include/SDL_video.h

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/

/** @file SDL_video.h
 *  Header file for access to the SDL raw framebuffer window
 */

#ifndef _SDL_video_h
#define _SDL_video_h

#include "SDL_stdinc.h"
#include "SDL_error.h"
#include "SDL_rwops.h"

#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif

/** @name Transparency definitions
 *  These define alpha as the opacity of a surface
 */
/*@{*/
#define SDL_ALPHA_OPAQUE 255
#define SDL_ALPHA_TRANSPARENT 0
/*@}*/

/** @name Useful data types */
/*@{*/
typedef struct SDL_Rect {
	Sint16 x, y;
	Uint16 w, h;
} SDL_Rect;

typedef struct SDL_Color {
	Uint8 r;
	Uint8 g;
	Uint8 b;
	Uint8 unused;
} SDL_Color;
#define SDL_Colour SDL_Color

typedef struct SDL_Palette {
	int       ncolors;
	SDL_Color *colors;
} SDL_Palette;
/*@}*/

/** Everything in the pixel format structure is read-only */
typedef struct SDL_PixelFormat {
	SDL_Palette *palette;
	Uint8  BitsPerPixel;
	Uint8  BytesPerPixel;
	Uint8  Rloss;
	Uint8  Gloss;
	Uint8  Bloss;
	Uint8  Aloss;
	Uint8  Rshift;
	Uint8  Gshift;
	Uint8  Bshift;
	Uint8  Ashift;
	Uint32 Rmask;
	Uint32 Gmask;
	Uint32 Bmask;
	Uint32 Amask;

	/** RGB color key information */
	Uint32 colorkey;
	/** Alpha value information (per-surface alpha) */
	Uint8  alpha;
} SDL_PixelFormat;

/** This structure should be treated as read-only, except for 'pixels',
 *  which, if not NULL, contains the raw pixel data for the surface.
 */
typedef struct SDL_Surface {
	Uint32 flags;				/**< Read-only */
	SDL_PixelFormat *format;		/**< Read-only */
	int w, h;				/**< Read-only */
	Uint16 pitch;				/**< Read-only */
	void *pixels;				/**< Read-write */
	int offset;				/**< Private */

	/** Hardware-specific surface info */
	struct private_hwdata *hwdata;

	/** clipping information */
	SDL_Rect clip_rect;			/**< Read-only */
	Uint32 unused1;				/**< for binary compatibility */

	/** Allow recursive locks */
	Uint32 locked;				/**< Private */

	/** info for fast blit mapping to other surfaces */
	struct SDL_BlitMap *map;		/**< Private */

	/** format version, bumped at every change to invalidate blit maps */
	unsigned int format_version;		/**< Private */

	/** Reference count -- used when freeing surface */
	int refcount;				/**< Read-mostly */
} SDL_Surface;

/** @name SDL_Surface Flags
 *  These are the currently supported flags for the SDL_surface
 */
/*@{*/

/** Available for SDL_CreateRGBSurface() or SDL_SetVideoMode() */
/*@{*/
#define SDL_SWSURFACE	0x00000000	/**< Surface is in system memory */
#define SDL_HWSURFACE	0x00000001	/**< Surface is in video memory */
#define SDL_ASYNCBLIT	0x00000004	/**< Use asynchronous blits if possible */
/*@}*/

/** Available for SDL_SetVideoMode() */
/*@{*/
#define SDL_ANYFORMAT	0x10000000	/**< Allow any video depth/pixel-format */
#define SDL_HWPALETTE	0x20000000	/**< Surface has exclusive palette */
#define SDL_DOUBLEBUF	0x40000000	/**< Set up double-buffered video mode */
#define SDL_FULLSCREEN	0x80000000	/**< Surface is a full screen display */
#define SDL_OPENGL      0x00000002      /**< Create an OpenGL rendering context */
#define SDL_OPENGLBLIT	0x0000000A	/**< Create an OpenGL rendering context and use it for blitting */
#define SDL_RESIZABLE	0x00000010	/**< This video mode may be resized */
#define SDL_NOFRAME	0x00000020	/**< No window caption or edge frame */
/*@}*/

/** Used internally (read-only) */
/*@{*/
#define SDL_HWACCEL	0x00000100	/**< Blit uses hardware acceleration */
#define SDL_SRCCOLORKEY	0x00001000	/**< Blit uses a source color key */
#define SDL_RLEACCELOK	0x00002000	/**< Private flag */
#define SDL_RLEACCEL	0x00004000	/**< Surface is RLE encoded */
#define SDL_SRCALPHA	0x00010000	/**< Blit uses source alpha blending */
#define SDL_PREALLOC	0x01000000	/**< Surface uses preallocated memory */
/*@}*/

/*@}*/

/** Evaluates to true if the surface needs to be locked before access */
#define SDL_MUSTLOCK(surface)	\
  (surface->offset ||		\
  ((surface->flags & (SDL_HWSURFACE|SDL_ASYNCBLIT|SDL_RLEACCEL)) != 0))

