Mercurial > sdl-ios-xcode
annotate 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 |
rev | line source |
---|---|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
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1 .TH "SDL_JoyHatEvent" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" |
0 | 2 .SH "NAME" |
3 SDL_JoyHatEvent\- Joystick hat position change event structure | |
4 .SH "STRUCTURE DEFINITION" | |
5 .PP | |
6 .nf | |
7 \f(CWtypedef struct{ | |
8 Uint8 type; | |
9 Uint8 which; | |
10 Uint8 hat; | |
11 Uint8 value; | |
12 } SDL_JoyHatEvent;\fR | |
13 .fi | |
14 .PP | |
15 .SH "STRUCTURE DATA" | |
16 .TP 20 | |
17 \fBtype\fR | |
18 \fBSDL_JOY\fP | |
19 .TP 20 | |
20 \fBwhich\fR | |
21 Joystick device index | |
22 .TP 20 | |
23 \fBhat\fR | |
24 Joystick hat index | |
25 .TP 20 | |
26 \fBvalue\fR | |
27 Hat position | |
28 .SH "DESCRIPTION" | |
29 .PP | |
30 \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\&. | |
31 .PP | |
32 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:) : | |
33 .IP "" 10 | |
34 \fBSDL_HAT_CENTERED\fP | |
35 .IP "" 10 | |
36 \fBSDL_HAT_UP\fP | |
37 .IP "" 10 | |
38 \fBSDL_HAT_RIGHT\fP | |
39 .IP "" 10 | |
40 \fBSDL_HAT_DOWN\fP | |
41 .IP "" 10 | |
42 \fBSDL_HAT_LEFT\fP | |
43 .PP | |
44 The following defines are also provided: | |
45 .IP "" 10 | |
46 \fBSDL_HAT_RIGHTUP\fP | |
47 .IP "" 10 | |
48 \fBSDL_HAT_RIGHTDOWN\fP | |
49 .IP "" 10 | |
50 \fBSDL_HAT_LEFTUP\fP | |
51 .IP "" 10 | |
52 \fBSDL_HAT_LEFTDOWN\fP | |
53 .SH "SEE ALSO" | |
54 .PP | |
55 \fI\fBSDL_Event\fR\fR, \fIJoystick Functions\fR, \fI\fBSDL_JoystickEventState\fP\fR, \fI\fBSDL_JoystickGetHat\fP\fR | |
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
56 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59 |