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source: OGRE/trunk/ogre_changes/Ogre1.2/PlugIns/OctreeSceneManager/src/OgreTerrainRenderable.cpp @ 921

Revision 921, 55.8 KB checked in by mattausch, 18 years ago (diff)
added updates for visibility

Line
1	/*
2	-----------------------------------------------------------------------------
3	This source file is part of OGRE
4	(Object-oriented Graphics Rendering Engine)
5	For the latest info, see http://www.ogre3d.org/
6
7	Copyright (c) 2000-2005 The OGRE Team
8	Also see acknowledgements in Readme.html
9
10	This program is free software; you can redistribute it and/or modify it under
11	the terms of the GNU Lesser General Public License as published by the Free Software
12	Foundation; either version 2 of the License, or (at your option) any later
13	version.
14
15	This program is distributed in the hope that it will be useful, but WITHOUT
16	ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17	FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
18
19	You should have received a copy of the GNU Lesser General Public License along with
20	this program; if not, write to the Free Software Foundation, Inc., 59 Temple
21	Place - Suite 330, Boston, MA 02111-1307, USA, or go to
22	http://www.gnu.org/copyleft/lesser.txt.
23	-----------------------------------------------------------------------------
24	*/
25	/***************************************************************************
26	terrainrenderable.cpp - description
27	-------------------
28	begin : Sat Oct 5 2002
29	copyright : (C) 2002 by Jon Anderson
30	email : janders@users.sf.net
31
32	Enhancements 2003 - 2004 (C) The OGRE Team
33
34	***************************************************************************/
35
36	#include "OgreTerrainRenderable.h"
37	#include "OgreSceneNode.h"
38	#include "OgreRenderQueue.h"
39	#include "OgreRenderOperation.h"
40	#include "OgreCamera.h"
41	#include "OgreRoot.h"
42	#include "OgreTerrainSceneManager.h"
43	#include "OgreLogManager.h"
44	#include "OgreStringConverter.h"
45	#include "OgreViewport.h"
46	#include "OgreException.h"
47
48	namespace Ogre
49	{
50	//-----------------------------------------------------------------------
51	#define MAIN_BINDING 0
52	#define DELTA_BINDING 1
53	//-----------------------------------------------------------------------
54	//-----------------------------------------------------------------------
55	String TerrainRenderable::mType = "TerrainMipMap";
56	//-----------------------------------------------------------------------
57	//-----------------------------------------------------------------------
58	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
59	int TerrainRenderable::msCurrentRenderLevelIndex = 0;
60	#endif // GTP_VISIBILITY_MODIFIED_OGRE
61	//-----------------------------------------------------------------------
62	TerrainRenderable::TerrainRenderable(const String& name, TerrainSceneManager* tsm)
63	: Renderable(), MovableObject(name), mSceneManager(tsm), mTerrain(0), mDeltaBuffers(0), mPositionBuffer(0)
64	{
65	mForcedRenderLevel = -1;
66	mLastNextLevel = -1;
67
68	mMinLevelDistSqr = 0;
69
70	mInit = false;
71	mLightListDirty = true;
72	MovableObject::mCastShadows = false;
73
74	for ( int i = 0; i < 4; i++ )
75	{
76	mNeighbors[ i ] = 0;
77	}
78
79	mOptions = &(mSceneManager->getOptions());
80
81
82	}
83	//-----------------------------------------------------------------------
84	TerrainRenderable::~TerrainRenderable()
85	{
86
87	deleteGeometry();
88	}
89	//-----------------------------------------------------------------------
90	uint32 TerrainRenderable::getTypeFlags(void) const
91	{
92	// return world flag
93	return SceneManager::WORLD_GEOMETRY_TYPE_MASK;
94	}
95	//-----------------------------------------------------------------------
96	void TerrainRenderable::deleteGeometry()
97	{
98	if(mTerrain)
99	delete mTerrain;
100
101	if (mPositionBuffer)
102	delete [] mPositionBuffer;
103
104	if (mDeltaBuffers)
105	delete [] mDeltaBuffers;
106
107	if ( mMinLevelDistSqr != 0 )
108	delete [] mMinLevelDistSqr;
109	}
110	//-----------------------------------------------------------------------
111	void TerrainRenderable::initialise(int startx, int startz,
112	Real* pageHeightData)
113	{
114
115	if ( mOptions->maxGeoMipMapLevel != 0 )
116	{
117	int i = ( int ) 1 << ( mOptions->maxGeoMipMapLevel - 1 ) ;
118
119	if ( ( i + 1 ) > mOptions->tileSize )
120	{
121	printf( "Invalid maximum mipmap specifed, must be n, such that 2^(n-1)+1 < tileSize \n" );
122	return ;
123	}
124	}
125
126	deleteGeometry();
127
128	//calculate min and max heights;
129	Real min = 256000, max = 0;
130
131	mTerrain = new VertexData;
132	mTerrain->vertexStart = 0;
133	mTerrain->vertexCount = mOptions->tileSize * mOptions->tileSize;
134
135	VertexDeclaration* decl = mTerrain->vertexDeclaration;
136	VertexBufferBinding* bind = mTerrain->vertexBufferBinding;
137
138	// positions
139	size_t offset = 0;
140	decl->addElement(MAIN_BINDING, offset, VET_FLOAT3, VES_POSITION);
