view docs/man3/SDL_JoyHatEvent.3 @ 1544:ab1e4c41ab71

Fixed bug #33 Mike Frysinger wrote: > with libsdl-1.2.9, some games (like bomberclone) started > segfaulting in Gentoo [...snip...] > the last change in the last hunk: [...snip...] > if i change the statement to read: > (table[which].blit_features & GetBlitFeatures()) == GetBlitFeatures() > bomberclone no longer segfaults on my box Alex Volkov wrote: > The test "(table[which].blit_features & GetBlitFeatures()) == > table[which].blit_features)" is correct, and the previous > "(table[which].cpu_mmx == SDL_HasMMX())" was actually broken. I think there is potentially a slightly different cause of the above problem. During the introduction of the Altivec code, the blit_table struct field 'alpha' got changed from a straightforward enum to a bitmask, which makes perfect sense by itself. However, now the table driven blitter selection code in SDL_CalculateBlitN() can choose the wrong blitters when searching for a NO_ALPHA blitter because of the following code: int a_need = 0; ... (a_need & table[which].alpha) == a_need && When searching through the normal_blit_2[] table, a SET_ALPHA blitter (like Blit_RGB565_ARGB8888) can now be selected instead of a NO_ALPHA one, causing alpha channel bits to appear in a non-alpha destination surface. I suppose this could theoretically be an indirect cause of the segfault mentioned above. I *think* this can be fixed by changing to int a_need = NO_ALPHA;
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Mar 2006 15:47:49 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.TH "SDL_JoyHatEvent" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_JoyHatEvent\- Joystick hat position change event structure
.SH "STRUCTURE DEFINITION"
.PP
.nf
\f(CWtypedef struct{
  Uint8 type;
  Uint8 which;
  Uint8 hat;
  Uint8 value;
} SDL_JoyHatEvent;\fR
.fi
.PP
.SH "STRUCTURE DATA"
.TP 20
\fBtype\fR
\fBSDL_JOY\fP
.TP 20
\fBwhich\fR
Joystick device index
.TP 20
\fBhat\fR
Joystick hat index
.TP 20
\fBvalue\fR
Hat position
.SH "DESCRIPTION"
.PP
\fBSDL_JoyHatEvent\fR is a member of the \fI\fBSDL_Event\fR\fR union and is used when an event of type \fBSDL_JOYHATMOTION\fP is reported\&.
.PP
A \fBSDL_JOYHATMOTION\fP event occurs when ever a user moves a hat on the joystick\&. The field \fBwhich\fR is the index of the joystick that reported the event and \fBhat\fR is the index of the hat (for a more detailed exlaination see the \fIJoystick section\fR)\&. \fBvalue\fR is the current position of the hat\&. It is a logically OR\&'d combination of the following values (whose meanings should be pretty obvious:) :
.IP "" 10
\fBSDL_HAT_CENTERED\fP
.IP "" 10
\fBSDL_HAT_UP\fP
.IP "" 10
\fBSDL_HAT_RIGHT\fP
.IP "" 10
\fBSDL_HAT_DOWN\fP
.IP "" 10
\fBSDL_HAT_LEFT\fP
.PP
The following defines are also provided:
.IP "" 10
\fBSDL_HAT_RIGHTUP\fP
.IP "" 10
\fBSDL_HAT_RIGHTDOWN\fP
.IP "" 10
\fBSDL_HAT_LEFTUP\fP
.IP "" 10
\fBSDL_HAT_LEFTDOWN\fP
.SH "SEE ALSO"
.PP
\fI\fBSDL_Event\fR\fR, \fIJoystick Functions\fR, \fI\fBSDL_JoystickEventState\fP\fR, \fI\fBSDL_JoystickGetHat\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59