//  main.cpp
//  OpenGL_HelloWorld
//  Created by pgAgent on 13/06/2015.
//  Copyright (c) 2015 RJM Programming. All rights reserved.
//
#include <stdlib.h>
#include </Applications/MAMP/htdocs/glew-1.12.0/include/GL/glew.h>
#ifdef __APPLE__
#  include <GLUT/glut.h>
#else
#  include <GL/glut.h>
#endif


// Thanks to https://www.opengl.org/archives/resources/code/samples/glut_examples/examples/examples.html
//GLfloat light_diffuse[] = {1.0, 0.0, 0.0, 1.0};  /* Red diffuse light. */
GLfloat light_diffuse[] = {0.0, 1.0, 0.0, 1.0};  /* Green ambient light. */
//GLfloat light_position[] = {1.0, 1.0, 1.0, 0.0};  /* Infinite light location. */
GLfloat light_position[] = {1.0, 1.0, 1.0, 100.0};  /* Not 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
displaynew(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_AMBIENT, 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, 0.0);      /* 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);
}
void display (void) {
    if (1 == 1) {
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        drawBox();
        glutSwapBuffers();
    } else {
    glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);
    glLoadIdentity();
    
    glFlush();
    }
}
static int make_resources(void) {
    return 1;
}
static void update_fade_factor(void) {
}
static void render(void) {
    glClearColor(0.5f, 0.5f, 0.5f, 0.5f);
    glClear(GL_COLOR_BUFFER_BIT);
    glutSwapBuffers();
}
int main (int argc, char **argv) {
    if (1 == 1) { // thanks to https://www.opengl.org/archives/resources/code/samples/glut_examples/examples/examples.html
        glutInit(&argc, argv);
        glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
        glutCreateWindow("Green 3D lighted cube");
        glutDisplayFunc(displaynew);
        init();
        glutMainLoop();
    } else if (1 == 1) {  // thanks to http://duriansoftware.com/joe/An-intro-to-modern-OpenGL.-Chapter-2:-Hello-World:-The-Slideshow.html
        glutInit(&argc, argv);
        glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
        glutInitWindowSize(400, 300);
        glutCreateWindow("Hello World");
        glutDisplayFunc(&render);
        glutIdleFunc(&update_fade_factor);
        glutMainLoop();
    } else {
        glutInit(&argc, argv);
        glutInitDisplayMode (GLUT_SINGLE);
        glutInitWindowSize (500, 500);
        glutInitWindowPosition (100, 100);
        glutCreateWindow ("Your first OpenGL Window ... Hello World");
        glutDisplayFunc(display);
        glutMainLoop();
    }
}