#include <stdlib.h>                 /* rand() */
#include <GL/gl.h>
#include <GL/glu.h>

#include <iostream>

#include <gdkmm/cursor.h>

#include "SierpinskiDA.h"

using namespace std;

SierpinskiDA::SierpinskiDA(const Glib::RefPtr<const Gdk::GL::Config> & config)
    : Gtk::GL::DrawingArea(config)
{
    set_gl_capability(config);
    set_events(Gdk::POINTER_MOTION_MASK
             | Gdk::BUTTON_PRESS_MASK
             | Gdk::BUTTON_RELEASE_MASK
             | Gdk::SCROLL_MASK);
}

void SierpinskiDA::regenerate(int npts)
{
#define deg2rad(x) ((x)/180.0*M_PI)
    const static float pts[][3] = {
        {0, 0, sqrt(1 + sin(deg2rad(60))*sin(deg2rad(60))+1.5*1.5)},
        {0, 1, 0},
        {sin(deg2rad(60)), -cos(deg2rad(60)), 0},
        {-sin(deg2rad(60)), -cos(deg2rad(60)), 0}
    };

    gl_begin();
    glNewList(m_dl, GL_COMPILE);
    glBegin(GL_POINTS);

    double pt[3];
    double r = rand() / RAND_MAX;
    for (int i = 0; i < 3; i++)
    {
        pt[i] = pts[0][i] + r * pts[1][i] - pts[0][i];
    }
    for (int i = 0; i < npts; i++)
    {
        glVertex3dv(pt);
        int pt_idx = rand() & 0x3;
        for (int j = 0; j < 3; j++)
        {
            pt[j] = (pt[j] + pts[pt_idx][j]) / 2.0;
        }
    }

    glEnd();
    glEndList();
    gl_end();
}

bool SierpinskiDA::gl_begin()
{
    Glib::RefPtr<Gdk::GL::Window> glwindow = get_gl_window();
    return glwindow->gl_begin(get_gl_context());
}

void SierpinskiDA::gl_end()
{
    Glib::RefPtr<Gdk::GL::Window> glwindow = get_gl_window();
    glwindow->gl_end();
}

bool SierpinskiDA::draw()
{
    if (!gl_begin())
        return false;

    glClearColor(0.0, 0.0, 0.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(60, get_width()/(double)get_height(), 0.01, 1000.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluLookAt(0, -3, 1,
              0, 0, 0.7,
              0, 0, 1);

    glCallList(m_dl);

    if (get_gl_window()->is_double_buffered())
        get_gl_window()->swap_buffers();
    else
        glFlush();

    gl_end();
    return true;
}

bool SierpinskiDA::on_motion_notify_event(GdkEventMotion * event)
{
    get_pointer(m_x, m_y);
    return true;
}

bool SierpinskiDA::on_button_press_event(GdkEventButton * event)
{
    return false;
}

bool SierpinskiDA::on_button_release_event(GdkEventButton * event)
{
    return false;
}

bool SierpinskiDA::on_scroll_event(GdkEventScroll * event)
{
    return false;
}

void SierpinskiDA::on_realize()
{
    Gtk::GL::DrawingArea::on_realize();

    if (!gl_begin())
        return;

    glViewport(0, 0, get_width(), get_height());
    m_dl = glGenLists(1);
//    glEnable(GL_LIGHTING);
//    glEnable(GL_LIGHT0);
//    float color[] = {1, 1, 1, 1};
//    glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, color);
    glColor3f(1, 1, 1);

    gl_end();

    regenerate(10);
}

/*
 * called on widget resizes
 */
bool SierpinskiDA::on_configure_event(GdkEventConfigure * event)
{
    if (!gl_begin())
        return false;

    glViewport(0, 0, get_width(), get_height());

    gl_end();

    return true;
}

bool SierpinskiDA::on_expose_event(GdkEventExpose * event)
{
    return draw();
}