include/SDL_video.h
author Sam Lantinga <slouken@libsdl.org>
Sun, 02 Jan 2005 05:11:16 +0000
changeset 1020 5b1cb1e9140d
parent 911 04a403e4ccf5
child 1312 c9b51268668f
permissions -rw-r--r--
Allow SDL to be loaded by Matlab
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2004 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@libsdl.org
    21 */
    22 
    23 #ifdef SAVE_RCSID
    24 static char rcsid =
    25  "@(#) $Id$";
    26 #endif
    27 
    28 /* Header file for access to the SDL raw framebuffer window */
    29 
    30 #ifndef _SDL_video_h
    31 #define _SDL_video_h
    32 
    33 #include <stdio.h>
    34 
    35 #include "SDL_types.h"
    36 #include "SDL_mutex.h"
    37 #include "SDL_rwops.h"
    38 
    39 #include "begin_code.h"
    40 /* Set up for C function definitions, even when using C++ */
    41 #ifdef __cplusplus
    42 extern "C" {
    43 #endif
    44 
    45 /* Transparency definitions: These define alpha as the opacity of a surface */
    46 #define SDL_ALPHA_OPAQUE 255
    47 #define SDL_ALPHA_TRANSPARENT 0
    48 
    49 /* Useful data types */
    50 typedef struct SDL_Rect {
    51 	Sint16 x, y;
    52 	Uint16 w, h;
    53 } SDL_Rect;
    54 
    55 typedef struct SDL_Color {
    56 	Uint8 r;
    57 	Uint8 g;
    58 	Uint8 b;
    59 	Uint8 unused;
    60 } SDL_Color;
    61 #define SDL_Colour SDL_Color
    62 
    63 typedef struct SDL_Palette {
    64 	int       ncolors;
    65 	SDL_Color *colors;
    66 } SDL_Palette;
    67 
    68 /* Everything in the pixel format structure is read-only */
    69 typedef struct SDL_PixelFormat {
    70 	SDL_Palette *palette;
    71 	Uint8  BitsPerPixel;
    72 	Uint8  BytesPerPixel;
    73 	Uint8  Rloss;
    74 	Uint8  Gloss;
    75 	Uint8  Bloss;
    76 	Uint8  Aloss;
    77 	Uint8  Rshift;
    78 	Uint8  Gshift;
    79 	Uint8  Bshift;
    80 	Uint8  Ashift;
    81 	Uint32 Rmask;
    82 	Uint32 Gmask;
    83 	Uint32 Bmask;
    84 	Uint32 Amask;
    85 
    86 	/* RGB color key information */
    87 	Uint32 colorkey;
    88 	/* Alpha value information (per-surface alpha) */
    89 	Uint8  alpha;
    90 } SDL_PixelFormat;
    91 
    92 /* This structure should be treated as read-only, except for 'pixels',
    93    which, if not NULL, contains the raw pixel data for the surface.
    94 */
    95 typedef struct SDL_Surface {
    96 	Uint32 flags;				/* Read-only */
    97 	SDL_PixelFormat *format;		/* Read-only */
    98 	int w, h;				/* Read-only */
    99 	Uint16 pitch;				/* Read-only */
   100 	void *pixels;				/* Read-write */
   101 	int offset;				/* Private */
   102 
   103 	/* Hardware-specific surface info */
   104 	struct private_hwdata *hwdata;
   105 
   106 	/* clipping information */
   107 	SDL_Rect clip_rect;			/* Read-only */
   108 	Uint32 unused1;				/* for binary compatibility */
   109 
   110 	/* Allow recursive locks */
   111 	Uint32 locked;				/* Private */
   112 
   113 	/* info for fast blit mapping to other surfaces */
   114 	struct SDL_BlitMap *map;		/* Private */
   115 
   116 	/* format version, bumped at every change to invalidate blit maps */
   117 	unsigned int format_version;		/* Private */
   118 
   119 	/* Reference count -- used when freeing surface */
   120 	int refcount;				/* Read-mostly */
   121 } SDL_Surface;
   122 
   123 /* These are the currently supported flags for the SDL_surface */
   124 /* Available for SDL_CreateRGBSurface() or SDL_SetVideoMode() */
   125 #define SDL_SWSURFACE	0x00000000	/* Surface is in system memory */
   126 #define SDL_HWSURFACE	0x00000001	/* Surface is in video memory */
   127 #define SDL_ASYNCBLIT	0x00000004	/* Use asynchronous blits if possible */
   128 /* Available for SDL_SetVideoMode() */
   129 #define SDL_ANYFORMAT	0x10000000	/* Allow any video depth/pixel-format */
   130 #define SDL_HWPALETTE	0x20000000	/* Surface has exclusive palette */
   131 #define SDL_DOUBLEBUF	0x40000000	/* Set up double-buffered video mode */
   132 #define SDL_FULLSCREEN	0x80000000	/* Surface is a full screen display */
   133 #define SDL_OPENGL      0x00000002      /* Create an OpenGL rendering context */
   134 #define SDL_OPENGLBLIT	0x0000000A	/* Create an OpenGL rendering context and use it for blitting */
   135 #define SDL_RESIZABLE	0x00000010	/* This video mode may be resized */
   136 #define SDL_NOFRAME	0x00000020	/* No window caption or edge frame */
   137 /* Used internally (read-only) */
   138 #define SDL_HWACCEL	0x00000100	/* Blit uses hardware acceleration */
