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view docs/man3/SDL_JoystickOpen.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 |
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.TH "SDL_JoystickOpen" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" .SH "NAME" SDL_JoystickOpen\- Opens a joystick for use\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBSDL_Joystick *\fBSDL_JoystickOpen\fP\fR(\fBint index\fR); .SH "DESCRIPTION" .PP Opens a joystick for use within SDL\&. The \fBindex\fR refers to the N\&'th joystick in the system\&. A joystick must be opened before it game be used\&. .SH "RETURN VALUE" .PP Returns a \fBSDL_Joystick\fR structure on success\&. \fBNULL\fR on failure\&. .SH "EXAMPLES" .PP .PP .nf \f(CWSDL_Joystick *joy; // Check for joystick if(SDL_NumJoysticks()>0){ // Open joystick joy=SDL_JoystickOpen(0); if(joy) { printf("Opened Joystick 0 "); printf("Name: %s ", SDL_JoystickName(0)); printf("Number of Axes: %d ", SDL_JoystickNumAxes(joy)); printf("Number of Buttons: %d ", SDL_JoystickNumButtons(joy)); printf("Number of Balls: %d ", SDL_JoystickNumBalls(joy)); } else printf("Couldn\&'t open Joystick 0 "); // Close if opened if(SDL_JoystickOpened(0)) SDL_JoystickClose(joy); }\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_JoystickClose\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00