include/SDL_video.h
author Sam Lantinga <slouken@libsdl.org>
Mon, 19 Aug 2002 17:58:08 +0000
changeset 450 8a43e0cbf02f
parent 432 80a35d43a58f
child 639 6961e1c84e76
permissions -rw-r--r--
Added SDL_GL_STEREO for stereoscopic OpenGL contexts
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  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 {
    51 	Sint16 x, y;
    52 	Uint16 w, h;
    53 } SDL_Rect;
    54 
    55 typedef struct {
    56 	Uint8 r;
    57 	Uint8 g;
    58 	Uint8 b;
    59 	Uint8 unused;
    60 } SDL_Color;
    61 
    62 typedef struct {
    63 	int       ncolors;
    64 	SDL_Color *colors;
    65 } SDL_Palette;
    66 
    67 /* Everything in the pixel format structure is read-only */
    68 typedef struct SDL_PixelFormat {
    69 	SDL_Palette *palette;
    70 	Uint8  BitsPerPixel;
    71 	Uint8  BytesPerPixel;
    72 	Uint8  Rloss;
    73 	Uint8  Gloss;
    74 	Uint8  Bloss;
    75 	Uint8  Aloss;
    76 	Uint8  Rshift;
    77 	Uint8  Gshift;
    78 	Uint8  Bshift;
    79 	Uint8  Ashift;
    80 	Uint32 Rmask;
    81 	Uint32 Gmask;
    82 	Uint32 Bmask;
    83 	Uint32 Amask;
    84 
    85 	/* RGB color key information */
    86 	Uint32 colorkey;
    87 	/* Alpha value information (per-surface alpha) */
    88 	Uint8  alpha;
    89 } SDL_PixelFormat;
    90 
    91 /* typedef for private surface blitting functions */
    92 struct SDL_Surface;
    93 typedef int (*SDL_blit)(struct SDL_Surface *src, SDL_Rect *srcrect,
    94 			struct SDL_Surface *dst, SDL_Rect *dstrect);
    95 
    96 /* This structure should be treated as read-only, except for 'pixels',
    97    which, if not NULL, contains the raw pixel data for the surface.
    98 */
    99 typedef struct SDL_Surface {
   100 	Uint32 flags;				/* Read-only */
   101 	SDL_PixelFormat *format;		/* Read-only */
   102 	int w, h;				/* Read-only */
   103 	Uint16 pitch;				/* Read-only */
   104 	void *pixels;				/* Read-write */
   105 	int offset;				/* Private */
   106 
   107 	/* Hardware-specific surface info */
   108 	struct private_hwdata *hwdata;
   109 
   110 	/* clipping information */
   111 	SDL_Rect clip_rect;			/* Read-only */
   112 	Uint32 unused1;				/* for binary compatibility */
   113 
   114 	/* Allow recursive locks */
   115 	Uint32 locked;				/* Private */
   116 
   117 	/* info for fast blit mapping to other surfaces */
   118 	struct SDL_BlitMap *map;		/* Private */
   119 
   120 	/* format version, bumped at every change to invalidate blit maps */
   121 	unsigned int format_version;		/* Private */
   122 
   123 	/* Reference count -- used when freeing surface */
   124 	int refcount;				/* Read-mostly */
   125 } SDL_Surface;
   126 
   127 /* These are the currently supported flags for the SDL_surface */
   128 /* Available for SDL_CreateRGBSurface() or SDL_SetVideoMode() */
   129 #define SDL_SWSURFACE	0x00000000	/* Surface is in system memory */
   130 #define SDL_HWSURFACE	0x00000001	/* Surface is in video memory */
   131 #define SDL_ASYNCBLIT	0x00000004	/* Use asynchronous blits if possible */
   132 /* Available for SDL_SetVideoMode() */
   133 #define SDL_ANYFORMAT	0x10000000	/* Allow any video depth/pixel-format */
   134 #define SDL_HWPALETTE	0x20000000	/* Surface has exclusive palette */
   135 #define SDL_DOUBLEBUF	0x40000000	/* Set up double-buffered video mode */
   136 #define SDL_FULLSCREEN	0x80000000	/* Surface is a full screen display */
   137 #define SDL_OPENGL      0x00000002      /* Create an OpenGL rendering context */
   138 #define SDL_OPENGLBLIT	0x0000000A	/* Create an OpenGL rendering context and use it for blitting */
   139 #define SDL_RESIZABLE	0x00000010	/* This video mode may be resized */
   140 #define SDL_NOFRAME	0x00000020	/* No window caption or edge frame */
   141 /* Used internally (read-only) */
   142 #define SDL_HWACCEL	0x00000100	/* Blit uses hardware acceleration */
   143 #define SDL_SRCCOLORKEY	0x00001000	/* Blit uses a source color key */
   144 #define SDL_RLEACCELOK	0x00002000	/* Private flag */
   145 #define SDL_RLEACCEL	0x00004000	/* Surface is RLE encoded */
   146 #define SDL_SRCALPHA	0x00010000	/* Blit uses source alpha blending */
   147 #define SDL_PREALLOC	0x01000000	/* Surface uses preallocated memory */
   148 
   149 /* Evaluates to true if the surface needs to be locked before access */
   150 #define SDL_MUSTLOCK(surface)	\
   151   (surface->offset ||		\
   152   ((surface->flags & (SDL_HWSURFACE|SDL_ASYNCBLIT|SDL_RLEACCEL)) != 0))
   153 
   154 
   155 /* Useful for determining the video hardware capabilities */
   156 typedef struct {
   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_GLattr;
   221 
   222 /* flags for SDL_SetPalette() */
   223 #define SDL_LOGPAL 0x01
   224 #define SDL_PHYSPAL 0x02
   225 
   226 /* Function prototypes */
   227 
   228 /* These functions are used internally, and should not be used unless you
   229  * have a specific need to specify the video driver you want to use.
