main.cpp

#include <vector>
#include <iostream>

#include <OpenGl/gl.h>
#include <OpenGL/glu.h>
#include <GLUT/glut.h>
#include "boost/bind.hpp"

#include "Point.h"

std::vector<Point> g_points;

void Display()
{
    glClear(GL_COLOR_BUFFER_BIT);
    glBegin(GL_LINE_STRIP);
        glColor3f(1.0, 0.5, 0.5);
        glVertex2f(0.1, 0.1);
        glVertex2f(0.2, 0.2);
        glVertex2f(0.3,0.3);
        glVertex2f(0.4, 0.1);
        std::for_each(g_points.begin(), g_points.end(),
                        boost::bind(&Point::draw, _1));
        glVertex2f(0.8, 0.8);
    glEnd();
        GLenum err;

        if ((err = glGetError()) != GL_NO_ERROR)
        {
            std::cout << "Got an error: " << err << std::endl;
        }

   glFlush();
}

void Init()
{
    glClearColor(0,0,0,0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
}

void ResizeScene(int width, int height)
{
    glViewport(0,0, width, height);
}

void MouseControl(int button, int state, int x, int y)
{
    std::cout << "Got mouse change:" << std::endl;
    std::cout << "\tButton -> " << button << std::endl;
    std::cout << "\tState -> " << state << std::endl;
    std::cout << "\tX -> " << x << std::endl;
    std::cout << "\tY -> " << y << std::endl;

    std::cout << "GLUT_DOWN: " << GLUT_DOWN << std::endl;

    std::cout << "Number of points: " << g_points.size() << std::endl;

    g_points.push_back(Point(x / 1000.0, y / 1000.0,0));
    glutPostRedisplay();
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
    glutInitWindowSize(600, 600);
    glutInitWindowPosition(0, 0);
    glutCreateWindow("Level Up!");

    gluOrtho2D(0, 1, 0, 1);

    Init();

    glutDisplayFunc(Display);
    glutReshapeFunc(ResizeScene);
    glutMouseFunc(MouseControl);

    glutMainLoop();

    return 0;
}

Point.h

#ifndef POINT_H
#define POINT_H

#include <tr1/tuple>

class Point
{
  public:
    Point(double x, double y, double z)
      : _point(x,y,z)
    {}

    void draw()
    {
        std::cout << "Printing! (" << X() << ", " << Y() << ")" << std::endl;
        glVertex2d(X(), Y());
    }

    double X() { return std::tr1::get<0>(_point); }
    double Y() { return std::tr1::get<1>(_point); }
    double Z() { return std::tr1::get<2>(_point); }
    
  private:
    std::tr1::tuple<double, double, double> _point;
};

#endif POINT_H