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

SDL_SetRenderLogicalPresentation

Set a device independent resolution and presentation mode for rendering.

Header File

Syntax

bool SDL_SetRenderLogicalPresentation(SDL_Renderer *renderer, int w, int h, SDL_RendererLogicalPresentation mode);

Function Parameters

SDL_Renderer *	renderer	the rendering context.
int	w	the width of the logical resolution.
int	h	the height of the logical resolution.
SDL_RendererLogicalPresentation	mode	the presentation mode used.

Return Value

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

Remarks

This function sets the width and height of the logical rendering output. The renderer will act as if the window is always the requested dimensions, scaling to the actual window resolution as necessary.

This can be useful for games that expect a fixed size, but would like to scale the output to whatever is available, regardless of how a user resizes a window, or if the display is high DPI.

You can disable logical coordinates by setting the mode to SDL_LOGICAL_PRESENTATION_DISABLED, and in that case you get the full pixel resolution of the output window; it is safe to toggle logical presentation during the rendering of a frame: perhaps most of the rendering is done to specific dimensions but to make fonts look sharp, the app turns off logical presentation while drawing text.

Letterboxing will only happen if logical presentation is enabled during SDL_RenderPresent; be sure to reenable it first if you were using it.

You can convert coordinates in an event into rendering coordinates using SDL_ConvertEventToRenderCoordinates().

Thread Safety

This function should only be called on the main thread.

Version

This function is available since SDL 3.1.3.