SDL_gfxBlitFunc.c File Reference

#include "SDL_gfxBlitFunc.h"

Go to the source code of this file.

Functions

void _SDL_gfxBlitBlitterRGBA (SDL_gfxBlitInfo *info)
 Internal blitter using adjusted destination alpha during RGBA->RGBA blits.
int _SDL_gfxBlitRGBACall (SDL_Surface *src, SDL_Rect *srcrect, SDL_Surface *dst, SDL_Rect *dstrect)
 Internal blitter setup wrapper for RGBA->RGBA blits.
int SDL_gfxBlitRGBA (SDL_Surface *src, SDL_Rect *srcrect, SDL_Surface *dst, SDL_Rect *dstrect)
 Blitter for RGBA->RGBA blits with alpha adjustment.
int SDL_gfxSetAlpha (SDL_Surface *src, Uint8 a)
 Sets the alpha channel in a 32 bit surface.
int SDL_gfxMultiplyAlpha (SDL_Surface *src, Uint8 a)
 Multiply the alpha channel in a 32bit surface.

Function Documentation

void _SDL_gfxBlitBlitterRGBA ( SDL_gfxBlitInfo info  ) 

Internal blitter using adjusted destination alpha during RGBA->RGBA blits.

Performs the blit based on the 'info' structure and applies the transfer function to the destination 'a' values.

Parameters:
info The blit info to use.

Definition at line 285 of file SDL_gfxBlitFunc.c.

int _SDL_gfxBlitRGBACall ( SDL_Surface *  src,
SDL_Rect *  srcrect,
SDL_Surface *  dst,
SDL_Rect *  dstrect 
)

Internal blitter setup wrapper for RGBA->RGBA blits.

Sets up the blitter info based on the 'src' and 'dst' surfaces and rectangles.

Parameters:
src The source surface.
srcrect The source rectangle.
dst The destination surface.
dstrect The destination rectangle.
Returns:
Returns 1 if blit was performed, 0 otherwise.

Definition at line 335 of file SDL_gfxBlitFunc.c.

int SDL_gfxBlitRGBA ( SDL_Surface *  src,
SDL_Rect *  srcrect,
SDL_Surface *  dst,
SDL_Rect *  dstrect 
)

Blitter for RGBA->RGBA blits with alpha adjustment.

Verifies the input 'src' and 'dst' surfaces and rectangles and performs blit. The destination clip rectangle is honored.

Parameters:
src The source surface.
srcrect The source rectangle.
dst The destination surface.
dstrect The destination rectangle.
Returns:
Returns 1 if blit was performed, 0 otherwise, or -1 if an error occured.

Definition at line 390 of file SDL_gfxBlitFunc.c.

int SDL_gfxMultiplyAlpha ( SDL_Surface *  src,
Uint8  a 
)

Multiply the alpha channel in a 32bit surface.

Helper function that multiplies the alpha channel in a 32 bit surface with a constant value. The final alpha is always scaled to the range 0-255 (i.e. the factor is a/256). Only 32 bit surfaces can be used with this function.

Parameters:
src Pointer to the target surface to change.
a The alpha value to multiply with.
Returns:
Returns 1 if alpha was changed, 0 otherwise.

Definition at line 547 of file SDL_gfxBlitFunc.c.

int SDL_gfxSetAlpha ( SDL_Surface *  src,
Uint8  a 
)

Sets the alpha channel in a 32 bit surface.

Helper function that sets the alpha channel in a 32 bit surface to a constant value. Only 32 bit surfaces can be used with this function.

Parameters:
src Pointer to the target surface to change.
a The alpha value to set.
Returns:
Returns 1 if alpha was changed, 0 otherwise.

Definition at line 503 of file SDL_gfxBlitFunc.c.


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