default palette */
   633 		if ( mode->format->palette ) {
   634 	        	SDL_PixelFormat *vf = mode->format;
   635 			SDL_DitherColors(vf->palette->colors, vf->BitsPerPixel);
   636 			video->SetColors(this, 0, vf->palette->ncolors,
   637 			                           vf->palette->colors);
   638 		}
   639 
   640 		/* Clear the surface to black */
   641 		video->offset_x = 0;
   642 		video->offset_y = 0;
   643 		mode->offset = 0;
   644 		SDL_SetClipRect(mode, NULL);
   645 		SDL_ClearSurface(mode);
   646 
   647 		/* Now adjust the offsets to match the desired mode */
   648 		video->offset_x = (mode->w-width)/2;
   649 		video->offset_y = (mode->h-height)/2;
   650 		mode->offset = video->offset_y*mode->pitch +
   651 				video->offset_x*mode->format->BytesPerPixel;
   652 #ifdef DEBUG_VIDEO
   653   fprintf(stderr,
   654 	"Requested mode: %dx%dx%d, obtained mode %dx%dx%d (offset %d)\n",
   655 		width, height, bpp,
   656 		mode->w, mode->h, mode->format->BitsPerPixel, mode->offset);
   657 #endif
   658 		mode->w = width;
   659 		mode->h = height;
   660 		SDL_SetClipRect(mode, NULL);
   661 	}
   662 	SDL_ResetCursor();
   663 	SDL_UnlockCursor();
   664 
   665 	/* If we failed setting a video mode, return NULL... (Uh Oh!) */
   666 	if ( mode == NULL ) {
   667 		return(NULL);
   668 	}
   669 
   670 	/* If there is no window manager, set the SDL_NOFRAME flag */
   671 	if ( ! video->info.wm_available ) {
   672 		mode->flags |= SDL_NOFRAME;
   673 	}
   674 
   675 	/* Reset the mouse cursor and grab for new video mode */
   676 	SDL_SetCursor(NULL);
   677 	if ( video->UpdateMouse ) {
   678 		video->UpdateMouse(this);
   679 	}
   680 	SDL_WM_GrabInput(saved_grab);
   681 	SDL_GetRelativeMouseState(NULL, NULL); /* Clear first large delta */
   682 
   683 	/* If we're running OpenGL, make the context current */
   684 	if ( (video->screen->flags & SDL_OPENGL) &&
   685 	      video->GL_MakeCurrent ) {
   686 		if ( video->GL_MakeCurrent(this) < 0 ) {
   687 			return(NULL);
   688 		}
   689 	}
   690 
   691 	/* Set up a fake SDL surface for OpenGL "blitting" */
   692 	if ( (flags & SDL_OPENGLBLIT) == SDL_OPENGLBLIT ) {
   693 		/* Load GL functions for performing the texture updates */
   694 #ifdef HAVE_OPENGL
   695 #define SDL_PROC(ret,func,params) \
   696 do { \
   697 	video->func = SDL_GL_GetProcAddress(#func); \
   698 	if ( ! video->func ) { \
   699 		SDL_SetError("Couldn't load GL function: %s\n", #func); \
   700 		return(NULL); \
   701 	} \
   702 } while ( 0 );
   703 #include "SDL_glfuncs.h"
   704 #undef SDL_PROC	
   705 
   706 		/* Create a software surface for blitting */
   707 #ifdef GL_VERSION_1_2
   708 		/* If the implementation either supports the packed pixels
   709 		   extension, or implements the core OpenGL 1.2 API, it will
   710 		   support the GL_UNSIGNED_SHORT_5_6_5 texture format.
   711 		 */
   712 		if ( (bpp == 16) &&
   713 		     (strstr((const char *)video->glGetString(GL_EXTENSIONS),
   714 		                           "GL_EXT_packed_pixels") ||
   715 		     (strncmp((const char *)video->glGetString(GL_VERSION),
   716 		              "1.2", 3) == 0)) )
   717 		{
   718 			video->is_32bit = 0;
   719 			SDL_VideoSurface = SDL_CreateRGBSurface(
   720 				flags, 
   721 				width, 
   722 				height,  
   723 				16,
   724 				31 << 11,
   725 				63 << 5,
   726 				31,
   727 				0
   728 				);
   729 		}
   730 		else
   731 #endif /* OpenGL 1.2 */
   732 		{
   733 			video->is_32bit = 1;
   734 			SDL_VideoSurface = SDL_CreateRGBSurface(
   735 				flags, 
   736 				width, 
   737 				height, 
   738 				32, 
   739 #if SDL_BYTEORDER == SDL_LIL_ENDIAN
   740 				0x000000FF,
   741 				0x0000FF00,
   742 				0x00FF0000,
   743 				0xFF000000
   744 #else
   745 				0xFF000000,
   746 				0x00FF0000,
   747 				0x0000FF00,
   748 				0x000000FF
   749 #endif
   750 				);
   751 		}
   752 		if ( ! SDL_VideoSurface ) {
   753 			return(NULL);
   754 		}
   755 		SDL_VideoSurface->flags = mode->flags | SDL_OPENGLBLIT;
   756 
   757 		/* Free the original video mode surface (is this safe?) */
   758 		SDL_FreeSurface(mode);
   759 
   760                 /* Set the surface completely opaque & white by default */
   761 		memset( SDL_VideoSurface->pixels, 255, SDL_VideoSurface->h * SDL_VideoSurface->pitch );
   762 		video->glGenTextures( 1, &video->texture );
   763 		video->glBindTexture( GL_TEXTURE_2D, video->texture );
   764 		video->glTexImage2D(
   765 			GL_TEXTURE_2D,
   766 			0,
   767 			video->is_32bit ? GL_RGBA : GL_RGB,
   768 			256,
   769 			256,
   770 			0,
   771 			video->is_32bit ? GL_RGBA : GL_RGB,
   772 #ifdef GL_VERSION_1_2
   773 			video->is_32bit ? GL_UNSIGNED_BYTE : GL_UNSIGNED_SHORT_5_6_5,
   774 #else
   775 			GL_UNSIGNED_BYTE,
   776 #endif
   777 			NULL);
   778 
   779 		video->UpdateRects = SDL_GL_UpdateRectsLock;
   780 #else
   781 		SDL_SetError("Somebody forgot to #define HAVE_OPENGL");
   782 		return(NULL);
   783 #endif
   784 	}
   785 
   786 	/* Create a shadow surface if necessary */
   787 	/* There are three conditions under which we create a shadow surface:
   788 		1.  We need a particular bits-per-pixel that we didn't get.