   230  * You should normally use SDL_Init() or SDL_InitSubSystem().
   231  *
   232  * SDL_VideoInit() initializes the video subsystem -- sets up a connection
   233  * to the window manager, etc, and determines the current video mode and
   234  * pixel format, but does not initialize a window or graphics mode.
   235  * Note that event handling is activated by this routine.
   236  *
   237  * If you use both sound and video in your application, you need to call
   238  * SDL_Init() before opening the sound device, otherwise under Win32 DirectX,
   239  * you won't be able to set full-screen display modes.
   240  */
   241 extern DECLSPEC int SDLCALL SDL_VideoInit(const char *driver_name, Uint32 flags);
   242 extern DECLSPEC void SDLCALL SDL_VideoQuit(void);
   243 
   244 /* This function fills the given character buffer with the name of the
   245  * video driver, and returns a pointer to it if the video driver has
   246  * been initialized.  It returns NULL if no driver has been initialized.
   247  */
   248 extern DECLSPEC char * SDLCALL SDL_VideoDriverName(char *namebuf, int maxlen);
   249 
   250 /*
   251  * This function returns a pointer to the current display surface.
   252  * If SDL is doing format conversion on the display surface, this
   253  * function returns the publicly visible surface, not the real video
   254  * surface.
   255  */
   256 extern DECLSPEC SDL_Surface * SDLCALL SDL_GetVideoSurface(void);
   257 
   258 /*
   259  * This function returns a read-only pointer to information about the
   260  * video hardware.  If this is called before SDL_SetVideoMode(), the 'vfmt'
   261  * member of the returned structure will contain the pixel format of the
   262  * "best" video mode.
   263  */
   264 extern DECLSPEC const SDL_VideoInfo * SDLCALL SDL_GetVideoInfo(void);
   265 
   266 /* 
   267  * Check to see if a particular video mode is supported.
   268  * It returns 0 if the requested mode is not supported under any bit depth,
   269  * or returns the bits-per-pixel of the closest available mode with the
   270  * given width and height.  If this bits-per-pixel is different from the
   271  * one used when setting the video mode, SDL_SetVideoMode() will succeed,
   272  * but will emulate the requested bits-per-pixel with a shadow surface.
   273  *
   274  * The arguments to SDL_VideoModeOK() are the same ones you would pass to
   275  * SDL_SetVideoMode()
   276  */
   277 extern DECLSPEC int SDLCALL SDL_VideoModeOK(int width, int height, int bpp, Uint32 flags);
   278 
   279 /*
   280  * Return a pointer to an array of available screen dimensions for the
   281  * given format and video flags, sorted largest to smallest.  Returns 
   282  * NULL if there are no dimensions available for a particular format, 
   283  * or (SDL_Rect **)-1 if any dimension is okay for the given format.
   284  *
   285  * If 'format' is NULL, the mode list will be for the format given 
   286  * by SDL_GetVideoInfo()->vfmt
   287  */
   288 extern DECLSPEC SDL_Rect ** SDLCALL SDL_ListModes(SDL_PixelFormat *format, Uint32 flags);
   289 
   290 /*
   291  * Set up a video mode with the specified width, height and bits-per-pixel.
   292  *
   293  * If 'bpp' is 0, it is treated as the current display bits per pixel.
   294  *
   295  * If SDL_ANYFORMAT is set in 'flags', the SDL library will try to set the
   296  * requested bits-per-pixel, but will return whatever video pixel format is
   297  * available.  The default is to emulate the requested pixel format if it
   298  * is not natively available.
   299  *
   300  * If SDL_HWSURFACE is set in 'flags', the video surface will be placed in
   301  * video memory, if possible, and you may have to call SDL_LockSurface()
   302  * in order to access the raw framebuffer.  Otherwise, the video surface
   303  * will be created in system memory.
   304  *
   305  * If SDL_ASYNCBLIT is set in 'flags', SDL will try to perform rectangle
   306  * updates asynchronously, but you must always lock before accessing pixels.
   307  * SDL will wait for updates to complete before returning from the lock.
