#include <stdlib.h>
#include <time.h>
#include <math.h>
#include <sys/types.h>
#include <unistd.h>

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

#include "Starfield.h"

Starfield::Starfield(GnomeScreensaver & gs)
{
    uint64_t ticks = gs.getTicks();
    m_last_ticks = ticks;
    srand(time(NULL) + getpid());
    for (int i = 0; i < NUM_STARS; i++)
        newStar(i, ticks);
}

Starfield::~Starfield()
{
}

bool Starfield::expose (GnomeScreensaver & gs)
{
    uint64_t ticks = gs.getTicks();

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glViewport(0, 0, gs.getWidth(), gs.getHeight());

    glPushMatrix();
    glTranslatef(0, 0, -30);
    m_logobox.draw();
    glPopMatrix();

    m_last_ticks = gs.getTicks();

    return true;
}

bool Starfield::configure (GnomeScreensaver & gs)
{
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(60.0, gs.getAspectRatio(), 0.01, MAX_STAR_DIST);

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

    return true;
}

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

void Starfield::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);
}

void Starfield::newStar(int idx, uint64_t ticks)
{
    m_stars[idx].create_time = ticks;
    getRandomAxis(&m_stars[idx].axis);
}