   139 #define SDL_SRCCOLORKEY	0x00001000	/* Blit uses a source color key */
   140 #define SDL_RLEACCELOK	0x00002000	/* Private flag */
   141 #define SDL_RLEACCEL	0x00004000	/* Surface is RLE encoded */
   142 #define SDL_SRCALPHA	0x00010000	/* Blit uses source alpha blending */
   143 #define SDL_PREALLOC	0x01000000	/* Surface uses preallocated memory */
   144 
   145 /* Evaluates to true if the surface needs to be locked before access */
   146 #define SDL_MUSTLOCK(surface)	\
   147   (surface->offset ||		\
   148   ((surface->flags & (SDL_HWSURFACE|SDL_ASYNCBLIT|SDL_RLEACCEL)) != 0))
   149 
   150 /* typedef for private surface blitting functions */
   151 typedef int (*SDL_blit)(struct SDL_Surface *src, SDL_Rect *srcrect,
   152 			struct SDL_Surface *dst, SDL_Rect *dstrect);
   153 
   154 
   155 /* Useful for determining the video hardware capabilities */
   156 typedef struct SDL_VideoInfo {
   157 	Uint32 hw_available :1;	/* Flag: Can you create hardware surfaces? */
   158 	Uint32 wm_available :1;	/* Flag: Can you talk to a window manager? */
   159 	Uint32 UnusedBits1  :6;
   160 	Uint32 UnusedBits2  :1;
   161 	Uint32 blit_hw      :1;	/* Flag: Accelerated blits HW --> HW */
   162 	Uint32 blit_hw_CC   :1;	/* Flag: Accelerated blits with Colorkey */
   163 	Uint32 blit_hw_A    :1;	/* Flag: Accelerated blits with Alpha */
   164 	Uint32 blit_sw      :1;	/* Flag: Accelerated blits SW --> HW */
   165 	Uint32 blit_sw_CC   :1;	/* Flag: Accelerated blits with Colorkey */
   166 	Uint32 blit_sw_A    :1;	/* Flag: Accelerated blits with Alpha */
   167 	Uint32 blit_fill    :1;	/* Flag: Accelerated color fill */
   168 	Uint32 UnusedBits3  :16;
   169 	Uint32 video_mem;	/* The total amount of video memory (in K) */
   170 	SDL_PixelFormat *vfmt;	/* Value: The format of the video surface */
   171 } SDL_VideoInfo;
   172 
   173 
   174 /* The most common video overlay formats.
   175    For an explanation of these pixel formats, see:
   176 	http://www.webartz.com/fourcc/indexyuv.htm
   177 
   178    For information on the relationship between color spaces, see:
   179    http://www.neuro.sfc.keio.ac.jp/~aly/polygon/info/color-space-faq.html
   180  */
   181 #define SDL_YV12_OVERLAY  0x32315659	/* Planar mode: Y + V + U  (3 planes) */
   182 #define SDL_IYUV_OVERLAY  0x56555949	/* Planar mode: Y + U + V  (3 planes) */
   183 #define SDL_YUY2_OVERLAY  0x32595559	/* Packed mode: Y0+U0+Y1+V0 (1 plane) */
   184 #define SDL_UYVY_OVERLAY  0x59565955	/* Packed mode: U0+Y0+V0+Y1 (1 plane) */
   185 #define SDL_YVYU_OVERLAY  0x55595659	/* Packed mode: Y0+V0+Y1+U0 (1 plane) */
   186 
   187 /* The YUV hardware video overlay */
   188 typedef struct SDL_Overlay {
   189 	Uint32 format;				/* Read-only */
   190 	int w, h;				/* Read-only */
   191 	int planes;				/* Read-only */
   192 	Uint16 *pitches;			/* Read-only */
   193 	Uint8 **pixels;				/* Read-write */
   194 
   195 	/* Hardware-specific surface info */
   196 	struct private_yuvhwfuncs *hwfuncs;
   197 	struct private_yuvhwdata *hwdata;
   198 
   199 	/* Special flags */
   200 	Uint32 hw_overlay :1;	/* Flag: This overlay hardware accelerated? */
   201 	Uint32 UnusedBits :31;
   202 } SDL_Overlay;
   203 
   204 
   205 /* Public enumeration for setting the OpenGL window attributes. */
   206 typedef enum {
   207     SDL_GL_RED_SIZE,
   208     SDL_GL_GREEN_SIZE,
   209     SDL_GL_BLUE_SIZE,
   210     SDL_GL_ALPHA_SIZE,
   211     SDL_GL_BUFFER_SIZE,
   212     SDL_GL_DOUBLEBUFFER,
   213     SDL_GL_DEPTH_SIZE,
   214     SDL_GL_STENCIL_SIZE,
   215     SDL_GL_ACCUM_RED_SIZE,
   216     SDL_GL_ACCUM_GREEN_SIZE,
   217     SDL_GL_ACCUM_BLUE_SIZE,
   218     SDL_GL_ACCUM_ALPHA_SIZE,
   219     SDL_GL_STEREO,
   220     SDL_GL_MULTISAMPLEBUFFERS,
   221     SDL_GL_MULTISAMPLESAMPLES
   222 } SDL_GLattr;
   223 
   224 /* flags for SDL_SetPalette() */
   225 #define SDL_LOGPAL 0x01
   226 #define SDL_PHYSPAL 0x02
   227 
   228 /* Function prototypes */
   229 
   230 /* These functions are used internally, and should not be used unless you
   231  * have a specific need to specify the video driver you want to use.
   232  * You should normally use SDL_Init() or SDL_InitSubSystem().
   233  *
   234  * SDL_VideoInit() initializes the video subsystem -- sets up a connection
   235  * to the window manager, etc, and determines the current video mode and
   236  * pixel format, but does not initialize a window or graphics mode.
