view include/SDL_surface.h @ 3469:8c5fb2a3b11d

RenderReadPixels and RenderWritePixels functions work with back buffer now and all asynchronous operations are flushed before reading or writing to backbuffer. Thanks Sam for clarification of this.
author Mike Gorchak <lestat@i.com.ua>
date Sat, 21 Nov 2009 06:17:50 +0000
parents 147d6ef5be03
children 0267b8b1595c
line wrap: on
line source

/*
    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_surface.h
 *  
 *  Header file for ::SDL_surface definition and management functions.
 */

#ifndef _SDL_surface_h
#define _SDL_surface_h

#include "SDL_stdinc.h"
#include "SDL_pixels.h"
#include "SDL_rect.h"
#include "SDL_rwops.h"

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

/**
 *  \name Surface flags
 *  
 *  These are the currently supported flags for the ::SDL_surface.
 *  
 *  \internal
 *  Used internally (read-only).
 */
/*@{*/
#define SDL_PREALLOC        0x00000001  /**< Surface uses preallocated memory */
#define SDL_RLEACCEL        0x00000002  /**< Surface is RLE encoded */
/*@}*//*Surface flags*/

/**
 *  Evaluates to true if the surface needs to be locked before access.
 */
#define SDL_MUSTLOCK(S)	(((S)->flags & SDL_RLEACCEL) != 0)

/**
 * \brief A collection of pixels used in software blitting.
 *
 * \note  This structure should be treated as read-only, except for \c 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 */
    int pitch;                  /**< Read-only */
    void *pixels;               /**< Read-write */

    /** Application data associated with the surfade */
    void *userdata;             /**< Read-write */

    /** information needed for surfaces requiring locks */
    int locked;                 /**< Read-only */
    void *lock_data;            /**< Read-only */

    /** clipping information */
    SDL_Rect clip_rect;         /**< Read-only */

    /** 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;

/**
 * \brief The type of function used for surface blitting functions.
 */
typedef int (*SDL_blit) (struct SDL_Surface * src, SDL_Rect * srcrect,
                         struct SDL_Surface * dst, SDL_Rect * dstrect);

/**
 *  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.
 *  
 *  \param flags The \c flags are obsolete and should be set to 0.
 */
extern DECLSPEC SDL_Surface *SDLCALL SDL_CreateRGBSurface
    (Uint32 flags, int width, int height, int depth,
     Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
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);

/**
 *  \brief Set the palette used by a surface.
 *  
 *  \return 0, or -1 if the surface format doesn't use a palette.
 *  
 *  \note A single palette can be shared with many surfaces.
 */
extern DECLSPEC int SDLCALL SDL_SetSurfacePalette(SDL_Surface * surface,
                                                  SDL_Palette * palette);

/**
 *  \brief Sets up a surface for directly accessing the pixels.
 *  
 *  Between calls to SDL_LockSurface() / SDL_UnlockSurface(), you can write
 *  to and read from \c surface->pixels, using the pixel format stored in 
 *  \c 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.
 *  
 *  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.
 *  
 *  \sa SDL_UnlockSurface()
 */
extern DECLSPEC int SDLCALL SDL_LockSurface(SDL_Surface * surface);
/** \sa SDL_LockSurface() */
extern DECLSPEC void SDLCALL SDL_UnlockSurface(SDL_Surface * surface);

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

/**
 *  Load a surface from a file.
 *  
 *  Convenience macro.
 */
#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 \c freedst is non-zero, the source will be closed after being written.
 *  
 *  \return 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);

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

/**
 *  \brief Sets the RLE acceleration hint for a surface.
 *  
 *  \return 0 on success, or -1 if the surface is not valid
 *  
 *  \note If RLE is enabled, colorkey and alpha blending blits are much faster,
 *        but the surface must be locked before directly accessing the pixels.
 */
extern DECLSPEC int SDLCALL SDL_SetSurfaceRLE(SDL_Surface * surface,
                                              int flag);

/**
 *  \brief Sets the color key (transparent pixel) in a blittable surface.
 *  
 *  \param surface The surface to update
 *  \param flag Non-zero to enable colorkey and 0 to disable colorkey 
 *  \param key The transparent pixel in the native surface format
 *  
 *  \return 0 on success, or -1 if the surface is not valid
 */
extern DECLSPEC int SDLCALL SDL_SetColorKey(SDL_Surface * surface,
                                            Uint32 flag, Uint32 key);

