Mercurial > sdl-ios-xcode
view docs/man3/SDL_JoystickGetBall.3 @ 4392:2b8c1aea633b SDL-1.2
Fixed bug #898
Jeremiah Morris 2009-12-09 16:07:17 PST
No-op GlobalToLocal translations in fullscreen mode
On my MacBook Pro running 10.6, I noticed a small upward bias on mouse movement
in a fullscreen SDL application. The app uses WarpCursor and GetMouseState in a
loop to measure relative movement. I tracked it down to NSWindow's
convertBaseToScreen: routine, which added a 2-pixel offset on the Y coordinate
instead of the expected (+0,+0) translation.
In fullscreen mode, QZ_PrivateWarpCursor() does not translate the desired
position through QZ_PrivateGlobalToLocal() before passing it to the Core
Graphics system. However, QZ_GetMouseLocation() does call the reverse
QZ_PrivateLocalToGlobal() even in fullscreen mode. This asymmetry caused
problems each time the mouse was moved.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 11 Dec 2009 15:31:37 +0000 |
| parents | 1238da4a7112 |
| children |
line wrap: on
line source
.TH "SDL_JoystickGetBall" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" .SH "NAME" SDL_JoystickGetBall \- Get relative trackball motion .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBint \fBSDL_JoystickGetBall\fP\fR(\fBSDL_Joystick *joystick, int ball, int *dx, int *dy\fR); .SH "DESCRIPTION" .PP Get the \fBball\fR axis change\&. .PP Trackballs can only return relative motion since the last call to \fBSDL_JoystickGetBall\fP, these motion deltas a placed into \fBdx\fR and \fBdy\fR\&. .SH "RETURN VALUE" .PP Returns \fB0\fR on success or \fB-1\fR on failure .SH "EXAMPLES" .PP .PP .nf \f(CWint delta_x, delta_y; SDL_Joystick *joy; \&. \&. \&. SDL_JoystickUpdate(); if(SDL_JoystickGetBall(joy, 0, &delta_x, &delta_y)==-1) printf("TrackBall Read Error! "); printf("Trackball Delta- X:%d, Y:%d ", delta_x, delta_y);\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_JoystickNumBalls\fP\fR .\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00