/** typedef for private surface blitting functions */
typedef int (*SDL_blit)(struct SDL_Surface *src, SDL_Rect *srcrect,
			struct SDL_Surface *dst, SDL_Rect *dstrect);


/** Useful for determining the video hardware capabilities */
typedef struct SDL_VideoInfo {
	Uint32 hw_available :1;	/**< Flag: Can you create hardware surfaces? */
	Uint32 wm_available :1;	/**< Flag: Can you talk to a window manager? */
	Uint32 UnusedBits1  :6;
	Uint32 UnusedBits2  :1;
	Uint32 blit_hw      :1;	/**< Flag: Accelerated blits HW --> HW */
	Uint32 blit_hw_CC   :1;	/**< Flag: Accelerated blits with Colorkey */
	Uint32 blit_hw_A    :1;	/**< Flag: Accelerated blits with Alpha */
	Uint32 blit_sw      :1;	/**< Flag: Accelerated blits SW --> HW */
	Uint32 blit_sw_CC   :1;	/**< Flag: Accelerated blits with Colorkey */
	Uint32 blit_sw_A    :1;	/**< Flag: Accelerated blits with Alpha */
	Uint32 blit_fill    :1;	/**< Flag: Accelerated color fill */
	Uint32 UnusedBits3  :16;
	Uint32 video_mem;	/**< The total amount of video memory (in K) */
	SDL_PixelFormat *vfmt;	/**< Value: The format of the video surface */
	int    current_w;	/**< Value: The current video mode width */
	int    current_h;	/**< Value: The current video mode height */
} SDL_VideoInfo;


/** @name Overlay Formats
 *  The most common video overlay formats.
 *  For an explanation of these pixel formats, see:
 *	http://www.webartz.com/fourcc/indexyuv.htm
 *
 *  For information on the relationship between color spaces, see:
 *  http://www.neuro.sfc.keio.ac.jp/~aly/polygon/info/color-space-faq.html
 */
/*@{*/
#define SDL_YV12_OVERLAY  0x32315659	/**< Planar mode: Y + V + U  (3 planes) */
#define SDL_IYUV_OVERLAY  0x56555949	/**< Planar mode: Y + U + V  (3 planes) */
#define SDL_YUY2_OVERLAY  0x32595559	/**< Packed mode: Y0+U0+Y1+V0 (1 plane) */
#define SDL_UYVY_OVERLAY  0x59565955	/**< Packed mode: U0+Y0+V0+Y1 (1 plane) */
#define SDL_YVYU_OVERLAY  0x55595659	/**< Packed mode: Y0+V0+Y1+U0 (1 plane) */
/*@}*/

/** The YUV hardware video overlay */
typedef struct SDL_Overlay {
	Uint32 format;				/**< Read-only */
	int w, h;				/**< Read-only */
	int planes;				/**< Read-only */
	Uint16 *pitches;			/**< Read-only */
	Uint8 **pixels;				/**< Read-write */

	/** @name Hardware-specific surface info */
        /*@{*/
	struct private_yuvhwfuncs *hwfuncs;
	struct private_yuvhwdata *hwdata;
        /*@{*/

	/** @name Special flags */
        /*@{*/
	Uint32 hw_overlay :1;	/**< Flag: This overlay hardware accelerated? */
	Uint32 UnusedBits :31;
        /*@}*/
} SDL_Overlay;


/** Public enumeration for setting the OpenGL window attributes. */
typedef enum {
    SDL_GL_RED_SIZE,
    SDL_GL_GREEN_SIZE,
    SDL_GL_BLUE_SIZE,
    SDL_GL_ALPHA_SIZE,
    SDL_GL_BUFFER_SIZE,
    SDL_GL_DOUBLEBUFFER,
    SDL_GL_DEPTH_SIZE,
    SDL_GL_STENCIL_SIZE,
    SDL_GL_ACCUM_RED_SIZE,
    SDL_GL_ACCUM_GREEN_SIZE,
    SDL_GL_ACCUM_BLUE_SIZE,
    SDL_GL_ACCUM_ALPHA_SIZE,
    SDL_GL_STEREO,
    SDL_GL_MULTISAMPLEBUFFERS,
    SDL_GL_MULTISAMPLESAMPLES,
    SDL_GL_ACCELERATED_VISUAL,
    SDL_GL_SWAP_CONTROL
} SDL_GLattr;

/** @name flags for SDL_SetPalette() */
/*@{*/
#define SDL_LOGPAL 0x01
#define SDL_PHYSPAL 0x02
/*@}*/

/* Function prototypes */

/**
 * @name Video Init and Quit
 * These functions are used internally, and should not be used unless you
 * have a specific need to specify the video driver you want to use.
 * You should normally use SDL_Init() or SDL_InitSubSystem().
 */
/*@{*/
/**
 * Initializes the video subsystem. Sets up a connection
 * to the window manager, etc, and determines the current video mode and
 * pixel format, but does not initialize a window or graphics mode.
 * Note that event handling is activated by this routine.
 *
 * If you use both sound and video in your application, you need to call
 * SDL_Init() before opening the sound device, otherwise under Win32 DirectX,
 * you won't be able to set full-screen display modes.
 */
extern DECLSPEC int SDLCALL SDL_VideoInit(const char *driver_name, Uint32 flags);
extern DECLSPEC void SDLCALL SDL_VideoQuit(void);
/*@}*/