   789 		2.  We need a hardware palette and didn't get one.
   790 		3.  We need a software surface and got a hardware surface.
   791 	*/
   792 	if ( !(SDL_VideoSurface->flags & SDL_OPENGL) &&
   793 	     (
   794 	     (  !(flags&SDL_ANYFORMAT) &&
   795 			(SDL_VideoSurface->format->BitsPerPixel != bpp)) ||
   796 	     (   (flags&SDL_HWPALETTE) && 
   797 				!(SDL_VideoSurface->flags&SDL_HWPALETTE)) ||
   798 		/* If the surface is in hardware, video writes are visible
   799 		   as soon as they are performed, so we need to buffer them
   800 		 */
   801 	     (   ((flags&SDL_HWSURFACE) == SDL_SWSURFACE) &&
   802 				(SDL_VideoSurface->flags&SDL_HWSURFACE))
   803 	     ) ) {
   804 		SDL_CreateShadowSurface(bpp);
   805 		if ( SDL_ShadowSurface == NULL ) {
   806 			SDL_SetError("Couldn't create shadow surface");
   807 			return(NULL);
   808 		}
   809 		SDL_PublicSurface = SDL_ShadowSurface;
   810 	} else {
   811 		SDL_PublicSurface = SDL_VideoSurface;
   812 	}
   813 	video->info.vfmt = SDL_VideoSurface->format;
   814 
   815 	/* We're done! */
   816 	return(SDL_PublicSurface);
   817 }
   818 
   819 /* 
   820  * Convert a surface into the video pixel format.
   821  */
   822 SDL_Surface * SDL_DisplayFormat (SDL_Surface *surface)
   823 {
   824 	Uint32 flags;
   825 
   826 	if ( ! SDL_PublicSurface ) {
   827 		SDL_SetError("No video mode has been set");
   828 		return(NULL);
   829 	}
   830 	/* Set the flags appropriate for copying to display surface */
   831 	flags  = (SDL_PublicSurface->flags&SDL_HWSURFACE);
   832 #ifdef AUTORLE_DISPLAYFORMAT
   833 	flags |= (surface->flags & (SDL_SRCCOLORKEY|SDL_SRCALPHA));
   834 	flags |= SDL_RLEACCELOK;
   835 #else
   836 	flags |= surface->flags & (SDL_SRCCOLORKEY|SDL_SRCALPHA|SDL_RLEACCELOK);
   837 #endif
   838 	return(SDL_ConvertSurface(surface, SDL_PublicSurface->format, flags));
   839 }
   840 
   841 /*
   842  * Convert a surface into a format that's suitable for blitting to
   843  * the screen, but including an alpha channel.
   844  */
   845 SDL_Surface *SDL_DisplayFormatAlpha(SDL_Surface *surface)
   846 {
   847 	SDL_PixelFormat *vf;
   848 	SDL_PixelFormat *format;
   849 	SDL_Surface *converted;
   850 	Uint32 flags;
   851 	/* default to ARGB8888 */
   852 	Uint32 amask = 0xff000000;
   853 	Uint32 rmask = 0x00ff0000;
   854 	Uint32 gmask = 0x0000ff00;
   855 	Uint32 bmask = 0x000000ff;
   856 
   857 	if ( ! SDL_PublicSurface ) {
   858 		SDL_SetError("No video mode has been set");
   859 		return(NULL);
   860 	}
   861 	vf = SDL_PublicSurface->format;
   862 
   863 	switch(vf->BytesPerPixel) {
   864 	    case 2:
   865 		/* For XGY5[56]5, use, AXGY8888, where {X, Y} = {R, B}.
   866 		   For anything else (like ARGB4444) it doesn't matter
   867 		   since we have no special code for it anyway */
   868 		if ( (vf->Rmask == 0x1f) &&
   869 		     (vf->Bmask == 0xf800 || vf->Bmask == 0x7c00)) {
   870 			rmask = 0xff;
   871 			bmask = 0xff0000;
   872 		}
   873 		break;
   874 
   875 	    case 3:
   876 	    case 4:
   877 		/* Keep the video format, as long as the high 8 bits are
   878 		   unused or alpha */
   879 		if ( (vf->Rmask == 0xff) && (vf->Bmask == 0xff0000) ) {
   880 			rmask = 0xff;
   881 			bmask = 0xff0000;
   882 		}
   883 		break;
   884 
   885 	    default:
   886 		/* We have no other optimised formats right now. When/if a new
   887 		   optimised alpha format is written, add the converter here */
   888 		break;
   889 	}
   890 	format = SDL_AllocFormat(32, rmask, gmask, bmask, amask);
   891 	flags = SDL_PublicSurface->flags & SDL_HWSURFACE;
   892 	flags |= surface->flags & (SDL_SRCALPHA | SDL_RLEACCELOK);
   893 	converted = SDL_ConvertSurface(surface, format, flags);
   894 	SDL_FreeFormat(format);
   895 	return(converted);
   896 }
   897 
   898 /*
   899  * Update a specific portion of the physical screen
   900  */
   901 void SDL_UpdateRect(SDL_Surface *screen, Sint32 x, Sint32 y, Uint32 w, Uint32 h)
   902 {
   903 	if ( screen ) {
   904 		SDL_Rect rect;
   905 
   906 		/* Perform some checking */
   907 		if ( w == 0 )
   908 			w = screen->w;
   909 		if ( h == 0 )
   910 			h = screen->h;
   911 		if ( (int)(x+w) > screen->w )
   912 			return;
   913 		if ( (int)(y+h) > screen->h )
   914 			return;
   915 
   916 		/* Fill the rectangle */
   917 		rect.x = x;
   918 		rect.y = y;
   919 		rect.w = w;
   920 		rect.h = h;
   921 		SDL_UpdateRects(screen, 1, &rect);
   922 	}
   923 }
   924 void SDL_UpdateRects (SDL_Surface *screen, int numrects, SDL_Rect *rects)
   925 {
   926 	int i;
   927 	SDL_VideoDevice *video = current_video;
   928 	SDL_VideoDevice *this = current_video;
   929 
