/* 色変化しながら回転する星を作る */
#include <eggx.h>
#include <math.h>

#define WIN_SIZE 18
#define RSTEP 10
#define COLORMODE DS9_COOL

int main()
{
    int win ;
    int i,j,ii,icolor,color_r,color_g,color_b ;
    float x[5],y[5],r,theta ;
    win = gopen(WIN_SIZE,WIN_SIZE) ;
    layer(win,0,1) ;
    
    for( i=0 ; i<2*360/RSTEP ; i++ ){
	gclr(win) ;
	r = WIN_SIZE/2.0-1 ;
	if( 360/RSTEP < i ) icolor=2*360/RSTEP-i ;
	else icolor=i ;
	makecolor(COLORMODE,0,360/RSTEP,icolor,
		  &color_r,&color_g,&color_b) ;
	newrgbcolor(win,color_r,color_g,color_b+1) ;
	for( j=0 ; j<5 ; j++ ){
	    ii=i*RSTEP+j*72*2 ;
	    x[j] = r+r*cos((theta=M_PI*ii/180.0)) ;
	    y[j] = r+r*sin(theta) ;
	}
	fillpoly(win,x,y,5,0) ;
	copylayer(win,1,0) ;
	saveimg(win,0, 0,0,WIN_SIZE-1,WIN_SIZE-1,
		"ppmtogif",256,"img%d.gif",100+i) ;
    }
    gclose(win) ;
    return(0) ;
}