source: GTP/trunk/App/Demos/Geom/OgreStuff/include/opt/OgreTerrainRenderable.h @ 1812

Revision 1812, 13.7 KB checked in by gumbau, 18 years ago (diff)
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1/*
2-----------------------------------------------------------------------------
3This source file is part of OGRE
4(Object-oriented Graphics Rendering Engine)
5For the latest info, see http://www.ogre3d.org/
6
7Copyright (c) 2000-2005 The OGRE Team
8Also see acknowledgements in Readme.html
9
10This program is free software; you can redistribute it and/or modify it under
11the terms of the GNU Lesser General Public License as published by the Free Software
12Foundation; either version 2 of the License, or (at your option) any later
13version.
14
15This program is distributed in the hope that it will be useful, but WITHOUT
16ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
18
19You should have received a copy of the GNU Lesser General Public License along with
20this program; if not, write to the Free Software Foundation, Inc., 59 Temple
21Place - Suite 330, Boston, MA 02111-1307, USA, or go to
22http://www.gnu.org/copyleft/lesser.txt.
23-----------------------------------------------------------------------------
24*/
25/***************************************************************************
26terrainrenderable.h  -  description
27-------------------
28begin                : Sat Oct 5 2002
29copyright            : (C) 2002 by Jon Anderson
30email                : janders@users.sf.net
31
32Enhancements 2003 - 2004 (C) The OGRE Team
33
34***************************************************************************/
35
36#ifndef TERRAINRENDERABLE_H
37#define TERRAINRENDERABLE_H
38
39#include "OgreTerrainPrerequisites.h"
40#include <OgreRenderable.h>
41#include <OgreMovableObject.h>
42#include <OgreAxisAlignedBox.h>
43#include <OgreString.h>
44#include <OgreHardwareBufferManager.h>
45
46#include <vector>
47
48#define MORPH_CUSTOM_PARAM_ID 77
49
50namespace Ogre
51{
52
53    typedef std::map <unsigned int, IndexData* > IndexMap;
54    typedef std::vector < IndexData* > IndexArray;
55    typedef std::vector < IndexMap* > LevelArray;
56
57    /**
58    * A cache of TerrainIndexBuffers.  Used to keep track of the buffers, and
59    * delete them when the program finishes.
60    */
61    class TerrainBufferCache
62    {
63    public:
64        void shutdown(void)
65        {
66            for( size_t i=0; i<mCache.size(); i++ )
67            {
68                delete mCache[i];
69            }
70            mCache.clear();
71        }
72        ~TerrainBufferCache()
73        {
74            shutdown();
75        }
76
77        IndexArray mCache;
78    };
79
80    inline Real _max( Real x, Real y )
81    {
82        return ( x > y ) ? x : y;
83    }
84
85    /** A simple class for encapsulating parameters which are commonly needed by
86    both TerrainSceneManager and TerrainRenderable.
87    */
88    class TerrainOptions
89    {
90    public:
91        TerrainOptions()
92        {
93            pageSize = 0;
94            tileSize = 0;
95            tilesPerPage = 0;
96            maxGeoMipMapLevel = 0;
97            scale = Vector3::UNIT_SCALE;
98            maxPixelError = 4;
99            detailTile = 1;
100            lit = false;
101            coloured = false;
102            lodMorph = false;
103            lodMorphStart = 0.5;
104            useTriStrips = false;
105            primaryCamera = 0;
106            terrainMaterial.setNull();
107        };
108        /// The size of one edge of a terrain page, in vertices
109        size_t pageSize;
110        /// The size of one edge of a terrain tile, in vertices
111        size_t tileSize;
112        /// Precalculated number of tiles per page
113        size_t tilesPerPage;
114        /// The primary camera, used for error metric calculation and page choice
115        const Camera* primaryCamera;
116        /// The maximum terrain geo-mipmap level
117        size_t maxGeoMipMapLevel;
118        /// The scale factor to apply to the terrain (each vertex is 1 unscaled unit
119        /// away from the next, and height is from 0 to 1)
120        Vector3 scale;
121        /// The maximum pixel error allowed
122        size_t maxPixelError;
123        /// Whether we should use triangle strips
124        bool useTriStrips;
125        /// The number of times to repeat a detail texture over a tile
126        size_t detailTile;
127        /// Whether LOD morphing is enabled
128        bool lodMorph;
129        /// At what point (parametric) should LOD morphing start
130        Real lodMorphStart;
131        /// Whether dynamic lighting is enabled
132        bool lit;
133        /// Whether vertex colours are enabled
134        bool coloured;
135        /// Pointer to the material to use to render the terrain
136        MaterialPtr terrainMaterial;
137
138    };
