Mercurial > sdl-ios-xcode
view src/video/x11/SDL_x11opengl.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 | 214880ed48c3 |
children | 99210400e8b9 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" #ifndef _SDL_x11opengl_h #define _SDL_x11opengl_h #if SDL_VIDEO_OPENGL_GLX #include "SDL_opengl.h" #include <GL/glx.h> struct SDL_GLDriverData { int initialized; SDL_bool HAS_GLX_EXT_visual_rating; void *(*glXGetProcAddress) (const GLubyte * procName); XVisualInfo *(*glXChooseVisual) (Display * dpy, int screen, int *attribList); GLXContext(*glXCreateContext) (Display * dpy, XVisualInfo * vis, GLXContext shareList, Bool direct); void (*glXDestroyContext) (Display * dpy, GLXContext ctx); Bool(*glXMakeCurrent) (Display * dpy, GLXDrawable drawable, GLXContext ctx); void (*glXSwapBuffers) (Display * dpy, GLXDrawable drawable); int (*glXSwapIntervalSGI) (int interval); GLint(*glXSwapIntervalMESA) (unsigned interval); GLint(*glXGetSwapIntervalMESA) (void); }; /* OpenGL functions */ extern int X11_GL_LoadLibrary(_THIS, const char *path); extern void *X11_GL_GetProcAddress(_THIS, const char *proc); extern int X11_GL_Initialize(_THIS); extern void X11_GL_Shutdown(_THIS); extern XVisualInfo *X11_GL_GetVisual(_THIS, Display * display, int screen); extern SDL_GLContext X11_GL_CreateContext(_THIS, SDL_Window * window); extern int X11_GL_MakeCurrent(_THIS, SDL_Window * window, SDL_GLContext context); extern int X11_GL_SetSwapInterval(_THIS, int interval); extern int X11_GL_GetSwapInterval(_THIS); extern void X11_GL_SwapWindow(_THIS, SDL_Window * window); extern void X11_GL_DeleteContext(_THIS, SDL_GLContext context); #endif /* SDL_VIDEO_OPENGL_GLX */ #endif /* _SDL_x11opengl_h */ /* vi: set ts=4 sw=4 expandtab: */