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_UserEvent" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_UserEvent\- A user-defined event type
.SH "STRUCTURE DEFINITION"
.PP
.nf
\f(CWtypedef struct{
  Uint8 type;
  int code;
  void *data1;
  void *data2;
} SDL_UserEvent;\fR
.fi
.PP
.SH "STRUCTURE DATA"
.TP 20
\fBtype\fR
\fBSDL_USEREVENT\fP through to \fBSDL_NUMEVENTS-1\fP
.TP 20
\fBcode\fR
User defined event code
.TP 20
\fBdata1\fR
User defined data pointer
.TP 20
\fBdata2\fR
User defined data pointer
.SH "DESCRIPTION"
.PP
\fBSDL_UserEvent\fR is in the \fBuser\fR member of the structure \fI\fBSDL_Event\fR\fR\&. This event is unique, it is never created by SDL but only by the user\&. The event can be pushed onto the event queue using \fI\fBSDL_PushEvent\fP\fR\&. The contents of the structure members or completely up to the programmer, the only requirement is that \fBtype\fR is a value from \fBSDL_USEREVENT\fP to \fBSDL_NUMEVENTS-1\fP (inclusive)\&.
.SH "EXAMPLES"
.PP
.PP
.nf
\f(CWSDL_Event event;

event\&.type = SDL_USEREVENT;
event\&.user\&.code = my_event_code;
event\&.user\&.data1 = significant_data;
event\&.user\&.data2 = 0;
SDL_PushEvent(&event);\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_Event\fR\fR, \fI\fBSDL_PushEvent\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00