   308  *
   309  * If SDL_HWPALETTE is set in 'flags', the SDL library will guarantee
   310  * that the colors set by SDL_SetColors() will be the colors you get.
   311  * Otherwise, in 8-bit mode, SDL_SetColors() may not be able to set all
   312  * of the colors exactly the way they are requested, and you should look
   313  * at the video surface structure to determine the actual palette.
   314  * If SDL cannot guarantee that the colors you request can be set, 
   315  * i.e. if the colormap is shared, then the video surface may be created
   316  * under emulation in system memory, overriding the SDL_HWSURFACE flag.
   317  *
   318  * If SDL_FULLSCREEN is set in 'flags', the SDL library will try to set
   319  * a fullscreen video mode.  The default is to create a windowed mode
   320  * if the current graphics system has a window manager.
   321  * If the SDL library is able to set a fullscreen video mode, this flag 
   322  * will be set in the surface that is returned.
   323  *
   324  * If SDL_DOUBLEBUF is set in 'flags', the SDL library will try to set up
   325  * two surfaces in video memory and swap between them when you call 
   326  * SDL_Flip().  This is usually slower than the normal single-buffering
   327  * scheme, but prevents "tearing" artifacts caused by modifying video 
   328  * memory while the monitor is refreshing.  It should only be used by 
   329  * applications that redraw the entire screen on every update.
   330  *
   331  * If SDL_RESIZABLE is set in 'flags', the SDL library will allow the
   332  * window manager, if any, to resize the window at runtime.  When this
   333  * occurs, SDL will send a SDL_VIDEORESIZE event to you application,
   334  * and you must respond to the event by re-calling SDL_SetVideoMode()
   335  * with the requested size (or another size that suits the application).
   336  *
   337  * If SDL_NOFRAME is set in 'flags', the SDL library will create a window
   338  * without any title bar or frame decoration.  Fullscreen video modes have
   339  * this flag set automatically.
   340  *
   341  * This function returns the video framebuffer surface, or NULL if it fails.
   342  *
   343  * If you rely on functionality provided by certain video flags, check the
   344  * flags of the returned surface to make sure that functionality is available.
   345  * SDL will fall back to reduced functionality if the exact flags you wanted
   346  * are not available.
   347  */
   348 extern DECLSPEC SDL_Surface * SDLCALL SDL_SetVideoMode
   349 			(int width, int height, int bpp, Uint32 flags);
   350 
   351 /*
   352  * Makes sure the given list of rectangles is updated on the given screen.
   353  * If 'x', 'y', 'w' and 'h' are all 0, SDL_UpdateRect will update the entire
   354  * screen.
   355  * These functions should not be called while 'screen' is locked.
   356  */
   357 extern DECLSPEC void SDLCALL SDL_UpdateRects
   358 		(SDL_Surface *screen, int numrects, SDL_Rect *rects);
   359 extern DECLSPEC void SDLCALL SDL_UpdateRect
   360 		(SDL_Surface *screen, Sint32 x, Sint32 y, Uint32 w, Uint32 h);
   361 
   362 /*
   363  * On hardware that supports double-buffering, this function sets up a flip
   364  * and returns.  The hardware will wait for vertical retrace, and then swap
   365  * video buffers before the next video surface blit or lock will return.
   366  * On hardware that doesn not support double-buffering, this is equivalent
   367  * to calling SDL_UpdateRect(screen, 0, 0, 0, 0);
   368  * The SDL_DOUBLEBUF flag must have been passed to SDL_SetVideoMode() when
   369  * setting the video mode for this function to perform hardware flipping.
   370  * This function returns 0 if successful, or -1 if there was an error.
   371  */
   372 extern DECLSPEC int SDLCALL SDL_Flip(SDL_Surface *screen);
   373 
   374 /*
   375  * Set the gamma correction for each of the color channels.
   376  * The gamma values range (approximately) between 0.1 and 10.0
   377  * 
   378  * If this function isn't supported directly by the hardware, it will
   379  * be emulated using gamma ramps, if available.  If successful, this
   380  * function returns 0, otherwise it returns -1.
   381  */
   382 extern DECLSPEC int SDLCALL SDL_SetGamma(float red, float green, float blue);
   383 
   384 /*
   385  * Set the gamma translation table for the red, green, and blue channels
   386  * of the video hardware.  Each table is an array of 256 16-bit quantities,
   387  * representing a mapping between the input and output for that channel.
   388  * The input is the index into the array, and the output is the 16-bit
   389  * gamma value at that index, scaled to the output color precision.
   390  * 
   391  * You may pass NULL for any of the channels to leave it unchanged.
   392  * If the call succeeds, it will return 0.  If the display driver or
   393  * hardware does not support gamma translation, or otherwise fails,
   394  * this function will return -1.
   395  */
   396 extern DECLSPEC int SDLCALL SDL_SetGammaRamp(Uint16 *red, Uint16 *green, Uint16 *blue);
   397 
   398 /*
   399  * Retrieve the current values of the gamma translation tables.