   930 	if ( screen == SDL_ShadowSurface ) {
   931 		/* Blit the shadow surface using saved mapping */
   932 	        SDL_Palette *pal = screen->format->palette;
   933 		SDL_Color *saved_colors = NULL;
   934 	        if ( pal && !(SDL_VideoSurface->flags & SDL_HWPALETTE) ) {
   935 			/* simulated 8bpp, use correct physical palette */
   936 			saved_colors = pal->colors;
   937 			if ( video->gammacols ) {
   938 				/* gamma-corrected palette */
   939 				pal->colors = video->gammacols;
   940 			} else if ( video->physpal ) {
   941 				/* physical palette different from logical */
   942 				pal->colors = video->physpal->colors;
   943 			}
   944 		}
   945 		if ( SHOULD_DRAWCURSOR(SDL_cursorstate) ) {
   946 			SDL_LockCursor();
   947 			SDL_DrawCursor(SDL_ShadowSurface);
   948 			for ( i=0; i<numrects; ++i ) {
   949 				SDL_LowerBlit(SDL_ShadowSurface, &rects[i], 
   950 						SDL_VideoSurface, &rects[i]);
   951 			}
   952 			SDL_EraseCursor(SDL_ShadowSurface);
   953 			SDL_UnlockCursor();
   954 		} else {
   955 			for ( i=0; i<numrects; ++i ) {
   956 				SDL_LowerBlit(SDL_ShadowSurface, &rects[i], 
   957 						SDL_VideoSurface, &rects[i]);
   958 			}
   959 		}
   960 		if ( saved_colors )
   961 			pal->colors = saved_colors;
   962 
   963 		/* Fall through to video surface update */
   964 		screen = SDL_VideoSurface;
   965 	}
   966 	if ( screen == SDL_VideoSurface ) {
   967 		/* Update the video surface */
   968 		if ( screen->offset ) {
   969 			for ( i=0; i<numrects; ++i ) {
   970 				rects[i].x += video->offset_x;
   971 				rects[i].y += video->offset_y;
   972 			}
   973 			video->UpdateRects(this, numrects, rects);
   974 			for ( i=0; i<numrects; ++i ) {
   975 				rects[i].x -= video->offset_x;
   976 				rects[i].y -= video->offset_y;
   977 			}
   978 		} else {
   979 			video->UpdateRects(this, numrects, rects);
   980 		}
   981 	}
   982 }
   983 
   984 /*
   985  * Performs hardware double buffering, if possible, or a full update if not.
   986  */
   987 int SDL_Flip(SDL_Surface *screen)
   988 {
   989 	SDL_VideoDevice *video = current_video;
   990 	/* Copy the shadow surface to the video surface */
   991 	if ( screen == SDL_ShadowSurface ) {
   992 		SDL_Rect rect;
   993 	        SDL_Palette *pal = screen->format->palette;
   994 		SDL_Color *saved_colors = NULL;
   995 	        if ( pal && !(SDL_VideoSurface->flags & SDL_HWPALETTE) ) {
   996 			/* simulated 8bpp, use correct physical palette */
   997 			saved_colors = pal->colors;
   998 			if ( video->gammacols ) {
   999 				/* gamma-corrected palette */
  1000 				pal->colors = video->gammacols;
  1001 			} else if ( video->physpal ) {
  1002 				/* physical palette different from logical */
  1003 				pal->colors = video->physpal->colors;
  1004 			}
  1005 		}
  1006 
  1007 		rect.x = 0;
  1008 		rect.y = 0;
  1009 		rect.w = screen->w;
  1010 		rect.h = screen->h;
  1011 		SDL_LowerBlit(SDL_ShadowSurface,&rect, SDL_VideoSurface,&rect);
  1012 
  1013 		if ( saved_colors )
  1014 			pal->colors = saved_colors;
  1015 		screen = SDL_VideoSurface;
  1016 	}
  1017 	if ( (screen->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF ) {
  1018 		SDL_VideoDevice *this  = current_video;
  1019 		return(video->FlipHWSurface(this, SDL_VideoSurface));
  1020 	} else {
  1021 		SDL_UpdateRect(screen, 0, 0, 0, 0);
  1022 	}
  1023 	return(0);
  1024 }
  1025 
  1026 static void SetPalette_logical(SDL_Surface *screen, SDL_Color *colors,
  1027 			       int firstcolor, int ncolors)
  1028 {
  1029         SDL_Palette *pal = screen->format->palette;
  1030 	SDL_Palette *vidpal;
  1031 
  1032 	if ( colors != (pal->colors + firstcolor) ) {
  1033 	        memcpy(pal->colors + firstcolor, colors,
  1034 		       ncolors * sizeof(*colors));
  1035 	}
  1036 
  1037 	vidpal = SDL_VideoSurface->format->palette;
  1038 	if ( (screen == SDL_ShadowSurface) && vidpal ) {
  1039 	        /*
  1040 		 * This is a shadow surface, and the physical
  1041 		 * framebuffer is also indexed. Propagate the
  1042 		 * changes to its logical palette so that
  1043 		 * updates are always identity blits
  1044 		 */
  1045 		memcpy(vidpal->colors + firstcolor, colors,
  1046 		       ncolors * sizeof(*colors));
  1047 	}
  1048 	SDL_FormatChanged(screen);
  1049 }
  1050 
  1051 static int SetPalette_physical(SDL_Surface *screen,
  1052                                SDL_Color *colors, int firstcolor, int ncolors)
  1053 {
  1054 	SDL_VideoDevice *video = current_video;
  1055 	int gotall = 1;
  1056 
  1057 	if ( video->physpal ) {
  1058 		/* We need to copy the new colors, since we haven't
  1059 		 * already done the copy in the logical set above.
