/* Copyright (c) Mark J. Kilgard, 1997. */

/* This program is freely distributable without licensing fees
 and is provided without guarantee or warrantee expressed or
 implied. This program is -not- in the public domain. */

/* This program was requested by Patrick Earl; hopefully someone else
 will write the equivalent Direct3D immediate mode program. */

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

GLfloat light_diffuse[] = { 1.0, 0.0, 0.0, 1.0 }; /* Red diffuse light. */
GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 }; /* Infinite light location. */
GLfloat n[6][3] = { /* Normals for the 6 faces of a cube. */
{ -1.0, 0.0, 0.0 }, { 0.0, 1.0, 0.0 }, { 1.0, 0.0, 0.0 }, { 0.0, -1.0, 0.0 }, {
		0.0, 0.0, 1.0 }, { 0.0, 0.0, -1.0 } };
GLint faces[6][4] = { /* Vertex indices for the 6 faces of a cube. */
{ 0, 1, 2, 3 }, { 3, 2, 6, 7 }, { 7, 6, 5, 4 }, { 4, 5, 1, 0 }, { 5, 6, 2, 1 },
		{ 7, 4, 0, 3 } };
GLfloat v[8][3]; /* Will be filled in with X,Y,Z vertexes. */

void drawBox(void) {
	int i;

	for (i = 0; i < 6; i++) {
		glBegin(GL_QUADS);
		glNormal3fv(&n[i][0]);
		glVertex3fv(&v[faces[i][0]][0]);
		glVertex3fv(&v[faces[i][1]][0]);
		glVertex3fv(&v[faces[i][2]][0]);
		glVertex3fv(&v[faces[i][3]][0]);
		glEnd();
	}
}

void display(void) {
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	drawBox();
	glutSwapBuffers();
}

void init(void) {
	/* Setup cube vertex data. */
	v[0][0] = v[1][0] = v[2][0] = v[3][0] = -1;
	v[4][0] = v[5][0] = v[6][0] = v[7][0] = 1;
	v[0][1] = v[1][1] = v[4][1] = v[5][1] = -1;
	v[2][1] = v[3][1] = v[6][1] = v[7][1] = 1;
	v[0][2] = v[3][2] = v[4][2] = v[7][2] = 1;
	v[1][2] = v[2][2] = v[5][2] = v[6][2] = -1;

	/* Enable a single OpenGL light. */
	glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
	glLightfv(GL_LIGHT0, GL_POSITION, light_position);
	glEnable(GL_LIGHT0);
	glEnable(GL_LIGHTING);

	/* Use depth buffering for hidden surface elimination. */
	glEnable(GL_DEPTH_TEST);

	/* Setup the view of the cube. */
	glMatrixMode(GL_PROJECTION);
	gluPerspective( /* field of view in degree */40.0,
	/* aspect ratio */1.0,
	/* Z near */1.0, /* Z far */10.0);
	glMatrixMode(GL_MODELVIEW);
	gluLookAt(0.0, 0.0, 5.0, /* eye is at (0,0,5) */
	0.0, 0.0, 0.0, /* center is at (0,0,0) */
	0.0, 1.0, 0.); /* up is in positive Y direction */

	/* Adjust cube position to be asthetic angle. */
	glTranslatef(0.0, 0.0, -1.0);
	glRotatef(60, 1.0, 0.0, 0.0);
	glRotatef(-20, 0.0, 0.0, 1.0);
}

int main(int argc, char **argv) {
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
	glutCreateWindow("red 3D lighted cube");
	glutDisplayFunc(display);
	init();
	glutMainLoop();
	return 0; /* ANSI C requires main to return int. */
}