#include <GL/glut.h>

void init() {
	// set matrix mode to PROJECTION mode
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(0,200,0,200);
	
	
}



void drawLine() {
	//delete buffers
	glClear(GL_COLOR_BUFFER_BIT);
	glLineWidth(5.0);
	glShadeModel(GL_SMOOTH);
	glBegin(GL_LINES);
		glColor3f(1.0f, 0.0f, 0.0f); /* red */
		glVertex2i(0,0);
		
		glColor3f(0.0f, 0.0f, 1.0f); /* blue */
		glVertex2i(200,200);
	glEnd();
}

void keyboard(unsigned char key, int x, int y) {
	switch(key) {
		case 27: 
			exit(0);
			break;
	}
}

// Called to draw scene
void RenderScene(void)
	{
	// Clear the window with current clearing color
	glClear(GL_COLOR_BUFFER_BIT);
	
	drawLine();

	// Flush drawing commands
	glFlush();
	}


// Setup the rendering state
void SetupRC(void)
    {
    // Set clear color to black
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
	
	

    }




// Main program entry point
int main(int argc, char* argv[])
    {
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize(100,100);
	glutInitWindowPosition(20,20);
	
	glutCreateWindow("Points");
	SetupRC();
	
	init();
	glutDisplayFunc(RenderScene);
	glutKeyboardFunc(keyboard);
	

	

	glutMainLoop();

	return 0;
    }