###### (This is the legacy documentation for stable SDL2, the current stable version; [SDL3](https://wiki.libsdl.org/SDL3/) is the current development version.)
# SDL_BlitSurface

Performs a fast blit from the source surface to the destination surface.

## Header File

Defined in [SDL_surface.h](https://github.com/libsdl-org/SDL/blob/SDL2/include/SDL_surface.h)

## Syntax

```c
#define SDL_BlitSurface SDL_UpperBlit
```

## Return Value

Returns 0 if the blit is successful, otherwise it returns -1.

## Remarks

This 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.

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 matching 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 matching 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 matching 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 matching the
      source color key.
```

You should call [SDL_BlitSurface](SDL_BlitSurface)() unless you know
exactly how SDL blitting works internally and how to use the other blit
functions.

----
[CategoryAPI](CategoryAPI), [CategoryAPIMacro](CategoryAPIMacro), [CategorySurface](CategorySurface)