141	offset += VertexElement::getTypeSize(VET_FLOAT3);
142	if (mOptions->lit)
143	{
144	decl->addElement(MAIN_BINDING, offset, VET_FLOAT3, VES_NORMAL);
145	offset += VertexElement::getTypeSize(VET_FLOAT3);
146	}
147	// texture coord sets
148	decl->addElement(MAIN_BINDING, offset, VET_FLOAT2, VES_TEXTURE_COORDINATES, 0);
149	offset += VertexElement::getTypeSize(VET_FLOAT2);
150	decl->addElement(MAIN_BINDING, offset, VET_FLOAT2, VES_TEXTURE_COORDINATES, 1);
151	offset += VertexElement::getTypeSize(VET_FLOAT2);
152	if (mOptions->coloured)
153	{
154	decl->addElement(MAIN_BINDING, offset, VET_COLOUR, VES_DIFFUSE);
155	offset += VertexElement::getTypeSize(VET_COLOUR);
156	}
157
158	// Create shared vertex buffer
159	mMainBuffer =
160	HardwareBufferManager::getSingleton().createVertexBuffer(
161	decl->getVertexSize(MAIN_BINDING),
162	mTerrain->vertexCount,
163	HardwareBuffer::HBU_STATIC_WRITE_ONLY);
164	// Create system memory copy with just positions in it, for use in simple reads
165	mPositionBuffer = new float[mTerrain->vertexCount * 3];
166
167	bind->setBinding(MAIN_BINDING, mMainBuffer);
168
169	if (mOptions->lodMorph)
170	{
171	// Create additional element for delta
172	decl->addElement(DELTA_BINDING, 0, VET_FLOAT1, VES_BLEND_WEIGHTS);
173	// NB binding is not set here, it is set when deriving the LOD
174	}
175
176
177	mInit = true;
178
179	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
180	for (int i = 0; i < MAX_RENDERLEVEL_INDEX; ++i)
181	{
182	mRenderLevel[i] = 1;
183	}
184	#else
185	mRenderLevel = 1;
186	#endif // GTP_VISIBILITY_MODIFIED_OGRE
187
188	mMinLevelDistSqr = new Real[ mOptions->maxGeoMipMapLevel ];
189
190	int endx = startx + mOptions->tileSize;
191
192	int endz = startz + mOptions->tileSize;
193
194	Vector3 left, down, here;
195
196	const VertexElement* poselem = decl->findElementBySemantic(VES_POSITION);
197	const VertexElement* texelem0 = decl->findElementBySemantic(VES_TEXTURE_COORDINATES, 0);
198	const VertexElement* texelem1 = decl->findElementBySemantic(VES_TEXTURE_COORDINATES, 1);
199	float* pSysPos = mPositionBuffer;
200
201	unsigned char* pBase = static_cast<unsigned char*>(mMainBuffer->lock(HardwareBuffer::HBL_DISCARD));
202
203	for ( int j = startz; j < endz; j++ )
204	{
205	for ( int i = startx; i < endx; i++ )
206	{
207	float pPos, pTex0, *pTex1;
208	poselem->baseVertexPointerToElement(pBase, &pPos);
209	texelem0->baseVertexPointerToElement(pBase, &pTex0);
210	texelem1->baseVertexPointerToElement(pBase, &pTex1);
211
212	Real height = pageHeightData[j * mOptions->pageSize + i];
213	height = height * mOptions->scale.y; // scale height
214
215	pSysPos++ = pPos++ = ( float ) i * mOptions->scale.x; //x
216	pSysPos++ = pPos++ = height; // y
217	pSysPos++ = pPos++ = ( float ) j * mOptions->scale.z; //z
218
219	*pTex0++ = ( float ) i / ( float ) ( mOptions->pageSize - 1 );
220	*pTex0++ = ( float ) j / ( float ) ( mOptions->pageSize - 1 );
221
222	pTex1++ = ( ( float ) i / ( float ) ( mOptions->tileSize - 1 ) ) mOptions->detailTile;
223	pTex1++ = ( ( float ) j / ( float ) ( mOptions->tileSize - 1 ) ) mOptions->detailTile;
224
225	if ( height < min )
226	min = ( Real ) height;
227
228	if ( height > max )
229	max = ( Real ) height;
230
231	pBase += mMainBuffer->getVertexSize();
232	}
233	}
234
235	mMainBuffer->unlock();
236
237	mBounds.setExtents(
238	( Real ) startx * mOptions->scale.x,
239	min,
240	( Real ) startz * mOptions->scale.z,
241	( Real ) ( endx - 1 ) * mOptions->scale.x,
242	max,
243	( Real ) ( endz - 1 ) * mOptions->scale.z );
244
245
246	mCenter = Vector3( ( startx * mOptions->scale.x + (endx - 1) * mOptions->scale.x ) / 2,
247	( min + max ) / 2,
248	( startz * mOptions->scale.z + (endz - 1) * mOptions->scale.z ) / 2 );
249
250	mBoundingRadius =
251	std::max(max - min,
252	std::max((endx - 1 - startx) * mOptions->scale.x,
253	(endz - 1 - startz) * mOptions->scale.z)) / 2;
254
255	// Create delta buffer list if required to morph
256	if (mOptions->lodMorph)
257	{
258	// Create delta buffer for all except the lowest mip
259	mDeltaBuffers = new HardwareVertexBufferSharedPtr[mOptions->maxGeoMipMapLevel - 1];
260	}
261
262	Real C = _calculateCFactor();
263
264	_calculateMinLevelDist2( C );
265
266	}
267	//-----------------------------------------------------------------------
268	void TerrainRenderable::_getNormalAt( float x, float z, Vector3 * result )
269	{
270
271	assert(mOptions->lit && "No normals present");
272
273	Vector3 here, left, down;
274	here.x = x;
275	here.y = getHeightAt( x, z );
276	here.z = z;
277
278	left.x = x - 1;
279	left.y = getHeightAt( x - 1, z );
280	left.z = z;
281
282	down.x = x;
283	down.y = getHeightAt( x, z + 1 );
284	down.z = z + 1;
285
286	left = left - here;
287
288	down = down - here;
289
290	left.normalise();
291	down.normalise();
292
293	*result = left.crossProduct( down );
294	result -> normalise();
295
296	// result->x = - result->x;
297	// result->y = - result->y;
298	// result->z = - result->z;
299	}