/**
 * This function fills the given character buffer with the name of the
 * video driver, and returns a pointer to it if the video driver has
 * been initialized.  It returns NULL if no driver has been initialized.
 */
extern DECLSPEC char * SDLCALL SDL_VideoDriverName(char *namebuf, int maxlen);

/**
 * This function returns a pointer to the current display surface.
 * If SDL is doing format conversion on the display surface, this
 * function returns the publicly visible surface, not the real video
 * surface.
 */
extern DECLSPEC SDL_Surface * SDLCALL SDL_GetVideoSurface(void);

/**
 * This function returns a read-only pointer to information about the
 * video hardware.  If this is called before SDL_SetVideoMode(), the 'vfmt'
 * member of the returned structure will contain the pixel format of the
 * "best" video mode.
 */
extern DECLSPEC const SDL_VideoInfo * SDLCALL SDL_GetVideoInfo(void);

/**
 * Check to see if a particular video mode is supported.
 * It returns 0 if the requested mode is not supported under any bit depth,
 * or returns the bits-per-pixel of the closest available mode with the
 * given width and height.  If this bits-per-pixel is different from the
 * one used when setting the video mode, SDL_SetVideoMode() will succeed,
 * but will emulate the requested bits-per-pixel with a shadow surface.
 *
 * The arguments to SDL_VideoModeOK() are the same ones you would pass to
 * SDL_SetVideoMode()
 */
extern DECLSPEC int SDLCALL SDL_VideoModeOK(int width, int height, int bpp, Uint32 flags);

/**
 * Return a pointer to an array of available screen dimensions for the
 * given format and video flags, sorted largest to smallest.  Returns 
 * NULL if there are no dimensions available for a particular format, 
 * or (SDL_Rect **)-1 if any dimension is okay for the given format.
 *
 * If 'format' is NULL, the mode list will be for the format given 
 * by SDL_GetVideoInfo()->vfmt
 */
extern DECLSPEC SDL_Rect ** SDLCALL SDL_ListModes(SDL_PixelFormat *format, Uint32 flags);

/**
 * Set up a video mode with the specified width, height and bits-per-pixel.
 *
 * If 'bpp' is 0, it is treated as the current display bits per pixel.
 *
 * If SDL_ANYFORMAT is set in 'flags', the SDL library will try to set the
 * requested bits-per-pixel, but will return whatever video pixel format is
 * available.  The default is to emulate the requested pixel format if it
 * is not natively available.
 *
 * If SDL_HWSURFACE is set in 'flags', the video surface will be placed in
 * video memory, if possible, and you may have to call SDL_LockSurface()
 * in order to access the raw framebuffer.  Otherwise, the video surface
 * will be created in system memory.
 *
 * If SDL_ASYNCBLIT is set in 'flags', SDL will try to perform rectangle
 * updates asynchronously, but you must always lock before accessing pixels.
 * SDL will wait for updates to complete before returning from the lock.
 *
 * If SDL_HWPALETTE is set in 'flags', the SDL library will guarantee
 * that the colors set by SDL_SetColors() will be the colors you get.
 * Otherwise, in 8-bit mode, SDL_SetColors() may not be able to set all
 * of the colors exactly the way they are requested, and you should look
 * at the video surface structure to determine the actual palette.
 * If SDL cannot guarantee that the colors you request can be set, 
 * i.e. if the colormap is shared, then the video surface may be created
 * under emulation in system memory, overriding the SDL_HWSURFACE flag.
 *
 * If SDL_FULLSCREEN is set in 'flags', the SDL library will try to set
 * a fullscreen video mode.  The default is to create a windowed mode
 * if the current graphics system has a window manager.
 * If the SDL library is able to set a fullscreen video mode, this flag 
 * will be set in the surface that is returned.
 *
 * If SDL_DOUBLEBUF is set in 'flags', the SDL library will try to set up
 * two surfaces in video memory and swap between them when you call 
 * SDL_Flip().  This is usually slower than the normal single-buffering
 * scheme, but prevents "tearing" artifacts caused by modifying video 
 * memory while the monitor is refreshing.  It should only be used by 
 * applications that redraw the entire screen on every update.
 *
 * If SDL_RESIZABLE is set in 'flags', the SDL library will allow the
 * window manager, if any, to resize the window at runtime.  When this
 * occurs, SDL will send a SDL_VIDEORESIZE event to you application,
 * and you must respond to the event by re-calling SDL_SetVideoMode()
 * with the requested size (or another size that suits the application).
 *
 * If SDL_NOFRAME is set in 'flags', the SDL library will create a window
 * without any title bar or frame decoration.  Fullscreen video modes have
 * this flag set automatically.
 *
 * This function returns the video framebuffer surface, or NULL if it fails.
 *
 * If you rely on functionality provided by certain video flags, check the
 * flags of the returned surface to make sure that functionality is available.
 * SDL will fall back to reduced functionality if the exact flags you wanted
 * are not available.
 */
extern DECLSPEC SDL_Surface * SDLCALL SDL_SetVideoMode
			(int width, int height, int bpp, Uint32 flags);

