Mercurial > sdl-ios-xcode
view include/SDL_loadso.h @ 1259:36f24cdfcda7
te: Thu, 17 Apr 2003 11:25:26 -0700
From: "Jim"
Subject: [SDL] Frame buffer patches...
Would seem that GCC 3.2.2 promotes all signed values to unsigned if any single vlaue is unsigned in an expression...
for instance when calculating an elo touch position....evertyhign is an (int) except for cach_vinfo.xres which is unsigned. THerefore if y
ou reverse the SDL_ELO_MIN_X and SDL_ELO_MAX_X values the resulging negative value pegs the expression to it's max. Attached it the accumu
lated patch to typecast the unsigned values to (int)
- *dx = (cache_vinfo.xres - (cache_vinfo.xres * (input_x - ELO_MIN_X)) / width);
+ *dx = ((int)cache_vinfo.xres - ((int)cache_vinfo.xres * (input_x - ELO_MIN_X)) / width);
and also to provide quite failure to operations which have the screen currently locked...
The touch screen I'm using the original values were exactly opposite of any position I touched on the screen - evaluating the math the expr
ession SHOULD have handled reversing the min and max values - and after casting the unsigned .xres and .yres to a signed int - worked well.
..
Jim
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Tue, 24 Jan 2006 06:36:43 +0000 |
parents | b8d311d90021 |
children | c9b51268668f |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2004 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@libsdl.org */ #ifdef SAVE_RCSID static char rcsid = "@(#) $Id$"; #endif /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* System dependent library loading routines */ /* Some things to keep in mind: - These functions only work on C function names. Other languages may have name mangling and intrinsic language support that varies from compiler to compiler. - Make sure you declare your function pointers with the same calling convention as the actual library function. Your code will crash mysteriously if you do not do this. - Avoid namespace collisions. If you load a symbol from the library, it is not defined whether or not it goes into the global symbol namespace for the application. If it does and it conflicts with symbols in your code or other shared libraries, you will not get the results you expect. :) */ #ifndef _SDL_loadso_h #define _SDL_loadso_h #include "begin_code.h" /* Set up for C function definitions, even when using C++ */ #ifdef __cplusplus extern "C" { #endif /* This function dynamically loads a shared object and returns a pointer * to the object handle (or NULL if there was an error). * The 'sofile' parameter is a system dependent name of the object file. */ extern DECLSPEC void * SDLCALL SDL_LoadObject(const char *sofile); /* Given an object handle, this function looks up the address of the * named function in the shared object and returns it. This address * is no longer valid after calling SDL_UnloadObject(). */ extern DECLSPEC void * SDLCALL SDL_LoadFunction(void *handle, const char *name); /* Unload a shared object from memory */ extern DECLSPEC void SDLCALL SDL_UnloadObject(void *handle); /* Ends C function definitions when using C++ */ #ifdef __cplusplus } #endif #include "close_code.h" #endif /* _SDL_loadso_h */