300	//-----------------------------------------------------------------------
301	void TerrainRenderable::_calculateNormals()
302	{
303
304	Vector3 norm;
305
306	assert (mOptions->lit && "No normals present");
307
308	HardwareVertexBufferSharedPtr vbuf =
309	mTerrain->vertexBufferBinding->getBuffer(MAIN_BINDING);
310	const VertexElement* elem = mTerrain->vertexDeclaration->findElementBySemantic(VES_NORMAL);
311	unsigned char* pBase = static_cast<unsigned char*>( vbuf->lock(HardwareBuffer::HBL_DISCARD) );
312	float* pNorm;
313
314	for ( size_t j = 0; j < mOptions->tileSize; j++ )
315	{
316	for ( size_t i = 0; i < mOptions->tileSize; i++ )
317	{
318
319	_getNormalAt( _vertex( i, j, 0 ), _vertex( i, j, 2 ), &norm );
320
321	// printf( "Normal = %5f,%5f,%5f\n", norm.x, norm.y, norm.z );
322	elem->baseVertexPointerToElement(pBase, &pNorm);
323	*pNorm++ = norm.x;
324	*pNorm++ = norm.y;
325	*pNorm++ = norm.z;
326	pBase += vbuf->getVertexSize();
327	}
328
329	}
330	vbuf->unlock();
331	}
332	//-----------------------------------------------------------------------
333	void TerrainRenderable::_notifyCurrentCamera( Camera* cam )
334	{
335	MovableObject::_notifyCurrentCamera(cam);
336
337	if ( mForcedRenderLevel >= 0 )
338	{
339	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
340	mRenderLevel[msCurrentRenderLevelIndex] = mForcedRenderLevel;
341	#else
342	mRenderLevel = mForcedRenderLevel;
343	#endif // GTP_VISIBILITY_MODIFIED_OGRE
344	return ;
345	}
346
347
348	Vector3 cpos = cam -> getDerivedPosition();
349	const AxisAlignedBox& aabb = getWorldBoundingBox(true);
350	Vector3 diff(0, 0, 0);
351	diff.makeFloor(cpos - aabb.getMinimum());
352	diff.makeCeil(cpos - aabb.getMaximum());
353
354	Real L = diff.squaredLength();
355
356	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
357	mRenderLevel[msCurrentRenderLevelIndex] = -1;;
358	#else
359	mRenderLevel = -1;
360	#endif // GTP_VISIBILITY_MODIFIED_OGRE
361
362
363	for ( int i = 0; i < mOptions->maxGeoMipMapLevel; i++ )
364	{
365	if ( mMinLevelDistSqr[ i ] > L )
366	{
367	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
368	mRenderLevel[msCurrentRenderLevelIndex] = i - 1;
369	#else
370	mRenderLevel = i - 1;
371	#endif // GTP_VISIBILITY_MODIFIED_OGRE
372	break;
373	}
374	}
375
376	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
377	if ( getRenderLevel() < 0 )
378	mRenderLevel[msCurrentRenderLevelIndex] = mOptions->maxGeoMipMapLevel - 1;
379	#else
380	if ( mRenderLevel < 0 )
381	mRenderLevel = mOptions->maxGeoMipMapLevel - 1;
382	#endif // GTP_VISIBILITY_MODIFIED_OGRE
383
384	if (mOptions->lodMorph)
385	{
386	// Get the next LOD level down
387	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
388	int nextLevel = mNextLevelDown[getRenderLevel()];
389	#else
390	int nextLevel = mNextLevelDown[mRenderLevel];
391	#endif // GTP_VISIBILITY_MODIFIED_OGRE
392	if (nextLevel == 0)
393	{
394	// No next level, so never morph
395	mLODMorphFactor = 0;
396	}
397	else
398	{
399	// Set the morph such that the morph happens in the last 0.25 of
400	// the distance range
401	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
402	Real range = mMinLevelDistSqr[nextLevel] - mMinLevelDistSqr[getRenderLevel()];
403	#else
404	Real range = mMinLevelDistSqr[nextLevel] - mMinLevelDistSqr[mRenderLevel];
405	#endif // GTP_VISIBILITY_MODIFIED_OGRE
406	if (range)
407	{
408	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
409	Real percent = (L - mMinLevelDistSqr[getRenderLevel()]) / range;
410	#else
411	Real percent = (L - mMinLevelDistSqr[mRenderLevel]) / range;
412	#endif // GTP_VISIBILITY_MODIFIED_OGRE
413	// scale result so that msLODMorphStart == 0, 1 == 1, clamp to 0 below that
414	Real rescale = 1.0f / (1.0f - mOptions->lodMorphStart);
415	mLODMorphFactor = std::max((percent - mOptions->lodMorphStart) * rescale,
416	static_cast<Real>(0.0));
417	}
418	else
419	{
420	// Identical ranges
421	mLODMorphFactor = 0.0f;
422	}
423
424	assert(mLODMorphFactor >= 0 && mLODMorphFactor <= 1);
425	}
426
427	// Bind the correct delta buffer if it has changed
428	// nextLevel - 1 since the first entry is for LOD 1 (since LOD 0 never needs it)
429	if (mLastNextLevel != nextLevel)
430	{
431	if (nextLevel > 0)
432	{
433	mTerrain->vertexBufferBinding->setBinding(DELTA_BINDING,
434	mDeltaBuffers[nextLevel - 1]);
435	}
436	else
437	{
438	// bind dummy (incase bindings checked)
439	mTerrain->vertexBufferBinding->setBinding(DELTA_BINDING,
440	mDeltaBuffers[0]);
441	}
442	}
443	mLastNextLevel = nextLevel;
444
445	}
446
447	}
448	//-----------------------------------------------------------------------
449	void TerrainRenderable::_updateRenderQueue( RenderQueue* queue )
450	{
451	// Notify need to calculate light list when our sending to render queue
452	mLightListDirty = true;
453
454	queue->addRenderable( this );
455	}
456	//-----------------------------------------------------------------------
457	void TerrainRenderable::getRenderOperation( RenderOperation& op )
458	{
459	//setup indexes for vertices and uvs...