/**
 *  \brief Sets the color key (transparent pixel) in a blittable surface.
 *  
 *  \param surface The surface to update
 *  \param key A pointer filled in with the transparent pixel in the native 
 *             surface format
 *  
 *  \return 0 on success, or -1 if the surface is not valid or colorkey is not 
 *          enabled.
 */
extern DECLSPEC int SDLCALL SDL_GetColorKey(SDL_Surface * surface,
                                            Uint32 * key);

/**
 *  \brief Set an additional color value used in blit operations.
 *  
 *  \param surface The surface to update.
 *  \param r The red source color value multiplied into blit operations.
 *  \param g The green source color value multiplied into blit operations.
 *  \param b The blue source color value multiplied into blit operations.
 *  
 *  \return 0 on success, or -1 if the surface is not valid.
 *  
 *  \sa SDL_GetSurfaceColorMod()
 */
extern DECLSPEC int SDLCALL SDL_SetSurfaceColorMod(SDL_Surface * surface,
                                                   Uint8 r, Uint8 g, Uint8 b);


/**
 *  \brief Get the additional color value used in blit operations.
 *  
 *  \param surface The surface to query.
 *  \param r A pointer filled in with the source red color value.
 *  \param g A pointer filled in with the source green color value.
 *  \param b A pointer filled in with the source blue color value.
 *  
 *  \return 0 on success, or -1 if the surface is not valid.
 *  
 *  \sa SDL_SetSurfaceColorMod()
 */
extern DECLSPEC int SDLCALL SDL_GetSurfaceColorMod(SDL_Surface * surface,
                                                   Uint8 * r, Uint8 * g,
                                                   Uint8 * b);

/**
 *  \brief Set an additional alpha value used in blit operations.
 *  
 *  \param surface The surface to update.
 *  \param alpha The source alpha value multiplied into blit operations.
 *  
 *  \return 0 on success, or -1 if the surface is not valid.
 *  
 *  \sa SDL_GetSurfaceAlphaMod()
 */
extern DECLSPEC int SDLCALL SDL_SetSurfaceAlphaMod(SDL_Surface * surface,
                                                   Uint8 alpha);

/**
 *  \brief Get the additional alpha value used in blit operations.
 *  
 *  \param surface The surface to query.
 *  \param alpha A pointer filled in with the source alpha value.
 *  
 *  \return 0 on success, or -1 if the surface is not valid.
 *  
 *  \sa SDL_SetSurfaceAlphaMod()
 */
extern DECLSPEC int SDLCALL SDL_GetSurfaceAlphaMod(SDL_Surface * surface,
                                                   Uint8 * alpha);

/**
 *  \brief Set the blend mode used for blit operations.
 *  
 *  \param surface The surface to update.
 *  \param blendMode ::SDL_BlendMode to use for blit blending.
 *  
 *  \return 0 on success, or -1 if the parameters are not valid.
 *  
 *  \sa SDL_GetSurfaceBlendMode()
 */
extern DECLSPEC int SDLCALL SDL_SetSurfaceBlendMode(SDL_Surface * surface,
                                                    int blendMode);

/**
 *  \brief Get the blend mode used for blit operations.
 *  
 *  \param surface   The surface to query.
 *  \param blendMode A pointer filled in with the current blend mode.
 *  
 *  \return 0 on success, or -1 if the surface is not valid.
 *  
 *  \sa SDL_SetSurfaceBlendMode()
 */
extern DECLSPEC int SDLCALL SDL_GetSurfaceBlendMode(SDL_Surface * surface,
                                                    int *blendMode);

/**
 *  \brief Set the scale mode used for blit operations.
 *  
 *  \param surface   The surface to update.
 *  \param scaleMode ::SDL_TextureScaleMode to use for blit scaling.
 *  
 *  \return 0 on success, or -1 if the surface is not valid or the scale mode is
 *          not supported.
 *  
 *  \note If the scale mode is not supported, the closest supported mode is 
 *        chosen.  Currently only ::SDL_TEXTURESCALEMODE_FAST is supported on 
 *        surfaces.
 *  
 *  \sa SDL_GetSurfaceScaleMode()
 */
extern DECLSPEC int SDLCALL SDL_SetSurfaceScaleMode(SDL_Surface * surface,
                                                    int scaleMode);