   237  * Note that event handling is activated by this routine.
   238  *
   239  * If you use both sound and video in your application, you need to call
   240  * SDL_Init() before opening the sound device, otherwise under Win32 DirectX,
   241  * you won't be able to set full-screen display modes.
   242  */
   243 extern DECLSPEC int SDLCALL SDL_VideoInit(const char *driver_name, Uint32 flags);
   244 extern DECLSPEC void SDLCALL SDL_VideoQuit(void);
   245 
   246 /* This function fills the given character buffer with the name of the
   247  * video driver, and returns a pointer to it if the video driver has
   248  * been initialized.  It returns NULL if no driver has been initialized.
   249  */
   250 extern DECLSPEC char * SDLCALL SDL_VideoDriverName(char *namebuf, int maxlen);
   251 
   252 /*
   253  * This function returns a pointer to the current display surface.
   254  * If SDL is doing format conversion on the display surface, this
   255  * function returns the publicly visible surface, not the real video
   256  * surface.
   257  */
   258 extern DECLSPEC SDL_Surface * SDLCALL SDL_GetVideoSurface(void);
   259 
   260 /*
   261  * This function returns a read-only pointer to information about the
   262  * video hardware.  If this is called before SDL_SetVideoMode(), the 'vfmt'
   263  * member of the returned structure will contain the pixel format of the
   264  * "best" video mode.
   265  */
   266 extern DECLSPEC const SDL_VideoInfo * SDLCALL SDL_GetVideoInfo(void);
   267 
   268 /* 
   269  * Check to see if a particular video mode is supported.
   270  * It returns 0 if the requested mode is not supported under any bit depth,
   271  * or returns the bits-per-pixel of the closest available mode with the
   272  * given width and height.  If this bits-per-pixel is different from the
   273  * one used when setting the video mode, SDL_SetVideoMode() will succeed,
   274  * but will emulate the requested bits-per-pixel with a shadow surface.
   275  *
   276  * The arguments to SDL_VideoModeOK() are the same ones you would pass to
   277  * SDL_SetVideoMode()
   278  */
   279 extern DECLSPEC int SDLCALL SDL_VideoModeOK(int width, int height, int bpp, Uint32 flags);
   280 
   281 /*
   282  * Return a pointer to an array of available screen dimensions for the
   283  * given format and video flags, sorted largest to smallest.  Returns 
   284  * NULL if there are no dimensions available for a particular format, 
   285  * or (SDL_Rect **)-1 if any dimension is okay for the given format.
   286  *
   287  * If 'format' is NULL, the mode list will be for the format given 
   288  * by SDL_GetVideoInfo()->vfmt
   289  */
   290 extern DECLSPEC SDL_Rect ** SDLCALL SDL_ListModes(SDL_PixelFormat *format, Uint32 flags);
   291 
   292 /*
   293  * Set up a video mode with the specified width, height and bits-per-pixel.
   294  *
   295  * If 'bpp' is 0, it is treated as the current display bits per pixel.
   296  *
   297  * If SDL_ANYFORMAT is set in 'flags', the SDL library will try to set the
   298  * requested bits-per-pixel, but will return whatever video pixel format is
   299  * available.  The default is to emulate the requested pixel format if it
   300  * is not natively available.
   301  *
   302  * If SDL_HWSURFACE is set in 'flags', the video surface will be placed in
   303  * video memory, if possible, and you may have to call SDL_LockSurface()
   304  * in order to access the raw framebuffer.  Otherwise, the video surface
   305  * will be created in system memory.
   306  *
   307  * If SDL_ASYNCBLIT is set in 'flags', SDL will try to perform rectangle
   308  * updates asynchronously, but you must always lock before accessing pixels.
   309  * SDL will wait for updates to complete before returning from the lock.
   310  *
   311  * If SDL_HWPALETTE is set in 'flags', the SDL library will guarantee
   312  * that the colors set by SDL_SetColors() will be the colors you get.
   313  * Otherwise, in 8-bit mode, SDL_SetColors() may not be able to set all
   314  * of the colors exactly the way they are requested, and you should look
   315  * at the video surface structure to determine the actual palette.
   316  * If SDL cannot guarantee that the colors you request can be set, 
   317  * i.e. if the colormap is shared, then the video surface may be created
   318  * under emulation in system memory, overriding the SDL_HWSURFACE flag.
   319  *
   320  * If SDL_FULLSCREEN is set in 'flags', the SDL library will try to set
   321  * a fullscreen video mode.  The default is to create a windowed mode
   322  * if the current graphics system has a window manager.
   323  * If the SDL library is able to set a fullscreen video mode, this flag 
   324  * will be set in the surface that is returned.
   325  *
   326  * If SDL_DOUBLEBUF is set in 'flags', the SDL library will try to set up
   327  * two surfaces in video memory and swap between them when you call 
   328  * SDL_Flip().  This is usually slower than the normal single-buffering
   329  * scheme, but prevents "tearing" artifacts caused by modifying video 
   330  * memory while the monitor is refreshing.  It should only be used by 
   331  * applications that redraw the entire screen on every update.
   332  *
   333  * If SDL_RESIZABLE is set in 'flags', the SDL library will allow the
   334  * window manager, if any, to resize the window at runtime.  When this
   335  * occurs, SDL will send a SDL_VIDEORESIZE event to you application,
   336  * and you must respond to the event by re-calling SDL_SetVideoMode()
   337  * with the requested size (or another size that suits the application).
   338  *
   339  * If SDL_NOFRAME is set in 'flags', the SDL library will create a window
   340  * without any title bar or frame decoration.  Fullscreen video modes have
   341  * this flag set automatically.