   400  * 
   401  * You must pass in valid pointers to arrays of 256 16-bit quantities.
   402  * Any of the pointers may be NULL to ignore that channel.
   403  * If the call succeeds, it will return 0.  If the display driver or
   404  * hardware does not support gamma translation, or otherwise fails,
   405  * this function will return -1.
   406  */
   407 extern DECLSPEC int SDLCALL SDL_GetGammaRamp(Uint16 *red, Uint16 *green, Uint16 *blue);
   408 
   409 /*
   410  * Sets a portion of the colormap for the given 8-bit surface.  If 'surface'
   411  * is not a palettized surface, this function does nothing, returning 0.
   412  * If all of the colors were set as passed to SDL_SetColors(), it will
   413  * return 1.  If not all the color entries were set exactly as given,
   414  * it will return 0, and you should look at the surface palette to
   415  * determine the actual color palette.
   416  *
   417  * When 'surface' is the surface associated with the current display, the
   418  * display colormap will be updated with the requested colors.  If 
   419  * SDL_HWPALETTE was set in SDL_SetVideoMode() flags, SDL_SetColors()
   420  * will always return 1, and the palette is guaranteed to be set the way
   421  * you desire, even if the window colormap has to be warped or run under
   422  * emulation.
   423  */
   424 extern DECLSPEC int SDLCALL SDL_SetColors(SDL_Surface *surface, 
   425 			SDL_Color *colors, int firstcolor, int ncolors);
   426 
   427 /*
   428  * Sets a portion of the colormap for a given 8-bit surface.
   429  * 'flags' is one or both of:
   430  * SDL_LOGPAL  -- set logical palette, which controls how blits are mapped
   431  *                to/from the surface,
   432  * SDL_PHYSPAL -- set physical palette, which controls how pixels look on
   433  *                the screen
   434  * Only screens have physical palettes. Separate change of physical/logical
   435  * palettes is only possible if the screen has SDL_HWPALETTE set.
   436  *
   437  * The return value is 1 if all colours could be set as requested, and 0
   438  * otherwise.
   439  *
   440  * SDL_SetColors() is equivalent to calling this function with
   441  *     flags = (SDL_LOGPAL|SDL_PHYSPAL).
   442  */
   443 extern DECLSPEC int SDLCALL SDL_SetPalette(SDL_Surface *surface, int flags,
   444 				   SDL_Color *colors, int firstcolor,
   445 				   int ncolors);
   446 
   447 /*
   448  * Maps an RGB triple to an opaque pixel value for a given pixel format
   449  */
   450 extern DECLSPEC Uint32 SDLCALL SDL_MapRGB
   451 			(SDL_PixelFormat *format, Uint8 r, Uint8 g, Uint8 b);
   452 
   453 /*
   454  * Maps an RGBA quadruple to a pixel value for a given pixel format
   455  */
   456 extern DECLSPEC Uint32 SDLCALL SDL_MapRGBA(SDL_PixelFormat *format,
   457 				   Uint8 r, Uint8 g, Uint8 b, Uint8 a);
   458 
   459 /*
   460  * Maps a pixel value into the RGB components for a given pixel format
   461  */
   462 extern DECLSPEC void SDLCALL SDL_GetRGB(Uint32 pixel, SDL_PixelFormat *fmt,
   463 				Uint8 *r, Uint8 *g, Uint8 *b);
   464 
   465 /*
   466  * Maps a pixel value into the RGBA components for a given pixel format
   467  */
   468 extern DECLSPEC void SDLCALL SDL_GetRGBA(Uint32 pixel, SDL_PixelFormat *fmt,
   469 				 Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a);
   470 
   471 /*
   472  * Allocate and free an RGB surface (must be called after SDL_SetVideoMode)
   473  * If the depth is 4 or 8 bits, an empty palette is allocated for the surface.
   474  * If the depth is greater than 8 bits, the pixel format is set using the
   475  * flags '[RGB]mask'.
   476  * If the function runs out of memory, it will return NULL.
   477  *
   478  * The 'flags' tell what kind of surface to create.
   479  * SDL_SWSURFACE means that the surface should be created in system memory.
   480  * SDL_HWSURFACE means that the surface should be created in video memory,
   481  * with the same format as the display surface.  This is useful for surfaces
   482  * that will not change much, to take advantage of hardware acceleration
   483  * when being blitted to the display surface.
   484  * SDL_ASYNCBLIT means that SDL will try to perform asynchronous blits with
   485  * this surface, but you must always lock it before accessing the pixels.
   486  * SDL will wait for current blits to finish before returning from the lock.
   487  * SDL_SRCCOLORKEY indicates that the surface will be used for colorkey blits.
   488  * If the hardware supports acceleration of colorkey blits between
   489  * two surfaces in video memory, SDL will try to place the surface in
   490  * video memory. If this isn't possible or if there is no hardware
   491  * acceleration available, the surface will be placed in system memory.
