Mercurial > sdl-ios-xcode
view docs/man3/SDL_ResizeEvent.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 | ab40b9b2d0d5 |
children | 546f7c1eb755 |
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.TH "SDL_ResizeEvent" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" .SH "NAME" SDL_ResizeEvent\- Window resize event structure .SH "STRUCTURE DEFINITION" .PP .nf \f(CWtypedef struct{ Uint8 type; int w, h; } SDL_ResizeEvent;\fR .fi .PP .SH "STRUCTURE DATA" .TP 20 \fBtype\fR \fBSDL_VIDEORESIZE\fP .TP 20 \fBw\fR, \fBh\fR New width and height of the window .SH "DESCRIPTION" .PP \fBSDL_ResizeEvent\fR is a member of the \fI\fBSDL_Event\fR\fR union and is used when an event of type \fBSDL_VIDEORESIZE\fP is reported\&. .PP When \fBSDL_RESIZABLE\fP is passed as a \fBflag\fR to \fI\fBSDL_SetVideoMode\fP\fR the user is allowed to resize the applications window\&. When the window is resized an \fBSDL_VIDEORESIZE\fP is report, with the new window width and height values stored in \fBw\fR and \fBh\fR, respectively\&. When an \fBSDL_VIDEORESIZE\fP is received the window should be resized to the new dimensions using \fI\fBSDL_SetVideoMode\fP\fR\&. .SH "SEE ALSO" .PP \fI\fBSDL_Event\fR\fR, \fI\fBSDL_SetVideoMode\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59