Mercurial > sdl-ios-xcode
view docs/man3/SDL_InitSubSystem.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_InitSubSystem" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" .SH "NAME" SDL_InitSubSystem\- Initialize subsystems .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBint \fBSDL_InitSubSystem\fP\fR(\fBUint32 flags\fR); .SH "DESCRIPTION" .PP After SDL has been initialized with \fI\fBSDL_Init\fP\fR you may initialize uninitialized subsystems with \fBSDL_InitSubSystem\fP\&. The \fBflags\fR parameter is the same as that used in \fI\fBSDL_Init\fP\fR\&. .SH "EXAMPLES" .PP .nf \f(CW/* Seperating Joystick and Video initialization\&. */ SDL_Init(SDL_INIT_VIDEO); \&. \&. SDL_SetVideoMode(640, 480, 16, SDL_DOUBLEBUF|SDL_FULLSCREEN); \&. /* Do Some Video stuff */ \&. \&. /* Initialize the joystick subsystem */ SDL_InitSubSystem(SDL_INIT_JOYSTICK); /* Do some stuff with video and joystick */ \&. \&. \&. /* Shut them both down */ SDL_Quit();\fR .fi .PP .SH "RETURN VALUE" .PP Returns \fB-1\fR on an error or \fB0\fR on success\&. .SH "SEE ALSO" .PP \fI\fBSDL_Init\fP\fR, \fI\fBSDL_Quit\fP\fR, \fI\fBSDL_QuitSubSystem\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00