view docs/man3/SDL_ListModes.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
line wrap: on
line source
.TH "SDL_ListModes" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_ListModes\- Returns a pointer to an array of available screen dimensions for the given format and video flags
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBSDL_Rect **\fBSDL_ListModes\fP\fR(\fBSDL_PixelFormat *format, Uint32 flags\fR);
.SH "DESCRIPTION"
.PP
Return a pointer to an array of available screen dimensions for the given format and video flags, sorted largest to smallest\&. Returns \fBNULL\fP if there are no dimensions available for a particular format, or \fB-1\fR if any dimension is okay for the given format\&.
.PP
If \fBformat\fR is \fBNULL\fP, the mode list will be for the format returned by \fISDL_GetVideoInfo()\fR->\fBvfmt\fR\&. The \fBflag\fR parameter is an OR\&'d combination of \fIsurface\fR flags\&. The flags are the same as those used \fI\fBSDL_SetVideoMode\fP\fR and they play a strong role in deciding what modes are valid\&. For instance, if you pass \fBSDL_HWSURFACE\fP as a flag only modes that support hardware video surfaces will be returned\&.
.SH "EXAMPLE"
.PP
.nf
\f(CWSDL_Rect **modes;
int i;
\&.
\&.
\&.

/* Get available fullscreen/hardware modes */
modes=SDL_ListModes(NULL, SDL_FULLSCREEN|SDL_HWSURFACE);

/* Check is there are any modes available */
if(modes == (SDL_Rect **)0){
  printf("No modes available!
");
  exit(-1);
}

/* Check if or resolution is restricted */
if(modes == (SDL_Rect **)-1){
  printf("All resolutions available\&.
");
}
else{
  /* Print valid modes */
  printf("Available Modes
");
  for(i=0;modes[i];++i)
    printf("  %d x %d
", modes[i]->w, modes[i]->h);
}
\&.
\&.\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_SetVideoMode\fP\fR, \fI\fBSDL_GetVideoInfo\fP\fR, \fI\fBSDL_Rect\fR\fR, \fI\fBSDL_PixelFormat\fR\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01