// Some experiments in 2-D graphics.


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


#define LLX 50.0
#define LLY 50.0


GLfloat height = 100.0;
GLfloat width = 100.0;


void redisplay(void);

// Experiment 0: Implement the following functions.  See stubs below.
// You also need to add one line near the beginning of main()!!!

void paint(void);
void line(GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2);
void boxOutline(GLfloat llx, GLfloat lly, GLfloat width, GLfloat height);
void boxFill(GLfloat llx, GLfloat lly, GLfloat width, GLfloat height);


int main(int argc, char *argv[])
{
	int scale;

	glutInit(&argc, argv);

	if (argc != 2)
	{
		printf("Work with me --- I need a scale factor!!!\n");
		return 1;
	}

	// Get scale from command line and use to adjust width and height.

	width *= (scale / 100.0);
	height *= (scale / 100.0);

	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize(300, 300);
	glutInitWindowPosition(50, 50);
	glutCreateWindow("Two Dimensional Drawing");

	glClearColor(1.0, 1.0, 1.0, 0.0);
	glutDisplayFunc(redisplay);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(0.0, 300.0, 0.0, 300.0, -1.0, 1.0);
	glMatrixMode(GL_MODELVIEW);

	glutPostRedisplay();

	//paint();

	glutMainLoop();

	return 0;
}


void redisplay(void)
{
	// Experiment 1 after getting program to work: Comment-out following
	// paint() call, un-comment paint() call in main and determine what the
	// difference is.  Restore original call sequence when finished.

	paint();

	// Experiment 2 after getting program to work: Comment-out following
	// glFlush() call and determine the difference.

	glFlush();
}


void paint(void)
{
	// Clear window, draw red box outline at LLX, LLY, width of width,
	// height of height.  Draw blue vertical and horizontal lines bisecting
	// box.  Draw green box filled in upper right quadrant of red box.
}


void line(GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2)
{
}


void boxOutline(GLfloat llx, GLfloat lly, GLfloat width, GLfloat height)
{
	// Wind counter-clockwise (CCW).
	// llx = x coordinate of lower left vertex.
	// lly = y coordinate of lower left vertex.
}


void boxFill(GLfloat llx, GLfloat lly, GLfloat width, GLfloat height)
{
	// Wind CCW.
	// llx = x coordinate of lower left vertex.
	// lly = y coordinate of lower left vertex.
}