  1060 		 */
  1061 		memcpy(video->physpal->colors + firstcolor,
  1062 		       colors, ncolors * sizeof(*colors));
  1063 	}
  1064 	if ( screen == SDL_ShadowSurface ) {
  1065 		if ( SDL_VideoSurface->flags & SDL_HWPALETTE ) {
  1066 			/*
  1067 			 * The real screen is also indexed - set its physical
  1068 			 * palette. The physical palette does not include the
  1069 			 * gamma modification, we apply it directly instead,
  1070 			 * but this only happens if we have hardware palette.
  1071 			 */
  1072 			screen = SDL_VideoSurface;
  1073 		} else {
  1074 			/*
  1075 			 * The video surface is not indexed - invalidate any
  1076 			 * active shadow-to-video blit mappings.
  1077 			 */
  1078 			if ( screen->map->dst == SDL_VideoSurface ) {
  1079 				SDL_InvalidateMap(screen->map);
  1080 			}
  1081 			if ( video->gamma ) {
  1082 				if( ! video->gammacols ) {
  1083 					SDL_Palette *pp = video->physpal;
  1084 					if(!pp)
  1085 						pp = screen->format->palette;
  1086 					video->gammacols = malloc(pp->ncolors
  1087 							  * sizeof(SDL_Color));
  1088 					SDL_ApplyGamma(video->gamma,
  1089 						       pp->colors,
  1090 						       video->gammacols,
  1091 						       pp->ncolors);
  1092 				} else {
  1093 					SDL_ApplyGamma(video->gamma, colors,
  1094 						       video->gammacols
  1095 						       + firstcolor,
  1096 						       ncolors);
  1097 				}
  1098 			}
  1099 			SDL_UpdateRect(screen, 0, 0, 0, 0);
  1100 		}
  1101 	}
  1102 
  1103 	if ( screen == SDL_VideoSurface ) {
  1104 		SDL_Color gcolors[256];
  1105 
  1106 	        if ( video->gamma ) {
  1107 		        SDL_ApplyGamma(video->gamma, colors, gcolors, ncolors);
  1108 			colors = gcolors;
  1109 		}
  1110 		gotall = video->SetColors(video, firstcolor, ncolors, colors);
  1111 		if ( ! gotall ) {
  1112 			/* The video flags shouldn't have SDL_HWPALETTE, and
  1113 			   the video driver is responsible for copying back the
  1114 			   correct colors into the video surface palette.
  1115 			*/
  1116 			;
  1117 		}
  1118 		SDL_CursorPaletteChanged();
  1119 	}
  1120 	return gotall;
  1121 }
  1122 
  1123 /*
  1124  * Set the physical and/or logical colormap of a surface:
  1125  * Only the screen has a physical colormap. It determines what is actually
  1126  * sent to the display.
  1127  * The logical colormap is used to map blits to/from the surface.
  1128  * 'which' is one or both of SDL_LOGPAL, SDL_PHYSPAL
  1129  *
  1130  * Return nonzero if all colours were set as requested, or 0 otherwise.
  1131  */
  1132 int SDL_SetPalette(SDL_Surface *screen, int which,
  1133 		   SDL_Color *colors, int firstcolor, int ncolors)
  1134 {
  1135         SDL_Palette *pal;
  1136 	int gotall;
  1137 	int palsize;
  1138 
  1139 	if ( ! current_video ) {
  1140 		return 0;
  1141 	}
  1142 	if ( screen != SDL_PublicSurface ) {
  1143 	        /* only screens have physical palettes */
  1144 	        which &= ~SDL_PHYSPAL;
  1145 	} else if( (screen->flags & SDL_HWPALETTE) != SDL_HWPALETTE ) {
  1146 	        /* hardware palettes required for split colormaps */
  1147 	        which |= SDL_PHYSPAL | SDL_LOGPAL;
  1148 	}
  1149 
  1150 	/* Verify the parameters */
  1151 	pal = screen->format->palette;
  1152 	if( !pal ) {
  1153 	        return 0;	/* not a palettized surface */
  1154 	}
  1155 	gotall = 1;
  1156 	palsize = 1 << screen->format->BitsPerPixel;
  1157 	if ( ncolors > (palsize - firstcolor) ) {
  1158 	        ncolors = (palsize - firstcolor);
  1159 		gotall = 0;
  1160 	}
  1161 
  1162 	if ( which & SDL_LOGPAL ) {
  1163 		/*
  1164 		 * Logical palette change: The actual screen isn't affected,
  1165 		 * but the internal colormap is altered so that the
  1166 		 * interpretation of the pixel values (for blits etc) is
  1167 		 * changed.
  1168 		 */
  1169 	        SetPalette_logical(screen, colors, firstcolor, ncolors);
  1170 	}
  1171 	if ( which & SDL_PHYSPAL ) {
  1172 		SDL_VideoDevice *video = current_video;
  1173 	        /*
  1174 		 * Physical palette change: This doesn't affect the
  1175 		 * program's idea of what the screen looks like, but changes
  1176 		 * its actual appearance.
