/*
     uses  de Casteljau to compute one coordinate
     value of a  Bezier curve. Has to be called 
     for each coordinate  (x,y, and/or z) of a control polygon.
     Input:   degree: degree of curve.
              coeff:  array with coefficients of curve.
              t:      parameter value.
      Output: coordinate value.
*/


 float decas(degree,coeff,t)
	float coeff[];
	float t;
	int degree;
{
	int r,i;
	float t1;
	float coeffa[30];  /* an auxiliary array. Change dim. if too small*/

	t1 = 1.0 - t;
	for(i=0; i<=degree; i++) coeffa[i]=coeff[i]; /* save input */

	for (r=1; r<= degree; r++)
		for (i=0; i<= degree - r; i++)
		{
			coeffa[i]= t1* coeffa[i]  +   t * coeffa[i+1] ;
		}

	return (coeffa[0]);
}


main()
{
float t=0.5;
int degree=3;

float coordx[ ]={0, 0.5, 1, 3};
 printf("Coordinata x= %6.4 f\n ", decas(degree, coordx, t) );
float  coordy[ ]={0, 1, 1, 5}; 
 printf("Coordinata y= %6.4 f\n ", decas(degree, coordy,t) );
float  coordz[ ]={0, 3, 4, 8}; 
 printf("Coordinata z= %6.4 f\n ", decas(degree, coordz,t) );
 
}