Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_UserEvent.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 |
rev | line source |
---|---|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
1 .TH "SDL_UserEvent" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" |
0 | 2 .SH "NAME" |
3 SDL_UserEvent\- A user-defined event type | |
4 .SH "STRUCTURE DEFINITION" | |
5 .PP | |
6 .nf | |
7 \f(CWtypedef struct{ | |
8 Uint8 type; | |
9 int code; | |
10 void *data1; | |
11 void *data2; | |
12 } SDL_UserEvent;\fR | |
13 .fi | |
14 .PP | |
15 .SH "STRUCTURE DATA" | |
16 .TP 20 | |
17 \fBtype\fR | |
18 \fBSDL_USEREVENT\fP through to \fBSDL_NUMEVENTS-1\fP | |
19 .TP 20 | |
20 \fBcode\fR | |
21 User defined event code | |
22 .TP 20 | |
23 \fBdata1\fR | |
24 User defined data pointer | |
25 .TP 20 | |
26 \fBdata2\fR | |
27 User defined data pointer | |
28 .SH "DESCRIPTION" | |
29 .PP | |
30 \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)\&. | |
31 .SH "EXAMPLES" | |
32 .PP | |
33 .PP | |
34 .nf | |
35 \f(CWSDL_Event event; | |
36 | |
37 event\&.type = SDL_USEREVENT; | |
38 event\&.user\&.code = my_event_code; | |
39 event\&.user\&.data1 = significant_data; | |
40 event\&.user\&.data2 = 0; | |
41 SDL_PushEvent(&event);\fR | |
42 .fi | |
43 .PP | |
44 .SH "SEE ALSO" | |
45 .PP | |
46 \fI\fBSDL_Event\fR\fR, \fI\fBSDL_PushEvent\fP\fR | |
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
47 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00 |