###### (This is the legacy documentation for stable SDL2, the current stable version; [SDL3](https://wiki.libsdl.org/SDL3/) is the current development version.) # SDL_MouseWheelEvent Mouse wheel event structure (event.wheel.*) ## Header File Defined in [SDL_events.h](https://github.com/libsdl-org/SDL/blob/SDL2/include/SDL_events.h) ## Syntax ```c typedef struct SDL_MouseWheelEvent { Uint32 type; /**< SDL_MOUSEWHEEL */ Uint32 timestamp; /**< In milliseconds, populated using SDL_GetTicks() */ Uint32 windowID; /**< The window with mouse focus, if any */ Uint32 which; /**< The mouse instance id, or SDL_TOUCH_MOUSEID */ Sint32 x; /**< The amount scrolled horizontally, positive to the right and negative to the left */ Sint32 y; /**< The amount scrolled vertically, positive away from the user and negative toward the user */ Uint32 direction; /**< Set to one of the SDL_MOUSEWHEEL_* defines. When FLIPPED the values in X and Y will be opposite. Multiply by -1 to change them back */ float preciseX; /**< The amount scrolled horizontally, positive to the right and negative to the left, with float precision (added in 2.0.18) */ float preciseY; /**< The amount scrolled vertically, positive away from the user and negative toward the user, with float precision (added in 2.0.18) */ Sint32 mouseX; /**< X coordinate, relative to window (added in 2.26.0) */ Sint32 mouseY; /**< Y coordinate, relative to window (added in 2.26.0) */ } SDL_MouseWheelEvent; ``` ---- [CategoryAPI](CategoryAPI), [CategoryAPIStruct](CategoryAPIStruct), [CategoryStruct](CategoryStruct), [CategoryEvents](CategoryEvents)