SDL_CreateRGBSurface

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SDL_CreateRGBSurface

Name

SDL_CreateRGBSurface -- Create an empty SDL_Surface

Synopsis

#include "SDL.h"

SDL_Surface *SDL_CreateRGBSurface(Uint32 flags, int width, int height, int depth, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);


  
    
    Description
    Allocate an empty surface (must be called after SDL_SetVideoMode)
    If depth is 8 bits an empty palette is allocated for the surface, otherwise a 'packed-pixel' SDL_PixelFormat is created using the [RGBA]mask's provided (see SDL_PixelFormat). The flags specifies the type of surface that should be created, it is an OR'd combination of the following possible values.
    
      
      
      

        
          
            
              SDL_SWSURFACE
            
            SDL will create the surface in system memory. This improves the performance of pixel level access, however you may not be able to take advantage of some types of hardware blitting.
          
          
            
              SDL_HWSURFACE
            
            SDL will attempt to create the surface in video memory. This will allow SDL to take advantage of Video->Video blits (which are often accelerated).
          
          
            
              SDL_SRCCOLORKEY
            
            This flag turns on colourkeying for blits from this surface. If
SDL_HWSURFACE is also specified and colourkeyed blits
are hardware-accelerated, then SDL will attempt to place the surface in
video memory.
Use SDL_SetColorKey
to set or clear this flag after surface creation.
          
          
            
              SDL_SRCALPHA
            
            This flag turns on alpha-blending for blits from this surface. If
SDL_HWSURFACE is also specified and alpha-blending blits
are hardware-accelerated, then the surface will be placed in video memory if
possible.
Use SDL_SetAlpha to
set or clear this flag after surface creation.
          
        
      
      
    
    
      
        Note: If an alpha-channel is specified (that is, if Amask is
nonzero), then the SDL_SRCALPHA flag is automatically
set. You may remove this flag by calling 
SDL_SetAlpha
after surface creation.
      
    
  
  
    
    Return Value
    Returns the created surface, or NULL upon error.
  
  
    
    Example
        /* Create a 32-bit surface with the bytes of each pixel in R,G,B,A order,
       as expected by OpenGL for textures */
    SDL_Surface *surface;
    Uint32 rmask, gmask, bmask, amask;

    /* SDL interprets each pixel as a 32-bit number, so our masks must depend
       on the endianness (byte order) of the machine */
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
    rmask = 0xff000000;
    gmask = 0x00ff0000;
    bmask = 0x0000ff00;
    amask = 0x000000ff;
#else
    rmask = 0x000000ff;
    gmask = 0x0000ff00;
    bmask = 0x00ff0000;
    amask = 0xff000000;
#endif

    surface = SDL_CreateRGBSurface(SDL_SWSURFACE, width, height, 32,
                                   rmask, gmask, bmask, amask);
    if(surface == NULL) {
        fprintf(stderr, "CreateRGBSurface failed: %s\n", SDL_GetError());
        exit(1);
    }
  
  
    
    See Also
    SDL_CreateRGBSurfaceFrom,
SDL_FreeSurface,
SDL_SetVideoMode,
SDL_LockSurface,
SDL_PixelFormat,
SDL_Surface
SDL_SetAlpha
SDL_SetColorKey
  
  
    
    
      
        
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`SDL_SWSURFACE`	SDL will create the surface in system memory. This improves the performance of pixel level access, however you may not be able to take advantage of some types of hardware blitting.
`SDL_HWSURFACE`	SDL will attempt to create the surface in video memory. This will allow SDL to take advantage of Video->Video blits (which are often accelerated).
`SDL_SRCCOLORKEY`	This flag turns on colourkeying for blits from this surface. If `SDL_HWSURFACE` is also specified and colourkeyed blits are hardware-accelerated, then SDL will attempt to place the surface in video memory. Use `SDL_SetColorKey` to set or clear this flag after surface creation.
`SDL_SRCALPHA`	This flag turns on alpha-blending for blits from this surface. If `SDL_HWSURFACE` is also specified and alpha-blending blits are hardware-accelerated, then the surface will be placed in video memory if possible. Use `SDL_SetAlpha` to set or clear this flag after surface creation.