   492  * SDL_SRCALPHA means that the surface will be used for alpha blits and 
   493  * if the hardware supports hardware acceleration of alpha blits between
   494  * two surfaces in video memory, to place the surface in video memory
   495  * if possible, otherwise it will be placed in system memory.
   496  * If the surface is created in video memory, blits will be _much_ faster,
   497  * but the surface format must be identical to the video surface format,
   498  * and the only way to access the pixels member of the surface is to use
   499  * the SDL_LockSurface() and SDL_UnlockSurface() calls.
   500  * If the requested surface actually resides in video memory, SDL_HWSURFACE
   501  * will be set in the flags member of the returned surface.  If for some
   502  * reason the surface could not be placed in video memory, it will not have
   503  * the SDL_HWSURFACE flag set, and will be created in system memory instead.
   504  */
   505 #define SDL_AllocSurface    SDL_CreateRGBSurface
   506 extern DECLSPEC SDL_Surface * SDLCALL SDL_CreateRGBSurface
   507 			(Uint32 flags, int width, int height, int depth, 
   508 			Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
   509 extern DECLSPEC SDL_Surface * SDLCALL SDL_CreateRGBSurfaceFrom(void *pixels,
   510 			int width, int height, int depth, int pitch,
   511 			Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
   512 extern DECLSPEC void SDLCALL SDL_FreeSurface(SDL_Surface *surface);
   513 
   514 /*
   515  * SDL_LockSurface() sets up a surface for directly accessing the pixels.
   516  * Between calls to SDL_LockSurface()/SDL_UnlockSurface(), you can write
   517  * to and read from 'surface->pixels', using the pixel format stored in 
   518  * 'surface->format'.  Once you are done accessing the surface, you should 
   519  * use SDL_UnlockSurface() to release it.
   520  *
   521  * Not all surfaces require locking.  If SDL_MUSTLOCK(surface) evaluates
   522  * to 0, then you can read and write to the surface at any time, and the
   523  * pixel format of the surface will not change.  In particular, if the
   524  * SDL_HWSURFACE flag is not given when calling SDL_SetVideoMode(), you
   525  * will not need to lock the display surface before accessing it.
   526  * 
   527  * No operating system or library calls should be made between lock/unlock
   528  * pairs, as critical system locks may be held during this time.
   529  *
   530  * SDL_LockSurface() returns 0, or -1 if the surface couldn't be locked.
   531  */
   532 extern DECLSPEC int SDLCALL SDL_LockSurface(SDL_Surface *surface);
   533 extern DECLSPEC void SDLCALL SDL_UnlockSurface(SDL_Surface *surface);
   534 
   535 /*
   536  * Load a surface from a seekable SDL data source (memory or file.)
   537  * If 'freesrc' is non-zero, the source will be closed after being read.
   538  * Returns the new surface, or NULL if there was an error.
   539  * The new surface should be freed with SDL_FreeSurface().
   540  */
   541 extern DECLSPEC SDL_Surface * SDLCALL SDL_LoadBMP_RW(SDL_RWops *src, int freesrc);
   542 
   543 /* Convenience macro -- load a surface from a file */
   544 #define SDL_LoadBMP(file)	SDL_LoadBMP_RW(SDL_RWFromFile(file, "rb"), 1)
   545 
   546 /*
   547  * Save a surface to a seekable SDL data source (memory or file.)
   548  * If 'freedst' is non-zero, the source will be closed after being written.
   549  * Returns 0 if successful or -1 if there was an error.
   550  */
   551 extern DECLSPEC int SDLCALL SDL_SaveBMP_RW
   552 		(SDL_Surface *surface, SDL_RWops *dst, int freedst);
   553 
   554 /* Convenience macro -- save a surface to a file */
   555 #define SDL_SaveBMP(surface, file) \
   556 		SDL_SaveBMP_RW(surface, SDL_RWFromFile(file, "wb"), 1)
   557 
   558 /*
   559  * Sets the color key (transparent pixel) in a blittable surface.
   560  * If 'flag' is SDL_SRCCOLORKEY (optionally OR'd with SDL_RLEACCEL), 
   561  * 'key' will be the transparent pixel in the source image of a blit.
   562  * SDL_RLEACCEL requests RLE acceleration for the surface if present,
   563  * and removes RLE acceleration if absent.
   564  * If 'flag' is 0, this function clears any current color key.
   565  * This function returns 0, or -1 if there was an error.
   566  */
   567 extern DECLSPEC int SDLCALL SDL_SetColorKey
   568 			(SDL_Surface *surface, Uint32 flag, Uint32 key);
   569 
   570 /*
   571  * This function sets the alpha value for the entire surface, as opposed to
   572  * using the alpha component of each pixel. This value measures the range
   573  * of transparency of the surface, 0 being completely transparent to 255
   574  * being completely opaque. An 'alpha' value of 255 causes blits to be
   575  * opaque, the source pixels copied to the destination (the default). Note
   576  * that per-surface alpha can be combined with colorkey transparency.
   577  *
   578  * If 'flag' is 0, alpha blending is disabled for the surface.
