view docs/man3/SDL_JoystickOpen.3 @ 688:c0522010bb6d

Date: Tue, 12 Aug 2003 14:26:19 +0200 (MEST) From: "Mattias Engdeg?rd" Subject: bug in SDL_GetRGB/GetRGBA There's an embarrassing bug in GetRGB/GetRGBA which apparently has been there for years. It incorrectly converts colours with < 8 bits/channel. It came to my attention today in #sdl. What it does now is (for each channel): rv = (pixel & fmt->Rmask) >> fmt->Rshift; *r = (rv << fmt->Rloss) + (rv >> (8 - fmt->Rloss)); which is wrong; the last line should be *r = (rv << fmt->Rloss) + (rv >> (8 - (fmt->Rloss << 1)));
author Sam Lantinga <slouken@libsdl.org>
date Tue, 12 Aug 2003 15:17:20 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.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