(This is the legacy documentation for SDL2, the previous stable version; SDL3 is the current stable version.)

SDL_LockTexture

Lock a portion of the texture for write-only pixel access.

Header File

Syntax

int SDL_LockTexture(SDL_Texture * texture,
                    const SDL_Rect * rect,
                    void **pixels, int *pitch);

Function Parameters

SDL_Texture *	texture	the texture to lock for access, which was created with `SDL_TEXTUREACCESS_STREAMING`.
const SDL_Rect *	rect	an SDL_Rect structure representing the area to lock for access; NULL to lock the entire texture.
void **	pixels	this is filled in with a pointer to the locked pixels, appropriately offset by the locked area.
int *	pitch	this is filled in with the pitch of the locked pixels; the pitch is the length of one row in bytes.

Return Value

(int) Returns 0 on success or a negative error code if the texture is not valid or was not created with SDL_TEXTUREACCESS_STREAMING; call SDL_GetError() for more information.

Remarks

As an optimization, the pixels made available for editing don't necessarily contain the old texture data. This is a write-only operation, and if you need to keep a copy of the texture data you should do that at the application level.

You must use SDL_UnlockTexture() to unlock the pixels and apply any changes.

Version

This function is available since SDL 2.0.0.