157 lines
4.7 KiB
C++
157 lines
4.7 KiB
C++
/*
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* This program source code file is part of KICAD, a free EDA CAD application.
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*
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* Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
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* Copyright (C) CERN
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* Copyright (C) 2021 KiCad Developers, see AUTHORS.txt for contributors.
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*
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* @author Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
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*
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* The equals() method to compare two floating point values adapted from
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* AlmostEqualRelativeAndAbs() on
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* https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/
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* (C) Bruce Dawson subject to the Apache 2.0 license.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program 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
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, you may find one here:
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* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
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* or you may search the http://www.gnu.org website for the version 2 license,
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* or you may write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
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*/
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#ifndef UTIL_H
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#define UTIL_H
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#include <config.h>
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#include <cmath>
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#include <cstdint>
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#include <limits>
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#include <typeinfo>
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#include <type_traits>
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/**
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* Helper to avoid directly including wx/log.h for the templated functions in kimath
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*/
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void kimathLogDebug( const char* aFormatString, ... );
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/**
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* Limit @a value within the range @a lower <= @a value <= @a upper.
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*
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* It will work on temporary expressions, since they are evaluated only once, and it should
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* work on most if not all numeric types, string types, or any type for which "operator < ()"
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* is present. The arguments are accepted in this order so you can remember the expression as
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* a memory aid:
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* <p>
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* result is: lower <= value <= upper
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*</p>
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*/
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template <typename T> inline constexpr T Clamp( const T& lower, const T& value, const T& upper )
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{
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if( value < lower )
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return lower;
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else if( upper < value )
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return upper;
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return value;
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}
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// Suppress an annoying warning that the explicit rounding we do is not precise
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#ifdef HAVE_WIMPLICIT_FLOAT_CONVERSION
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_Pragma( "GCC diagnostic push" ) \
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_Pragma( "GCC diagnostic ignored \"-Wimplicit-int-float-conversion\"" )
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#endif
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/**
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* Round a floating point number to an integer using "round halfway cases away from zero".
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*
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* In Debug build an assert fires if will not fit into the return type.
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*/
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template <typename fp_type, typename ret_type = int>
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constexpr ret_type KiROUND( fp_type v )
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{
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using max_ret = long long int;
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fp_type ret = v < 0 ? v - 0.5 : v + 0.5;
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if( std::numeric_limits<ret_type>::max() < ret ||
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std::numeric_limits<ret_type>::lowest() > ret )
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{
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kimathLogDebug( "Overflow KiROUND converting value %f to %s", double( v ),
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typeid( ret_type ).name() );
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return 0;
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}
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return ret_type( max_ret( ret ) );
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}
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#ifdef HAVE_WIMPLICIT_FLOAT_CONVERSION
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_Pragma( "GCC diagnostic pop" )
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#endif
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/**
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* Scale a number (value) by rational (numerator/denominator). Numerator must be <= denominator.
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*/
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template <typename T>
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T rescale( T aNumerator, T aValue, T aDenominator )
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{
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return aNumerator * aValue / aDenominator;
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}
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template <typename T>
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int sign( T val )
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{
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return ( T( 0 ) < val) - ( val < T( 0 ) );
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}
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// explicit specializations for integer types, taking care of overflow.
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template <>
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int rescale( int aNumerator, int aValue, int aDenominator );
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template <>
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int64_t rescale( int64_t aNumerator, int64_t aValue, int64_t aDenominator );
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/**
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* Template to compare two floating point values for equality within a required epsilon.
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*
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* @param aFirst value to compare.
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* @param aSecond value to compare.
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* @param aEpsilon allowed error.
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* @return true if the values considered equal within the specified epsilon, otherwise false.
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*/
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template <class T>
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typename std::enable_if<std::is_floating_point<T>::value, bool>::type
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equals( T aFirst, T aSecond, T aEpsilon = std::numeric_limits<T>::epsilon() )
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{
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T diff = std::abs( aFirst - aSecond );
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if( diff < aEpsilon )
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{
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return true;
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}
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aFirst = std::abs( aFirst );
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aSecond = std::abs( aSecond );
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T largest = aFirst > aSecond ? aFirst : aSecond;
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if( diff <= largest * aEpsilon )
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{
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return true;
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}
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return false;
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}
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#endif // UTIL_H
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