(This is the documentation for SDL3, which is the current stable version. SDL2 was the previous version!)

SDL_BlitSurface9Grid

Perform a scaled blit using the 9-grid algorithm to a destination surface, which may be of a different format.

Header File

Syntax

bool SDL_BlitSurface9Grid(SDL_Surface *src, const SDL_Rect *srcrect, int left_width, int right_width, int top_height, int bottom_height, float scale, SDL_ScaleMode scaleMode, SDL_Surface *dst, const SDL_Rect *dstrect);

Function Parameters

SDL_Surface *	src	the SDL_Surface structure to be copied from.
const SDL_Rect *	srcrect	the SDL_Rect structure representing the rectangle to be used for the 9-grid, or NULL to use the entire surface.
int	left_width	the width, in pixels, of the left corners in `srcrect`.
int	right_width	the width, in pixels, of the right corners in `srcrect`.
int	top_height	the height, in pixels, of the top corners in `srcrect`.
int	bottom_height	the height, in pixels, of the bottom corners in `srcrect`.
float	scale	the scale used to transform the corner of `srcrect` into the corner of `dstrect`, or 0.0f for an unscaled blit.
SDL_ScaleMode	scaleMode	scale algorithm to be used.
SDL_Surface *	dst	the SDL_Surface structure that is the blit target.
const SDL_Rect *	dstrect	the SDL_Rect structure representing the target rectangle in the destination surface, or NULL to fill the entire surface.

Return Value

(bool) Returns true on success or false on failure; call SDL_GetError() for more information.

Remarks

The pixels in the source surface are split into a 3x3 grid, using the different corner sizes for each corner, and the sides and center making up the remaining pixels. The corners are then scaled using scale and fit into the corners of the destination rectangle. The sides and center are then stretched into place to cover the remaining destination rectangle.

Thread Safety

The same destination surface should not be used from two threads at once. It is safe to use the same source surface from multiple threads.

Version

This function is available since SDL 3.1.3.