   342  *
   343  * This function returns the video framebuffer surface, or NULL if it fails.
   344  *
   345  * If you rely on functionality provided by certain video flags, check the
   346  * flags of the returned surface to make sure that functionality is available.
   347  * SDL will fall back to reduced functionality if the exact flags you wanted
   348  * are not available.
   349  */
   350 extern DECLSPEC SDL_Surface * SDLCALL SDL_SetVideoMode
   351 			(int width, int height, int bpp, Uint32 flags);
   352 
   353 /*
   354  * Makes sure the given list of rectangles is updated on the given screen.
   355  * If 'x', 'y', 'w' and 'h' are all 0, SDL_UpdateRect will update the entire
   356  * screen.
   357  * These functions should not be called while 'screen' is locked.
   358  */
   359 extern DECLSPEC void SDLCALL SDL_UpdateRects
   360 		(SDL_Surface *screen, int numrects, SDL_Rect *rects);
   361 extern DECLSPEC void SDLCALL SDL_UpdateRect
   362 		(SDL_Surface *screen, Sint32 x, Sint32 y, Uint32 w, Uint32 h);
   363 
   364 /*
   365  * On hardware that supports double-buffering, this function sets up a flip
   366  * and returns.  The hardware will wait for vertical retrace, and then swap
   367  * video buffers before the next video surface blit or lock will return.
   368  * On hardware that doesn not support double-buffering, this is equivalent
   369  * to calling SDL_UpdateRect(screen, 0, 0, 0, 0);
   370  * The SDL_DOUBLEBUF flag must have been passed to SDL_SetVideoMode() when
   371  * setting the video mode for this function to perform hardware flipping.
   372  * This function returns 0 if successful, or -1 if there was an error.
   373  */
   374 extern DECLSPEC int SDLCALL SDL_Flip(SDL_Surface *screen);
   375 
   376 /*
   377  * Set the gamma correction for each of the color channels.
   378  * The gamma values range (approximately) between 0.1 and 10.0
   379  * 
   380  * If this function isn't supported directly by the hardware, it will
   381  * be emulated using gamma ramps, if available.  If successful, this
   382  * function returns 0, otherwise it returns -1.
   383  */
   384 extern DECLSPEC int SDLCALL SDL_SetGamma(float red, float green, float blue);
   385 
   386 /*
   387  * Set the gamma translation table for the red, green, and blue channels
   388  * of the video hardware.  Each table is an array of 256 16-bit quantities,
   389  * representing a mapping between the input and output for that channel.
   390  * The input is the index into the array, and the output is the 16-bit
   391  * gamma value at that index, scaled to the output color precision.
   392  * 
   393  * You may pass NULL for any of the channels to leave it unchanged.
   394  * If the call succeeds, it will return 0.  If the display driver or
   395  * hardware does not support gamma translation, or otherwise fails,
   396  * this function will return -1.
   397  */
   398 extern DECLSPEC int SDLCALL SDL_SetGammaRamp(const Uint16 *red, const Uint16 *green, const Uint16 *blue);
   399 
   400 /*
   401  * Retrieve the current values of the gamma translation tables.
   402  * 
   403  * You must pass in valid pointers to arrays of 256 16-bit quantities.
   404  * Any of the pointers may be NULL to ignore that channel.
   405  * If the call succeeds, it will return 0.  If the display driver or
   406  * hardware does not support gamma translation, or otherwise fails,
   407  * this function will return -1.
   408  */
   409 extern DECLSPEC int SDLCALL SDL_GetGammaRamp(Uint16 *red, Uint16 *green, Uint16 *blue);
   410 
   411 /*
   412  * Sets a portion of the colormap for the given 8-bit surface.  If 'surface'
   413  * is not a palettized surface, this function does nothing, returning 0.
   414  * If all of the colors were set as passed to SDL_SetColors(), it will
   415  * return 1.  If not all the color entries were set exactly as given,
   416  * it will return 0, and you should look at the surface palette to
   417  * determine the actual color palette.
   418  *
   419  * When 'surface' is the surface associated with the current display, the
   420  * display colormap will be updated with the requested colors.  If 
   421  * SDL_HWPALETTE was set in SDL_SetVideoMode() flags, SDL_SetColors()
   422  * will always return 1, and the palette is guaranteed to be set the way
   423  * you desire, even if the window colormap has to be warped or run under
   424  * emulation.
   425  */
   426 extern DECLSPEC int SDLCALL SDL_SetColors(SDL_Surface *surface, 
   427 			SDL_Color *colors, int firstcolor, int ncolors);
   428 
   429 /*
   430  * Sets a portion of the colormap for a given 8-bit surface.
   431  * 'flags' is one or both of:
   432  * SDL_LOGPAL  -- set logical palette, which controls how blits are mapped
   433  *                to/from the surface,
   434  * SDL_PHYSPAL -- set physical palette, which controls how pixels look on
   435  *                the screen
   436  * Only screens have physical palettes. Separate change of physical/logical
   437  * palettes is only possible if the screen has SDL_HWPALETTE set.
   438  *
   439  * The return value is 1 if all colours could be set as requested, and 0
   440  * otherwise.
   441  *
   442  * SDL_SetColors() is equivalent to calling this function with
   443  *     flags = (SDL_LOGPAL|SDL_PHYSPAL).
