//
//  glgrav - OpenGL N-Body gravity simulator
//
//  Copyright (C) 2003  Ian Cowburn (ianc@noddybox.demon.co.uk)
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
//  -------------------------------------------------------------------------
//
//  Mass
//
static const char id[]="$Id$";

#include "mass.h"


// ---------------------------------------- CONSTRUCT/DESTRUCT/ASSIGN
//
Mass::Mass()
{
    m_name="";

    m_massless=false;
    m_mass=1.0;
    m_scale=1.0;
    calcSize();

    m_x=0.0;
    m_y=0.0;
    m_z=0.0;

    m_r=1.0;
    m_g=1.0;
    m_b=1.0;

    m_shield=0;

    m_textured=false;
    m_texture_id=0;

    m_ring=false;
    m_ring_textured=false;
    m_ring_id=0;
    m_rr=0.0;
    m_rg=0.0;
    m_rb=0.0;
    m_ring_alpha=1.0;

    m_prevx=m_x;
    m_prevy=m_y;
    m_prevz=m_z;
}


Mass::Mass(const string& name, double mass, double scale,
	   double posx, double posy, double posz,
	   double dx, double dy, double dz,
	   GLfloat r, GLfloat g, GLfloat b, double rot, int shield)
	   	: m_delta(dx, dy, dz)
{
    m_name=name;

    m_mass=mass;
    m_scale=scale;
    calcSize();

    m_x=posx;
    m_y=posy;
    m_z=posz;

    m_r=r;
    m_g=g;
    m_b=b;

    m_rot=rot;
    m_ang=0;

    m_shield=shield;

    if (m_mass<=0.0)
    {
	m_mass=0.0001;
	m_massless=true;
    }
    else
    {
	m_massless=false;
    }

    m_ring=false;
    m_ring_textured=false;
    m_ring_id=0;
    m_rr=0.0;
    m_rg=0.0;
    m_rb=0.0;
    m_ring_alpha=1.0;

    m_prevx=m_x;
    m_prevy=m_y;
    m_prevz=m_z;
}


Mass::~Mass()
{
}


// ---------------------------------------- PUBLIC MEMBERS
//
void Mass::setRing(double from, double to, 
		   GLfloat r, GLfloat g, GLfloat b, GLfloat alpha,
		   double rot, double ang)
{
    m_ring=true;
    m_ring_from=from;
    m_ring_to=to;
    m_rr=r;
    m_rg=g;
    m_rb=b;
    m_ring_alpha=alpha;
    m_ring_rot=rot;
    m_ring_tilt=ang;
    m_ring_ang=0.0;
}


void Mass::setTexture(GLuint id)
{
    m_textured=true;
    m_texture_id=id;
}


bool Mass::getTexture(GLuint& id) const
{
    id=m_texture_id;
    return m_textured;
}


void Mass::setRingTexture(GLuint id)
{
    if (m_ring)
    {
	m_ring_textured=true;
	m_ring_id=id;
    }
}


bool Mass::getRingTexture(GLuint& id) const
{
    id=m_ring_id;
    return m_ring_textured;
}


string Mass::getName() const
{
    return m_name;
}


double Mass::getMass() const
{
    return m_mass;
}


double Mass::getSize() const
{
    return m_size;
}


bool Mass::isMassless() const
{
    return m_massless;
}


void Mass::getPosition(double& x, double& y, double& z) const
{
    x=m_x;
    y=m_y;
    z=m_z;
}


void Mass::getPreviousPosition(double& x, double& y, double& z) const
{
    x=m_prevx;
    y=m_prevy;
    z=m_prevz;
}


void Mass::getDelta(double& dx, double& dy, double& dz) const
{
    dx = m_delta.dx();
    dy = m_delta.dy();
    dz = m_delta.dz();
}


void Mass::getColour(GLfloat& r, GLfloat& g, GLfloat& b) const
{
    r=m_r;
    g=m_g;
    b=m_b;
}


void Mass::reset(double mass, double dx, double dy, double dz)
{
    m_mass=mass;
    calcSize();

    m_delta.Set(dx, dy, dz);

    if (m_mass<=0.0)
    {
	m_mass=0.0001;
	m_massless=true;
    }
    else
    {
	m_massless=false;
    }
}


void Mass::reset(double mass)
{
    m_mass=mass;
    calcSize();

    if (m_mass<=0.0)
    {
	m_mass=0.0001;
	m_massless=true;
    }
    else
    {
	m_massless=false;
    }
}


bool Mass::calcAttraction(Mass& m, double gr_const)
{
    bool collide;
    double dist;
    double ga;
    double dx,dy,dz;

    if (m.m_massless)
    {
	return false;
    }

    dist=calcDistance2(m,dx,dy,dz);

    if (dist==0.0)
    {
	return !m_massless;
    }

    if (dist<(m_size + m.m_size) && (m_shield==0 || m.m_shield==0))
    {
	collide=true;
    }
    else
    {
	collide=false;
    }

    ga = gr_const * (m.m_mass / (dist * dist));