  1177 		 */
  1178 	        if(!video)
  1179 		        return gotall;	/* video not yet initialized */
  1180 		if(!video->physpal && !(which & SDL_LOGPAL) ) {
  1181 			/* Lazy physical palette allocation */
  1182 		        int size;
  1183 			SDL_Palette *pp = malloc(sizeof(*pp));
  1184 			current_video->physpal = pp;
  1185 			pp->ncolors = pal->ncolors;
  1186 			size = pp->ncolors * sizeof(SDL_Color);
  1187 			pp->colors = malloc(size);
  1188 			memcpy(pp->colors, pal->colors, size);
  1189 		}
  1190 		if ( ! SetPalette_physical(screen,
  1191 		                           colors, firstcolor, ncolors) ) {
  1192 			gotall = 0;
  1193 		}
  1194 	}
  1195 	return gotall;
  1196 }
  1197 
  1198 int SDL_SetColors(SDL_Surface *screen, SDL_Color *colors, int firstcolor,
  1199 		  int ncolors)
  1200 {
  1201         return SDL_SetPalette(screen, SDL_LOGPAL | SDL_PHYSPAL,
  1202 			      colors, firstcolor, ncolors);
  1203 }
  1204 
  1205 /*
  1206  * Clean up the video subsystem
  1207  */
  1208 void SDL_VideoQuit (void)
  1209 {
  1210 	SDL_Surface *ready_to_go;
  1211 
  1212 	if ( current_video ) {
  1213 		SDL_VideoDevice *video = current_video;
  1214 		SDL_VideoDevice *this  = current_video;
  1215 
  1216 		/* Halt event processing before doing anything else */
  1217 		SDL_StopEventLoop();
  1218 
  1219 		/* Clean up allocated window manager items */
  1220 		if ( SDL_PublicSurface ) {
  1221 			SDL_PublicSurface = NULL;
  1222 		}
  1223 		SDL_CursorQuit();
  1224 
  1225 		/* Just in case... */
  1226 		SDL_WM_GrabInputOff();
  1227 
  1228 		/* Clean up the system video */
  1229 		video->VideoQuit(this);
  1230 
  1231 		/* Free any lingering surfaces */
  1232 		ready_to_go = SDL_ShadowSurface;
  1233 		SDL_ShadowSurface = NULL;
  1234 		SDL_FreeSurface(ready_to_go);
  1235 		if ( SDL_VideoSurface != NULL ) {
  1236 			ready_to_go = SDL_VideoSurface;
  1237 			SDL_VideoSurface = NULL;
  1238 			SDL_FreeSurface(ready_to_go);
  1239 		}
  1240 		SDL_PublicSurface = NULL;
  1241 
  1242 		/* Clean up miscellaneous memory */
  1243 		if ( video->physpal ) {
  1244 			free(video->physpal->colors);
  1245 			free(video->physpal);
  1246 			video->physpal = NULL;
  1247 		}
  1248 		if ( video->gammacols ) {
  1249 			free(video->gammacols);
  1250 			video->gammacols = NULL;
  1251 		}
  1252 		if ( video->gamma ) {
  1253 			free(video->gamma);
  1254 			video->gamma = NULL;
  1255 		}
  1256 		if ( video->wm_title != NULL ) {
  1257 			free(video->wm_title);
  1258 			video->wm_title = NULL;
  1259 		}
  1260 		if ( video->wm_icon != NULL ) {
  1261 			free(video->wm_icon);
  1262 			video->wm_icon = NULL;
  1263 		}
  1264 
  1265 		/* Finish cleaning up video subsystem */
  1266 		video->free(this);
  1267 		current_video = NULL;
  1268 	}
  1269 	return;
  1270 }
  1271 
  1272 /* Load the GL driver library */
  1273 int SDL_GL_LoadLibrary(const char *path)
  1274 {
  1275 	SDL_VideoDevice *video = current_video;
  1276 	SDL_VideoDevice *this = current_video;
  1277 	int retval;
  1278 
  1279 	retval = -1;
  1280 	if ( video && video->GL_LoadLibrary ) {
  1281 		retval = video->GL_LoadLibrary(this, path);
  1282 	} else {
  1283 		SDL_SetError("No dynamic GL support in video driver");
  1284 	}
  1285 	return(retval);
  1286 }
  1287 
  1288 void *SDL_GL_GetProcAddress(const char* proc)
  1289 {
  1290 	SDL_VideoDevice *video = current_video;
  1291 	SDL_VideoDevice *this = current_video;
  1292 	void *func;
  1293 
  1294 	func = NULL;
  1295 	if ( video->GL_GetProcAddress ) {
  1296 		if ( video->gl_config.driver_loaded ) {
  1297 			func = video->GL_GetProcAddress(this, proc);
  1298 		} else {
  1299 			SDL_SetError("No GL driver has been loaded");
  1300 		}
  1301 	} else {
  1302 		SDL_SetError("No dynamic GL support in video driver");
  1303 	}
  1304 	return func;
  1305 }
  1306 
  1307 /* Set the specified GL attribute for setting up a GL video mode */
  1308 int SDL_GL_SetAttribute( SDL_GLattr attr, int value )
  1309 {
  1310 	int retval;
  1311 	SDL_VideoDevice *video = current_video;
  1312 
  1313 	retval = 0;
  1314 	switch (attr) {
  1315 		case SDL_GL_RED_SIZE:
  1316 			video->gl_config.red_size = value;
  1317 			break;
  1318 		case SDL_GL_GREEN_SIZE:
  1319 			video->gl_config.green_size = value;
  1320 			break;
  1321 		case SDL_GL_BLUE_SIZE:
  1322 			video->gl_config.blue_size = value;
  1323 			break;
  1324 		case SDL_GL_ALPHA_SIZE:
  1325 			video->gl_config.alpha_size = value;
  1326 			break;
  1327 		case SDL_GL_DOUBLEBUFFER:
  1328 			video->gl_config.double_buffer = value;
  1329 			break;
  1330         	case SDL_GL_BUFFER_SIZE:
  1331 	        	video->gl_config.buffer_size = value;
  1332 			break;
  1333 		case SDL_GL_DEPTH_SIZE:
  1334 			video->gl_config.depth_size = value;
  1335 			break;
  1336 		case SDL_GL_STENCIL_SIZE:
  1337 			video->gl_config.stencil_size = value;
  1338 			break;
  1339 	        case SDL_GL_ACCUM_RED_SIZE:
  1340 			video->gl_config.accum_red_size = value;
  1341 			break;
  1342 	        case SDL_GL_ACCUM_GREEN_SIZE:
  1343 			video->gl_config.accum_green_size = value;
  1344 			break;
  1345 	        case SDL_GL_ACCUM_BLUE_SIZE:
  1346 			video->gl_config.accum_blue_size = value;
  1347 			break;
  1348 	        case SDL_GL_ACCUM_ALPHA_SIZE:
  1349 			video->gl_config.accum_alpha_size = value;
  1350 			break;
  1351 		default:
  1352 			SDL_SetError("Unknown OpenGL attribute");
  1353 			retval = -1;
  1354 			break;
  1355 	}
  1356 	return(retval);
  1357 }
  1358 
  1359 /* Retrieve an attribute value from the windowing system. */
  1360 int SDL_GL_GetAttribute(SDL_GLattr attr, int* value)
  1361 {
  1362 	int retval = -1;
  1363 	SDL_VideoDevice* video = current_video;
