nmath.c

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/*
 * See Licensing and Copyright notice in naev.h
 */
#include <math.h>
 
#include "naev.h"
#include "nmath.h"
 
#include "array.h"
#include "log.h"
#include "rng.h"
 
int nmath_solve2Eq( double results[2], double a, double b, double c )
{
   /* Calculate the root. */
   double root = b * b - 4 * a * c;
   if (root < 0.)
      return -1;
   root = sqrt(root);
   /* Set the results. */
   results[0] = (-b + root) / (2 * a);
   results[1] = (-b - root) / (2 * a);
   return 0;
}
 
double max3( double v1, double v2, double v3 )
{
   double max = (v1 > v2) ? v1 : v2;
   max = (max > v3) ? max : v3;
   return(max);
}
 
double min3( double v1, double v2, double v3 )
{
   double min;
   min = (v1 < v2) ? v1 : v2;
   min = (min < v3) ? min : v3;
   return(min);
}
 
void arrayShuffle( void** array )
{
   for (int n=array_size( array ); n > 1; ) {
      int k       = RNG(0, n);
      void *tmp   = array[--n];
      array[n]    = array[k];
      array[k]    = tmp;
   }
}
 
int rectOverlap( double x, double y, double w, double h,
      double x2, double y2, double w2, double h2 )
{
   /* Too far left, down, right, or up, respectively. */
   if ((x+w < x2) || (y+h < y2) || (x > x2+w2) || (y > y2+h2))
      return 0;
 
   return 1;
}
 
double ease_SineInOut( double x )
{
   return 0.5 * (1. - cos(x * M_PI));
}
 
double ease_QuadraticInOut( double x )
{
   if (x < 0.5)
      return 2.*x*x;
   return -2.*x*x + 4*x - 1.;
}
 
double ease_CubicInOut( double x )
{
   if (x < 0.5)
      return 4.*x*x*x;
   double y = 2.*x - 2.;
   return 0.5*y*y*y+1.;
}