Mercurial > sdl-ios-xcode
view docs/man3/SDL_ActiveEvent.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 |
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.TH "SDL_ActiveEvent" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" .SH "NAME" SDL_ActiveEvent\- Application visibility event structure .SH "STRUCTURE DEFINITION" .PP .nf \f(CWtypedef struct{ Uint8 type; Uint8 gain; Uint8 state; } SDL_ActiveEvent;\fR .fi .PP .SH "STRUCTURE DATA" .TP 20 \fBtype\fR \fBSDL_ACTIVEEVENT\&.\fP .TP 20 \fBgain\fR 0 if the event is a loss or 1 if it is a gain\&. .TP 20 \fBstate\fR \fBSDL_APPMOUSEFOCUS\fP if mouse focus was gained or lost, \fBSDL_APPINPUTFOCUS\fP if input focus was gained or lost, or \fBSDL_APPACTIVE\fP if the application was iconified (\fBgain\fR=0) or restored(\fBgain\fR=1)\&. .SH "DESCRIPTION" .PP \fBSDL_ActiveEvent\fR is a member of the \fI\fBSDL_Event\fR\fR union and is used when an event of type \fBSDL_ACTIVEEVENT\fP is reported\&. .PP When the mouse leaves or enters the window area a \fBSDL_APPMOUSEFOCUS\fP type activation event occurs, if the mouse entered the window then \fBgain\fR will be 1, otherwise \fBgain\fR will be 0\&. A \fBSDL_APPINPUTFOCUS\fP type activation event occurs when the application loses or gains keyboard focus\&. This usually occurs when another application is made active\&. Finally, a \fBSDL_APPACTIVE\fP type event occurs when the application is either minimised/iconified (\fBgain\fR=0) or restored\&. .PP .RS \fBNote: .PP This event does not occur when an application window is first created\&. .RE .SH "SEE ALSO" .PP \fI\fBSDL_Event\fR\fR, \fI\fBSDL_GetAppState\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59