460
461	assert( mInit && "Uninitialized" );
462
463	op.useIndexes = true;
464	op.operationType = mOptions->useTriStrips ?
465	RenderOperation::OT_TRIANGLE_STRIP : RenderOperation::OT_TRIANGLE_LIST;
466	op.vertexData = mTerrain;
467	op.indexData = getIndexData();
468
469
470	}
471	//-----------------------------------------------------------------------
472	void TerrainRenderable::getWorldTransforms( Matrix4* xform ) const
473	{
474	*xform = mParentNode->_getFullTransform();
475	}
476	//-----------------------------------------------------------------------
477	const Quaternion& TerrainRenderable::getWorldOrientation(void) const
478	{
479	return mParentNode->_getDerivedOrientation();
480	}
481	//-----------------------------------------------------------------------
482	const Vector3& TerrainRenderable::getWorldPosition(void) const
483	{
484	return mParentNode->_getDerivedPosition();
485	}
486	//-----------------------------------------------------------------------
487	bool TerrainRenderable::_checkSize( int n )
488	{
489	for ( int i = 0; i < 10; i++ )
490	{
491	if ( ( ( 1 << i ) + 1 ) == n )
492	return true;
493	}
494
495	return false;
496	}
497	//-----------------------------------------------------------------------
498	void TerrainRenderable::_calculateMinLevelDist2( Real C )
499	{
500	//level 0 has no delta.
501	mMinLevelDistSqr[ 0 ] = 0;
502
503	int i, j;
504
505	for ( int level = 1; level < mOptions->maxGeoMipMapLevel; level++ )
506	{
507	mMinLevelDistSqr[ level ] = 0;
508
509	int step = 1 << level;
510	// The step of the next higher LOD
511	int higherstep = step >> 1;
512
513	float* pDeltas = 0;
514	if (mOptions->lodMorph)
515	{
516	// Create a set of delta values (store at index - 1 since 0 has none)
517	mDeltaBuffers[level - 1] = createDeltaBuffer();
518	// Lock, but don't discard (we want the pre-initialised zeros)
519	pDeltas = static_cast<float*>(
520	mDeltaBuffers[level - 1]->lock(HardwareBuffer::HBL_NORMAL));
521	}
522
523	for ( j = 0; j < mOptions->tileSize - step; j += step )
524	{
525	for ( i = 0; i < mOptions->tileSize - step; i += step )
526	{
527	/* Form planes relating to the lower detail tris to be produced
528	For tri lists and even tri strip rows, they are this shape:
529	x---x
530	\| / \|
531	x---x
532	For odd tri strip rows, they are this shape:
533	x---x
534	\| \ \|
535	x---x
536	*/
537
538	Vector3 v1(_vertex( i, j, 0 ), _vertex( i, j, 1 ), _vertex( i, j, 2 ));
539	Vector3 v2(_vertex( i + step, j, 0 ), _vertex( i + step, j, 1 ), _vertex( i + step, j, 2 ));
540	Vector3 v3(_vertex( i, j + step, 0 ), _vertex( i, j + step, 1 ), _vertex( i, j + step, 2 ));
541	Vector3 v4(_vertex( i + step, j + step, 0 ), _vertex( i + step, j + step, 1 ), _vertex( i + step, j + step, 2 ));
542
543	Plane t1, t2;
544	bool backwardTri = false;
545	if (!mOptions->useTriStrips \|\| j % 2 == 0)
546	{
547	t1.redefine(v1, v3, v2);
548	t2.redefine(v2, v3, v4);
549	}
550	else
551	{
552	t1.redefine(v1, v3, v4);
553	t2.redefine(v1, v4, v2);
554	backwardTri = true;
555	}
556
557	// include the bottommost row of vertices if this is the last row
558	int zubound = (j == (mOptions->tileSize - step)? step : step - 1);
559	for ( int z = 0; z <= zubound; z++ )
560	{
561	// include the rightmost col of vertices if this is the last col
562	int xubound = (i == (mOptions->tileSize - step)? step : step - 1);
563	for ( int x = 0; x <= xubound; x++ )
564	{
565	int fulldetailx = i + x;
566	int fulldetailz = j + z;
567	if ( fulldetailx % step == 0 &&
568	fulldetailz % step == 0 )
569	{
570	// Skip, this one is a vertex at this level
571	continue;
572	}
573
574	Real zpct = (Real)z / (Real)step;
575	Real xpct = (Real)x / (Real)step;
576
577	//interpolated height
578	Vector3 actualPos(
579	_vertex( fulldetailx, fulldetailz, 0 ),
580	_vertex( fulldetailx, fulldetailz, 1 ),
581	_vertex( fulldetailx, fulldetailz, 2 ));
582	Real interp_h;
583	// Determine which tri we're on
584	if ((xpct + zpct <= 1.0f && !backwardTri) \|\|
585	(xpct + (1-zpct) <= 1.0f && backwardTri))
586	{
587	// Solve for x/z
588	interp_h =
589	(-(t1.normal.x * actualPos.x)
590	- t1.normal.z * actualPos.z
591	- t1.d) / t1.normal.y;
592	}
593	else
594	{
595	// Second tri
596	interp_h =
597	(-(t2.normal.x * actualPos.x)
598	- t2.normal.z * actualPos.z
599	- t2.d) / t2.normal.y;
600	}
601
602	Real actual_h = _vertex( fulldetailx, fulldetailz, 1 );
603	Real delta = fabs( interp_h - actual_h );
604
605	Real D2 = delta * delta * C * C;
606
607	if ( mMinLevelDistSqr[ level ] < D2 )
608	mMinLevelDistSqr[ level ] = D2;
609
610	// Should be save height difference?
