Mercurial > sdl-ios-xcode
view src/video/os2fslib/SDL_os2fslib.h @ 2752:edd2839b36f7
http://sources.redhat.com/ml/newlib/2002/msg00230.html
Stephen L Moshier wrote:
>
> pow(x,y) returns 0 when x is very close to -1.0 and y is very large.
> The following test program prints
>
> pow(1.0000000000000002e+00 4.5035996273704970e+15) = 2.7182818284590455e+00
> pow(-1.0000000000000002e+00 4.5035996273704970e+15) =0.0000000000000000e+00
> pow(9.9999999999999978e-01 4.5035996273704970e+15) = 3.6787944117144222e-01
> pow(-9.9999999999999978e-01 4.5035996273704970e+15) = 0.0000000000000000e+00
>
> which is incorrect for the negative arguments raised to an odd integer
> power.
>
> -----
> double pow (double, double);
>
> int
> main ()
> {
> double x, y, z;
>
> x = 1.0 + pow (2.0, -52.0);
> y = 1.0 + pow (2.0, 52.0);
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> x = -x;
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> x = 1.0 - pow (2.0, -52.0);
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> x = -x;
> z = pow (x, y);
> printf ("pow(%.16e %.16e) = %.16e\n", x, y, z);
> }
> -----
>
> Here is a patch for newlib/libm/math/epow.c:
Patch checked in and duplicated for ef_pow.c. Thanks.
-- Jeff J.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Mon, 15 Sep 2008 04:31:30 +0000 |
parents | c121d94672cb |
children | 99210400e8b9 |
line wrap: on
line source
/* SDL - Simple DirectMedia Layer Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 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 */ #include "SDL_config.h" #ifndef _SDL_os2fslib_h #define _SDL_os2fslib_h // OS2 specific includes #define INCL_TYPES #define INCL_DOS #define INCL_DOSERRORS #define INCL_DOSPROCESS #define INCL_WIN #define INCL_GPI #include <os2.h> #include <FSLib.h> /* Hidden "this" pointer for the video functions */ #define _THIS SDL_VideoDevice *_this /* Private display data */ struct SDL_PrivateVideoData { FSLib_VideoMode_p pAvailableFSLibVideoModes; SDL_Rect **pListModesResult; // Allocated memory to return list of modes for os2fslib_ListModes() API FSLib_VideoMode SrcBufferDesc; // Description of current source image buffer char *pchSrcBuffer; // The source image buffer itself SDL_Surface *pSDLSurface; // The SDL surface describing the buffer HMTX hmtxUseSrcBuffer; // Mutex semaphore to manipulate src buffer HWND hwndFrame, hwndClient; // Window handle of frame and client int iPMThreadStatus; // 0: Not running // 1: Running // Other: Not running, had an error int tidPMThread; // Thread ID of PM Thread int fInFocus; // True if we're in focus! int iSkipWMMOUSEMOVE; // Number of WM_MOUSEMOVE messages to skip! int iMouseVisible; // PFNWP pfnOldFrameProc; // Old window frame procedure int bProportionalResize; // 0: No proportional resizing // 1: Do proportional resizing ULONG ulResizingFlag; // First resizing flag value }; /* OS/2 specific backdoor function to be able to set FrameControlFlags of */ /* the SDL window before creating it. */ extern DECLSPEC void SDLCALL SDL_OS2FSLIB_SetFCFToUse(ULONG ulFCF); #endif /* _SDL_os2fslib_h */ /* vi: set ts=4 sw=4 expandtab: */