#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "GrWin.h"

#define X(I) ((float)cos((I)*PAI2/N))
#define Y(I) ((float)sin((I)*PAI2/N))
#define RAND(n) ((rand()-1)/(RAND_MAX/(n)))

#define BFFLEN 6

int main()
{
	char buff[BFFLEN];
	float PAI2=6.28319f, XM, YM;
	int MCPY=4, MXOR=7, NLBRS=0, NLHCH=0;
	int N, NC, I, J, K=1, IBS, IBH, LLW, LLH;

	printf("N = ");
	N = atoi(fgets(buff,BFFLEN,stdin));
	GWopen(0);
	NC = GWncolor();
	GWvport(0.0f,0.0f,1.0f,1.0f);
	if(GWsize(5, &LLW, &LLH)) {
		if(LLW > LLH)
			LLW = LLH;
		else
			LLH = LLW;
		GWsize(-5, &LLW, &LLH);
		GWsize(-3, NULL, NULL);
	}
	GWindow(-1.1f,-1.1f,1.1f,1.1f);
	GWsetpen(K,-1,-1,MXOR);
	for(I=0; I < N - 1; ++I) {
		for(J=I+1; J < N; ++J) {
			K %= NC;
			GWsetpen(K,-1,-1,-1);
			GWline(X(I),Y(I),X(J),Y(J));
			++K;
		}
	}
	GWsetpen(-999, -1, -1, MCPY);
	GWsetbrs(-1,NLBRS,NLHCH);
	GWrect(-1.05f, -1.05f, 1.05f, 1.05f);
	GWellipse(-1.05f, -1.05f, 1.05f, 1.05f);
	printf("Click L-button at any point to fill the area, \n");
	printf("   or at any point near the center to quit.\n");
	GWcappnt(&XM,&YM,"Click at any point");
	while(XM*XM+YM*YM > 0.1) {
		K = RAND(36);
//         0..19: Windows Palette,   20..35: Custom Palette
		IBS = 1 + RAND(2);
		IBH = 1 + RAND(5);
		GWsetbrs(K,IBS,IBH);
		GWflood(XM,YM);
		GWcappnt(&XM,&YM,"Click at any point");
	}
	GWquit();
	return 0;
}