611	// Don't morph along edges
612	if (mOptions->lodMorph &&
613	fulldetailx != 0 && fulldetailx != (mOptions->tileSize - 1) &&
614	fulldetailz != 0 && fulldetailz != (mOptions->tileSize - 1) )
615	{
616	// Save height difference
617	pDeltas[fulldetailx + (fulldetailz * mOptions->tileSize)] =
618	interp_h - actual_h;
619	}
620
621	}
622
623	}
624	}
625	}
626
627	// Unlock morph deltas if required
628	if (mOptions->lodMorph)
629	{
630	mDeltaBuffers[level - 1]->unlock();
631	}
632	}
633
634
635
636	// Post validate the whole set
637	for ( i = 1; i < mOptions->maxGeoMipMapLevel; i++ )
638	{
639
640	// Make sure no LOD transition within the tile
641	// This is especially a problem when using large tiles with flat areas
642	/* Hmm, this can look bad on some areas, disable for now
643	Vector3 delta(_vertex(0,0,0), mCenter.y, _vertex(0,0,2));
644	delta = delta - mCenter;
645	Real minDist = delta.squaredLength();
646	mMinLevelDistSqr[ i ] = std::max(mMinLevelDistSqr[ i ], minDist);
647	*/
648
649	//make sure the levels are increasing...
650	if ( mMinLevelDistSqr[ i ] < mMinLevelDistSqr[ i - 1 ] )
651	{
652	mMinLevelDistSqr[ i ] = mMinLevelDistSqr[ i - 1 ];
653	}
654	}
655
656	// Now reverse traverse the list setting the 'next level down'
657	Real lastDist = -1;
658	int lastIndex = 0;
659	for (i = mOptions->maxGeoMipMapLevel - 1; i >= 0; --i)
660	{
661	if (i == mOptions->maxGeoMipMapLevel - 1)
662	{
663	// Last one is always 0
664	lastIndex = i;
665	lastDist = mMinLevelDistSqr[i];
666	mNextLevelDown[i] = 0;
667	}
668	else
669	{
670	mNextLevelDown[i] = lastIndex;
671	if (mMinLevelDistSqr[i] != lastDist)
672	{
673	lastIndex = i;
674	lastDist = mMinLevelDistSqr[i];
675	}
676	}
677
678	}
679
680
681	}
682	//-----------------------------------------------------------------------
683	void TerrainRenderable::_adjustRenderLevel( int i )
684	{
685
686	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
687	mRenderLevel[msCurrentRenderLevelIndex] = i;
688	#else
689	mRenderLevel = i;
690	#endif // GTP_VISIBILITY_MODIFIED_OGRE
691	}
692	//-----------------------------------------------------------------------
693	Real TerrainRenderable::_calculateCFactor()
694	{
695	Real A, T;
696
697	if (!mOptions->primaryCamera)
698	{
699	OGRE_EXCEPT(Exception::ERR_ITEM_NOT_FOUND,
700	"You have not created a camera yet!",
701	"TerrainRenderable::_calculateCFactor");
702	}
703
704	//A = 1 / Math::Tan(Math::AngleUnitsToRadians(opts.primaryCamera->getFOVy()));
705	// Turn off detail compression at higher FOVs
706	A = 1.0f;
707
708	int vertRes = mOptions->primaryCamera->getViewport()->getActualHeight();
709
710	T = 2 * ( Real ) mOptions->maxPixelError / ( Real ) vertRes;
711
712	return A / T;
713	}
714	//-----------------------------------------------------------------------
715	float TerrainRenderable::getHeightAt( float x, float z )
716	{
717	Vector3 start;
718	Vector3 end;
719
720	start.x = _vertex( 0, 0, 0 );
721	start.y = _vertex( 0, 0, 1 );
722	start.z = _vertex( 0, 0, 2 );
723
724	end.x = _vertex( mOptions->tileSize - 1, mOptions->tileSize - 1, 0 );
725	end.y = _vertex( mOptions->tileSize - 1, mOptions->tileSize - 1, 1 );
726	end.z = _vertex( mOptions->tileSize - 1, mOptions->tileSize - 1, 2 );
727
728	/* Safety catch, if the point asked for is outside
729	* of this tile, it will ask the appropriate tile
730	*/
731
732	if ( x < start.x )
733	{
734	if ( mNeighbors[ WEST ] != 0 )
735	return mNeighbors[ WEST ] ->getHeightAt( x, z );
736	else
737	x = start.x;
738	}
739
740	if ( x > end.x )
741	{
742	if ( mNeighbors[ EAST ] != 0 )
743	return mNeighbors[ EAST ] ->getHeightAt( x, z );
744	else
745	x = end.x;
746	}
747
748	if ( z < start.z )
749	{
750	if ( mNeighbors[ NORTH ] != 0 )
751	return mNeighbors[ NORTH ] ->getHeightAt( x, z );
752	else
753	z = start.z;
754	}
755
756	if ( z > end.z )
757	{
758	if ( mNeighbors[ SOUTH ] != 0 )
759	return mNeighbors[ SOUTH ] ->getHeightAt( x, z );
760	else
761	z = end.z;
762	}
763
764
765
766	float x_pct = ( x - start.x ) / ( end.x - start.x );
767	float z_pct = ( z - start.z ) / ( end.z - start.z );
768
769	float x_pt = x_pct * ( float ) ( mOptions->tileSize - 1 );
770	float z_pt = z_pct * ( float ) ( mOptions->tileSize - 1 );
771
772	int x_index = ( int ) x_pt;
773	int z_index = ( int ) z_pt;
774
775	// If we got to the far right / bottom edge, move one back
776	if (x_index == mOptions->tileSize - 1)
777	{
778	--x_index;
779	x_pct = 1.0f;
780	}
781	else
782	{
783	// get remainder
784	x_pct = x_pt - x_index;
785	}
786	if (z_index == mOptions->tileSize - 1)
787	{
788	--z_index;
789	z_pct = 1.0f;
790	}
791	else
792	{
793	z_pct = z_pt - z_index;
794	}
795
796	//bilinear interpolate to find the height.
