Mercurial > sdl-ios-xcode
view src/video/nanox/SDL_nxmodes.c @ 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 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2004 Sam Lantinga Copyright (C) 2001 Hsieh-Fu Tsai 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 Hsieh-Fu Tsai clare@setabox.com */ #include "SDL_config.h" #include "SDL_stdinc.h" #include "SDL_nxmodes_c.h" SDL_Rect ** NX_ListModes(_THIS, SDL_PixelFormat * format, Uint32 flags) { if (flags & SDL_FULLSCREEN) return SDL_modelist; if (SDL_Visual.bpp == format->BitsPerPixel) { return ((SDL_Rect **) - 1); } else { return ((SDL_Rect **) 0); } } void NX_FreeVideoModes(_THIS) { int i; if (SDL_modelist) { for (i = 0; SDL_modelist[i]; ++i) { SDL_free(SDL_modelist[i]); } SDL_free(SDL_modelist); SDL_modelist = NULL; } } int NX_EnterFullScreen(_THIS) { if (!currently_fullscreen) { GR_SCREEN_INFO si; GrGetScreenInfo(&si); GrResizeWindow(FSwindow, si.cols, si.rows); GrUnmapWindow(SDL_Window); GrMapWindow(FSwindow); GrRaiseWindow(FSwindow); GrSetFocus(FSwindow); currently_fullscreen = 1; } return 1; } int NX_LeaveFullScreen(_THIS) { if (currently_fullscreen) { GrUnmapWindow(FSwindow); GrMapWindow(SDL_Window); GrRaiseWindow(SDL_Window); GrSetFocus(SDL_Window); currently_fullscreen = 0; } return 0; } /* vi: set ts=4 sw=4 expandtab: */