/*  drawpolyp.c  */
/* cc -lX11 drawpolyp.c */

#include <stdio.h>

#include "xwmy.c"

int main(void)
{
    int i,n;
    int i1,i2;
    double xmin,xmax,ymin,ymax;
    double xd,yd;
    double x[101],y[101];
    FILE *fp;

    fp = fopen("polyn.txt", "r");
    fscanf(fp,"%d",&n);
    for (i=0; i<n; i++)  {
        fscanf(fp,"%lf %lf",&x[i],&y[i]);
    }
    fclose(fp);

    xmin=x[0]; xmax=x[0];
    ymin=y[0]; ymax=y[0];
    for (i=1; i<n; i++)  {
        if (xmin>x[i]) { xmin=x[i]; }
        if (xmax<x[i]) { xmax=x[i]; }
        if (ymin>y[i]) { ymin=y[i]; }
        if (ymax<y[i]) { ymax=y[i]; }
    }
    xd=(xmax-xmin)*0.2;
    yd=(ymax-ymin)*0.2;

    printf("n=%d\n",n);
    printf("xmin=%f : xmax=%f\n",xmin,xmax);
    printf("ymin=%f : ymax=%f\n",ymin,ymax);

    XW_Open();

    DB_WindowNV(xmin-xd, ymin-yd, xmax+xd, ymax+yd);

    XW_SetColor(XW_Color_White);

    DB_DrawRect(DB_WX1, DB_WY1, DB_WX2, DB_WY2);

    XW_SetColor(XW_Color_Green);

    for (i=0; i<n; i++)  {
        i1=i;
        i2=i+1;
        if (i2>n-1) { i2=0; }
        DB_DrawLine(x[i1], y[i1], x[i2], y[i2]);
    }

    XW_Refresh();

    printf("Push key");
    getchar();

    XW_Close();

    return 0;
}