/* Both normals and colors are assigned to the vertices */
/* Model is centered at origin so (unnormalized) normals
 are the same as the vertex values */

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

GLfloat vertices[][2] = {{1.0, -1.0}, {-1.0, 1.0}};
GLfloat normals[][2] = {{-1.0, -1.0},{1.0, -1.0}};
GLfloat colors[][3] = {{0.0, 0.0, 1.0},{1.0, 0.0, 0.0}};

void polygon(int a, int b)
{
/* draw a polygon via list of vertices */

	/* Draw lines first...*/
 	glBegin(GL_LINES);
		glColor3fv(colors[a]);
		//glNormal2fv(normals[a]);
		glVertex2fv(vertices[a]);
		
		glColor3fv(colors[b]);
		//glNormal2fv(normals[b]);
		glVertex2fv(vertices[b]);

		
	glEnd();

	/* ...than draw vertices*/
	glBegin(GL_POINTS);
		glColor3fv(colors[a]);
		//glNormal2fv(normals[a]);
		glVertex2fv(vertices[a]);
		
		glColor3fv(colors[b]);
		//glNormal2fv(normals[b]);
		glVertex2fv(vertices[b]);

		
	glEnd();
																										
}

void vertex_mapping(void)
{
/* map vertices to faces */

	polygon(0,1);
}


void display(void)
{
/* display callback, clear frame buffer and z buffer, swap buffers */

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
	
	glPointSize(5);
	vertex_mapping();

	glFlush();
	glutSwapBuffers();
}

/* Idle callback */
/* If you want to make your model do some constant movement, 
   place any motion stuff here! */
void idle(void)
{

	/* display(); */
	glutPostRedisplay();
}

void mouse(int btn, int state, int x, int y)
{
/* mouse callback */
	

	if(btn==GLUT_LEFT_BUTTON && state == GLUT_DOWN) { /* NULL */ }
	if(btn==GLUT_MIDDLE_BUTTON && state == GLUT_DOWN) { /* NULL */ }
	if(btn==GLUT_RIGHT_BUTTON && state == GLUT_DOWN) { /* NULL */ }
}

void myReshape(int w, int h)
{
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if (w <= h)
        glOrtho(-2.0, 2.0, -2.0 * (GLfloat) h / (GLfloat) w,
            2.0 * (GLfloat) h / (GLfloat) w, -10.0, 10.0);
    else
        glOrtho(-2.0 * (GLfloat) w / (GLfloat) h,
            2.0 * (GLfloat) w / (GLfloat) h, -2.0, 2.0, -10.0, 10.0);
    glMatrixMode(GL_MODELVIEW);
}

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

/* need both double buffering and z buffer */

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(500, 500);
    glutCreateWindow("colorcube");
    glutReshapeFunc(myReshape);
    glutDisplayFunc(display);
	glutIdleFunc(idle);
	glutMouseFunc(mouse);
	glEnable(GL_DEPTH_TEST); /* Enable hidden--surface--removal */
    glutMainLoop();
}