   579  * If 'flag' is SDL_SRCALPHA, alpha blending is enabled for the surface.
   580  * OR:ing the flag with SDL_RLEACCEL requests RLE acceleration for the
   581  * surface; if SDL_RLEACCEL is not specified, the RLE accel will be removed.
   582  *
   583  * The 'alpha' parameter is ignored for surfaces that have an alpha channel.
   584  */
   585 extern DECLSPEC int SDLCALL SDL_SetAlpha(SDL_Surface *surface, Uint32 flag, Uint8 alpha);
   586 
   587 /*
   588  * Sets the clipping rectangle for the destination surface in a blit.
   589  *
   590  * If the clip rectangle is NULL, clipping will be disabled.
   591  * If the clip rectangle doesn't intersect the surface, the function will
   592  * return SDL_FALSE and blits will be completely clipped.  Otherwise the
   593  * function returns SDL_TRUE and blits to the surface will be clipped to
   594  * the intersection of the surface area and the clipping rectangle.
   595  *
   596  * Note that blits are automatically clipped to the edges of the source
   597  * and destination surfaces.
   598  */
   599 extern DECLSPEC SDL_bool SDLCALL SDL_SetClipRect(SDL_Surface *surface, const SDL_Rect *rect);
   600 
   601 /*
   602  * Gets the clipping rectangle for the destination surface in a blit.
   603  * 'rect' must be a pointer to a valid rectangle which will be filled
   604  * with the correct values.
   605  */
   606 extern DECLSPEC void SDLCALL SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect);
   607 
   608 /*
   609  * Creates a new surface of the specified format, and then copies and maps 
   610  * the given surface to it so the blit of the converted surface will be as 
   611  * fast as possible.  If this function fails, it returns NULL.
   612  *
   613  * The 'flags' parameter is passed to SDL_CreateRGBSurface() and has those 
   614  * semantics.  You can also pass SDL_RLEACCEL in the flags parameter and
   615  * SDL will try to RLE accelerate colorkey and alpha blits in the resulting
   616  * surface.
   617  *
   618  * This function is used internally by SDL_DisplayFormat().
   619  */
   620 extern DECLSPEC SDL_Surface * SDLCALL SDL_ConvertSurface
   621 			(SDL_Surface *src, SDL_PixelFormat *fmt, Uint32 flags);
   622 
   623 /*
   624  * This performs a fast blit from the source surface to the destination
   625  * surface.  It assumes that the source and destination rectangles are
   626  * the same size.  If either 'srcrect' or 'dstrect' are NULL, the entire
   627  * surface (src or dst) is copied.  The final blit rectangles are saved
   628  * in 'srcrect' and 'dstrect' after all clipping is performed.
   629  * If the blit is successful, it returns 0, otherwise it returns -1.
   630  *
   631  * The blit function should not be called on a locked surface.
   632  *
   633  * The blit semantics for surfaces with and without alpha and colorkey
   634  * are defined as follows:
   635  *
   636  * RGBA->RGB:
   637  *     SDL_SRCALPHA set:
   638  * 	alpha-blend (using alpha-channel).
   639  * 	SDL_SRCCOLORKEY ignored.
   640  *     SDL_SRCALPHA not set:
   641  * 	copy RGB.
   642  * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
   643  * 	RGB values of the source colour key, ignoring alpha in the
   644  * 	comparison.
   645  * 
   646  * RGB->RGBA:
   647  *     SDL_SRCALPHA set:
   648  * 	alpha-blend (using the source per-surface alpha value);
   649  * 	set destination alpha to opaque.
   650  *     SDL_SRCALPHA not set:
   651  * 	copy RGB, set destination alpha to source per-surface alpha value.
   652  *     both:
   653  * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
   654  * 	source colour key.
   655  * 
   656  * RGBA->RGBA:
   657  *     SDL_SRCALPHA set:
   658  * 	alpha-blend (using the source alpha channel) the RGB values;
   659  * 	leave destination alpha untouched. [Note: is this correct?]
   660  * 	SDL_SRCCOLORKEY ignored.
   661  *     SDL_SRCALPHA not set:
   662  * 	copy all of RGBA to the destination.
   663  * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
   664  * 	RGB values of the source colour key, ignoring alpha in the
   665  * 	comparison.
   666  * 
   667  * RGB->RGB: 
   668  *     SDL_SRCALPHA set:
   669  * 	alpha-blend (using the source per-surface alpha value).
   670  *     SDL_SRCALPHA not set:
   671  * 	copy RGB.
   672  *     both:
   673  * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
   674  * 	source colour key.
   675  *
   676  * If either of the surfaces were in video memory, and the blit returns -2,
   677  * the video memory was lost, so it should be reloaded with artwork and 
   678  * re-blitted:
   679 	while ( SDL_BlitSurface(image, imgrect, screen, dstrect) == -2 ) {
   680 		while ( SDL_LockSurface(image) < 0 )
   681 			Sleep(10);
   682 		-- Write image pixels to image->pixels --
   683 		SDL_UnlockSurface(image);
   684 	}
   685  * This happens under DirectX 5.0 when the system switches away from your
   686  * fullscreen application.  The lock will also fail until you have access
   687  * to the video memory again.