   444  */
   445 extern DECLSPEC int SDLCALL SDL_SetPalette(SDL_Surface *surface, int flags,
   446 				   SDL_Color *colors, int firstcolor,
   447 				   int ncolors);
   448 
   449 /*
   450  * Maps an RGB triple to an opaque pixel value for a given pixel format
   451  */
   452 extern DECLSPEC Uint32 SDLCALL SDL_MapRGB
   453 			(SDL_PixelFormat *format, Uint8 r, Uint8 g, Uint8 b);
   454 
   455 /*
   456  * Maps an RGBA quadruple to a pixel value for a given pixel format
   457  */
   458 extern DECLSPEC Uint32 SDLCALL SDL_MapRGBA(SDL_PixelFormat *format,
   459 				   Uint8 r, Uint8 g, Uint8 b, Uint8 a);
   460 
   461 /*
   462  * Maps a pixel value into the RGB components for a given pixel format
   463  */
   464 extern DECLSPEC void SDLCALL SDL_GetRGB(Uint32 pixel, SDL_PixelFormat *fmt,
   465 				Uint8 *r, Uint8 *g, Uint8 *b);
   466 
   467 /*
   468  * Maps a pixel value into the RGBA components for a given pixel format
   469  */
   470 extern DECLSPEC void SDLCALL SDL_GetRGBA(Uint32 pixel, SDL_PixelFormat *fmt,
   471 				 Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a);
   472 
   473 /*
   474  * Allocate and free an RGB surface (must be called after SDL_SetVideoMode)
   475  * If the depth is 4 or 8 bits, an empty palette is allocated for the surface.
   476  * If the depth is greater than 8 bits, the pixel format is set using the
   477  * flags '[RGB]mask'.
   478  * If the function runs out of memory, it will return NULL.
   479  *
   480  * The 'flags' tell what kind of surface to create.
   481  * SDL_SWSURFACE means that the surface should be created in system memory.
   482  * SDL_HWSURFACE means that the surface should be created in video memory,
   483  * with the same format as the display surface.  This is useful for surfaces
   484  * that will not change much, to take advantage of hardware acceleration
   485  * when being blitted to the display surface.
   486  * SDL_ASYNCBLIT means that SDL will try to perform asynchronous blits with
   487  * this surface, but you must always lock it before accessing the pixels.
   488  * SDL will wait for current blits to finish before returning from the lock.
   489  * SDL_SRCCOLORKEY indicates that the surface will be used for colorkey blits.
   490  * If the hardware supports acceleration of colorkey blits between
   491  * two surfaces in video memory, SDL will try to place the surface in
   492  * video memory. If this isn't possible or if there is no hardware
   493  * acceleration available, the surface will be placed in system memory.
   494  * SDL_SRCALPHA means that the surface will be used for alpha blits and 
   495  * if the hardware supports hardware acceleration of alpha blits between
   496  * two surfaces in video memory, to place the surface in video memory
   497  * if possible, otherwise it will be placed in system memory.
   498  * If the surface is created in video memory, blits will be _much_ faster,
   499  * but the surface format must be identical to the video surface format,
   500  * and the only way to access the pixels member of the surface is to use
   501  * the SDL_LockSurface() and SDL_UnlockSurface() calls.
   502  * If the requested surface actually resides in video memory, SDL_HWSURFACE
   503  * will be set in the flags member of the returned surface.  If for some
   504  * reason the surface could not be placed in video memory, it will not have
   505  * the SDL_HWSURFACE flag set, and will be created in system memory instead.
   506  */
   507 #define SDL_AllocSurface    SDL_CreateRGBSurface
   508 extern DECLSPEC SDL_Surface * SDLCALL SDL_CreateRGBSurface
   509 			(Uint32 flags, int width, int height, int depth, 
   510 			Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
   511 extern DECLSPEC SDL_Surface * SDLCALL SDL_CreateRGBSurfaceFrom(void *pixels,
   512 			int width, int height, int depth, int pitch,
   513 			Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
   514 extern DECLSPEC void SDLCALL SDL_FreeSurface(SDL_Surface *surface);
   515 
   516 /*
   517  * SDL_LockSurface() sets up a surface for directly accessing the pixels.
   518  * Between calls to SDL_LockSurface()/SDL_UnlockSurface(), you can write
   519  * to and read from 'surface->pixels', using the pixel format stored in 
   520  * 'surface->format'.  Once you are done accessing the surface, you should 
   521  * use SDL_UnlockSurface() to release it.
   522  *
   523  * Not all surfaces require locking.  If SDL_MUSTLOCK(surface) evaluates
   524  * to 0, then you can read and write to the surface at any time, and the
   525  * pixel format of the surface will not change.  In particular, if the
   526  * SDL_HWSURFACE flag is not given when calling SDL_SetVideoMode(), you
   527  * will not need to lock the display surface before accessing it.
   528  * 
   529  * No operating system or library calls should be made between lock/unlock
   530  * pairs, as critical system locks may be held during this time.
   531  *
   532  * SDL_LockSurface() returns 0, or -1 if the surface couldn't be locked.
   533  */
   534 extern DECLSPEC int SDLCALL SDL_LockSurface(SDL_Surface *surface);
   535 extern DECLSPEC void SDLCALL SDL_UnlockSurface(SDL_Surface *surface);
   536 
   537 /*
   538  * Load a surface from a seekable SDL data source (memory or file.)
   539  * If 'freesrc' is non-zero, the source will be closed after being read.
   540  * Returns the new surface, or NULL if there was an error.
   541  * The new surface should be freed with SDL_FreeSurface().
   542  */
   543 extern DECLSPEC SDL_Surface * SDLCALL SDL_LoadBMP_RW(SDL_RWops *src, int freesrc);
   544 
   545 /* Convenience macro -- load a surface from a file */
   546 #define SDL_LoadBMP(file)	SDL_LoadBMP_RW(SDL_RWFromFile(file, "rb"), 1)
   547 
   548 /*
   549  * Save a surface to a seekable SDL data source (memory or file.)