  1364 	SDL_VideoDevice* this = current_video;
  1365 
  1366 	if ( video->GL_GetAttribute ) {
  1367 		retval = this->GL_GetAttribute(this, attr, value);
  1368 	} else {
  1369 		*value = 0;
  1370 		SDL_SetError("GL_GetAttribute not supported");
  1371 	}
  1372 	return retval;
  1373 }
  1374 
  1375 /* Perform a GL buffer swap on the current GL context */
  1376 void SDL_GL_SwapBuffers(void)
  1377 {
  1378 	SDL_VideoDevice *video = current_video;
  1379 	SDL_VideoDevice *this = current_video;
  1380 
  1381 	if ( video->screen->flags & SDL_OPENGL ) {
  1382 		video->GL_SwapBuffers( this );
  1383 	}
  1384 }
  1385 
  1386 /* Update rects with locking */
  1387 void SDL_GL_UpdateRectsLock(SDL_VideoDevice* this, int numrects, SDL_Rect *rects)
  1388 {
  1389 	SDL_GL_Lock();
  1390  	SDL_GL_UpdateRects(numrects, rects);
  1391 	SDL_GL_Unlock();
  1392 }
  1393 
  1394 /* Update rects without state setting and changing (the caller is responsible for it) */
  1395 void SDL_GL_UpdateRects(int numrects, SDL_Rect *rects)
  1396 {
  1397 #ifdef HAVE_OPENGL
  1398 	SDL_VideoDevice *this = current_video;
  1399 	SDL_Rect update, tmp;
  1400 	int x, y, i;
  1401 
  1402 	for ( i = 0; i < numrects; i++ )
  1403 	{
  1404 		tmp.y = rects[i].y;
  1405 		tmp.h = rects[i].h;
  1406 		for ( y = 0; y <= rects[i].h / 256; y++ )
  1407 		{
  1408 			tmp.x = rects[i].x;
  1409 			tmp.w = rects[i].w;
  1410 			for ( x = 0; x <= rects[i].w / 256; x++ )
  1411 			{
  1412 				update.x = tmp.x;
  1413 				update.y = tmp.y;
  1414 				update.w = tmp.w;
  1415 				update.h = tmp.h;
  1416 
  1417 				if ( update.w > 256 )
  1418 					update.w = 256;
  1419 
  1420 				if ( update.h > 256 )
  1421 					update.h = 256;
  1422 			
  1423 				this->glFlush();
  1424 				this->glTexSubImage2D( 
  1425 					GL_TEXTURE_2D, 
  1426 					0, 
  1427 					0, 
  1428 					0, 
  1429 					update.w, 
  1430 					update.h, 
  1431 					this->is_32bit? GL_RGBA : GL_RGB,
  1432 #ifdef GL_VERSION_1_2
  1433 					this->is_32bit ? GL_UNSIGNED_BYTE : GL_UNSIGNED_SHORT_5_6_5,
  1434 #else
  1435 					GL_UNSIGNED_BYTE,
  1436 #endif
  1437 					(Uint8 *)this->screen->pixels + 
  1438 						this->screen->format->BytesPerPixel * update.x + 
  1439 						update.y * this->screen->pitch );
  1440 	
  1441 				this->glFlush();
  1442 				/*
  1443 				* Note the parens around the function name:
  1444 				* This is because some OpenGL implementations define glTexCoord etc 
  1445 				* as macros, and we don't want them expanded here.
  1446 				*/
  1447 				this->glBegin(GL_TRIANGLE_STRIP);
  1448 					(this->glTexCoord2f)( 0.0, 0.0 );	
  1449 					(this->glVertex2i)( update.x, update.y );
  1450 					(this->glTexCoord2f)( (float)(update.w / 256.0), 0.0 );	
  1451 					(this->glVertex2i)( update.x + update.w, update.y );
  1452 					(this->glTexCoord2f)( 0.0, (float)(update.h / 256.0) );
  1453 					(this->glVertex2i)( update.x, update.y + update.h );
  1454 					(this->glTexCoord2f)( (float)(update.w / 256.0), (float)(update.h / 256.0) );	
  1455 					(this->glVertex2i)( update.x + update.w	, update.y + update.h );
  1456 				this->glEnd();	
  1457 			
  1458 				tmp.x += 256;
  1459 				tmp.w -= 256;
  1460 			}
  1461 			tmp.y += 256;
  1462 			tmp.h -= 256;
  1463 		}
  1464 	}
  1465 #endif
  1466 }
  1467 
  1468 /* Lock == save current state */
  1469 void SDL_GL_Lock()
  1470 {
  1471 #ifdef HAVE_OPENGL
  1472 	lock_count--;
  1473 	if (lock_count==-1)
  1474 	{
  1475 		SDL_VideoDevice *this = current_video;
  1476 
  1477 		this->glPushAttrib( GL_ALL_ATTRIB_BITS );	/* TODO: narrow range of what is saved */
  1478 #ifdef GL_CLIENT_PIXEL_STORE_BIT
  1479 		this->glPushClientAttrib( GL_CLIENT_PIXEL_STORE_BIT );
  1480 #endif
  1481 
  1482 		this->glEnable(GL_TEXTURE_2D);
  1483 		this->glEnable(GL_BLEND);
  1484 		this->glDisable(GL_FOG);
  1485 		this->glDisable(GL_ALPHA_TEST);
  1486 		this->glDisable(GL_DEPTH_TEST);
  1487 		this->glDisable(GL_SCISSOR_TEST);	
  1488 		this->glDisable(GL_STENCIL_TEST);
  1489 		this->glDisable(GL_CULL_FACE);
  1490 
  1491 		this->glBindTexture( GL_TEXTURE_2D, this->texture );
  1492 		this->glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
  1493 		this->glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  1494 		this->glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
  1495 		this->glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
  1496 		this->glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
  1497 
  1498 		this->glPixelStorei( GL_UNPACK_ROW_LENGTH, this->screen->pitch / this->screen->format->BytesPerPixel );
  1499 		this->glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  1500 		(this->glColor4f)(1.0, 1.0, 1.0, 1.0);		/* Solaris workaround */
  1501 
  1502 		this->glViewport(0, 0, this->screen->w, this->screen->h);
  1503 		this->glMatrixMode(GL_PROJECTION);
  1504 		this->glPushMatrix();
  1505 		this->glLoadIdentity();
  1506 
  1507 		this->glOrtho(0.0, (GLdouble) this->screen->w, (GLdouble) this->screen->h, 0.0, 0.0, 1.0);
  1508 
  1509 		this->glMatrixMode(GL_MODELVIEW);
  1510 		this->glPushMatrix();
  1511 		this->glLoadIdentity();
  1512 	}
  1513 #endif
  1514 }
  1515 
  1516 /* Unlock == restore saved state */
  1517 void SDL_GL_Unlock()
  1518 {
  1519 #ifdef HAVE_OPENGL
  1520 	lock_count++;
  1521 	if (lock_count==0)
  1522 	{
  1523 		SDL_VideoDevice *this = current_video;
  1524 
  1525 		this->glPopMatrix();
  1526 		this->glMatrixMode(GL_PROJECTION);
  1527 		this->glPopMatrix();
  1528 
  1529 		this->glPopClientAttrib();
  1530 		this->glPopAttrib();
  1531 	}
  1532 #endif
  1533 }
  1534 
  1535 /*
  1536  * Sets/Gets the title and icon text of the display window, if any.