/** @name SDL_Update Functions
 * These functions should not be called while 'screen' is locked.
 */
/*@{*/
/**
 * Makes sure the given list of rectangles is updated on the given screen.
 */
extern DECLSPEC void SDLCALL SDL_UpdateRects
		(SDL_Surface *screen, int numrects, SDL_Rect *rects);
/**
 * If 'x', 'y', 'w' and 'h' are all 0, SDL_UpdateRect will update the entire
 * screen.
 */
extern DECLSPEC void SDLCALL SDL_UpdateRect
		(SDL_Surface *screen, Sint32 x, Sint32 y, Uint32 w, Uint32 h);
/*@}*/

/**
 * On hardware that supports double-buffering, this function sets up a flip
 * and returns.  The hardware will wait for vertical retrace, and then swap
 * video buffers before the next video surface blit or lock will return.
 * On hardware that doesn not support double-buffering, this is equivalent
 * to calling SDL_UpdateRect(screen, 0, 0, 0, 0);
 * The SDL_DOUBLEBUF flag must have been passed to SDL_SetVideoMode() when
 * setting the video mode for this function to perform hardware flipping.
 * This function returns 0 if successful, or -1 if there was an error.
 */
extern DECLSPEC int SDLCALL SDL_Flip(SDL_Surface *screen);

/**
 * Set the gamma correction for each of the color channels.
 * The gamma values range (approximately) between 0.1 and 10.0
 * 
 * If this function isn't supported directly by the hardware, it will
 * be emulated using gamma ramps, if available.  If successful, this
 * function returns 0, otherwise it returns -1.
 */
extern DECLSPEC int SDLCALL SDL_SetGamma(float red, float green, float blue);

/**
 * Set the gamma translation table for the red, green, and blue channels
 * of the video hardware.  Each table is an array of 256 16-bit quantities,
 * representing a mapping between the input and output for that channel.
 * The input is the index into the array, and the output is the 16-bit
 * gamma value at that index, scaled to the output color precision.
 * 
 * You may pass NULL for any of the channels to leave it unchanged.
 * If the call succeeds, it will return 0.  If the display driver or
 * hardware does not support gamma translation, or otherwise fails,
 * this function will return -1.
 */
extern DECLSPEC int SDLCALL SDL_SetGammaRamp(const Uint16 *red, const Uint16 *green, const Uint16 *blue);

/**
 * Retrieve the current values of the gamma translation tables.
 * 
 * You must pass in valid pointers to arrays of 256 16-bit quantities.
 * Any of the pointers may be NULL to ignore that channel.
 * If the call succeeds, it will return 0.  If the display driver or
 * hardware does not support gamma translation, or otherwise fails,
 * this function will return -1.
 */
extern DECLSPEC int SDLCALL SDL_GetGammaRamp(Uint16 *red, Uint16 *green, Uint16 *blue);

/**
 * Sets a portion of the colormap for the given 8-bit surface.  If 'surface'
 * is not a palettized surface, this function does nothing, returning 0.
 * If all of the colors were set as passed to SDL_SetColors(), it will
 * return 1.  If not all the color entries were set exactly as given,
 * it will return 0, and you should look at the surface palette to
 * determine the actual color palette.
 *
 * When 'surface' is the surface associated with the current display, the
 * display colormap will be updated with the requested colors.  If 
 * SDL_HWPALETTE was set in SDL_SetVideoMode() flags, SDL_SetColors()
 * will always return 1, and the palette is guaranteed to be set the way
 * you desire, even if the window colormap has to be warped or run under
 * emulation.
 */
extern DECLSPEC int SDLCALL SDL_SetColors(SDL_Surface *surface, 
			SDL_Color *colors, int firstcolor, int ncolors);

/**
 * Sets a portion of the colormap for a given 8-bit surface.
 * 'flags' is one or both of:
 * SDL_LOGPAL  -- set logical palette, which controls how blits are mapped
 *                to/from the surface,
 * SDL_PHYSPAL -- set physical palette, which controls how pixels look on
 *                the screen
 * Only screens have physical palettes. Separate change of physical/logical
 * palettes is only possible if the screen has SDL_HWPALETTE set.
 *
 * The return value is 1 if all colours could be set as requested, and 0
 * otherwise.
 *
 * SDL_SetColors() is equivalent to calling this function with
 *     flags = (SDL_LOGPAL|SDL_PHYSPAL).
 */
extern DECLSPEC int SDLCALL SDL_SetPalette(SDL_Surface *surface, int flags,
				   SDL_Color *colors, int firstcolor,
				   int ncolors);