139
140#define STITCH_NORTH_SHIFT 0
141#define STITCH_SOUTH_SHIFT 8
142#define STITCH_WEST_SHIFT  16
143#define STITCH_EAST_SHIFT  24
144
145#define STITCH_NORTH  128 << STITCH_NORTH_SHIFT
146#define STITCH_SOUTH  128 << STITCH_SOUTH_SHIFT
147#define STITCH_WEST   128 << STITCH_WEST_SHIFT
148#define STITCH_EAST   128 << STITCH_EAST_SHIFT
149
150    /**
151    Represents a terrain tile.
152    @remarks
153    A TerrainRenderable represents a tile used to render a block of terrain using the geomipmap approach
154    for LOD.
155    *@author Jon Anderson
156    */
157
158    class _OgreTerrainExport TerrainRenderable : public Renderable, public MovableObject
159    {
160    public:
161
162        TerrainRenderable(const String& name, TerrainSceneManager* tsm);
163        ~TerrainRenderable();
164
165        void deleteGeometry();
166
167        enum Neighbor
168        {
169            NORTH = 0,
170            SOUTH = 1,
171            EAST = 2,
172            WEST = 3,
173            HERE = 4
174        };
175
176        /** Initializes the TerrainRenderable.
177        @param startx, startz
178        The starting points of the top-left of this tile, in terms of the
179        number of vertices.
180        @param pageHeightData The source height data for the entire parent page
181        */
182        void initialise(int startx, int startz, Real* pageHeightData);
183
184        //movable object methods
185
186        /** Returns the type of the movable. */
187        virtual const String& getMovableType( void ) const
188        {
189            return mType;
190        };
191
192        /** Returns the bounding box of this TerrainRenderable */
193        const AxisAlignedBox& getBoundingBox( void ) const
194        {
195            return mBounds;
196        };
197
198        /** Updates the level of detail to be used for rendering this TerrainRenderable based on the passed in Camera */
199        virtual void _notifyCurrentCamera( Camera* cam );
200
201        virtual void _updateRenderQueue( RenderQueue* queue );
202
203        /**
204        Constructs a RenderOperation to render the TerrainRenderable.
205        @remarks
206        Each TerrainRenderable has a block of vertices that represent the terrain.  Index arrays are dynamically
207        created for mipmap level, and then cached.
208        */
209        virtual void getRenderOperation( RenderOperation& rend );
210
211        virtual const MaterialPtr& getMaterial( void ) const
212        {
213            return mMaterial;
214        };
215
216        virtual void getWorldTransforms( Matrix4* xform ) const;
217
218        virtual const Quaternion& getWorldOrientation(void) const;
219        virtual const Vector3& getWorldPosition(void) const;
220
221        /** Returns the mipmap level that will be rendered for this frame. */
222        inline int getRenderLevel() const
223        {
224            return mRenderLevel;
225        };
226
227        /** Forces the LOD to the given level from this point on. */
228        inline void setForcedRenderLevel( int i )
229        {
230            mForcedRenderLevel = i;
231        }
232
233        /** Calculates the normal at the given location */
234        void _getNormalAt( float x, float y, Vector3 * result );
235
236        /** Returns the terrain height at the given coordinates */
237        float getHeightAt( float x, float y );
238
239        /** Intersects the segment witht he terrain tile
240        */
241        bool intersectSegment( const Vector3 & start, const Vector3 & end, Vector3 * result );
242
243        /** Sets the appropriate neighbor for this TerrainRenderable.  Neighbors are necessary
244        to know when to bridge between LODs.
245        */
246        void _setNeighbor( Neighbor n, TerrainRenderable *t )
247        {
248            mNeighbors[ n ] = t;
249        };
250
251        /** Returns the neighbor TerrainRenderable.
