view docs/man3/SDL_ListModes.3 @ 1543:98f9b16f565c

From: "Alex Volkov" Date: Thu, 10 Nov 2005 21:53:40 -0500 Subject: [SDL] BUG[?]: 32bpp RGBA->RGB colorkey blit, no SDL_SRCALPHA It seems there is either a documentation vs. reality mismatch or a real bug in SDL_blit_N.c:BlitNtoNKey(). The exact blit in question is a 32bpp RGBA->RGB, where RGBA has SDL_COLORKEY and *no* SDL_SRCALPHA flags. The doc in SDL_video.h states: * RGBA->RGB: * SDL_SRCALPHA not set: * copy RGB. * if SDL_SRCCOLORKEY set, only copy the pixels matching the * RGB values of the source colour key, ignoring alpha in the * comparison. BlitNtoNKey(), however, forgets to "ignore alpha in the comparison". The documentation makes perfect sense, so I think it is the code that is faulty. The attached patch corrects the code.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Mar 2006 15:43:15 +0000
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