view src/libm/s_copysign.c @ 3596:f638ded38b8a

Added SDL_RenderClear() as a fast method of clearing the screen to the drawing color. Renamed SDL_RenderPoint() and SDL_RenderLine() to SDL_RenderDrawPoint() and SDL_RenderDrawLine(). Added API for rectangle drawing (as opposed to filling) Added placeholder API functions for circles and ellipses ... I'm not sure whether these will stay. Optimized software line drawing quite a bit. Added support for Wu's anti-aliased line drawing, currently disabled by default.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 23 Dec 2009 01:55:00 +0000
parents dc1eb82ffdaa
children
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/* @(#)s_copysign.c 5.1 93/09/24 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#if defined(LIBM_SCCS) && !defined(lint)
static const char rcsid[] =
    "$NetBSD: s_copysign.c,v 1.8 1995/05/10 20:46:57 jtc Exp $";
#endif

/*
 * copysign(double x, double y)
 * copysign(x,y) returns a value with the magnitude of x and
 * with the sign bit of y.
 */

#include "math.h"
#include "math_private.h"

libm_hidden_proto(copysign)
#ifdef __STDC__
     double copysign(double x, double y)
#else
     double copysign(x, y)
     double x, y;
#endif
{
    u_int32_t hx, hy;
    GET_HIGH_WORD(hx, x);
    GET_HIGH_WORD(hy, y);
    SET_HIGH_WORD(x, (hx & 0x7fffffff) | (hy & 0x80000000));
    return x;
}

libm_hidden_def(copysign)