Unlock a texture, uploading the changes to video memory, if needed.
void SDL_UnlockTexture(SDL_Texture * texture);
a texture locked by SDL_LockTexture()
Warning: Please note that SDL_LockTexture() is intended to be write-only; it will not guarantee the previous contents of the texture will be provided. You must fully initialize any area of a texture that you lock before unlocking it, as the pixels might otherwise be uninitialized memory.
Which is to say: locking and immediately unlocking a texture can result in corrupted textures, depending on the renderer in use.
This function is available since SDL 2.0.0.