// Lahde: http://www.cs.uct.ac.za/Courses/CS300W/ICG/Resources/OpenGL/quick.html

#include "GL/glaux.h"
#include "GL/gl.h"
#include "GL/glu.h"


/* We will fill in this function later. */
void myinit(void)
{
  /* Red ambient light source */
    GLfloat light_ambient[] = { 1.0, 0.0, 0.0, 1.0 };

    GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
    GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
    GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };

    glDepthFunc(GL_LESS);
    glEnable(GL_DEPTH_TEST);

    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);

    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);

    glEnable(GL_LIGHT0);
    glEnable(GL_LIGHTING);

    glEnable(GL_CULL_FACE);
}

/* This draws the scene, using the convenient functions supplied by the auxiliary library */
void display(void)
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix ();
    glRotatef (20.0, 1.0, 0.0, 0.0);

    glPushMatrix ();
    glTranslatef (-0.75, -0.5, 0.0);
    glRotatef (270.0, 1.0, 0.0, 0.0);
    auxWireCone (1.0, 2.0);
    glPopMatrix ();

    glPushMatrix ();
    glTranslatef (-0.75, 0.5, 0.0);
    glRotatef (90.0, 1.0, 0.0, 0.0);
    auxWireTorus (0.275, 0.85);
    glPopMatrix ();

    glPopMatrix ();
    glFlush();
}

/* This sets the perspective, and is called once initially and then whenever the window
is resized. */
void myReshape(long w, long h)
{
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if (w <= h)
        glOrtho (-2.5, 2.5, -2.5*(GLfloat)h/(GLfloat)w,
            2.5*(GLfloat)h/(GLfloat)w, -10.0, 10.0);
    else
        glOrtho (-2.5*(GLfloat)w/(GLfloat)h,
            2.5*(GLfloat)w/(GLfloat)h, -2.5, 2.5, -10.0, 10.0);
    glMatrixMode(GL_MODELVIEW);
}

/*  Main Loop
 */
int main(int argc, char** argv)
{
    auxInitDisplayMode (AUX_SINGLE | AUX_RGB | AUX_DEPTH);
    auxInitPosition (0, 0, 500, 500);
    auxInitWindow (argv[0]);
    myinit();
    auxReshapeFunc (/*(AUXRESHAPEPROC)*/ myReshape); /* Note the explicit type-casting */
    auxMainLoop(/*(AUXMAINPROC)*/ display);
    return 1;
}