---
name: "SDL_BlitSurface"
section: "3"
platform: "linux"
package: "libsdl3-doc"
version: "3.2.10+ds-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/SDL_BlitSurface"
---

# SDL\_BlitSurface(3)

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

## NAME

SDL\_BlitSurface - Performs a fast blit from the source surface to the destination surface with clipping.

## HEADER FILE

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

Only one thread should be using the **src** and **dst** surfaces at any given time.

## AVAILABILITY

This function is available since SDL 3.2.0.

## SEE ALSO

**•**(3), [**SDL\_BlitSurfaceScaled**(3)](/SDL_BlitSurfaceScaled/3.md)