797
798	float t1 = _vertex( x_index, z_index, 1 );
799	float t2 = _vertex( x_index + 1, z_index, 1 );
800	float b1 = _vertex( x_index, z_index + 1, 1 );
801	float b2 = _vertex( x_index + 1, z_index + 1, 1 );
802
803	float midpoint = (b1 + t2) / 2.0;
804
805	if (x_pct + z_pct <= 1) {
806	b2 = midpoint + (midpoint - t1);
807	} else {
808	t1 = midpoint + (midpoint - b2);
809	}
810
811	float t = ( t1 * ( 1 - x_pct ) ) + ( t2 * ( x_pct ) );
812	float b = ( b1 * ( 1 - x_pct ) ) + ( b2 * ( x_pct ) );
813
814	float h = ( t * ( 1 - z_pct ) ) + ( b * ( z_pct ) );
815
816	return h;
817	}
818	//-----------------------------------------------------------------------
819	bool TerrainRenderable::intersectSegment( const Vector3 & start, const Vector3 & end, Vector3 * result )
820	{
821	Vector3 dir = end - start;
822	Vector3 ray = start;
823
824	//special case...
825	if ( dir.x == 0 && dir.z == 0 )
826	{
827	if ( ray.y <= getHeightAt( ray.x, ray.z ) )
828	{
829	if ( result != 0 )
830	* result = start;
831
832	return true;
833	}
834	}
835
836	dir.normalise();
837
838	//dir.x *= mScale.x;
839	//dir.y *= mScale.y;
840	//dir.z *= mScale.z;
841
842	const Vector3 * corners = getBoundingBox().getAllCorners();
843
844	//start with the next one...
845	ray += dir;
846
847
848	while ( ! ( ( ray.x < corners[ 0 ].x ) \|\|
849	( ray.x > corners[ 4 ].x ) \|\|
850	( ray.z < corners[ 0 ].z ) \|\|
851	( ray.z > corners[ 4 ].z ) ) )
852	{
853
854
855	float h = getHeightAt( ray.x, ray.z );
856
857	if ( ray.y <= h )
858	{
859	if ( result != 0 )
860	* result = ray;
861
862	return true;
863	}
864
865	else
866	{
867	ray += dir;
868	}
869
870	}
871
872	if ( ray.x < corners[ 0 ].x && mNeighbors[ WEST ] != 0 )
873	return mNeighbors[ WEST ] ->intersectSegment( ray, end, result );
874	else if ( ray.z < corners[ 0 ].z && mNeighbors[ NORTH ] != 0 )
875	return mNeighbors[ NORTH ] ->intersectSegment( ray, end, result );
876	else if ( ray.x > corners[ 4 ].x && mNeighbors[ EAST ] != 0 )
877	return mNeighbors[ EAST ] ->intersectSegment( ray, end, result );
878	else if ( ray.z > corners[ 4 ].z && mNeighbors[ SOUTH ] != 0 )
879	return mNeighbors[ SOUTH ] ->intersectSegment( ray, end, result );
880	else
881	{
882	if ( result != 0 )
883	* result = Vector3( -1, -1, -1 );
884
885	return false;
886	}
887	}
888	//-----------------------------------------------------------------------
889	void TerrainRenderable::_generateVertexLighting( const Vector3 &sun, ColourValue ambient )
890	{
891
892	Vector3 pt;
893	Vector3 normal;
894	Vector3 light;
895
896	HardwareVertexBufferSharedPtr vbuf =
897	mTerrain->vertexBufferBinding->getBuffer(MAIN_BINDING);
898	const VertexElement* elem = mTerrain->vertexDeclaration->findElementBySemantic(VES_DIFFUSE);
899	//for each point in the terrain, see if it's in the line of sight for the sun.
