source: orxonox.OLD/branches/terrain.old/src/lib/graphics/importer/terrain/terrain.h

/*
        orxonox - the future of 3D-vertical-scrollers
 
        Copyright (C) 2006 orx
 
        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, or (at your option)
        any later version.
 
        ### File Specific:
        main programmer: Marco Biasini

 */

#ifndef _TERRAIN_H
#define _TERRAIN_H

#define USE_VBO
#ifdef USE_VBO
#include "buffer_broker.h"
#endif

#include "vector.h"
#include "terrain_page.h"
#include "terrain_quad.h"
#include <cstdlib>
#include <string>
#include <vector>
#include "texture.h"
#include "frustum.h"

class Texture;
class Terrain;
typedef Terrain *pTerrain;
        
class Terrain {
        public:
                const static unsigned int PAGE_SIZE             = 17;
                const static unsigned int MAX_VERTICES          = PAGE_SIZE*PAGE_SIZE;
                const static unsigned int MAX_INDICES           = 2*( PAGE_SIZE*PAGE_SIZE + PAGE_SIZE -2 );
                /**
                 * The amount of geometry rendered is largely depending on this constant. So chose a
                 * reasonable value...
                 */
                inline float getDetail() { return 0.02f; }

        
                inline bool debug()
                {
                        return false;
                }
                
                inline pTerrainPage getActiveList() { return activePages; }

        
                inline void setCameraPosition( const Vector& _cameraPosition ) 
                { 
                        cameraPosition = _cameraPosition; 
                }
                
                inline const Vector& getCameraPosition() const
                {
                        return cameraPosition;
                }
        
                void getAltitude( Vector& _alt, Vector& _normal );
                
                inline void setLightmap( Texture *_lightmap )
                {
                        lightmap = _lightmap;
                }
                //What a bad name: Need to rename that :(
                void addLevelFourPage( int _numVertices, Vertex *_vertices, 
                        int _numIndices, unsigned short *_indices );
                void showPages( int _x0, int _z0, int _width, int _height );
                                        
                /**
                 * Create a new terrain.
                 */
                Terrain( )
                { 
                        pageSize = 17;
                        pagesX = pagesZ = 0;
                        lightmap = NULL;
                        heightmapSource = "";
                        root = NULL;
                        current = 0;
                        activePages = NULL;
                        scale  = Vector( 1.0f, 3.0f, 1.0f );
                        frustum = new Frustum();
                        activatedCount = deactivatedCount = 0;
                        vertices = new Vertex[MAX_VERTICES];
                        indices = new unsigned short[MAX_INDICES];
#ifdef USE_VBO
                        broker = new BufferBroker( 300, MAX_VERTICES*sizeof( Vertex ), 
                                MAX_INDICES*sizeof( short ) );
#endif                  
                }
                
                ~Terrain( ) 
                {
                        //The pages are deleted through the SAVE_DELETE( root ) call.
                        SAVE_DELETE_ARRAY( pages );
                        SAVE_DELETE_ARRAY( vertices );
                        SAVE_DELETE_ARRAY( indices );
                        SAVE_DELETE( lightmap );
                        SAVE_DELETE( root );
#ifdef USE_VBO
                        SAVE_DELETE( broker );
#endif                  
                }
                /**
                 * Draws the terrain.
                 */
                void draw( );

                void setPageSize( const Vector& _page ) { }
                
                void build();
                void tick( float _dt );
                inline void setActiveList( pTerrainPage _page )
                {
                        activePages = _page;
                }
                inline pFrustum getViewingFrustum()
                {
                        return frustum;
                }
                
                /**
                 * Returns the normalized ( range from [0..1] ) altitude from the heightmap for the given 
                 * coordinates.
                 */
                inline float getAltitude( int _x, int _z ) const;
                
                inline void addMaterialLayer( LayerInfo *_layer )
                { layers.push_back( _layer ); }
                
                inline void setHeightmap( const std::string &_heightmap ) 
                { 
                        heightmapSource = _heightmap; 
                }
                
                inline void setPageSize( int _pageSize )
                {
                        pageSize = _pageSize;
                }
                
                inline const Vector getScale() const { return scale; }
                
                inline int getPageSize() const 
                {
                        return pageSize;
                }
                
                inline void getCoord( int _x, int _z, TexCoord& _coord) const
                {
                        _coord.u = ( ( float )_x )/( heightfield.width-1 );
                        _coord.v = ( ( float )_z )/( heightfield.height-1 );                    
                }
                
                inline void setScale( const Vector& _scale )
                { scale = _scale; }
#ifdef USE_VBO
                inline pBufferBroker getBufferBroker() { return broker; }
#endif          
                inline TerrainPage *getPage( int _x, int _z )
                {
                        return pages[pagesX*_z+_x];
                }
        protected:
                        
                /**
                 * convenience method to create a new terrain page at position offset
                 * p = ( _xOffset, _zOffset ). 
                 */
                pTerrainPage createPage( int _xOffset, int _zOffset ) const;                            
                
                /**
                 * Creates the quad tree structure for fast culling of the terrain pages.
                 */             
                pTerrainQuad createQuadTree( int _x0, int _z0, 
                        int _x1, int _z1, int _depth = 0 );
                
                /**
                 * Walks the quad tree to determine which pages are visible, e.g. are in the viewing
                 * frustum of the camera.
                 */
                void determineVisiblePages( pTerrainQuad _node );                       
                void determineLayerVisibility( int _layer );                    
                
#ifdef USE_VBO
                pBufferBroker                           broker;
#endif
                pTerrainQuad                            root;           // The quad-tree root node.
                pTerrainPage                            *pages;         // the references to all pages
                std::string                                     heightmapSource;
                Texture                                         *lightmap;
                Heightfield                                     heightfield;
                Vector                                          scale;
                int                                             pagesX, 
                                                                        pagesZ;
                int                                                     pageSize;       
                int                                                     cullCount;
                
                int                                                     activatedCount, 
                                                                        deactivatedCount; // For debugging and statistics
                                                                
                //The next five members are for the level 4 pages.                                              
                Vertex                                          *vertices;                                              
                unsigned short                          *indices;
                int                                                     current;
                                                                        
                std::vector<BufferInfo>         buffers;                        
                        
                Vector                                          cameraPosition;
                pFrustum                                        frustum;
                pTerrainPage                            activePages;
                std::vector<LayerInfo*>         layers;
};

inline float Terrain::getAltitude( int _x, int _z ) const
{
        assert( heightfield.data );
        if ( _x < 0 || _x >= heightfield.width || _z < 0 || _z >= heightfield.height ) {
                return 0.0f;
                printf( "outside!\n" );
        }       
        return heightfield.data[heightfield.pitch*_z+_x]/255.0f;        
}

#endif