/**
 *  \brief Get the scale mode used for blit operations.
 *  
 *  \param surface   The surface to query.
 *  \param scaleMode A pointer filled in with the current scale mode.
 *  
 *  \return 0 on success, or -1 if the surface is not valid.
 *  
 *  \sa SDL_SetSurfaceScaleMode()
 */
extern DECLSPEC int SDLCALL SDL_GetSurfaceScaleMode(SDL_Surface * surface,
                                                    int *scaleMode);

/**
 *  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.
 *  
 *  \c 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 \c 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);

/**
 * \brief Copy a block of pixels of one format to another format
 */
extern DECLSPEC int SDLCALL SDL_ConvertPixels(int width, int height,
                                              Uint32 src_format,
                                              const void * src, int src_pitch,
                                              Uint32 dst_format,
                                              void * dst, int dst_pitch);

/**
 *  Draws a point with \c color.
 *
 *  The color should be a pixel of the format used by the surface, and 
 *  can be generated by the SDL_MapRGB() function.
 *  
 *  \return 0 on success, or -1 on error.
 */
extern DECLSPEC int SDLCALL SDL_DrawPoint
    (SDL_Surface * dst, int x, int y, Uint32 color);

/**
 *  Blends a point with an RGBA value.
 *  
 *  The color should be a pixel of the format used by the surface, and 
 *  can be generated by the SDL_MapRGB() function.
 *  
 *  \return 0 on success, or -1 on error.
 */
extern DECLSPEC int SDLCALL SDL_BlendPoint
    (SDL_Surface * dst, int x, int y, int blendMode,
     Uint8 r, Uint8 g, Uint8 b, Uint8 a);

/**
 *  Draws a line with \c color.
 *  
 *  The color should be a pixel of the format used by the surface, and 
 *  can be generated by the SDL_MapRGB() function.
 *  
 *  \return 0 on success, or -1 on error.
 */
extern DECLSPEC int SDLCALL SDL_DrawLine
    (SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color);

/**
 *  Blends an RGBA value along a line.
 *  
 *  \return 0 on success, or -1 on error.
 */
extern DECLSPEC int SDLCALL SDL_BlendLine
    (SDL_Surface * dst, int x1, int y1, int x2, int y2, int blendMode,
     Uint8 r, Uint8 g, Uint8 b, Uint8 a);

/**
 *  Performs a fast fill of the given rectangle with \c 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 \c dstrect is NULL, the whole surface will be filled with \c color.
 *  
 *  The color should be a pixel of the format used by the surface, and 
 *  can be generated by the SDL_MapRGB() function.
 *  
 *  \return 0 on success, or -1 on error.
 */
extern DECLSPEC int SDLCALL SDL_FillRect
    (SDL_Surface * dst, SDL_Rect * dstrect, Uint32 color);

/**
 *  Blends an RGBA value into the given rectangle.
 *  
 *  The given rectangle is clipped to the destination surface clip area
 *  and the final fill rectangle is saved in the passed in pointer.
 *  
 *  If \c dstrect is NULL, the whole surface will be filled with \c color.
 *  
 *  \return This function returns 0 on success, or -1 on error.
 */
extern DECLSPEC int SDLCALL SDL_BlendRect
    (SDL_Surface * dst, SDL_Rect * dstrect, int blendMode, Uint8 r, Uint8 g,
     Uint8 b, Uint8 a);

/**
 *  Performs a fast blit from the source surface to the destination surface.
 *  
 *  This assumes that the source and destination rectangles are
 *  the same size.  If either \c srcrect or \c dstrect are NULL, the entire
 *  surface (\c src or \c dst) is copied.  The final blit rectangles are saved
 *  in \c srcrect and \c dstrect after all clipping is performed.
 *  
 *  \return 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:
 *  \verbatim
    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.
    \endverbatim
 *  
 *  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);

/**
 *  \brief Perform a fast, low quality, stretch blit between two surfaces of the
 *         same pixel format.
 *  
 *  \note This function uses a static buffer, and is not thread-safe.
 */
extern DECLSPEC int SDLCALL SDL_SoftStretch(SDL_Surface * src,
                                            const SDL_Rect * srcrect,
                                            SDL_Surface * dst,
                                            const SDL_Rect * dstrect);

/* Ends C function definitions when using C++ */
#ifdef __cplusplus
/* *INDENT-OFF* */
}
/* *INDENT-ON* */
#endif
#include "close_code.h"

#endif /* _SDL_surface_h */

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