view src/video/gem/SDL_gemmodes.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 7e1caa8452f3
children 99210400e8b9
line wrap: on
line source

/*
    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"

#include "SDL_gemvideo.h"


void
GEM_InitModes(_THIS)
{
    SDL_VideoData *data = (SDL_VideoData *) _this->driverdata;
    Uint32 Rmask, Gmask, Bmask, Amask;
    SDL_VideoDisplay display;
    SDL_DisplayData *displaydata;
    SDL_DisplayMode mode;
    int bpp;

    /* read vdi bpp, rmask, gmask, bmask, amask */

    mode.format = SDL_MasksToPixelFormatEnum(bpp, Rmask, Gmask, Bmask, Amask);
    mode.w = 0 /* vdi width */ ;
    mode.h = 0 /* vdi height */ ;
    mode.refresh_rate = 0;
    mode.driverdata = NULL;

    displaydata = (SDL_DisplayData *) SDL_malloc(sizeof(*displaydata));
    if (!displaydata) {
        return;
    }
    /* fill display data */

    SDL_zero(display);
    display.desktop_mode = mode;
    display.current_mode = mode;
    display.driverdata = displaydata;
    SDL_AddVideoDisplay(&display);
}

void
GEM_GetDisplayModes(_THIS)
{
    SDL_DisplayData *data = (SDL_DisplayData *) SDL_CurrentDisplay.driverdata;
    SDL_DisplayMode mode;
    //SDL_AddDisplayMode(_this->current_display, &mode);
}

int
GEM_SetDisplayMode(_THIS, SDL_DisplayMode * mode)
{
    //SDL_DisplayModeData *data = (SDL_DisplayModeData *) mode->driverdata;
    return -1;
}

void
GEM_QuitModes(_THIS)
{
}

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