   688  */
   689 /* You should call SDL_BlitSurface() unless you know exactly how SDL
   690    blitting works internally and how to use the other blit functions.
   691 */
   692 #define SDL_BlitSurface SDL_UpperBlit
   693 
   694 /* This is the public blit function, SDL_BlitSurface(), and it performs
   695    rectangle validation and clipping before passing it to SDL_LowerBlit()
   696 */
   697 extern DECLSPEC int SDLCALL SDL_UpperBlit
   698 			(SDL_Surface *src, SDL_Rect *srcrect,
   699 			 SDL_Surface *dst, SDL_Rect *dstrect);
   700 /* This is a semi-private blit function and it performs low-level surface
   701    blitting only.
   702 */
   703 extern DECLSPEC int SDLCALL SDL_LowerBlit
   704 			(SDL_Surface *src, SDL_Rect *srcrect,
   705 			 SDL_Surface *dst, SDL_Rect *dstrect);
   706 
   707 /*
   708  * This function performs a fast fill of the given rectangle with 'color'
   709  * The given rectangle is clipped to the destination surface clip area
   710  * and the final fill rectangle is saved in the passed in pointer.
   711  * If 'dstrect' is NULL, the whole surface will be filled with 'color'
   712  * The color should be a pixel of the format used by the surface, and 
   713  * can be generated by the SDL_MapRGB() function.
   714  * This function returns 0 on success, or -1 on error.
   715  */
   716 extern DECLSPEC int SDLCALL SDL_FillRect
   717 		(SDL_Surface *dst, SDL_Rect *dstrect, Uint32 color);
   718 
   719 /* 
   720  * This function takes a surface and copies it to a new surface of the
   721  * pixel format and colors of the video framebuffer, suitable for fast
   722  * blitting onto the display surface.  It calls SDL_ConvertSurface()
   723  *
   724  * If you want to take advantage of hardware colorkey or alpha blit
   725  * acceleration, you should set the colorkey and alpha value before
   726  * calling this function.
   727  *
   728  * If the conversion fails or runs out of memory, it returns NULL
   729  */
   730 extern DECLSPEC SDL_Surface * SDLCALL SDL_DisplayFormat(SDL_Surface *surface);
   731 
   732 /* 
   733  * This function takes a surface and copies it to a new surface of the
   734  * pixel format and colors of the video framebuffer (if possible),
   735  * suitable for fast alpha blitting onto the display surface.
   736  * The new surface will always have an alpha channel.
   737  *
   738  * If you want to take advantage of hardware colorkey or alpha blit
   739  * acceleration, you should set the colorkey and alpha value before
   740  * calling this function.
   741  *
   742  * If the conversion fails or runs out of memory, it returns NULL
   743  */
   744 extern DECLSPEC SDL_Surface * SDLCALL SDL_DisplayFormatAlpha(SDL_Surface *surface);
   745 
   746 
   747 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   748 /* YUV video surface overlay functions                                       */
   749 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   750 
   751 /* This function creates a video output overlay
   752    Calling the returned surface an overlay is something of a misnomer because
   753    the contents of the display surface underneath the area where the overlay
   754    is shown is undefined - it may be overwritten with the converted YUV data.
   755 */
   756 extern DECLSPEC SDL_Overlay * SDLCALL SDL_CreateYUVOverlay(int width, int height,
   757 				Uint32 format, SDL_Surface *display);
   758 
   759 /* Lock an overlay for direct access, and unlock it when you are done */
   760 extern DECLSPEC int SDLCALL SDL_LockYUVOverlay(SDL_Overlay *overlay);
   761 extern DECLSPEC void SDLCALL SDL_UnlockYUVOverlay(SDL_Overlay *overlay);
   762 
   763 /* Blit a video overlay to the display surface.
   764    The contents of the video surface underneath the blit destination are
   765    not defined.  
   766    The width and height of the destination rectangle may be different from
   767    that of the overlay, but currently only 2x scaling is supported.
   768 */
   769 extern DECLSPEC int SDLCALL SDL_DisplayYUVOverlay(SDL_Overlay *overlay, SDL_Rect *dstrect);
   770 
   771 /* Free a video overlay */
   772 extern DECLSPEC void SDLCALL SDL_FreeYUVOverlay(SDL_Overlay *overlay);
   773 
   774 
   775 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   776 /* OpenGL support functions.                                                 */
   777 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   778 
   779 /*
   780  * Dynamically load a GL driver, if SDL is built with dynamic GL.
   781  *
   782  * SDL links normally with the OpenGL library on your system by default,
   783  * but you can compile it to dynamically load the GL driver at runtime.
   784  * If you do this, you need to retrieve all of the GL functions used in
   785  * your program from the dynamic library using SDL_GL_GetProcAddress().
