Mercurial > sdl-ios-xcode
view docs/man3/SDL_SetModState.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 (2006-03-15) |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
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.TH "SDL_SetModState" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" .SH "NAME" SDL_SetModState\- Set the current key modifier state .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBvoid \fBSDL_SetModState\fP\fR(\fBSDLMod modstate\fR); .SH "DESCRIPTION" .PP The inverse of \fI\fBSDL_GetModState\fP\fR, \fBSDL_SetModState\fP allows you to impose modifier key states on your application\&. .PP Simply pass your desired modifier states into \fBmodstate\fR\&. This value my be a logical OR\&'d combination of the following: .PP .nf \f(CWtypedef enum { KMOD_NONE = 0x0000, KMOD_LSHIFT= 0x0001, KMOD_RSHIFT= 0x0002, KMOD_LCTRL = 0x0040, KMOD_RCTRL = 0x0080, KMOD_LALT = 0x0100, KMOD_RALT = 0x0200, KMOD_LMETA = 0x0400, KMOD_RMETA = 0x0800, KMOD_NUM = 0x1000, KMOD_CAPS = 0x2000, KMOD_MODE = 0x4000, } SDLMod;\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_GetModState\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00