/**
 * Maps an RGB triple to an opaque pixel value for a given pixel format
 */
extern DECLSPEC Uint32 SDLCALL SDL_MapRGB
(const SDL_PixelFormat * const format,
 const Uint8 r, const Uint8 g, const Uint8 b);

/**
 * Maps an RGBA quadruple to a pixel value for a given pixel format
 */
extern DECLSPEC Uint32 SDLCALL SDL_MapRGBA
(const SDL_PixelFormat * const format,
 const Uint8 r, const Uint8 g, const Uint8 b, const Uint8 a);

/**
 * Maps a pixel value into the RGB components for a given pixel format
 */
extern DECLSPEC void SDLCALL SDL_GetRGB(Uint32 pixel,
				const SDL_PixelFormat * const fmt,
				Uint8 *r, Uint8 *g, Uint8 *b);

/**
 * Maps a pixel value into the RGBA components for a given pixel format
 */
extern DECLSPEC void SDLCALL SDL_GetRGBA(Uint32 pixel,
				const SDL_PixelFormat * const fmt,
				Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a);

/** @sa SDL_CreateRGBSurface */
#define SDL_AllocSurface    SDL_CreateRGBSurface
/**
 * Allocate and free an RGB surface (must be called after SDL_SetVideoMode)
 * If the depth is 4 or 8 bits, an empty palette is allocated for the surface.
 * If the depth is greater than 8 bits, the pixel format is set using the
 * flags '[RGB]mask'.
 * If the function runs out of memory, it will return NULL.
 *
 * The 'flags' tell what kind of surface to create.
 * SDL_SWSURFACE means that the surface should be created in system memory.
 * SDL_HWSURFACE means that the surface should be created in video memory,
 * with the same format as the display surface.  This is useful for surfaces
 * that will not change much, to take advantage of hardware acceleration
 * when being blitted to the display surface.
 * SDL_ASYNCBLIT means that SDL will try to perform asynchronous blits with
 * this surface, but you must always lock it before accessing the pixels.
 * SDL will wait for current blits to finish before returning from the lock.
 * SDL_SRCCOLORKEY indicates that the surface will be used for colorkey blits.
 * If the hardware supports acceleration of colorkey blits between
 * two surfaces in video memory, SDL will try to place the surface in
 * video memory. If this isn't possible or if there is no hardware
 * acceleration available, the surface will be placed in system memory.
 * SDL_SRCALPHA means that the surface will be used for alpha blits and 
 * if the hardware supports hardware acceleration of alpha blits between
 * two surfaces in video memory, to place the surface in video memory
 * if possible, otherwise it will be placed in system memory.
 * If the surface is created in video memory, blits will be _much_ faster,
 * but the surface format must be identical to the video surface format,
 * and the only way to access the pixels member of the surface is to use
 * the SDL_LockSurface() and SDL_UnlockSurface() calls.
 * If the requested surface actually resides in video memory, SDL_HWSURFACE
 * will be set in the flags member of the returned surface.  If for some
 * reason the surface could not be placed in video memory, it will not have
 * the SDL_HWSURFACE flag set, and will be created in system memory instead.
 */
extern DECLSPEC SDL_Surface * SDLCALL SDL_CreateRGBSurface
			(Uint32 flags, int width, int height, int depth, 
			Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
/** @sa SDL_CreateRGBSurface */
extern DECLSPEC SDL_Surface * SDLCALL SDL_CreateRGBSurfaceFrom(void *pixels,
			int width, int height, int depth, int pitch,
			Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
extern DECLSPEC void SDLCALL SDL_FreeSurface(SDL_Surface *surface);

/**
 * SDL_LockSurface() sets up a surface for directly accessing the pixels.
 * Between calls to SDL_LockSurface()/SDL_UnlockSurface(), you can write
 * to and read from 'surface->pixels', using the pixel format stored in 
 * 'surface->format'.  Once you are done accessing the surface, you should 
 * use SDL_UnlockSurface() to release it.
 *
 * Not all surfaces require locking.  If SDL_MUSTLOCK(surface) evaluates
 * to 0, then you can read and write to the surface at any time, and the
 * pixel format of the surface will not change.  In particular, if the
 * SDL_HWSURFACE flag is not given when calling SDL_SetVideoMode(), you
 * will not need to lock the display surface before accessing it.
 * 
 * No operating system or library calls should be made between lock/unlock
 * pairs, as critical system locks may be held during this time.
 *
 * SDL_LockSurface() returns 0, or -1 if the surface couldn't be locked.
 */
extern DECLSPEC int SDLCALL SDL_LockSurface(SDL_Surface *surface);
extern DECLSPEC void SDLCALL SDL_UnlockSurface(SDL_Surface *surface);

/**
 * Load a surface from a seekable SDL data source (memory or file.)
 * If 'freesrc' is non-zero, the source will be closed after being read.
 * Returns the new surface, or NULL if there was an error.
 * The new surface should be freed with SDL_FreeSurface().
 */
extern DECLSPEC SDL_Surface * SDLCALL SDL_LoadBMP_RW(SDL_RWops *src, int freesrc);