900	for ( size_t i = 0; i < mOptions->tileSize; i++ )
901	{
902	for ( size_t j = 0; j < mOptions->tileSize; j++ )
903	{
904	// printf( "Checking %f,%f,%f ", pt.x, pt.y, pt.z );
905	pt.x = _vertex( i, j, 0 );
906	pt.y = _vertex( i, j, 1 );
907	pt.z = _vertex( i, j, 2 );
908
909	light = sun - pt;
910
911	light.normalise();
912
913	if ( ! intersectSegment( pt, sun, 0 ) )
914	{
915	//
916	_getNormalAt( _vertex( i, j, 0 ), _vertex( i, j, 2 ), &normal );
917
918	float l = light.dotProduct( normal );
919
920	ColourValue v;
921	v.r = ambient.r + l;
922	v.g = ambient.g + l;
923	v.b = ambient.b + l;
924
925	if ( v.r > 1 ) v.r = 1;
926
927	if ( v.g > 1 ) v.g = 1;
928
929	if ( v.b > 1 ) v.b = 1;
930
931	if ( v.r < 0 ) v.r = 0;
932
933	if ( v.g < 0 ) v.g = 0;
934
935	if ( v.b < 0 ) v.b = 0;
936
937	RGBA colour;
938	Root::getSingleton().convertColourValue( v, &colour );
939	vbuf->writeData(
940	(_index( i, j ) * vbuf->getVertexSize()) + elem->getOffset(),
941	sizeof(RGBA), &colour);
942	}
943
944	else
945	{
946	RGBA colour;
947	Root::getSingleton().convertColourValue( ambient, &colour );
948
949	vbuf->writeData(
950	(_index( i, j ) * vbuf->getVertexSize()) + elem->getOffset(),
951	sizeof(RGBA), &colour);
952	}
953
954	}
955
956	}
957
958	printf( "." );
959	}
960	//-----------------------------------------------------------------------
961	Real TerrainRenderable::getSquaredViewDepth(const Camera* cam) const
962	{
963	Vector3 diff = mCenter - cam->getDerivedPosition();
964	// Use squared length to avoid square root
965	return diff.squaredLength();
966	}
967
968	//-----------------------------------------------------------------------
969	const LightList& TerrainRenderable::getLights(void) const
970	{
971	if (mLightListDirty)
972	{
973	getParentSceneNode()->getCreator()->_populateLightList(
974	mCenter, this->getBoundingRadius(), mLightList);
975	mLightListDirty = false;
976	}
977	return mLightList;
978	}
979	//-----------------------------------------------------------------------
980	IndexData* TerrainRenderable::getIndexData(void)
981	{
982	unsigned int stitchFlags = 0;
983
984	if ( mNeighbors[ EAST ] != 0 && mNeighbors[ EAST ] -> mRenderLevel > mRenderLevel )
985	{
986	stitchFlags \|= STITCH_EAST;
987	stitchFlags \|=
988	(mNeighbors[ EAST ] -> mRenderLevel - mRenderLevel) << STITCH_EAST_SHIFT;
989	}
990
991	if ( mNeighbors[ WEST ] != 0 && mNeighbors[ WEST ] -> mRenderLevel > mRenderLevel )
992	{
993	stitchFlags \|= STITCH_WEST;
994	stitchFlags \|=
995	(mNeighbors[ WEST ] -> mRenderLevel - mRenderLevel) << STITCH_WEST_SHIFT;
996	}
997
998	if ( mNeighbors[ NORTH ] != 0 && mNeighbors[ NORTH ] -> mRenderLevel > mRenderLevel )
999	{
1000	stitchFlags \|= STITCH_NORTH;
1001	stitchFlags \|=
1002	(mNeighbors[ NORTH ] -> mRenderLevel - mRenderLevel) << STITCH_NORTH_SHIFT;
1003	}
1004
1005	if ( mNeighbors[ SOUTH ] != 0 && mNeighbors[ SOUTH ] -> mRenderLevel > mRenderLevel )
1006	{
1007	stitchFlags \|= STITCH_SOUTH;
1008	stitchFlags \|=
1009	(mNeighbors[ SOUTH ] -> mRenderLevel - mRenderLevel) << STITCH_SOUTH_SHIFT;
1010	}
1011
1012	// Check preexisting
1013	LevelArray& levelIndex = mSceneManager->_getLevelIndex();
1014	/* msz: added for v1-2-0 compatibility */
1015	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
1016	IndexMap::iterator ii = levelIndex[ getRenderLevel() ]->find( stitchFlags );
1017	#else
1018	IndexMap::iterator ii = levelIndex[ mRenderLevel ]->find( stitchFlags );
1019	#endif // GTP_VISIBILITY_MODIFIED_OGRE
1020	IndexData* indexData;
1021	/* msz: added for v1-2-0 compatibility */
1022	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
1023	if ( ii == levelIndex[ getRenderLevel() ]->end())
1024	#else
1025	if ( ii == levelIndex[ mRenderLevel ]->end())
1026	#endif // GTP_VISIBILITY_MODIFIED_OGRE
1027	{
1028	// Create
1029	if (mOptions->useTriStrips)
1030	{
1031	indexData = generateTriStripIndexes(stitchFlags);
1032	}
1033	else
1034	{
1035	indexData = generateTriListIndexes(stitchFlags);
1036	}
1037	/* msz: added for v1-2-0 compatibility */
1038	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
1039	levelIndex[ getRenderLevel() ]->insert(
1040	IndexMap::value_type(stitchFlags, indexData));
1041	#else
1042	levelIndex[ mRenderLevel ]->insert(
1043	IndexMap::value_type(stitchFlags, indexData));
1044	#endif // GTP_VISIBILITY_MODIFIED_OGRE
1045	}
1046	else
1047	{
1048	indexData = ii->second;
1049	}
1050
1051
1052	return indexData;
1053
1054
1055	}
1056	//-----------------------------------------------------------------------
1057	IndexData* TerrainRenderable::generateTriStripIndexes(unsigned int stitchFlags)
1058	{
1059	/* msz: added for v1-2-0 compatibility */
1060	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
1061	// The step used for the current level
1062	int step = 1 << getRenderLevel();
1063	// The step used for the lower level
1064	int lowstep = 1 << (getRenderLevel() + 1);
1065	#else
1066	// The step used for the current level
1067	int step = 1 << mRenderLevel;
1068	// The step used for the lower level
1069	int lowstep = 1 << (mRenderLevel + 1);
1070	#endif // GTP_VISIBILITY_MODIFIED_OGRE
1071
1072	int numIndexes = 0;
1073
1074	// Calculate the number of indexes required
1075	// This is the number of 'cells' at this detail level x 2
1076	// plus 3 degenerates to turn corners
1077	int numTrisAcross = (((mOptions->tileSize-1) / step) * 2) + 3;
1078	// Num indexes is number of tris + 2
1079	int new_length = numTrisAcross * ((mOptions->tileSize-1) / step) + 2;
1080	//this is the maximum for a level. It wastes a little, but shouldn't be a problem.
