#include <stdlib.h>
#include <time.h>
#include <math.h>

#include <GL/gl.h>
#include <GL/glu.h>

#include "Spin.h"

Spin::Spin()
{
    m_num_monitors = 1;
    m_monitor_info = new monitor_info_t[m_num_monitors];
    m_last_ticks = 0;
    srand(time(NULL));
    initMonitorInfo();
}

Spin::~Spin()
{
    delete[] m_monitor_info;
}

bool Spin::expose (GnomeScreensaver & gs)
{
    if (m_last_ticks == 0)
        m_last_ticks = gs.getTicks();
    else for (int i = 0; i < m_num_monitors; i++)
    {
        if (gs.getTicks() - m_monitor_info[i].last_switch_ticks
                > m_monitor_info[i].switch_time)
        {
            getRandomAxis(&m_monitor_info[i].axis);
            m_monitor_info[i].switch_time = getRandomSwitchTime();
            m_monitor_info[i].last_switch_ticks = gs.getTicks();
        }
    }

    int width = gs.getWidth() / m_num_monitors;
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    for (int monitor_num = 0; monitor_num < m_num_monitors; monitor_num++)
    {
        glViewport(width * monitor_num, 0, width, gs.getHeight());

        glLoadMatrixf(&m_monitor_info[monitor_num].rotation[0]);

        glRotatef((gs.getTicks() - m_last_ticks) / 1000.0 * 360.0 / 4.0,
                m_monitor_info[monitor_num].axis[0],
                m_monitor_info[monitor_num].axis[1],
                m_monitor_info[monitor_num].axis[2]);
        glGetFloatv(GL_MODELVIEW_MATRIX,
                &m_monitor_info[monitor_num].rotation[0]);

        m_logobox.draw();
    }
    m_last_ticks = gs.getTicks();

    return true;
}

bool Spin::configure (GnomeScreensaver & gs)
{
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(60.0, gs.getAspectRatio() / gs.getNumMonitors(),
            0.01, 1000.0);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluLookAt(0, 0, 10, 0, 0, 0, 0, 1, 0);

    m_num_monitors = gs.getNumMonitors();
    delete[] m_monitor_info;
    m_monitor_info = new monitor_info_t[m_num_monitors];
    initMonitorInfo();

    return true;
}

bool Spin::update (GnomeScreensaver & gs)
{
    return true;
}

void Spin::initMonitorInfo()
{
    for (int i = 0; i < m_num_monitors; i++)
    {
        getRandomAxis(&m_monitor_info[i].axis);
        glGetFloatv(GL_MODELVIEW_MATRIX, &m_monitor_info[i].rotation[0]);
        m_monitor_info[i].switch_time = getRandomSwitchTime();
        m_monitor_info[i].last_switch_ticks = 0;
    }
}

void Spin::getRandomAxis(float (*axis)[3])
{
    double alpha = rand() / (double)RAND_MAX * 2.0 * M_PI;
    double beta = rand() / (double)RAND_MAX * M_PI;
    (*axis)[0] = cos(alpha) * sin(beta);
    (*axis)[1] = sin(alpha) * sin(beta);
    (*axis)[2] = cos(beta);
}

uint32_t Spin::getRandomSwitchTime()
{
    return 2000u + (uint32_t) (rand() / (double)RAND_MAX * 3000.0);
}