  1537  */
  1538 void SDL_WM_SetCaption (const char *title, const char *icon)
  1539 {
  1540 	SDL_VideoDevice *video = current_video;
  1541 	SDL_VideoDevice *this  = current_video;
  1542 
  1543 	if ( video ) {
  1544 		if ( title ) {
  1545 			if ( video->wm_title ) {
  1546 				free(video->wm_title);
  1547 			}
  1548 			video->wm_title = (char *)malloc(strlen(title)+1);
  1549 			if ( video->wm_title != NULL ) {
  1550 				strcpy(video->wm_title, title);
  1551 			}
  1552 		}
  1553 		if ( icon ) {
  1554 			if ( video->wm_icon ) {
  1555 				free(video->wm_icon);
  1556 			}
  1557 			video->wm_icon = (char *)malloc(strlen(icon)+1);
  1558 			if ( video->wm_icon != NULL ) {
  1559 				strcpy(video->wm_icon, icon);
  1560 			}
  1561 		}
  1562 		if ( (title || icon) && (video->SetCaption != NULL) ) {
  1563 			video->SetCaption(this, video->wm_title,video->wm_icon);
  1564 		}
  1565 	}
  1566 }
  1567 void SDL_WM_GetCaption (char **title, char **icon)
  1568 {
  1569 	SDL_VideoDevice *video = current_video;
  1570 
  1571 	if ( video ) {
  1572 		if ( title ) {
  1573 			*title = video->wm_title;
  1574 		}
  1575 		if ( icon ) {
  1576 			*icon = video->wm_icon;
  1577 		}
  1578 	}
  1579 }
  1580 
  1581 /* Utility function used by SDL_WM_SetIcon() */
  1582 static void CreateMaskFromColorKey(SDL_Surface *icon, Uint8 *mask)
  1583 {
  1584 	int x, y;
  1585 	Uint32 colorkey;
  1586 #define SET_MASKBIT(icon, x, y, mask) \
  1587 	mask[(y*((icon->w+7)/8))+(x/8)] &= ~(0x01<<(7-(x%8)))
  1588 
  1589 	colorkey = icon->format->colorkey;
  1590 	switch (icon->format->BytesPerPixel) {
  1591 		case 1: { Uint8 *pixels;
  1592 			for ( y=0; y<icon->h; ++y ) {
  1593 				pixels = (Uint8 *)icon->pixels + y*icon->pitch;
  1594 				for ( x=0; x<icon->w; ++x ) {
  1595 					if ( *pixels++ == colorkey ) {
  1596 						SET_MASKBIT(icon, x, y, mask);
  1597 					}
  1598 				}
  1599 			}
  1600 		}
  1601 		break;
  1602 
  1603 		case 2: { Uint16 *pixels;
  1604 			for ( y=0; y<icon->h; ++y ) {
  1605 				pixels = (Uint16 *)icon->pixels +
  1606 				                   y*icon->pitch/2;
  1607 				for ( x=0; x<icon->w; ++x ) {
  1608 					if ( *pixels++ == colorkey ) {
  1609 						SET_MASKBIT(icon, x, y, mask);
  1610 					}
  1611 				}
  1612 			}
  1613 		}
  1614 		break;
  1615 
  1616 		case 4: { Uint32 *pixels;
  1617 			for ( y=0; y<icon->h; ++y ) {
  1618 				pixels = (Uint32 *)icon->pixels +
  1619 				                   y*icon->pitch/4;
  1620 				for ( x=0; x<icon->w; ++x ) {
  1621 					if ( *pixels++ == colorkey ) {
  1622 						SET_MASKBIT(icon, x, y, mask);
  1623 					}
  1624 				}
  1625 			}
  1626 		}
  1627 		break;
  1628 	}
  1629 }
  1630 
  1631 /*
  1632  * Sets the window manager icon for the display window.
  1633  */
  1634 void SDL_WM_SetIcon (SDL_Surface *icon, Uint8 *mask)
  1635 {
  1636 	SDL_VideoDevice *video = current_video;
  1637 	SDL_VideoDevice *this  = current_video;
  1638 
  1639 	if ( icon && video->SetIcon ) {
  1640 		/* Generate a mask if necessary, and create the icon! */
  1641 		if ( mask == NULL ) {
  1642 			int mask_len = icon->h*(icon->w+7)/8;
  1643 			mask = (Uint8 *)malloc(mask_len);
  1644 			if ( mask == NULL ) {
  1645 				return;
  1646 			}
  1647 			memset(mask, ~0, mask_len);
  1648 			if ( icon->flags & SDL_SRCCOLORKEY ) {
  1649 				CreateMaskFromColorKey(icon, mask);
  1650 			}
  1651 			video->SetIcon(video, icon, mask);
  1652 			free(mask);
  1653 		} else {
  1654 			video->SetIcon(this, icon, mask);
  1655 		}
  1656 	}
  1657 }
  1658 
  1659 /*
  1660  * Grab or ungrab the keyboard and mouse input.
  1661  * This function returns the final grab mode after calling the
  1662  * driver dependent function.
