/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * This library 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 
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSGUTIL_SCENEGRAPHBUILDER
#define OSGUTIL_SCENEGRAPHBUILDER 1

#include <osg/Geode>
#include <osg/Geometry>
#include <osg/MatrixTransform>
#include <osg/GLU>

#include <osgUtil/Export>

#ifndef OSG_GLU_AVAILABLE
    // as we have no GLU we'll just define the required enum values
    #define GLU_FALSE           0
    #define GLU_FILL            100012
    #define GLU_SMOOTH          100000
    #define GLU_OUTSIDE         100020
    #define GLU_NONE            100002
    #define GLU_POINT           100010
    #define GLU_LINE            100011
    #define GLU_FILL            100012
    #define GLU_SILHOUETTE      100013
#endif

namespace osgUtil {

/** A class for assisting the building ascene graphs that is equivilant to OpenGL 1.0 style calls.
  */
class OSGUTIL_EXPORT SceneGraphBuilder
{
    public:

        SceneGraphBuilder();

        // 
        //  OpenGL 1.0 style building methods
        //
        void PushMatrix();
        void PopMatrix();
        void LoadIdentity();
        void LoadMatrixd(const GLdouble* m);
        void MultMatrixd(const GLdouble* m);
        void Translated(GLdouble x, GLdouble y, GLdouble z);
        void Scaled(GLdouble x, GLdouble y, GLdouble z);
        void Rotated(GLdouble angle, GLdouble x, GLdouble y, GLdouble z);
        
        void BlendFunc(GLenum srcFactor, GLenum dstFactor);
        void CullFace(GLenum mode);
        void DepthFunc(GLenum mode);
        void FrontFace(GLenum mode);
        void LineStipple(GLint factor, GLushort pattern);
        void LineWidth(GLfloat lineWidth);
        void PointSize(GLfloat pointSize);
        void PolygonMode(GLenum face, GLenum mode);
        void PolygonOffset(GLfloat factor, GLfloat units);
        void PolygonStipple(const GLubyte* mask);
        void ShadeModel(GLenum mode);
        
        void Enable(GLenum mode);
        void Disable(GLenum mode);
        
        void Color4f(GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha);
        void Color4fv(GLfloat* c) { Color4f(c[0], c[1], c[2], c[3]); }

        void Vertex3f(GLfloat x, GLfloat y, GLfloat z);
        void Vertex3fv(GLfloat* v) { Vertex3f(v[0], v[1], v[2]); }

        void Normal3f(GLfloat x, GLfloat y, GLfloat z);
        void Normal3fv(GLfloat* n) { Normal3f(n[0], n[1], n[2]); }

        void TexCoord1f(GLfloat x);
        void TexCoord1fv(GLfloat* tc) { TexCoord1f(tc[0]); }

        void TexCoord2f(GLfloat x, GLfloat y);
        void TexCoord2fv(GLfloat* tc) { TexCoord2f(tc[0],tc[1]); }

        void TexCoord3f(GLfloat x, GLfloat y, GLfloat z);
        void TexCoord3fv(GLfloat* tc) { TexCoord3f(tc[0], tc[1], tc[2]); }

        void TexCoord4f(GLfloat x, GLfloat y, GLfloat z, GLfloat w);
        void TexCoord4fv(GLfloat* tc) { TexCoord4f(tc[0], tc[1], tc[2], tc[3]); }

        void Begin(GLenum mode);
        void End();

        //
        // glu style building methods
        //
        void QuadricDrawStyle(GLenum aDrawStyle);
        void QuadricNormals(GLenum aNormals);
        void QuadricOrientation(GLenum aOrientation);
        void QuadricTexture(GLboolean aTexture);

        void Cylinder(GLfloat base,
                      GLfloat top,
                      GLfloat height,
                      GLint slices,
                      GLint stacks);

       void Disk(GLfloat inner,
                 GLfloat outer,
                 GLint slices,
                 GLint loops);

       void PartialDisk(GLfloat inner,
                        GLfloat outer,
                        GLint slices,
                        GLint loops,
                        GLfloat start,
                        GLfloat sweep);

       void Sphere(GLfloat radius,
                   GLint slices,
                   GLint stacks);


        //
        // methods for obtaining the built scene graph
        //
        osg::Node* getScene();
        osg::Node* takeScene();

    protected:
    
        typedef std::vector<osg::Matrixd> Matrices;

        void matrixChanged();
        void addAttribute(osg::StateAttribute* attribute);
        void addMode(GLenum mode, bool enabled);                
        void addTextureAttribute(unsigned int unit, osg::StateAttribute* attribute);
        void addTextureMode(unsigned int unit, GLenum mode, bool enabled);                
        void addShape(osg::Shape* shape);
        void addDrawable(osg::Drawable* drawable);
        void newGeometry();
        
        void allocateGeometry();
        void completeGeometry();
        
        void allocateStateSet();
        
        Matrices                            _matrixStack;
        osg::ref_ptr<osg::StateSet>         _stateset;
        bool                                _statesetAssigned;
        
        bool                                _normalSet;
        osg::Vec3f                          _normal;

        bool                                _colorSet;
        osg::Vec4f                          _color;

        unsigned int                        _maxNumTexCoordComponents;
        osg::Vec4f                          _texCoord;

        GLenum                              _primitiveMode;        
        osg::ref_ptr<osg::Vec3Array>        _vertices;
        osg::ref_ptr<osg::Vec3Array>        _normals;
        osg::ref_ptr<osg::Vec4Array>        _colors;
        osg::ref_ptr<osg::Vec4Array>        _texCoords;
    
        struct QuadricState
        {
            QuadricState():
                _drawStyle(GLU_FILL),
                _normals(GLU_SMOOTH),
                _orientation(GLU_OUTSIDE),
                _texture(GLU_FALSE) {}

            GLenum      _drawStyle;
            GLenum      _normals;
            GLenum      _orientation;
            GLboolean   _texture;
        };

        QuadricState _quadricState;


        osg::ref_ptr<osg::Geometry>         _geometry;
        osg::ref_ptr<osg::Geode>            _geode;
        osg::ref_ptr<osg::MatrixTransform>  _transform;
        osg::ref_ptr<osg::Group>            _group;
    
};


}

#endif