/* $Id: fixed.h,v 1.1.1.1 1999/08/19 00:55:41 jtg Exp $ */

/*
 * Mesa 3-D graphics library
 * Version:  3.1
 * 
 * Copyright (C) 1999  Brian Paul   All Rights Reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */





#ifndef FIXED_H
#define FIXED_H


typedef int GLfixed;

#define FIXED_ONE       0x00000800
#define FIXED_HALF      0x00000400
#define FIXED_FRAC_MASK 0x000007FF
#define FIXED_INT_MASK  (~FIXED_FRAC_MASK)
#define FIXED_EPSILON   1
#define FIXED_SCALE     2048.0f
#define FIXED_SHIFT     11
#define FloatToFixed(X) ((GLfixed) ((X) * FIXED_SCALE))
#define IntToFixed(I)   ((I) << FIXED_SHIFT)
#define FixedToInt(X)   ((X) >> FIXED_SHIFT)
#define FixedToUns(X)   (((unsigned int)(X)) >> 11)
#define FixedCeil(X)    (((X) + FIXED_ONE - FIXED_EPSILON) & FIXED_INT_MASK)
#define FixedFloor(X)   ((X) & FIXED_INT_MASK)
/* 0.00048828125 = 1/FIXED_SCALE */
#define FixedToFloat(X) ((X) * 0.00048828125f)
#define PosFloatToFixed(X)      FloatToFixed(X)
#define SignedFloatToFixed(X)   FloatToFixed(X)


#if DEPTH_BITS==16
/* use fixed-point interpolation */
#define FixedToDepth(I) ((I) >> FIXED_SHIFT)
#else
/* don't really use fixed-point */
#define FixedToDepth(I) (I)
#endif


#endif