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;

.TH "SDL_JoyAxisEvent" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_JoyAxisEvent\- Joystick axis motion event structure
.SH "STRUCTURE DEFINITION"
.PP
.nf
\f(CWtypedef struct{
  Uint8 type;
  Uint8 which;
  Uint8 axis;
  Sint16 value;
} SDL_JoyAxisEvent;\fR
.fi
.PP
.SH "STRUCTURE DATA"
.TP 20
\fBtype\fR
\fBSDL_JOYAXISMOTION\fP
.TP 20
\fBwhich\fR
Joystick device index
.TP 20
\fBaxis\fR
Joystick axis index
.TP 20
\fBvalue\fR
Axis value (range: -32768 to 32767)
.SH "DESCRIPTION"
.PP
\fBSDL_JoyAxisEvent\fR is a member of the \fI\fBSDL_Event\fR\fR union and is used when an event of type \fBSDL_JOYAXISMOTION\fP is reported\&.
.PP
A \fBSDL_JOYAXISMOTION\fP event occurs when ever a user moves an axis on the joystick\&. The field \fBwhich\fR is the index of the joystick that reported the event and \fBaxis\fR is the index of the axis (for a more detailed explaination see the \fIJoystick section\fR)\&. \fBvalue\fR is the current position of the axis\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_Event\fR\fR, \fIJoystick Functions\fR, \fI\fBSDL_JoystickEventState\fP\fR, \fI\fBSDL_JoystickGetAxis\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59