    Vec3D force(dx, dy, dz);

    force.SetLength(ga);

    m_delta.Add(force);

    return collide && !m_massless;
}


void Mass::move()
{
    m_prevx=m_x;
    m_prevy=m_y;
    m_prevz=m_z;

    m_x+=m_delta.dx();
    m_y+=m_delta.dy();
    m_z+=m_delta.dz();

    m_ang+=m_rot;
    m_ring_ang+=m_ring_rot;

    if (m_shield)
    {
	m_shield--;
    }
}


void Mass::draw(bool solid, bool texture, Mass::DrawItem item) const
{
    const GLint sp=32;
    GLUquadric *q;

    if (m_massless && item==eMass)
    {
	GLboolean l=glIsEnabled(GL_LIGHTING);

	glDisable(GL_LIGHTING);
	glBegin(GL_POINTS);
	glColor4f(m_r,m_g,m_b,1.0f);
	glVertex3d(m_x,m_y,m_z);
	glEnd();

	if (l)
	{
	    glEnable(GL_LIGHTING);
	}
    }
    else
    {
	// Render the object
	//
	if (item==eMass && (q=gluNewQuadric()))
	{
	    glColor4f(m_r,m_g,m_b,1.0f);
	    glTranslated(m_x,m_y,m_z);

	    if (!solid)
	    {
		gluQuadricDrawStyle(q,GLU_LINE);
	    }

	    gluQuadricNormals(q,GLU_SMOOTH);

	    if (m_textured && texture && solid)
	    {
		glEnable(GL_TEXTURE_2D);
		glBindTexture(GL_TEXTURE_2D,m_texture_id);
		gluQuadricTexture(q,1);
	    }
	    else
	    {
		glDisable(GL_TEXTURE_2D);
	    }

	    if (m_ang!=0.0)
	    {
		glRotated(m_ang,0.0,1.0,0.0);
	    }

	    glRotated(90.0,1.0,0.0,0.0);
	    gluSphere(q,m_size,sp,sp);

	    gluDeleteQuadric(q);
	}

	// Render the ring (if present)
	//
	if (m_ring && item==eRing && (q=gluNewQuadric()))
	{
	    glColor4f(m_rr,m_rg,m_rb,m_ring_alpha);
	    glTranslated(m_x,m_y,m_z);

	    if (!solid)
	    {
		gluQuadricDrawStyle(q,GLU_LINE);
	    }

	    gluQuadricNormals(q,GLU_SMOOTH);

	    if (m_ring_textured && texture && solid)
	    {
		glEnable(GL_TEXTURE_2D);
		glBindTexture(GL_TEXTURE_2D,m_ring_id);
		gluQuadricTexture(q,1);
	    }
	    else
	    {
		glDisable(GL_TEXTURE_2D);
	    }

	    glRotated(m_ring_tilt,1.0,0.0,0.0);

	    if (m_ring_ang!=0.0)
	    {
		glRotated(-m_ring_ang,0.0,0.0,1.0);
	    }

	    gluDisk(q,m_size*m_ring_from,m_size*m_ring_to,sp,1);

	    glRotated(180.0,1.0,0.0,0.0);

	    glRotated(180.0,0.0,0.0,1.0);

	    gluDisk(q,m_size*m_ring_from,m_size*m_ring_to,sp,1);

	    gluDeleteQuadric(q);
	}
    }
}


// ---------------------------------------- PRIVATE MEMBERS
//
double Mass::calcDistance2(Mass& m, double& dx, double& dy, double& dz)
{
    dx = m.m_x-m_x;
    dy = m.m_y-m_y;
    dz = m.m_z-m_z;

    return sqrt((dx*dx)+(dy*dy)+(dz*dz));
}


void Mass::calcSize()
{
    m_size=m_mass*(3.0/4.0)*(1.0/M_PI);
    m_size=pow(m_size,0.333333333333333333333)*m_scale;

    if (m_size<1.0)
    {
	m_size=1.0;
    }
}


// ---------------------------------------- OTHER FUNCTIONS
//
ostream& operator<<(ostream& os, const Mass& m)
{
    os << "Name " << m.m_name << "  (mass " << m.m_mass
	<< ", size " << m.m_size << ", shield " << m.m_shield << ")"  << endl
	<< "    P (" << m.m_x << ", " << m.m_y << ", " << m.m_z << ")" << endl
	<< "    D (" << m.m_delta.dx() << ", " << m.m_delta.dy()
		     << ", " << m.m_delta.dz() << ")" << endl
	<< "    R (" << m.m_rot << ", " << m.m_ang << ")" << endl
	<< "    T (" << m.m_textured << ", " << m.m_texture_id << ")" << endl
	<< " Ring (" << m.m_ring << ", " << m.m_ring_from 
	<< ", " << m.m_ring_to << ")" << endl;

    return os;
}


bool findMass(vector<Mass>& m, const string& name, Mass& ret)
{
    vector<Mass>::const_iterator i;

    for(i=m.begin();i!=m.end();i++)
    {
	if (i->getName()==name)
	{
	    ret=*i;
	    return true;
	}
    }

    return false;
}

bool findMass(vector<Mass>& m, const string& name, vector<Mass>::size_type& i)
{
    for(i=0;i<m.size();i++)
    {
	if (m[i].getName()==name)
	{
	    return true;
	}
    }

    return false;
}

// END OF FILE //