   550  * If 'freedst' is non-zero, the source will be closed after being written.
   551  * Returns 0 if successful or -1 if there was an error.
   552  */
   553 extern DECLSPEC int SDLCALL SDL_SaveBMP_RW
   554 		(SDL_Surface *surface, SDL_RWops *dst, int freedst);
   555 
   556 /* Convenience macro -- save a surface to a file */
   557 #define SDL_SaveBMP(surface, file) \
   558 		SDL_SaveBMP_RW(surface, SDL_RWFromFile(file, "wb"), 1)
   559 
   560 /*
   561  * Sets the color key (transparent pixel) in a blittable surface.
   562  * If 'flag' is SDL_SRCCOLORKEY (optionally OR'd with SDL_RLEACCEL), 
   563  * 'key' will be the transparent pixel in the source image of a blit.
   564  * SDL_RLEACCEL requests RLE acceleration for the surface if present,
   565  * and removes RLE acceleration if absent.
   566  * If 'flag' is 0, this function clears any current color key.
   567  * This function returns 0, or -1 if there was an error.
   568  */
   569 extern DECLSPEC int SDLCALL SDL_SetColorKey
   570 			(SDL_Surface *surface, Uint32 flag, Uint32 key);
   571 
   572 /*
   573  * This function sets the alpha value for the entire surface, as opposed to
   574  * using the alpha component of each pixel. This value measures the range
   575  * of transparency of the surface, 0 being completely transparent to 255
   576  * being completely opaque. An 'alpha' value of 255 causes blits to be
   577  * opaque, the source pixels copied to the destination (the default). Note
   578  * that per-surface alpha can be combined with colorkey transparency.
   579  *
   580  * If 'flag' is 0, alpha blending is disabled for the surface.
   581  * If 'flag' is SDL_SRCALPHA, alpha blending is enabled for the surface.
   582  * OR:ing the flag with SDL_RLEACCEL requests RLE acceleration for the
   583  * surface; if SDL_RLEACCEL is not specified, the RLE accel will be removed.
   584  *
   585  * The 'alpha' parameter is ignored for surfaces that have an alpha channel.
   586  */
   587 extern DECLSPEC int SDLCALL SDL_SetAlpha(SDL_Surface *surface, Uint32 flag, Uint8 alpha);
   588 
   589 /*
   590  * Sets the clipping rectangle for the destination surface in a blit.
   591  *
   592  * If the clip rectangle is NULL, clipping will be disabled.
   593  * If the clip rectangle doesn't intersect the surface, the function will
   594  * return SDL_FALSE and blits will be completely clipped.  Otherwise the
   595  * function returns SDL_TRUE and blits to the surface will be clipped to
   596  * the intersection of the surface area and the clipping rectangle.
   597  *
   598  * Note that blits are automatically clipped to the edges of the source
   599  * and destination surfaces.
   600  */
   601 extern DECLSPEC SDL_bool SDLCALL SDL_SetClipRect(SDL_Surface *surface, const SDL_Rect *rect);
   602 
   603 /*
   604  * Gets the clipping rectangle for the destination surface in a blit.
   605  * 'rect' must be a pointer to a valid rectangle which will be filled
   606  * with the correct values.
   607  */
   608 extern DECLSPEC void SDLCALL SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect);
   609 
   610 /*
   611  * Creates a new surface of the specified format, and then copies and maps 
   612  * the given surface to it so the blit of the converted surface will be as 
   613  * fast as possible.  If this function fails, it returns NULL.
   614  *
   615  * The 'flags' parameter is passed to SDL_CreateRGBSurface() and has those 
   616  * semantics.  You can also pass SDL_RLEACCEL in the flags parameter and
   617  * SDL will try to RLE accelerate colorkey and alpha blits in the resulting
   618  * surface.
   619  *
   620  * This function is used internally by SDL_DisplayFormat().
   621  */
   622 extern DECLSPEC SDL_Surface * SDLCALL SDL_ConvertSurface
   623 			(SDL_Surface *src, SDL_PixelFormat *fmt, Uint32 flags);
   624 
   625 /*
   626  * This performs a fast blit from the source surface to the destination
   627  * surface.  It assumes that the source and destination rectangles are
   628  * the same size.  If either 'srcrect' or 'dstrect' are NULL, the entire
   629  * surface (src or dst) is copied.  The final blit rectangles are saved
   630  * in 'srcrect' and 'dstrect' after all clipping is performed.
   631  * If the blit is successful, it returns 0, otherwise it returns -1.
   632  *
   633  * The blit function should not be called on a locked surface.
   634  *
   635  * The blit semantics for surfaces with and without alpha and colorkey
   636  * are defined as follows:
   637  *
   638  * RGBA->RGB:
   639  *     SDL_SRCALPHA set:
   640  * 	alpha-blend (using alpha-channel).
   641  * 	SDL_SRCCOLORKEY ignored.
   642  *     SDL_SRCALPHA not set:
   643  * 	copy RGB.
   644  * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
   645  * 	RGB values of the source colour key, ignoring alpha in the
   646  * 	comparison.
   647  * 
   648  * RGB->RGBA:
   649  *     SDL_SRCALPHA set:
   650  * 	alpha-blend (using the source per-surface alpha value);
   651  * 	set destination alpha to opaque.
   652  *     SDL_SRCALPHA not set:
   653  * 	copy RGB, set destination alpha to source per-surface alpha value.
   654  *     both:
   655  * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
   656  * 	source colour key.
