diff --git a/dix/ptrveloc.c b/dix/ptrveloc.c index 99efc794c..0a9a22ec2 100644 --- a/dix/ptrveloc.c +++ b/dix/ptrveloc.c @@ -994,14 +994,20 @@ acceleratePointerPredictable( if (dx) { tmp = mult * fdx + pDev->last.remainder[0]; - *px = (int)roundf(tmp); + /* Since it may not be apparent: lrintf() does not offer + * strong statements about rounding; however because we + * process each axis conditionally, there's no danger + * of a toggling remainder. Its lack of guarantees hopefully + * makes it faster on the average target. */ + *px = lrintf(tmp); pDev->last.remainder[0] = tmp - (float)*px; } if (dy) { tmp = mult * fdy + pDev->last.remainder[1]; - *py = (int)roundf(tmp); + *py = lrintf(tmp); pDev->last.remainder[1] = tmp - (float)*py; } + DebugAccelF("pos (%i | %i) remainders x: %.3f y: %.3f delta x:%.3f y:%.3f\n", *px, *py, pDev->last.remainder[0], pDev->last.remainder[1], fdx, fdy); } } }