169 lines
4.3 KiB
C
169 lines
4.3 KiB
C
#ifndef GIM_MATH_H_INCLUDED
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#define GIM_MATH_H_INCLUDED
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/*! \file gim_math.h
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\author Francisco León Nájera
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*/
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/*
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-----------------------------------------------------------------------------
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This source file is part of GIMPACT Library.
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For the latest info, see http://gimpact.sourceforge.net/
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Copyright (c) 2006 Francisco Leon Najera. C.C. 80087371.
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email: projectileman@yahoo.com
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This library is free software; you can redistribute it and/or
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modify it under the terms of EITHER:
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(1) The GNU Lesser General Public License as published by the Free
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Software Foundation; either version 2.1 of the License, or (at
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your option) any later version. The text of the GNU Lesser
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General Public License is included with this library in the
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file GIMPACT-LICENSE-LGPL.TXT.
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(2) The BSD-style license that is included with this library in
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the file GIMPACT-LICENSE-BSD.TXT.
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(3) The zlib/libpng license that is included with this library in
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the file GIMPACT-LICENSE-ZLIB.TXT.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files
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GIMPACT-LICENSE-LGPL.TXT, GIMPACT-LICENSE-ZLIB.TXT and GIMPACT-LICENSE-BSD.TXT for more details.
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-----------------------------------------------------------------------------
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*/
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#include <math.h>
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#include <float.h>
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/*! \defgroup BASIC_TYPES
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Basic types and constants
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Conventions:
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Types starting with G
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Constants starting with G_
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*/
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//! @{
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/*! Types */
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#define GREAL float
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#define GREAL2 double
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#define GINT long
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#define GUINT unsigned long
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#define GSHORT short
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#define GUSHORT unsigned short
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/*! Constants for integers*/
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#define GUINT_BIT_COUNT 32
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#define GUINT_EXPONENT 5
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#define G_FASTMATH 1
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#define G_PI 3.14159265358979f
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#define G_HALF_PI 1.5707963f
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//267948966
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#define G_TWO_PI 6.28318530f
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//71795864
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#define G_ROOT3 1.73205f
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#define G_ROOT2 1.41421f
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#define G_UINT_INFINITY 65534
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#define G_REAL_INFINITY FLT_MAX
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#define G_SIGN_BITMASK 0x80000000
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#define G_USE_EPSILON_TEST
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#define G_EPSILON 0.0000001f
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//! @}
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/*! \defgroup SCALAR_TYPES
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\brief
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Precision type constants
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*/
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//! @{
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#define G_STYPE_REAL 0
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#define G_STYPE_REAL2 1
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#define G_STYPE_SHORT 2
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#define G_STYPE_USHORT 3
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#define G_STYPE_INT 4
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#define G_STYPE_UINT 5
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//! @}
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/*! \defgroup MATH_FUNCTIONS
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mathematical functions
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*/
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//! @{
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#define G_DEGTORAD(X) ((X)*3.1415926f/180.0f)
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#define G_RADTODEG(X) ((X)*180.0f/3.1415926f)
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//! Integer representation of a floating-point value.
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#define GIM_IR(x) ((GUINT&)(x))
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//! Signed integer representation of a floating-point value.
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#define GIM_SIR(x) ((GINT&)(x))
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//! Absolute integer representation of a floating-point value
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#define GIM_AIR(x) (GIM_IR(x)&0x7fffffff)
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//! Floating-point representation of an integer value.
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#define GIM_FR(x) ((GREAL&)(x))
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#define GIM_MAX(a,b) (a<b?b:a)
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#define GIM_MIN(a,b) (a>b?b:a)
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#define GIM_MAX3(a,b,c) GIM_MAX(a,GIM_MAX(b,c))
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#define GIM_MIN3(a,b,c) GIM_MIN(a,GIM_MIN(b,c))
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#define GIM_IS_ZERO(value) (value < G_EPSILON && value > -G_EPSILON)
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#define GIM_IS_NEGATIVE(value) (value <= -G_EPSILON)
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#define GIM_IS_POSISITVE(value) (value >= G_EPSILON)
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///returns a clamped number
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#define GIM_CLAMP(number,minval,maxval) (number<minval?minval:(number>maxval?maxval:number))
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#define GIM_GREATER(x, y) fabsf(x) > (y)
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///Swap numbers
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#define GIM_SWAP_NUMBERS(a,b){ \
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a = a+b; \
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b = a-b; \
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a = a-b; \
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}\
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#define GIM_INV_SQRT(va,isva)\
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{\
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if(va<=0.0000001f)\
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{\
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isva = G_REAL_INFINITY;\
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}\
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else\
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{\
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GREAL _x = va * 0.5f;\
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GUINT _y = 0x5f3759df - ( GIM_IR(va) >> 1);\
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isva = GIM_FR(_y);\
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isva = isva * ( 1.5f - ( _x * isva * isva ) );\
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}\
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}\
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#define GIM_SQRT(va,sva)\
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{\
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GIM_INV_SQRT(va,sva);\
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sva = 1.0f/sva;\
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}\
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//! Computes 1.0f / sqrtf(x). Comes from Quake3. See http://www.magic-software.com/3DGEDInvSqrt.html
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GREAL gim_inv_sqrt(GREAL f);
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//! Computes sqrtf(x) faster.
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/*!
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\sa gim_inv_sqrt
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*/
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GREAL gim_sqrt(GREAL f);
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//!Initializes mathematical functions
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void gim_init_math();
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//! Generates an unit random
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GREAL gim_unit_random();
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//! @}
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#endif // GIM_MATH_H_INCLUDED
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