/** Convenience macro -- load a surface from a file */
#define SDL_LoadBMP(file)	SDL_LoadBMP_RW(SDL_RWFromFile(file, "rb"), 1)

/**
 * Save a surface to a seekable SDL data source (memory or file.)
 * If 'freedst' is non-zero, the source will be closed after being written.
 * Returns 0 if successful or -1 if there was an error.
 */
extern DECLSPEC int SDLCALL SDL_SaveBMP_RW
		(SDL_Surface *surface, SDL_RWops *dst, int freedst);

/** Convenience macro -- save a surface to a file */
#define SDL_SaveBMP(surface, file) \
		SDL_SaveBMP_RW(surface, SDL_RWFromFile(file, "wb"), 1)

/**
 * Sets the color key (transparent pixel) in a blittable surface.
 * If 'flag' is SDL_SRCCOLORKEY (optionally OR'd with SDL_RLEACCEL), 
 * 'key' will be the transparent pixel in the source image of a blit.
 * SDL_RLEACCEL requests RLE acceleration for the surface if present,
 * and removes RLE acceleration if absent.
 * If 'flag' is 0, this function clears any current color key.
 * This function returns 0, or -1 if there was an error.
 */
extern DECLSPEC int SDLCALL SDL_SetColorKey
			(SDL_Surface *surface, Uint32 flag, Uint32 key);

/**
 * This function sets the alpha value for the entire surface, as opposed to
 * using the alpha component of each pixel. This value measures the range
 * of transparency of the surface, 0 being completely transparent to 255
 * being completely opaque. An 'alpha' value of 255 causes blits to be
 * opaque, the source pixels copied to the destination (the default). Note
 * that per-surface alpha can be combined with colorkey transparency.
 *
 * If 'flag' is 0, alpha blending is disabled for the surface.
 * If 'flag' is SDL_SRCALPHA, alpha blending is enabled for the surface.
 * OR:ing the flag with SDL_RLEACCEL requests RLE acceleration for the
 * surface; if SDL_RLEACCEL is not specified, the RLE accel will be removed.
 *
 * The 'alpha' parameter is ignored for surfaces that have an alpha channel.
 */
extern DECLSPEC int SDLCALL SDL_SetAlpha(SDL_Surface *surface, Uint32 flag, Uint8 alpha);

/**
 * Sets the clipping rectangle for the destination surface in a blit.
 *
 * If the clip rectangle is NULL, clipping will be disabled.
 * If the clip rectangle doesn't intersect the surface, the function will
 * return SDL_FALSE and blits will be completely clipped.  Otherwise the
 * function returns SDL_TRUE and blits to the surface will be clipped to
 * the intersection of the surface area and the clipping rectangle.
 *
 * Note that blits are automatically clipped to the edges of the source
 * and destination surfaces.
 */
extern DECLSPEC SDL_bool SDLCALL SDL_SetClipRect(SDL_Surface *surface, const SDL_Rect *rect);

/**
 * Gets the clipping rectangle for the destination surface in a blit.
 * 'rect' must be a pointer to a valid rectangle which will be filled
 * with the correct values.
 */
extern DECLSPEC void SDLCALL SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect);

/**
 * Creates a new surface of the specified format, and then copies and maps 
 * the given surface to it so the blit of the converted surface will be as 
 * fast as possible.  If this function fails, it returns NULL.
 *
 * The 'flags' parameter is passed to SDL_CreateRGBSurface() and has those 
 * semantics.  You can also pass SDL_RLEACCEL in the flags parameter and
 * SDL will try to RLE accelerate colorkey and alpha blits in the resulting
 * surface.
 *
 * This function is used internally by SDL_DisplayFormat().
 */
extern DECLSPEC SDL_Surface * SDLCALL SDL_ConvertSurface
			(SDL_Surface *src, SDL_PixelFormat *fmt, Uint32 flags);

