Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_Color.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_Color" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" |
0 | 2 .SH "NAME" |
3 SDL_Color\- Format independent color description | |
4 .SH "STRUCTURE DEFINITION" | |
5 .PP | |
6 .nf | |
7 \f(CWtypedef struct{ | |
8 Uint8 r; | |
9 Uint8 g; | |
10 Uint8 b; | |
11 Uint8 unused; | |
12 } SDL_Color;\fR | |
13 .fi | |
14 .PP | |
15 .SH "STRUCTURE DATA" | |
16 .TP 20 | |
17 \fBr\fR | |
18 Red intensity | |
19 .TP 20 | |
20 \fBg\fR | |
21 Green intensity | |
22 .TP 20 | |
23 \fBb\fR | |
24 Blue intensity | |
25 .TP 20 | |
26 \fBunused\fR | |
27 Unused | |
28 .SH "DESCRIPTION" | |
29 .PP | |
30 \fBSDL_Color\fR describes a color in a format independent way\&. You can convert a \fBSDL_Color\fR to a pixel value for a certain pixel format using \fI\fBSDL_MapRGB\fP\fR\&. | |
31 .SH "SEE ALSO" | |
32 .PP | |
33 \fI\fBSDL_PixelFormat\fR\fR, \fI\fBSDL_SetColors\fP\fR, \fI\fBSDL_Palette\fP\fR | |
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
34 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01 |