Original Post
Hallo, I'm doing a simple solar system modelling program with OpenGL. my main goal is to understand better and practice the advanced features of c++ as well as learn to design classes. I wrote code to read in the data about planets from a file and render the planets. What I need help with is design. It would be great if you could tell me if there's anything wrong with my current design or maybe suggest something better. Another thing i need help with is error checking. What to do with errors? throw an exeption? call exit() or what? how do you handle errors in game programming? here's the .h file:
#ifndef SOLAR_SYS_H
#define SOLAR_SYS_H
#include <windows.h>
#include <GL\gl.h>
#include <GL\glu.h>
#include <fstream>
#include <string>
#include <vector>
#include <list>
#include <stdexcept>
#include <cmath>
#include <cstdlib>
//Abstract base class
class Shape
{
public:
virtual void draw() = 0;
virtual bool create() = 0;
};
//Sphere class, based on Shape
class Sphere : public Shape
{
public:
virtual ~Sphere()
{
dlat = dlng = 0;
r = 0.0;
vert.clear();
vnum = 0;
}
//explicit Ctor: radius, points for lattitude, points for longitude
explicit Sphere(GLfloat rad = 1.0, GLint dl = 42, GLint dg = 84);
//draw the sphere
void draw();
protected:
bool create(); //virtual
// gen_sphere: create() wrapper, if change == true, then replace the params given in Ctor
void gen_sphere(GLfloat, GLint, GLint, bool change = false);
struct Vertex //coords
{
GLfloat z, y, x;
};
private:
GLint dlat, dlng; //lattitude & longitude
GLfloat r; //radius
std::vector<Vertex> vert; //coords vector
size_t vnum; //should be same as vert.size()
//no copy ctor & op=
Sphere(const Sphere&);
Sphere & operator=(const Sphere &);
};
//defined later
class Planet_info;
// Planets class holds information about all planets
// of the solar system. Only one instance should be
// created for all planets. This is because Planets
// inherits from Sphere and only one sphere should be
// generated in the program. All planets will reuse this
// one sphere.
class Planets : public Sphere
{
public:
Planets(const char *s);
Planets();
~Planets();
void draw(); //replace the virual Sphere::draw()
protected:
std:: istream & add_planet(std::istream &); //add a planet from file
//void del_planet(const Planet_info &);
size_t planet_num; //number of loaded planets
private:
//no copy ctor & op=
Planets(const Planets &);
Planets & operator=(const Planets &);
// a std::list with info about all planets
std::list<Planet_info*> planets;
//TEXTURE support goes here (?)
};
// friend of Planets, with info such as
// radius, orbit, name and other.
class Planet_info
{
public:
friend class Planets;
Planet_info();
Planet_info(const Planet_info &);
//op=
Planet_info & operator=(const Planet_info &);
//read info from file
friend std::istream & operator>>(std::istream &, Planet_info &);
private:
std::string name;
GLfloat radius;
GLfloat orbit;
GLfloat mass;
GLfloat spd;
GLfloat revol;
//std::list<Planet_info*> satellites;
GLfloat rot1, rot2; //orbit- and revolution-angles
};
#endif