/**
 * This performs a fast blit from the source surface to the destination
 * surface.  It assumes that the source and destination rectangles are
 * the same size.  If either 'srcrect' or 'dstrect' are NULL, the entire
 * surface (src or dst) is copied.  The final blit rectangles are saved
 * in 'srcrect' and 'dstrect' after all clipping is performed.
 * If the blit is successful, it returns 0, otherwise it returns -1.
 *
 * The blit function should not be called on a locked surface.
 *
 * The blit semantics for surfaces with and without alpha and colorkey
 * are defined as follows:
 *
 * RGBA->RGB:
 *     SDL_SRCALPHA set:
 * 	alpha-blend (using alpha-channel).
 * 	SDL_SRCCOLORKEY ignored.
 *     SDL_SRCALPHA not set:
 * 	copy RGB.
 * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
 * 	RGB values of the source colour key, ignoring alpha in the
 * 	comparison.
 * 
 * RGB->RGBA:
 *     SDL_SRCALPHA set:
 * 	alpha-blend (using the source per-surface alpha value);
 * 	set destination alpha to opaque.
 *     SDL_SRCALPHA not set:
 * 	copy RGB, set destination alpha to source per-surface alpha value.
 *     both:
 * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
 * 	source colour key.
 * 
 * RGBA->RGBA:
 *     SDL_SRCALPHA set:
 * 	alpha-blend (using the source alpha channel) the RGB values;
 * 	leave destination alpha untouched. [Note: is this correct?]
 * 	SDL_SRCCOLORKEY ignored.
 *     SDL_SRCALPHA not set:
 * 	copy all of RGBA to the destination.
 * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
 * 	RGB values of the source colour key, ignoring alpha in the
 * 	comparison.
 * 
 * RGB->RGB: 
 *     SDL_SRCALPHA set:
 * 	alpha-blend (using the source per-surface alpha value).
 *     SDL_SRCALPHA not set:
 * 	copy RGB.
 *     both:
 * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
 * 	source colour key.
 *
 * If either of the surfaces were in video memory, and the blit returns -2,
 * the video memory was lost, so it should be reloaded with artwork and 
 * re-blitted:
 * @code
 *	while ( SDL_BlitSurface(image, imgrect, screen, dstrect) == -2 ) {
 *		while ( SDL_LockSurface(image) < 0 )
 *			Sleep(10);
 *		-- Write image pixels to image->pixels --
 *		SDL_UnlockSurface(image);
 *	}
 * @endcode
 *
 * This happens under DirectX 5.0 when the system switches away from your
 * fullscreen application.  The lock will also fail until you have access
 * to the video memory again.
 *
 * You should call SDL_BlitSurface() unless you know exactly how SDL
 * blitting works internally and how to use the other blit functions.
 */
#define SDL_BlitSurface SDL_UpperBlit

/** This is the public blit function, SDL_BlitSurface(), and it performs
 *  rectangle validation and clipping before passing it to SDL_LowerBlit()
 */
extern DECLSPEC int SDLCALL SDL_UpperBlit
			(SDL_Surface *src, SDL_Rect *srcrect,
			 SDL_Surface *dst, SDL_Rect *dstrect);
/** This is a semi-private blit function and it performs low-level surface
 *  blitting only.
 */
extern DECLSPEC int SDLCALL SDL_LowerBlit
			(SDL_Surface *src, SDL_Rect *srcrect,
			 SDL_Surface *dst, SDL_Rect *dstrect);

/**
 * This function performs a fast fill of the given rectangle with 'color'
 * The given rectangle is clipped to the destination surface clip area
 * and the final fill rectangle is saved in the passed in pointer.
 * If 'dstrect' is NULL, the whole surface will be filled with 'color'
 * The color should be a pixel of the format used by the surface, and 
 * can be generated by the SDL_MapRGB() function.
 * This function returns 0 on success, or -1 on error.
 */
extern DECLSPEC int SDLCALL SDL_FillRect
		(SDL_Surface *dst, SDL_Rect *dstrect, Uint32 color);

/**
 * This function takes a surface and copies it to a new surface of the
 * pixel format and colors of the video framebuffer, suitable for fast
 * blitting onto the display surface.  It calls SDL_ConvertSurface()
 *
 * If you want to take advantage of hardware colorkey or alpha blit
 * acceleration, you should set the colorkey and alpha value before
 * calling this function.
 *
 * If the conversion fails or runs out of memory, it returns NULL
 */
extern DECLSPEC SDL_Surface * SDLCALL SDL_DisplayFormat(SDL_Surface *surface);

/**
 * This function takes a surface and copies it to a new surface of the
 * pixel format and colors of the video framebuffer (if possible),
 * suitable for fast alpha blitting onto the display surface.
 * The new surface will always have an alpha channel.
 *
 * If you want to take advantage of hardware colorkey or alpha blit
 * acceleration, you should set the colorkey and alpha value before
 * calling this function.
 *
 * If the conversion fails or runs out of memory, it returns NULL
 */
extern DECLSPEC SDL_Surface * SDLCALL SDL_DisplayFormatAlpha(SDL_Surface *surface);


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/** @name YUV video surface overlay functions                                */ /*@{*/
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/** This function creates a video output overlay
 *  Calling the returned surface an overlay is something of a misnomer because
 *  the contents of the display surface underneath the area where the overlay
 *  is shown is undefined - it may be overwritten with the converted YUV data.
 */
extern DECLSPEC SDL_Overlay * SDLCALL SDL_CreateYUVOverlay(int width, int height,
				Uint32 format, SDL_Surface *display);

/** Lock an overlay for direct access, and unlock it when you are done */
extern DECLSPEC int SDLCALL SDL_LockYUVOverlay(SDL_Overlay *overlay);
extern DECLSPEC void SDLCALL SDL_UnlockYUVOverlay(SDL_Overlay *overlay);

