// OPEN_GL_test.cpp : Defines the entry point for the console application.

#include "stdafx.h"

#define GL_PI 3.1415f

// Keep track of windows changing width and height
GLfloat windowWidth;
GLfloat windowHeight;

// Called to draw scene

void RenderScene(void)
    {GLfloat xRot = 0.3f;
	GLfloat yRot = 0.5f;

    GLfloat x,y,z,angle; // Storage for coordinates and angles

    // Clear the window with current clearing color
    glClear(GL_COLOR_BUFFER_BIT);
    
	glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
	gluLookAt (0.3, -0.3, -1.5, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
    glRotatef(xRot, 1.0f, 0.0f, 0.0f);
    glRotatef(yRot, 0.0f, 1.0f, 0.0f);

    // Call only once for all remaining points

    glBegin(GL_POINTS);
		z = -50.0f;
        for(angle = 0.0f; angle <= (2.0f*GL_PI)*3.0f; angle += 0.2f)

        {	x = 50.0f*sin(angle);
			y = 50.0f*cos(angle);

        // Specify the point and move the Z value up a little
	        glVertex3f(x, y, z);
		    z += 0.01f;
        }
    glEnd();

	// Flush drawing commands
    glFlush();
    }

// Setup the rendering state
void SetupRC()
    {glClearColor(0.0f, 0.0f, 0.0f, 1.0f );// Black background
     glColor3f(0.0f, 1.0f, 0.0f);          // Set drawing color to green
    }

// Called by GLUT library when the window has changed size

void ChangeSize(GLsizei w, GLsizei h)
    {
    GLfloat aspectRatio;
        if(h == 0) h = 1;	// Prevent a divide by zero
    glViewport(0, 0, w, h); // Set Viewport to window dimensions

    glMatrixMode(GL_PROJECTION); 	// Reset coordinate system
    glLoadIdentity();

    // Establish clipping volume (left, right, bottom, top, near, far)
    aspectRatio = (GLfloat)w / (GLfloat)h;
    if (w <= h)
        {      windowWidth = 100;
		        windowHeight = 100 / aspectRatio;
	        glOrtho (-100.0, 100.0, -windowHeight, windowHeight, 1.0, -50.0);
        }
    else
        {       windowWidth = 100 * aspectRatio;
	        windowHeight = 100;
			glOrtho (-windowWidth, windowWidth, -100.0, 100.0, 1.0, -50.0);
        }
    }

///////////////////////////////////////////////////////////



int main(int argc, char** argv)
{
glutInit(&argc, argv);
 glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);

 glutCreateWindow (argv[0]);
 glutDisplayFunc(RenderScene);
    glutReshapeFunc(ChangeSize);
    SetupRC();
    glutMainLoop();
return 0;
}