diff --git a/src/video/cocoa/SDL_cocoamouse.m b/src/video/cocoa/SDL_cocoamouse.m index 17fb24452c..1cc1022be5 100644 --- a/src/video/cocoa/SDL_cocoamouse.m +++ b/src/video/cocoa/SDL_cocoamouse.m @@ -618,17 +618,27 @@ void Cocoa_HandleMouseWheel(SDL_Window *window, NSEvent *event) SDL_MouseWheelDirection direction; CGFloat x, y; - x = -[event scrollingDeltaX]; - y = [event scrollingDeltaY]; + x = -[event deltaX]; + y = [event deltaY]; direction = SDL_MOUSEWHEEL_NORMAL; if ([event isDirectionInvertedFromDevice] == YES) { direction = SDL_MOUSEWHEEL_FLIPPED; } - if ([event hasPreciseScrollingDeltas]) { - x *= 0.1; - y *= 0.1; + /* For discrete scroll events from conventional mice, always send a full tick. + For continuous scroll events from trackpads, send fractional deltas for smoother scrolling. */ + if (![event hasPreciseScrollingDeltas]) { + if (x > 0) { + x = SDL_ceil(x); + } else if (x < 0) { + x = SDL_floor(x); + } + if (y > 0) { + y = SDL_ceil(y); + } else if (y < 0) { + y = SDL_floor(y); + } } SDL_SendMouseWheel(Cocoa_GetEventTimestamp([event timestamp]), window, mouseID, x, y, direction);