252        */
253        TerrainRenderable * _getNeighbor( Neighbor n )
254        {
255            return mNeighbors[ n ];
256        }
257
258
259        void setMaterial(const MaterialPtr& m )
260        {
261            mMaterial = m;
262        };
263
264        /** Calculates static normals for lighting the terrain. */
265        void _calculateNormals();
266
267
268
269
270        /** Generates terrain shadows and lighting using vertex colors
271        */
272        void _generateVertexLighting( const Vector3 &sunlight, ColourValue ambient );
273
274
275        /** Overridden, see Renderable */
276        Real getSquaredViewDepth(const Camera* cam) const;
277
278        /** Overridden from MovableObject */
279        Real getBoundingRadius(void) const { return mBoundingRadius; }
280
281        /** @copydoc Renderable::getLights */
282        const LightList& getLights(void) const;
283
284        /// Overridden from Renderable to allow the morph LOD entry to be set
285        void _updateCustomGpuParameter(
286            const GpuProgramParameters::AutoConstantEntry& constantEntry,
287            GpuProgramParameters* params) const;
288                /// @see MovableObject
289                uint32 getTypeFlags(void) const;
290    protected:
291                /// Parent SceneManager
292                TerrainSceneManager* mSceneManager;
293        /// Link to shared options
294        const TerrainOptions* mOptions;
295
296        /** Returns the index into the height array for the given coords. */
297        inline size_t _index( int x, int z ) const
298        {
299            return ( x + z * mOptions->tileSize );
300        };
301
302        /** Returns the  vertex coord for the given coordinates */
303        inline float _vertex( int x, int z, int n )
304        {
305            return mPositionBuffer[x * 3 + z * mOptions->tileSize * 3 + n];
306        };
307
308
309        inline int _numNeighbors() const
310        {
311            int n = 0;
312
313            for ( int i = 0; i < 4; i++ )
314            {
315                if ( mNeighbors[ i ] != 0 )
316                    n++;
317            }
318
319            return n;
320        }
321
322        inline bool _hasNeighborRenderLevel( int i ) const
323        {
324            for ( int j = 0; j < 4; j++ )
325            {
326                if ( mNeighbors[ j ] != 0 && mNeighbors[ j ] ->mRenderLevel == i )
327                    return true;
328            }
329
330            return false;
331
332        }
333
334        void _adjustRenderLevel( int i );
335
336        bool _checkSize( int n );
337
338        void _calculateMinLevelDist2( Real C );
339
340        Real _calculateCFactor();
341
342        VertexData* mTerrain;
343
344        /// The current LOD level
345        int mRenderLevel;
346        /// The previous 'next' LOD level down, for frame coherency
347        int mLastNextLevel;
348        /// The morph factor between this and the next LOD level down
349        Real mLODMorphFactor;
350        /// List of squared distances at which LODs change
351        Real *mMinLevelDistSqr;
352        /// Connection to tiles four neighbours
353        TerrainRenderable *mNeighbors [ 4 ];
354        /// Whether light list need to re-calculate
355        mutable bool mLightListDirty;
356        /// Cached light list
357        mutable LightList mLightList;
358        /// The bounding radius of this tile
359        Real mBoundingRadius;
360        /// Bounding box of this tile
361        AxisAlignedBox mBounds;
362        /// The center point of this tile
363        Vector3 mCenter;
364        /// The MovableObject type
365        static String mType;
366        /// Current material used by this tile
367        MaterialPtr mMaterial;   
368        /// Whether this tile has been initialised   
369        bool mInit;
370        /// The buffer with all the renderable geometry in it
371        HardwareVertexBufferSharedPtr mMainBuffer;
372        /// Optional set of delta buffers, used to morph from one LOD to the next
373        HardwareVertexBufferSharedPtr* mDeltaBuffers;
374        /// System-memory buffer with just positions in it, for CPU operations
375        float* mPositionBuffer;
376        /// Forced rendering LOD level, optional
377        int mForcedRenderLevel;
378        /// Array of LOD indexes specifying which LOD is the next one down
379        /// (deals with clustered error metrics which cause LODs to be skipped)
380        int mNextLevelDown[10];
381        /// Gets the index data for this tile based on current settings
382        IndexData* getIndexData(void);
383        /// Internal method for generating stripified terrain indexes
384        IndexData* generateTriStripIndexes(unsigned int stitchFlags);
385        /// Internal method for generating triangle list terrain indexes
386        IndexData* generateTriListIndexes(unsigned int stitchFlags);
387        /** Utility method to generate stitching indexes on the edge of a tile
388        @param neighbor The neighbor direction to stitch
389        @param hiLOD The LOD of this tile
390        @param loLOD The LOD of the neighbor
391        @param omitFirstTri Whether the first tri of the stitch (always clockwise
392        relative to the centre of this tile) is to be omitted because an
393        adjoining edge is also being stitched
394        @param omitLastTri Whether the last tri of the stitch (always clockwise
395        relative to the centre of this tile) is to be omitted because an
396        adjoining edge is also being stitched
397        @param pIdx Pointer to a pointer to the index buffer to push the results
398        into (this pointer will be updated)
399        @returns The number of indexes added
400        */
401        int stitchEdge(Neighbor neighbor, int hiLOD, int loLOD,
402            bool omitFirstTri, bool omitLastTri, unsigned short** ppIdx);
403
404        /// Create a blank delta buffer for usein morphing
405        HardwareVertexBufferSharedPtr createDeltaBuffer(void);
406
407    };
408
409}
410
411#endif
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