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.

.TH "SDL_GL_GetAttribute" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_GL_GetAttribute\- Get the value of a special SDL/OpenGL attribute
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_GL_GetAttribute\fP\fR(\fBSDLGLattr attr, int *value\fR);
.SH "DESCRIPTION"
.PP
Places the value of the SDL/OpenGL \fIattribute\fR \fBattr\fR into \fBvalue\fR\&. This is useful after a call to \fI\fBSDL_SetVideoMode\fP\fR to check whether your attributes have been \fIset\fR as you expected\&.
.SH "RETURN VALUE"
.PP
Returns \fB0\fR on success, or \fB-1\fR on an error\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_GL_SetAttribute\fP\fR, \fIGL Attributes\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01