/

#include "stdafx.h"

#include<GL\glut.h>

#include<math.h>

#define PI 3.14

GLfloat xRot=0.0f;

GLfloat yRot=0.0f;

void Init()

{

    glClearColor(0.0,0.0,0.0,0.0);

}

void ChangeSize(int w,int h)

{

    glViewport(,,w,h);

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    GLfloat aspect=w/h;

    if (w<=h)

    {

        glOrtho(-100.0,100.0,-100.0/aspect,100.0/aspect,-100.0,100.0);

    }

    else

    {

        glOrtho(-100.0*aspect,100.0*aspect,-100.0,100.0,-100.0,100.0);

    }

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

}

void Mydisplay()

{

    GLfloat x,y,angle,z=0.0f;

    GLfloat sizes[];

    glColor3f(0.0f,1.0f,0.0f);

    glClear(GL_COLOR_BUFFER_BIT);

    glPushMatrix();

    glRotatef(xRot,1.0,0.0,0.0);

    glRotatef(yRot,0.0,1.0,0.0);

    for (angle = 0.0f; angle <*PI; angle+=0.1f)

    {

            glBegin(GL_LINES);

            x=50.0f*cos(angle);

            y=50.0f*sin(angle);

            glVertex3f(x,y,z);

            x=50.0f*cos(angle+PI);

            y=50.0f*sin(angle+PI);

            glVertex3f(x,y,z);

            glEnd();

    }

    glPopMatrix();

    glutSwapBuffers();

}

void Mykeys(int key,int x,int y)

{

    if (key==GLUT_KEY_LEFT)

    {

        yRot-=5.0f;

    }

    if (key==GLUT_KEY_RIGHT)

    {

        yRot+=5.0f;

    }

    if (key==GLUT_KEY_UP)

    {

        xRot-=5.0f;

    }

    if (key==GLUT_KEY_DOWN)

    {

        xRot+=5.0f;

    }

    if (xRot>355.0f)

    {

        xRot=0.0f;

    }

    if (xRot<=-5.0f)

    {

        xRot=355.0f;

    }

    if (yRot>355.0f)

    {

        yRot=0.0f;

    }

    if (yRot<=-5.0f)

    {

        yRot=355.0f;

    }

    glutPostRedisplay();

}

int main(int argc,char ** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE);

    glutInitWindowPosition(,);

    glutInitWindowSize(,);

    glutCreateWindow("Points");

    Init();

    glutDisplayFunc(Mydisplay);

    glutReshapeFunc(ChangeSize);

    glutSpecialFunc(Mykeys);

    glutMainLoop();

}