Read pixels from the current rendering target to an array of pixels.
int SDL_RenderReadPixels(SDL_Renderer * renderer, const SDL_Rect * rect, Uint32 format,void *pixels, int pitch);
|renderer||the rendering context|
|rect||an SDL_Rect structure representing the area to read, or NULL for the entire render target|
|format||an SDL_PixelFormatEnum value of the desired format of the pixel data, or 0 to use the format of the rendering target|
|pixels||a pointer to the pixel data to copy into|
|pitch||the pitch of the
Returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.
WARNING: This is a very slow operation, and should not be used frequently. If you're using this on the main rendering target, it should be called after rendering and before SDL_RenderPresent().
pitch specifies the number of bytes between rows in the destination
pixels data. This allows you to write to a subrectangle or have padded rows in the destination. Generally,
pitch should equal the number of pixels per row in the
pixels data times the number of bytes per pixel, but it might contain additional padding (for example, 24bit RGB Windows Bitmap data pads all rows to multiples of 4 bytes).
This function is available since SDL 2.0.0.