// Calculation Program for calculating shape of a flower with the use of a circle (part D), July 4th, 2012

// file name: flower_curve_D.c

#include< stdio.h>
#include< math.h>

void main(void)
{
	double a,pi;// "a" is the radius of original circle of petal and pi=3.1415...
	double b; // coefficient on effect of sharpening the tip of a petal
	double r,z;// "r" and "z"（-π/2 =< z =< π/2）are the moving radius and the phase angle of petal respectively.
	double dz;// increment of "z"
	double f;// the phase angle of petal made of a sharpened original circle
	double p;// phase angle of center circle
	double dp;// increment of "p"
	int n;// numbers of petals
	double alpha;// the sharp angle of the bottom of the petal (The criterion value is "alpha=2*pi/n" in this program.)
	double beta;// angular range to be occupied by a petal around the center circle
	double dbeta;// beta の変分
	double k;// magnification factor of the criterion angle "alpha=2*pi/n" where 0 < k.
	double l;// magnification factor of the angular range "beta" where 0 < l )
	int m;
	int nz;// division numbers of both phases "z" and "beta"
	double zmin,zmax;// the minimum and the maximum values of phase angle "z" respectively
	int i,imax,j;
	double c;// the radius of the center circle
	double xx[30001],yy[30001];// Take care of the upper limit of storage memory capacitance.

	FILE *fp;

// setting of the constants
	pi=3.141592;
	a=1.0;//a=1.0

	b=1.0;//b=1.0


// setting of the other parameters
	printf("Input the numbers of petals. \n n=? ");
	scanf("%d",&n);
	printf("n=%d\n",n);

	alpha=2*pi/n;// the shsarpened angle of the botom of a petal
	beta=alpha;// fundamentally criteria value of "beta" is supposed to be equal to "alpha".


	k=5.3;// k=5.3 //magnification factor of the criterion angle 'alpha=2*pi/n' where 0 < k


	alpha=k*alpha;// the magnificated angle of the botom of the petal


	l=0.3;// l=0.3 // magnification factor of the criterion angular range "beta" where 0 < l


	beta=l*beta;// the magnificated angular range to be occupied by a petal around the center circle


	c=1.5; // c=1.5 // the radius of the center circle

	zmin=-pi/2;
	zmax=pi/2;

	nz=200;

	dz=(zmax-zmin)/nz;// plotting interval of "z"

	dbeta=beta/nz;// plotting interval of "beta"

	dp=2*pi/n/20;// plotting interval of "p"

// execution of calculation
	i=0;

	for(j=1;j<=n;j++) // sweep of n numbers of petals
	{
		m=0;

		for(z=zmin;z<=zmax+dz;z=z+dz) // sweep of phase angle "z" of the each petal
		{
			i++;
			m++;

			r=2*a*cos(z)/(((b+0.1)+fabs(sin(z)))/(b+0.1));
			
			f=-alpha*z/pi+pi/2-2*pi*(j-1)/n;

			xx[i]=r*cos(f)+c*cos(-2*pi*(j-1)/n+pi/2+beta/2-m*dbeta);
			yy[i]=r*sin(f)+c*sin(-2*pi*(j-1)/n+pi/2+beta/2-m*dbeta);

			printf("i=%d,x=%f,y=%f\n",i,xx[i],yy[i]);
		}

		for(p=2*pi*(j-1)/n+beta/2;p<2*pi*j/n-beta/2+dp;p=p+dp)
		{
			i++;

			xx[i]=c*cos(-p+pi/2);
			yy[i]=c*sin(-p+pi/2);

			printf("i=%d,x=%f,y=%f\n",i,xx[i],yy[i]);
		}
	}


	for(p=-beta/2+dp;p<2*pi-beta/2+dp;p=p+dp) // Simply for drawing an additional circle of underlying petal.   By the way, "statement for" may be deleted.
	{
		i++;

		xx[i]=c*cos(-p+pi/2);
		yy[i]=c*sin(-p+pi/2);
	}


	imax=i;

	xx[imax+1]=xx[1];
	yy[imax+1]=yy[1];

// writing the calculated coordinates data of the curve into a textfile named "flower_curve_D.txt"
	fp=fopen("flower_curve_D.txt","w");
	if(fp==NULL)
		{
		printf("FILE OPEN ERROR\n");
		}
	else
		{
		for(i=1;i<=imax+1;i++)
			{
			fprintf(fp,"%f,%f\n",xx[i],yy[i]);
			}
		fflush(fp);
		fclose(fp);
		}
	printf("end\n");
}// the end of the program

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