/* Copyright (C) 2001-2017 Peter Selinger. * This file is part of Potrace. It is free software and it is covered * by the GNU General Public License. See the file COPYING for details. */ /* This header file collects some general-purpose macros (and static * inline functions) that are used in various places. */ #ifndef AUXILIARY_H #define AUXILIARY_H #ifdef HAVE_CONFIG_H #include <config.h> #endif #include <stdlib.h> /* ---------------------------------------------------------------------- */ /* point arithmetic */ #include "potracelib.h" struct point_s { long x; long y; }; typedef struct point_s point_t; typedef potrace_dpoint_t dpoint_t; /* convert point_t to dpoint_t */ static inline dpoint_t dpoint( point_t p ) { dpoint_t res; res.x = p.x; res.y = p.y; return res; } /* range over the straight line segment [a,b] when lambda ranges over [0,1] */ static inline dpoint_t interval( double lambda, dpoint_t a, dpoint_t b ) { dpoint_t res; res.x = a.x + lambda * ( b.x - a.x ); res.y = a.y + lambda * ( b.y - a.y ); return res; } /* ---------------------------------------------------------------------- */ /* some useful macros. Note: the "mod" macro works correctly for * negative a. Also note that the test for a>=n, while redundant, * speeds up the mod function by 70% in the average case (significant * since the program spends about 16% of its time here - or 40% * without the test). The "floordiv" macro returns the largest integer * <= a/n, and again this works correctly for negative a, as long as * a,n are integers and n>0. */ /* integer arithmetic */ static inline int mod( int a, int n ) { return a >= n ? a % n : a >= 0 ? a : n - 1 - ( -1 - a ) % n; } static inline int floordiv( int a, int n ) { return a >= 0 ? a / n : -1 - ( -1 - a ) / n; } /* Note: the following work for integers and other numeric types. */ #undef sign #undef abs #undef min #undef max #undef sq #undef cu #define sign( x ) ( ( x ) > 0 ? 1 : ( x ) < 0 ? -1 : 0 ) #define abs( a ) ( ( a ) > 0 ? ( a ) : -( a ) ) #define min( a, b ) ( ( a ) < ( b ) ? ( a ) : ( b ) ) #define max( a, b ) ( ( a ) > ( b ) ? ( a ) : ( b ) ) #define sq( a ) ( ( a ) * ( a ) ) #define cu( a ) ( ( a ) * ( a ) * ( a ) ) #endif /* AUXILIARY_H */