   657  * 
   658  * RGBA->RGBA:
   659  *     SDL_SRCALPHA set:
   660  * 	alpha-blend (using the source alpha channel) the RGB values;
   661  * 	leave destination alpha untouched. [Note: is this correct?]
   662  * 	SDL_SRCCOLORKEY ignored.
   663  *     SDL_SRCALPHA not set:
   664  * 	copy all of RGBA to the destination.
   665  * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
   666  * 	RGB values of the source colour key, ignoring alpha in the
   667  * 	comparison.
   668  * 
   669  * RGB->RGB: 
   670  *     SDL_SRCALPHA set:
   671  * 	alpha-blend (using the source per-surface alpha value).
   672  *     SDL_SRCALPHA not set:
   673  * 	copy RGB.
   674  *     both:
   675  * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
   676  * 	source colour key.
   677  *
   678  * If either of the surfaces were in video memory, and the blit returns -2,
   679  * the video memory was lost, so it should be reloaded with artwork and 
   680  * re-blitted:
   681 	while ( SDL_BlitSurface(image, imgrect, screen, dstrect) == -2 ) {
   682 		while ( SDL_LockSurface(image) < 0 )
   683 			Sleep(10);
   684 		-- Write image pixels to image->pixels --
   685 		SDL_UnlockSurface(image);
   686 	}
   687  * This happens under DirectX 5.0 when the system switches away from your
   688  * fullscreen application.  The lock will also fail until you have access
   689  * to the video memory again.
   690  */
   691 /* You should call SDL_BlitSurface() unless you know exactly how SDL
   692    blitting works internally and how to use the other blit functions.
   693 */
   694 #define SDL_BlitSurface SDL_UpperBlit
   695 
   696 /* This is the public blit function, SDL_BlitSurface(), and it performs
   697    rectangle validation and clipping before passing it to SDL_LowerBlit()
   698 */
   699 extern DECLSPEC int SDLCALL SDL_UpperBlit
   700 			(SDL_Surface *src, SDL_Rect *srcrect,
   701 			 SDL_Surface *dst, SDL_Rect *dstrect);
   702 /* This is a semi-private blit function and it performs low-level surface
   703    blitting only.
   704 */
   705 extern DECLSPEC int SDLCALL SDL_LowerBlit
   706 			(SDL_Surface *src, SDL_Rect *srcrect,
   707 			 SDL_Surface *dst, SDL_Rect *dstrect);
   708 
   709 /*
   710  * This function performs a fast fill of the given rectangle with 'color'
   711  * The given rectangle is clipped to the destination surface clip area
   712  * and the final fill rectangle is saved in the passed in pointer.
   713  * If 'dstrect' is NULL, the whole surface will be filled with 'color'
   714  * The color should be a pixel of the format used by the surface, and 
   715  * can be generated by the SDL_MapRGB() function.
   716  * This function returns 0 on success, or -1 on error.
   717  */
   718 extern DECLSPEC int SDLCALL SDL_FillRect
   719 		(SDL_Surface *dst, SDL_Rect *dstrect, Uint32 color);
   720 
   721 /* 
   722  * This function takes a surface and copies it to a new surface of the
   723  * pixel format and colors of the video framebuffer, suitable for fast
   724  * blitting onto the display surface.  It calls SDL_ConvertSurface()
   725  *
   726  * If you want to take advantage of hardware colorkey or alpha blit
   727  * acceleration, you should set the colorkey and alpha value before
   728  * calling this function.
   729  *
   730  * If the conversion fails or runs out of memory, it returns NULL
   731  */
   732 extern DECLSPEC SDL_Surface * SDLCALL SDL_DisplayFormat(SDL_Surface *surface);
   733 
   734 /* 
   735  * This function takes a surface and copies it to a new surface of the
   736  * pixel format and colors of the video framebuffer (if possible),
   737  * suitable for fast alpha blitting onto the display surface.
   738  * The new surface will always have an alpha channel.
   739  *
   740  * If you want to take advantage of hardware colorkey or alpha blit
   741  * acceleration, you should set the colorkey and alpha value before
   742  * calling this function.
   743  *
   744  * If the conversion fails or runs out of memory, it returns NULL
   745  */
   746 extern DECLSPEC SDL_Surface * SDLCALL SDL_DisplayFormatAlpha(SDL_Surface *surface);
   747 
   748 
   749 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   750 /* YUV video surface overlay functions                                       */
   751 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   752 
   753 /* This function creates a video output overlay
   754    Calling the returned surface an overlay is something of a misnomer because
   755    the contents of the display surface underneath the area where the overlay
   756    is shown is undefined - it may be overwritten with the converted YUV data.
   757 */
   758 extern DECLSPEC SDL_Overlay * SDLCALL SDL_CreateYUVOverlay(int width, int height,
   759 				Uint32 format, SDL_Surface *display);
   760 
   761 /* Lock an overlay for direct access, and unlock it when you are done */
   762 extern DECLSPEC int SDLCALL SDL_LockYUVOverlay(SDL_Overlay *overlay);
   763 extern DECLSPEC void SDLCALL SDL_UnlockYUVOverlay(SDL_Overlay *overlay);
   764 
   765 /* Blit a video overlay to the display surface.
   766    The contents of the video surface underneath the blit destination are
   767    not defined.  
   768    The width and height of the destination rectangle may be different from
   769    that of the overlay, but currently only 2x scaling is supported.