/** Blit a video overlay to the display surface.
 *  The contents of the video surface underneath the blit destination are
 *  not defined.  
 *  The width and height of the destination rectangle may be different from
 *  that of the overlay, but currently only 2x scaling is supported.
 */
extern DECLSPEC int SDLCALL SDL_DisplayYUVOverlay(SDL_Overlay *overlay, SDL_Rect *dstrect);

/** Free a video overlay */
extern DECLSPEC void SDLCALL SDL_FreeYUVOverlay(SDL_Overlay *overlay);

/*@}*/

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/** @name OpenGL support functions.                                          */ /*@{*/
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/**
 * Dynamically load an OpenGL library, or the default one if path is NULL
 *
 * If you do this, you need to retrieve all of the GL functions used in
 * your program from the dynamic library using SDL_GL_GetProcAddress().
 */
extern DECLSPEC int SDLCALL SDL_GL_LoadLibrary(const char *path);

/**
 * Get the address of a GL function
 */
extern DECLSPEC void * SDLCALL SDL_GL_GetProcAddress(const char* proc);

/**
 * Set an attribute of the OpenGL subsystem before intialization.
 */
extern DECLSPEC int SDLCALL SDL_GL_SetAttribute(SDL_GLattr attr, int value);

/**
 * Get an attribute of the OpenGL subsystem from the windowing
 * interface, such as glX. This is of course different from getting
 * the values from SDL's internal OpenGL subsystem, which only
 * stores the values you request before initialization.
 *
 * Developers should track the values they pass into SDL_GL_SetAttribute
 * themselves if they want to retrieve these values.
 */
extern DECLSPEC int SDLCALL SDL_GL_GetAttribute(SDL_GLattr attr, int* value);

/**
 * Swap the OpenGL buffers, if double-buffering is supported.
 */
extern DECLSPEC void SDLCALL SDL_GL_SwapBuffers(void);

/** @name OpenGL Internal Functions
 * Internal functions that should not be called unless you have read
 * and understood the source code for these functions.
 */
/*@{*/
extern DECLSPEC void SDLCALL SDL_GL_UpdateRects(int numrects, SDL_Rect* rects);
extern DECLSPEC void SDLCALL SDL_GL_Lock(void);
extern DECLSPEC void SDLCALL SDL_GL_Unlock(void);
/*@}*/

/*@}*/

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/** @name Window Manager Functions                                           */
/** These functions allow interaction with the window manager, if any.       */ /*@{*/
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/**
 * Sets the title and icon text of the display window (UTF-8 encoded)
 */
extern DECLSPEC void SDLCALL SDL_WM_SetCaption(const char *title, const char *icon);
/**
 * Gets the title and icon text of the display window (UTF-8 encoded)
 */
extern DECLSPEC void SDLCALL SDL_WM_GetCaption(char **title, char **icon);

/**
 * Sets the icon for the display window.
 * This function must be called before the first call to SDL_SetVideoMode().
 * It takes an icon surface, and a mask in MSB format.
 * If 'mask' is NULL, the entire icon surface will be used as the icon.
 */
extern DECLSPEC void SDLCALL SDL_WM_SetIcon(SDL_Surface *icon, Uint8 *mask);

/**
 * This function iconifies the window, and returns 1 if it succeeded.
 * If the function succeeds, it generates an SDL_APPACTIVE loss event.
 * This function is a noop and returns 0 in non-windowed environments.
 */
extern DECLSPEC int SDLCALL SDL_WM_IconifyWindow(void);

/**
 * Toggle fullscreen mode without changing the contents of the screen.
 * If the display surface does not require locking before accessing
 * the pixel information, then the memory pointers will not change.
 *
 * If this function was able to toggle fullscreen mode (change from 
 * running in a window to fullscreen, or vice-versa), it will return 1.
 * If it is not implemented, or fails, it returns 0.
 *
 * The next call to SDL_SetVideoMode() will set the mode fullscreen
 * attribute based on the flags parameter - if SDL_FULLSCREEN is not
 * set, then the display will be windowed by default where supported.
 *
 * This is currently only implemented in the X11 video driver.
 */
extern DECLSPEC int SDLCALL SDL_WM_ToggleFullScreen(SDL_Surface *surface);

typedef enum {
	SDL_GRAB_QUERY = -1,
	SDL_GRAB_OFF = 0,
	SDL_GRAB_ON = 1,
	SDL_GRAB_FULLSCREEN	/**< Used internally */
} SDL_GrabMode;
/**
 * This function allows you to set and query the input grab state of
 * the application.  It returns the new input grab state.
 *
 * Grabbing means that the mouse is confined to the application window,
 * and nearly all keyboard input is passed directly to the application,
 * and not interpreted by a window manager, if any.
 */
extern DECLSPEC SDL_GrabMode SDLCALL SDL_WM_GrabInput(SDL_GrabMode mode);

/*@}*/

/** @internal Not in public API at the moment - do not use! */
extern DECLSPEC int SDLCALL SDL_SoftStretch(SDL_Surface *src, SDL_Rect *srcrect,
                                    SDL_Surface *dst, SDL_Rect *dstrect);
                    
/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"

#endif /* _SDL_video_h */