NAME¶

SDL_MouseMotionTransformCallback - A callback used to transform mouse motion delta from raw values.

SYNOPSIS¶

#include <SDL3/SDL_mouse.h>

typedef void (SDLCALL *SDL_MouseMotionTransformCallback)( void *userdata, Uint64 timestamp, SDL_Window *window, SDL_MouseID mouseID, float *x, float *y);

DESCRIPTION¶

This is called during SDL's handling of platform mouse events to scale the values of the resulting motion delta.

FUNCTION PARAMETERS¶

userdata

what was passed as userdata to SDL_SetRelativeMouseTransform().

timestamp

the associated time at which this mouse motion event was received.

window

the associated window to which this mouse motion event was addressed.

mouseID

the associated mouse from which this mouse motion event was emitted.

x

pointer to a variable that will be treated as the resulting x-axis motion.

y

pointer to a variable that will be treated as the resulting y-axis motion.

THREAD SAFETY¶

This callback is called by SDL's internal mouse input processing procedure, which may be a thread separate from the main event loop that is run at realtime priority. Stalling this thread with too much work in the callback can therefore potentially freeze the entire system. Care should be taken with proper synchronization practices when adding other side effects beyond mutation of the x and y values.

AVAILABILITY¶

This datatype is available since SDL 3.4.0.

SEE ALSO¶

SDL_SetRelativeMouseTransform(3)