   770 */
   771 extern DECLSPEC int SDLCALL SDL_DisplayYUVOverlay(SDL_Overlay *overlay, SDL_Rect *dstrect);
   772 
   773 /* Free a video overlay */
   774 extern DECLSPEC void SDLCALL SDL_FreeYUVOverlay(SDL_Overlay *overlay);
   775 
   776 
   777 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   778 /* OpenGL support functions.                                                 */
   779 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   780 
   781 /*
   782  * Dynamically load a GL driver, if SDL is built with dynamic GL.
   783  *
   784  * SDL links normally with the OpenGL library on your system by default,
   785  * but you can compile it to dynamically load the GL driver at runtime.
   786  * If you do this, you need to retrieve all of the GL functions used in
   787  * your program from the dynamic library using SDL_GL_GetProcAddress().
   788  *
   789  * This is disabled in default builds of SDL.
   790  */
   791 extern DECLSPEC int SDLCALL SDL_GL_LoadLibrary(const char *path);
   792 
   793 /*
   794  * Get the address of a GL function (for extension functions)
   795  */
   796 extern DECLSPEC void * SDLCALL SDL_GL_GetProcAddress(const char* proc);
   797 
   798 /*
   799  * Set an attribute of the OpenGL subsystem before intialization.
   800  */
   801 extern DECLSPEC int SDLCALL SDL_GL_SetAttribute(SDL_GLattr attr, int value);
   802 
   803 /*
   804  * Get an attribute of the OpenGL subsystem from the windowing
   805  * interface, such as glX. This is of course different from getting
   806  * the values from SDL's internal OpenGL subsystem, which only
   807  * stores the values you request before initialization.
   808  *
   809  * Developers should track the values they pass into SDL_GL_SetAttribute
   810  * themselves if they want to retrieve these values.
   811  */
   812 extern DECLSPEC int SDLCALL SDL_GL_GetAttribute(SDL_GLattr attr, int* value);
   813 
   814 /*
   815  * Swap the OpenGL buffers, if double-buffering is supported.
   816  */
   817 extern DECLSPEC void SDLCALL SDL_GL_SwapBuffers(void);
   818 
   819 /*
   820  * Internal functions that should not be called unless you have read
   821  * and understood the source code for these functions.
   822  */
   823 extern DECLSPEC void SDLCALL SDL_GL_UpdateRects(int numrects, SDL_Rect* rects);
   824 extern DECLSPEC void SDLCALL SDL_GL_Lock(void);
   825 extern DECLSPEC void SDLCALL SDL_GL_Unlock(void);
   826 
   827 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   828 /* These functions allow interaction with the window manager, if any.        */
   829 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   830 
   831 /*
   832  * Sets/Gets the title and icon text of the display window
   833  */
   834 extern DECLSPEC void SDLCALL SDL_WM_SetCaption(const char *title, const char *icon);
   835 extern DECLSPEC void SDLCALL SDL_WM_GetCaption(char **title, char **icon);
   836 
   837 /*
   838  * Sets the icon for the display window.
   839  * This function must be called before the first call to SDL_SetVideoMode().
   840  * It takes an icon surface, and a mask in MSB format.
   841  * If 'mask' is NULL, the entire icon surface will be used as the icon.
   842  */
   843 extern DECLSPEC void SDLCALL SDL_WM_SetIcon(SDL_Surface *icon, Uint8 *mask);
   844 
   845 /*
   846  * This function iconifies the window, and returns 1 if it succeeded.
   847  * If the function succeeds, it generates an SDL_APPACTIVE loss event.
   848  * This function is a noop and returns 0 in non-windowed environments.
   849  */
   850 extern DECLSPEC int SDLCALL SDL_WM_IconifyWindow(void);
   851 
   852 /*
   853  * Toggle fullscreen mode without changing the contents of the screen.
   854  * If the display surface does not require locking before accessing
   855  * the pixel information, then the memory pointers will not change.
   856  *
   857  * If this function was able to toggle fullscreen mode (change from 
   858  * running in a window to fullscreen, or vice-versa), it will return 1.
   859  * If it is not implemented, or fails, it returns 0.
   860  *
   861  * The next call to SDL_SetVideoMode() will set the mode fullscreen
   862  * attribute based on the flags parameter - if SDL_FULLSCREEN is not
   863  * set, then the display will be windowed by default where supported.
   864  *
   865  * This is currently only implemented in the X11 video driver.
   866  */
   867 extern DECLSPEC int SDLCALL SDL_WM_ToggleFullScreen(SDL_Surface *surface);
   868 
   869 /*
   870  * This function allows you to set and query the input grab state of
   871  * the application.  It returns the new input grab state.
   872  */
   873 typedef enum {
   874 	SDL_GRAB_QUERY = -1,
   875 	SDL_GRAB_OFF = 0,
   876 	SDL_GRAB_ON = 1,
   877 	SDL_GRAB_FULLSCREEN	/* Used internally */
   878 } SDL_GrabMode;
   879 /*
   880  * Grabbing means that the mouse is confined to the application window,
   881  * and nearly all keyboard input is passed directly to the application,
   882  * and not interpreted by a window manager, if any.
   883  */
   884 extern DECLSPEC SDL_GrabMode SDLCALL SDL_WM_GrabInput(SDL_GrabMode mode);
   885 
   886 /* Not in public API at the moment - do not use! */
   887 extern DECLSPEC int SDLCALL SDL_SoftStretch(SDL_Surface *src, SDL_Rect *srcrect,
   888                                     SDL_Surface *dst, SDL_Rect *dstrect);
   889                     
   890 /* Ends C function definitions when using C++ */
   891 #ifdef __cplusplus
   892 }
   893 #endif
   894 #include "close_code.h"
   895 
   896 #endif /* _SDL_video_h */