  1663  */
  1664 static SDL_GrabMode SDL_WM_GrabInputRaw(SDL_GrabMode mode)
  1665 {
  1666 	SDL_VideoDevice *video = current_video;
  1667 	SDL_VideoDevice *this  = current_video;
  1668 
  1669 	/* Only do something if we have support for grabs */
  1670 	if ( video->GrabInput == NULL ) {
  1671 		return(video->input_grab);
  1672 	}
  1673 
  1674 	/* If the final grab mode if off, only then do we actually grab */
  1675 #ifdef DEBUG_GRAB
  1676   printf("SDL_WM_GrabInputRaw(%d) ... ", mode);
  1677 #endif
  1678 	if ( mode == SDL_GRAB_OFF ) {
  1679 		if ( video->input_grab != SDL_GRAB_OFF ) {
  1680 			mode = video->GrabInput(this, mode);
  1681 		}
  1682 	} else {
  1683 		if ( video->input_grab == SDL_GRAB_OFF ) {
  1684 			mode = video->GrabInput(this, mode);
  1685 		}
  1686 	}
  1687 	if ( mode != video->input_grab ) {
  1688 		video->input_grab = mode;
  1689 		if ( video->CheckMouseMode ) {
  1690 			video->CheckMouseMode(this);
  1691 		}
  1692 	}
  1693 #ifdef DEBUG_GRAB
  1694   printf("Final mode %d\n", video->input_grab);
  1695 #endif
  1696 
  1697 	/* Return the final grab state */
  1698 	if ( mode >= SDL_GRAB_FULLSCREEN ) {
  1699 		mode -= SDL_GRAB_FULLSCREEN;
  1700 	}
  1701 	return(mode);
  1702 }
  1703 SDL_GrabMode SDL_WM_GrabInput(SDL_GrabMode mode)
  1704 {
  1705 	SDL_VideoDevice *video = current_video;
  1706 
  1707 	/* If the video isn't initialized yet, we can't do anything */
  1708 	if ( ! video ) {
  1709 		return SDL_GRAB_OFF;
  1710 	}
  1711 
  1712 	/* Return the current mode on query */
  1713 	if ( mode == SDL_GRAB_QUERY ) {
  1714 		mode = video->input_grab;
  1715 		if ( mode >= SDL_GRAB_FULLSCREEN ) {
  1716 			mode -= SDL_GRAB_FULLSCREEN;
  1717 		}
  1718 		return(mode);
  1719 	}
  1720 
  1721 #ifdef DEBUG_GRAB
  1722   printf("SDL_WM_GrabInput(%d) ... ", mode);
  1723 #endif
  1724 	/* If the video surface is fullscreen, we always grab */
  1725 	if ( mode >= SDL_GRAB_FULLSCREEN ) {
  1726 		mode -= SDL_GRAB_FULLSCREEN;
  1727 	}
  1728 	if ( SDL_VideoSurface && (SDL_VideoSurface->flags & SDL_FULLSCREEN) ) {
  1729 		mode += SDL_GRAB_FULLSCREEN;
  1730 	}
  1731 	return(SDL_WM_GrabInputRaw(mode));
  1732 }
  1733 static SDL_GrabMode SDL_WM_GrabInputOff(void)
  1734 {
  1735 	SDL_GrabMode mode;
  1736 
  1737 	/* First query the current grab state */
  1738 	mode = SDL_WM_GrabInput(SDL_GRAB_QUERY);
  1739 
  1740 	/* Now explicitly turn off input grab */
  1741 	SDL_WM_GrabInputRaw(SDL_GRAB_OFF);
  1742 
  1743 	/* Return the old state */
  1744 	return(mode);
  1745 }
  1746 
  1747 /*
  1748  * Iconify the window in window managed environments.
  1749  * A successful iconification will result in an SDL_APPACTIVE loss event.
  1750  */
  1751 int SDL_WM_IconifyWindow(void)
  1752 {
  1753 	SDL_VideoDevice *video = current_video;
  1754 	SDL_VideoDevice *this  = current_video;
  1755 	int retval;
  1756 
  1757 	retval = 0;
  1758 	if ( video->IconifyWindow ) {
  1759 		retval = video->IconifyWindow(this);
  1760 	}
  1761 	return(retval);
  1762 }
  1763 
  1764 /*
  1765  * Toggle fullscreen mode
  1766  */
  1767 int SDL_WM_ToggleFullScreen(SDL_Surface *surface)
  1768 {
  1769 	SDL_VideoDevice *video = current_video;
  1770 	SDL_VideoDevice *this  = current_video;
  1771 	int toggled;
  1772 
  1773 	toggled = 0;
  1774 	if ( SDL_PublicSurface && (surface == SDL_PublicSurface) &&
  1775 	     video->ToggleFullScreen ) {
  1776 		if ( surface->flags & SDL_FULLSCREEN ) {
  1777 			toggled = video->ToggleFullScreen(this, 0);
  1778 			if ( toggled ) {
  1779 				SDL_VideoSurface->flags &= ~SDL_FULLSCREEN;
  1780 				SDL_PublicSurface->flags &= ~SDL_FULLSCREEN;
  1781 			}
  1782 		} else {
  1783 			toggled = video->ToggleFullScreen(this, 1);
  1784 			if ( toggled ) {
  1785 				SDL_VideoSurface->flags |= SDL_FULLSCREEN;
  1786 				SDL_PublicSurface->flags |= SDL_FULLSCREEN;
  1787 			}
  1788 		}
  1789 		/* Double-check the grab state inside SDL_WM_GrabInput() */
  1790 		if ( toggled ) {
  1791 			SDL_WM_GrabInput(video->input_grab);
  1792 		}
  1793 	}
  1794 	return(toggled);
  1795 }
  1796 
  1797 /*
  1798  * Get some platform dependent window manager information
  1799  */
  1800 int SDL_GetWMInfo (SDL_SysWMinfo *info)
  1801 {
  1802 	SDL_VideoDevice *video = current_video;
  1803 	SDL_VideoDevice *this  = current_video;
  1804 
  1805 	if ( video && video->GetWMInfo ) {
  1806 		return(video->GetWMInfo(this, info));
  1807 	} else {
  1808 		return(0);
  1809 	}
  1810 }