   786  *
   787  * This is disabled in default builds of SDL.
   788  */
   789 extern DECLSPEC int SDLCALL SDL_GL_LoadLibrary(const char *path);
   790 
   791 /*
   792  * Get the address of a GL function (for extension functions)
   793  */
   794 extern DECLSPEC void * SDLCALL SDL_GL_GetProcAddress(const char* proc);
   795 
   796 /*
   797  * Set an attribute of the OpenGL subsystem before intialization.
   798  */
   799 extern DECLSPEC int SDLCALL SDL_GL_SetAttribute(SDL_GLattr attr, int value);
   800 
   801 /*
   802  * Get an attribute of the OpenGL subsystem from the windowing
   803  * interface, such as glX. This is of course different from getting
   804  * the values from SDL's internal OpenGL subsystem, which only
   805  * stores the values you request before initialization.
   806  *
   807  * Developers should track the values they pass into SDL_GL_SetAttribute
   808  * themselves if they want to retrieve these values.
   809  */
   810 extern DECLSPEC int SDLCALL SDL_GL_GetAttribute(SDL_GLattr attr, int* value);
   811 
   812 /*
   813  * Swap the OpenGL buffers, if double-buffering is supported.
   814  */
   815 extern DECLSPEC void SDLCALL SDL_GL_SwapBuffers(void);
   816 
   817 /*
   818  * Internal functions that should not be called unless you have read
   819  * and understood the source code for these functions.
   820  */
   821 extern DECLSPEC void SDLCALL SDL_GL_UpdateRects(int numrects, SDL_Rect* rects);
   822 extern DECLSPEC void SDLCALL SDL_GL_Lock(void);
   823 extern DECLSPEC void SDLCALL SDL_GL_Unlock(void);
   824 
   825 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   826 /* These functions allow interaction with the window manager, if any.        */
   827 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
   828 
   829 /*
   830  * Sets/Gets the title and icon text of the display window
   831  */
   832 extern DECLSPEC void SDLCALL SDL_WM_SetCaption(const char *title, const char *icon);
   833 extern DECLSPEC void SDLCALL SDL_WM_GetCaption(char **title, char **icon);
   834 
   835 /*
   836  * Sets the icon for the display window.
   837  * This function must be called before the first call to SDL_SetVideoMode().
   838  * It takes an icon surface, and a mask in MSB format.
   839  * If 'mask' is NULL, the entire icon surface will be used as the icon.
   840  */
   841 extern DECLSPEC void SDLCALL SDL_WM_SetIcon(SDL_Surface *icon, Uint8 *mask);
   842 
   843 /*
   844  * This function iconifies the window, and returns 1 if it succeeded.
   845  * If the function succeeds, it generates an SDL_APPACTIVE loss event.
   846  * This function is a noop and returns 0 in non-windowed environments.
   847  */
   848 extern DECLSPEC int SDLCALL SDL_WM_IconifyWindow(void);
   849 
   850 /*
   851  * Toggle fullscreen mode without changing the contents of the screen.
   852  * If the display surface does not require locking before accessing
   853  * the pixel information, then the memory pointers will not change.
   854  *
   855  * If this function was able to toggle fullscreen mode (change from 
   856  * running in a window to fullscreen, or vice-versa), it will return 1.
   857  * If it is not implemented, or fails, it returns 0.
   858  *
   859  * The next call to SDL_SetVideoMode() will set the mode fullscreen
   860  * attribute based on the flags parameter - if SDL_FULLSCREEN is not
   861  * set, then the display will be windowed by default where supported.
   862  *
   863  * This is currently only implemented in the X11 video driver.
   864  */
   865 extern DECLSPEC int SDLCALL SDL_WM_ToggleFullScreen(SDL_Surface *surface);
   866 
   867 /*
   868  * This function allows you to set and query the input grab state of
   869  * the application.  It returns the new input grab state.
   870  */
   871 typedef enum {
   872 	SDL_GRAB_QUERY = -1,
   873 	SDL_GRAB_OFF = 0,
   874 	SDL_GRAB_ON = 1,
   875 	SDL_GRAB_FULLSCREEN	/* Used internally */
   876 } SDL_GrabMode;
   877 /*
   878  * Grabbing means that the mouse is confined to the application window,
   879  * and nearly all keyboard input is passed directly to the application,
   880  * and not interpreted by a window manager, if any.
   881  */
   882 extern DECLSPEC SDL_GrabMode SDLCALL SDL_WM_GrabInput(SDL_GrabMode mode);
   883 
   884 /* Not in public API at the moment - do not use! */
   885 extern DECLSPEC int SDLCALL SDL_SoftStretch(SDL_Surface *src, SDL_Rect *srcrect,
   886                                     SDL_Surface *dst, SDL_Rect *dstrect);
   887                     
   888 /* Ends C function definitions when using C++ */
   889 #ifdef __cplusplus
   890 }
   891 #endif
   892 #include "close_code.h"
   893 
   894 #endif /* _SDL_video_h */