#include <iostream.h>
#include <GL/glut.h>

// function prototypes
void display(void);
void reshape(int width, int height);
void keyboard(unsigned char key, int x, int y);
void init(void);
void dtTimeStep(void);


int 
main(int argc, char **argv)
{
  // set up window
  glutInitWindowSize(400, 400);
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  glutCreateWindow("Test Harness");

  // register callback functions
  glutDisplayFunc(display);
  glutReshapeFunc(reshape); 
  glutKeyboardFunc(keyboard);
  
  // initalize opengl parameters
  init();

  // loop until something happens
  glutMainLoop();
  return 0;           
}
void init()
{
  // initialize viewing system
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(45.0, 1.0, 1.0, 3.0);
  glMatrixMode(GL_MODELVIEW);
 

  // initialize background color to black
  glClearColor(0.0,0.0,0.0,0.0);

  // enable depth buffering
  glEnable(GL_DEPTH_TEST);
}



void reshape(int width, int height)
{

  glViewport(0,0,width,height);
}

void display()
{
	// initialize modelview matrix
	glLoadIdentity();
	gluLookAt(0.0,0.0,2.0,0.0,0.0,0.0,0.0,1.0,0.0);
	glTranslatef(0.0f,-0.5f,0.0f);  // translate the world down so we aren't
									// looking at the triangle edge-on

	// clear buffers
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	// draw a blue triangle with vertices (0,0,0), (0.7,0,0) and (0.7,0,.3)
	float vertex1[3]={0.0f,0.0f,0.0f};
	float vertex2[3]={0.7f,0.0f,0.0f};
	float vertex3[3]={0.7f,0.0f,0.3f};
	float triangleColor[3]={0.0,0.0,1.0};
	// begin triangle draw
	glColor3f(triangleColor[0], triangleColor[1], triangleColor[2]);
	glBegin(GL_TRIANGLES);
		glVertex3f(vertex1[0],vertex1[1],vertex1[2]);
		glVertex3f(vertex2[0],vertex2[1],vertex2[2]);
		glVertex3f(vertex3[0],vertex3[1],vertex3[2]);
	glEnd(); //end triangle draw

	// draw a red sphere centered at (0.5,0.5,-0.5) with radius .05
	float circleCenter[3]={0.5f,0.5f,-0.4f};
	float circleRadius=0.05f;
	float circleColor[3]={1.0f,0.0f,0.0f};
	// begin sphere draw
	glColor3f(circleColor[0],circleColor[1],circleColor[2]);
	glPushMatrix();
	glTranslatef(circleCenter[0],circleCenter[1],circleCenter[2]); // move to center
	glScalef(circleRadius, circleRadius, circleRadius);    //scale radius in x,y, and z
	glutSolidSphere(1.0f,20,20);   // draw a unit square at the origin
	glPopMatrix(); //end sphere draw
	
	// draw to screen
	glutSwapBuffers();
}

void keyboard(unsigned char key, int x, int y)
{

	if (key==' ')
		dtTimeStep();
}

void dtTimeStep()
{
	// enter your code here
	cout << "You hit the space bar!" << endl;
	glutPostRedisplay();
}