/*  

In this lab, we will consider the viewing transformation, the modeling transformation,
and the projection transformation.

Answer the questions below, the answers will be discussed in lecture.

  1.  Compile and run this code.
  2.  Does the image look 3-dimensional?  Why?



  3.  Minimize the output window, and then maximize it.  Does the image change?
  Do you expect it to?



  4.  Comment out the	glLoadIdentity();	in	display()	and recompile.
  5.  Now, minimize and maximize the window a few times.  If the camera is moving back
  after each min and max, why doesn't the image "move away" from us?



  6.  Comment out the	glOrtho()	in	reshape()	and uncomment the	glFrustum() .
  The		glLoadIdentity();	in	display()	should still be commented.  Recompile.
  7.  Minimize the output window, and then maximize it.  Does the image change?
  Do you expect it to?



  8.  Uncomment the		glLoadIdentity();	in	display()	and recompile.
  9.  Minimize the output window, and then maximize it, and confirm that the output
  doesn't change.
  10.  Replace the call to	gluLookAt()		in	display()	with  glTranslatef( , , );
  Fill in the parameters so that it functions the same as the gluLookAt call.  What
  parameters did you use, and why did they work?



  11.  Uncomment the	glScale();	in	display()	and recompile.  What changes? 


*/
#include <GL/glut.h>
#include <cstdlib>

void myInit ()
{
	glClearColor(1.0 , 1.0 , 1.0 , 1.0);
}

void display ()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glColor3f(0.0 , 0.0 , 0.0);

	glLoadIdentity();

	// Viewing (NOT Viewport) transformation
	gluLookAt(0.0 , 0.0 , 5.0 , 0.0 , 0.0 , 0.0 , 0.0 , 1.0 , 0.0);
//	glTranslatef( x-move , y-move , z-move );

	// Modeling transformation
//	glScalef(1.0 , 2.0 , 1.0);

	glutWireCube(1.0);
	glFlush();
}

void reshape (GLint w, GLint h)
{
	glViewport(0,0,w,h);
	glMatrixMode(GL_PROJECTION);

	glLoadIdentity();

	// Projection transformation
	glOrtho(-1.0,1.0,-1.0,1.0,0,100);
//	glFrustum(-1.0,1.0,-1.0,1.0,1.5,20.0);

	glMatrixMode(GL_MODELVIEW);
}

void keyboard (unsigned char key , int x, int y)
{
if ( key=='q' || key=='Q' ) {
		exit( 0 );
	}
}

int main( int argc, char** argv )
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize(500,500);
	glutInitWindowPosition(100,100);
	glutCreateWindow(argv[0]);
	myInit();
	glutDisplayFunc(display);
	glutReshapeFunc(reshape);
	glutKeyboardFunc(keyboard);
	glutMainLoop();
	return 0;
}