File indexing completed on 2024-12-22 04:04:07

 /* Copyright (C) 2001-2019 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 */