// program to read in a GRS (short for 'gross' : my homegrown primitive
// file format for polyline drawings ), and draw the polylines in a window
// Sandy Hill, September, 1997 - revised Sept. 22, 1998
#include <windows.h>
#include <iostream.h>
#include <fstream.h>
#include <iomanip.h>
#include <gl/Gl.h>
#include <gl/Glu.h>
#include <gl/glut.h>
//###################### CLASSES ###################
//$$$$$$ Point $$$$$$$
class Point{
public:
float x, y;
void set(float xx, float yy){x=xx; y=yy;}
};
//$$$$$$ Rect $$$$$$
class Rect{
public:
float left, top, right, bott;
void set(float ll, float tt, float rr, float bb){left = ll; top = tt;
right = rr; bott = bb;}
};
//$$$$$$ PolyPoint $$$$$$
class PolyPoint{
public:
int num;
Point* pt;
};
//$$$$$$ PolyPointArray $$$$$$
class PolyPointArray{
public:
Rect window;
int numPolys;
PolyPoint* poly;
void readGRS(char* fname);
void draw();
void print();
};
//<<<<<<<<<<<<<<<<<<<<<<< PolyPointArray::draw >>>>>>>>>>>>>>>>>>>
void PolyPointArray::draw()
{
for(int j = 0; j <numPolys; j++)
{
glBegin(GL_LINE_STRIP);
for(int i = 0; i < poly[j].num; i++)
glVertex2f(poly[j].pt[i].x, poly[j].pt[i].y);
glEnd();
}
glFlush();
}
//<<<<<<<<<<<<<<<<<<<<<<<<<< readGRS >>>>>>>>>>>>>>>>>>>>>>>>>
void PolyPointArray::readGRS(char* fname)
{
fstream inStream;
inStream.open(fname, ios ::in);
if(inStream.fail()) { cout << "can't open it!"; return;}
while(1) / infinite loop - with a break
{
char buff[80];
if(!inStream.getline(buff,80)) // at end of file prematurely
{ cout << "at end of file, with no *** terminator!\n";exit(0);}
if(buff[0] == '*') break; // detect end of comment block
}

inStream >> window.left >> window.top >> window.right >> window.bott;
inStream >> numPolys;
poly = new PolyPoint[numPolys]; // make array of PolyPoints

for(int j = 0; j < numPolys; j++)
{
int numThisPoly;
inStream >> numThisPoly;
poly[j].num = numThisPoly;
poly[j].pt = new Point[numThisPoly];
for (int i = 0; i < numThisPoly; i++)
inStream >> poly[j].pt[i].x >> poly[j].pt[i].y;
}
inStream.close();
}