#include <iostream>
#include <glew.h> // Include the GLEW header file
#include <glut.h> // Include the GLUT header file
#include <conio.h>
#include <stdio.h>


using namespace std;

double rotate_by_key=0;

double rotate_x=0.5;

void keyPress(int key,int x,int y)
{

    if(key==27)
          exit(0);
    if (key == GLUT_KEY_UP)
            rotate_x += .05;
        if (key == GLUT_KEY_DOWN)
            rotate_x -= .05;

    glutPostRedisplay();

}

void initRendering()
{
    glEnable(GL_DEPTH_TEST);
}


//Called when the window is resized
void handleResize(int w, int h) {
    //Tell OpenGL how to convert from coordinates to pixel values
    glViewport(0, 0, w, h);

    glMatrixMode(GL_PROJECTION); //Switch to setting the camera perspective

    //Set the camera perspective
    glLoadIdentity(); //Reset the camera
    gluPerspective(45.0,                  //The camera angle
                   (double)w / (double)h, //The width-to-height ratio
                   1.0,                   //The near z clipping coordinate
                   200.0);                //The far z clipping coordinate
}

void drawScene()
{
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

    glScalef( rotate_x,rotate_x,1.0f );
    //glScalef(1.0f,1.0f,rotate_x);
    glRotatef(  rotate_by_key,-1.0f, 1.5f, -5.0f );

	glBegin(GL_POLYGON);


 glVertex3f(1.0f, 0.0f, -5.0f);
        glVertex3f(0.0f, 1.0f, -5.0f);

		   glVertex3f(0.0f, -1.0f, -5.0f);
 glEnd();

    glutSwapBuffers();
}

int main(int argc,char** argv)
{
    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);

    glutInitWindowSize(400,400);

    glutCreateWindow("My triangle");

    initRendering();

    glutDisplayFunc(drawScene);

    glutSpecialFunc(keyPress);

    glutReshapeFunc(handleResize);

    glutMainLoop();

    return(0);
}