// SceneGraph.h
// NKU CSC 480/580 - Kirby
// ------------------------------------------------------------------
// A first attempt at a scene graph. Bare bones.
// 
// Node
//    TransformationNode
//    EnvironmentNode
//       LightNode
//    AppearanceNode
//       MaterialNode
//    ArtifactNode
//       GlutSphere
//       GlutTeapot
//       Mesh
//
// This version only has an implicitly recursive render() function.
// ------------------------------------------------------------------

#ifndef SCENEGRAPH_H
#define SCENEGRAPH_H

#include "Geometry.h"
#include <iostream>
using namespace std ;
using namespace csc480 ;



// Node
// ----


class Node
// A base class for all nodes. 
// Concrete: may be used as a group node.
{
public:
    Node() : _next( NULL ), _child( NULL ) {}
    virtual ~Node() {} 
 
    void addChild( Node* pc )   { pc->_next= _child ; _child= pc ; }

    virtual void render() const { renderChildren() ; }

    void renderChildren() const 
    {
        for ( const Node* p= _child ;  p  ; p= p->_next )
            p->render() ;
    }

private:
    Node *_child, *_next ;
} ;




// TransformationNode
// ------------------


class TransformationNode : public Node
// A node representing an arbitrary homogeneous transformation.
{
public:
    TransformationNode() ;
    void set( const Vector3& axis, double angle, double scale, const Vector3& trans ) ;
    void set( const double m[16] ) ;
    virtual void render() const ;

private:
    double _m[16] ; // OpenGL's column-major order
} ;




// EnvironmentNode
// ---------------


class EnvironmentNode : public Node 
{
public:
    EnvironmentNode() ;
} ;



// LightNode
// --------- 


class LightNode : public EnvironmentNode
{
public:
    LightNode() ;
    void setPosition( const Point3& pt, double w =0 ) ;
    void setAmbientColor( float r, float g, float b, float a =1 ) ;
    void setDiffuseColor( float r, float g, float b, float a =1 ) ;
    void lightsOn( bool on ) ;
    virtual void render() const ;
private:
    bool       _isOn ;
    int        _id ;             // OpenGL light id is (GL_LIGHT0 + _id)
    static int _lightCount ;     // # of lights created so far
} ;






// AppearanceNode
// -------------- 


class AppearanceNode : public Node 
{
public:
    AppearanceNode() ;
} ;



// MaterialNode
// ------------


class MaterialNode : public AppearanceNode
{
public:
    MaterialNode() ;
    void setColor( float r, float g, float b, float a =1 ) ;
    virtual void render() const ;

private:
    float _color[4] ;
} ;




// ArtifactNode
// ------------


class ArtifactNode : public Node 
{
public:
    ArtifactNode() ;
    virtual  const Point3&   getCenter() const = 0 ;
    virtual  const Vector3&  getUpVec() const  = 0 ;
    virtual  double          getRadius() const = 0 ;
    virtual  double          getBaseDepth() const  = 0 ;
} ;



// GlutSphere (immutable)
// ----------------------

class GlutSphere : public ArtifactNode
{
public:
    GlutSphere() ;
    virtual  const Point3&   getCenter() const ;
    virtual  const Vector3&  getUpVec() const ;
    virtual  double          getRadius() const ;
    virtual  double          getBaseDepth() const ;
    virtual  void render() const ;
private:
    const Point3   _center ;
    const Vector3  _upVec ;
    int            _id ; // display list ID
} ;


#endif