Ubuntu Manpage: SDL_BlitSurface - Performs a fast blit from the source surface to the destination surface with clipping.

name
header file
synopsis
description
function parameters
return value
thread safety
availability
see also

NAME

       SDL_BlitSurface - Performs a fast blit from the source surface to the destination surface with clipping.

       Defined in SDL3/SDL_surface.h

SYNOPSIS

       #include "SDL3/SDL.h"

       bool SDL_BlitSurface(SDL_Surface *src, const SDL_Rect *srcrect, SDL_Surface *dst, const SDL_Rect *dstrect);

DESCRIPTION

If either srcrect or dstrect are NULL, the entire surface ( src or dst ) is copied while ensuring
clipping to dst->clip_rect .

The final blit rectangles are saved in srcrect and dstrect after all clipping is performed.

The blit function should not be called on a locked surface.

The blit semantics for surfaces with and without blending and colorkey are defined as follows:

RGBA->RGB:
Source surface blend mode set to SDL_BLENDMODE_BLEND:
alpha-blend (using the source alpha-channel and per-surface alpha)
SDL_SRCCOLORKEY ignored.
Source surface blend mode set to SDL_BLENDMODE_NONE:
copy RGB.
if SDL_SRCCOLORKEY set, only copy the pixels that do not match the
RGB values of the source color key, ignoring alpha in the
comparison.

RGB->RGBA:
Source surface blend mode set to SDL_BLENDMODE_BLEND:
alpha-blend (using the source per-surface alpha)
Source surface blend mode set to SDL_BLENDMODE_NONE:
copy RGB, set destination alpha to source per-surface alpha value.
both:
if SDL_SRCCOLORKEY set, only copy the pixels that do not match the
source color key.

RGBA->RGBA:
Source surface blend mode set to SDL_BLENDMODE_BLEND:
alpha-blend (using the source alpha-channel and per-surface alpha)
SDL_SRCCOLORKEY ignored.
Source surface blend mode set to SDL_BLENDMODE_NONE:
copy all of RGBA to the destination.
if SDL_SRCCOLORKEY set, only copy the pixels that do not match the
RGB values of the source color key, ignoring alpha in the
comparison.

RGB->RGB:
Source surface blend mode set to SDL_BLENDMODE_BLEND:
alpha-blend (using the source per-surface alpha)
Source surface blend mode set to SDL_BLENDMODE_NONE:
copy RGB.
both:
if SDL_SRCCOLORKEY set, only copy the pixels that do not match the
source color key.

FUNCTION PARAMETERS

       src    the SDL_Surface
               structure to be copied from.

       srcrect
              the SDL_Rect
               structure representing the rectangle to be copied, or NULL to copy the entire surface.

       dst    the SDL_Surface
               structure that is the blit target.

       dstrect
              the SDL_Rect
               structure representing the x and y position in the destination surface, or NULL  for  (0,0).  The
              width  and  height  are  ignored,  and  are copied from srcrect . If you want a specific width and
              height, you should use SDL_BlitSurfaceScaled ().

RETURN VALUE

       Returns true on success or false on failure; call

       SDL_GetError () for more information.

THREAD SAFETY

       The same destination surface should not be used from two threads at once.  It is safe  to  use  the  same
       source surface from multiple threads.

AVAILABILITY

       This function is available since SDL 3.2.0.