Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_FillRect.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> |
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date | Wed, 15 Mar 2006 15:47:49 +0000 |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
rev | line source |
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Sam Lantinga <slouken@libsdl.org>
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1 .TH "SDL_FillRect" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" |
0 | 2 .SH "NAME" |
3 SDL_FillRect\- This function performs a fast fill of the given rectangle with some color | |
4 .SH "SYNOPSIS" | |
5 .PP | |
6 \fB#include "SDL\&.h" | |
7 .sp | |
8 \fBint \fBSDL_FillRect\fP\fR(\fBSDL_Surface *dst, SDL_Rect *dstrect, Uint32 color\fR); | |
9 .SH "DESCRIPTION" | |
10 .PP | |
11 This function performs a fast fill of the given rectangle with \fBcolor\fR\&. If \fBdstrect\fR is \fBNULL\fP, the whole surface will be filled with \fBcolor\fR\&. | |
12 .PP | |
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13 The color should be a pixel of the format used by the surface, and can be generated by the \fISDL_MapRGB\fR or \fISDL_MapRGBA\fR functions\&. If the color value contains an alpha value then the destination is simply "filled" with that alpha information, no blending takes place\&. |
0 | 14 .PP |
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15 If there is a clip rectangle set on the destination (set via \fISDL_SetClipRect\fR) then this function will clip based on the intersection of the clip rectangle and the \fBdstrect\fR rectangle and the dstrect rectangle will be modified to represent the area actually filled\&. |
0 | 16 .SH "RETURN VALUE" |
17 .PP | |
18 This function returns \fB0\fR on success, or \fB-1\fR on error\&. | |
19 .SH "SEE ALSO" | |
20 .PP | |
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21 \fI\fBSDL_MapRGB\fP\fR, \fI\fBSDL_MapRGBA\fP\fR, \fI\fBSDL_BlitSurface\fP\fR, \fI\fBSDL_Rect\fR\fR |
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
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22 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01 |