1081
1082	IndexData* indexData = new IndexData;
1083	indexData->indexBuffer =
1084	HardwareBufferManager::getSingleton().createIndexBuffer(
1085	HardwareIndexBuffer::IT_16BIT,
1086	new_length, HardwareBuffer::HBU_STATIC_WRITE_ONLY);//, false);
1087
1088	mSceneManager->_getIndexCache().mCache.push_back( indexData );
1089
1090	unsigned short* pIdx = static_cast<unsigned short*>(
1091	indexData->indexBuffer->lock(0,
1092	indexData->indexBuffer->getSizeInBytes(),
1093	HardwareBuffer::HBL_DISCARD));
1094
1095	// Stripified mesh
1096	for ( int j = 0; j < mOptions->tileSize - 1; j += step )
1097	{
1098	int i;
1099	// Forward strip
1100	// We just do the \|/ here, final \| done after
1101	for ( i = 0; i < mOptions->tileSize - 1; i += step )
1102	{
1103	int x[4], y[4];
1104	x[0] = x[1] = i;
1105	x[2] = x[3] = i + step;
1106	y[0] = y[2] = j;
1107	y[1] = y[3] = j + step;
1108
1109	if (j == 0 && (stitchFlags & STITCH_NORTH))
1110	{
1111	// North reduction means rounding x[0] and x[2]
1112	if (x[0] % lowstep != 0)
1113	{
1114	// Since we know we only drop down one level of LOD,
1115	// removing 1 step of higher LOD should return to lower
1116	x[0] -= step;
1117	}
1118	if (x[2] % lowstep != 0)
1119	{
1120	x[2] -= step;
1121	}
1122	}
1123
1124	// Never get a south tiling on a forward strip (always finish on
1125	// a backward strip)
1126
1127	if (i == 0 && (stitchFlags & STITCH_WEST))
1128	{
1129	// West reduction means rounding y[0] / y[1]
1130	if (y[0] % lowstep != 0)
1131	{
1132	y[0] -= step;
1133	}
1134	if (y[1] % lowstep != 0)
1135	{
1136	y[1] -= step;
1137	}
1138	}
1139	if (i == (mOptions->tileSize - 1 - step) && (stitchFlags & STITCH_EAST))
1140	{
1141	// East tiling means rounding y[2] & y[3]
1142	if (y[2] % lowstep != 0)
1143	{
1144	y[2] -= step;
1145	}
1146	if (y[3] % lowstep != 0)
1147	{
1148	y[3] -= step;
1149	}
1150	}
1151
1152	//triangles
1153	if (i == 0)
1154	{
1155	// Starter
1156	*pIdx++ = _index( x[0], y[0] ); numIndexes++;
1157	}
1158	*pIdx++ = _index( x[1], y[1] ); numIndexes++;
1159	*pIdx++ = _index( x[2], y[2] ); numIndexes++;
1160
1161	if (i == mOptions->tileSize - 1 - step)
1162	{
1163	// Emit extra index to finish row
1164	*pIdx++ = _index( x[3], y[3] ); numIndexes++;
1165	if (j < mOptions->tileSize - 1 - step)
1166	{
1167	// Emit this index twice more (this is to turn around without
1168	// artefacts)
1169	// ** Hmm, looks like we can drop this and it's unnoticeable
1170	//*pIdx++ = _index( x[3], y[3] ); numIndexes++;
1171	//*pIdx++ = _index( x[3], y[3] ); numIndexes++;
1172	}
1173	}
1174
1175	}
1176	// Increment row
1177	j += step;
1178	// Backward strip
1179	for ( i = mOptions->tileSize - 1; i > 0 ; i -= step )
1180	{
1181	int x[4], y[4];
1182	x[0] = x[1] = i;
1183	x[2] = x[3] = i - step;
1184	y[0] = y[2] = j;
1185	y[1] = y[3] = j + step;
1186
1187	// Never get a north tiling on a backward strip (always
1188	// start on a forward strip)
1189	if (j == (mOptions->tileSize - 1 - step) && (stitchFlags & STITCH_SOUTH))
1190	{
1191	// South reduction means rounding x[1] / x[3]
1192	if (x[1] % lowstep != 0)
1193	{
1194	x[1] -= step;
1195	}
1196	if (x[3] % lowstep != 0)
1197	{
1198	x[3] -= step;
1199	}
1200	}
1201
1202	if (i == step && (stitchFlags & STITCH_WEST))
1203	{
1204	// West tiling on backward strip is rounding of y[2] / y[3]
1205	if (y[2] % lowstep != 0)
1206	{
1207	y[2] -= step;
1208	}
1209	if (y[3] % lowstep != 0)
1210	{
1211	y[3] -= step;
1212	}
1213	}
1214	if (i == mOptions->tileSize - 1 && (stitchFlags & STITCH_EAST))
1215	{
1216	// East tiling means rounding y[0] and y[1] on backward strip
1217	if (y[0] % lowstep != 0)
1218	{
1219	y[0] -= step;
1220	}
1221	if (y[1] % lowstep != 0)
1222	{
1223	y[1] -= step;
1224	}
1225	}
1226
1227	//triangles
1228	if (i == mOptions->tileSize)
1229	{
1230	// Starter
1231	*pIdx++ = _index( x[0], y[0] ); numIndexes++;
1232	}
1233	*pIdx++ = _index( x[1], y[1] ); numIndexes++;
1234	*pIdx++ = _index( x[2], y[2] ); numIndexes++;
1235
1236	if (i == step)
1237	{
1238	// Emit extra index to finish row
1239	*pIdx++ = _index( x[3], y[3] ); numIndexes++;
1240	if (j < mOptions->tileSize - 1 - step)
1241	{
1242	// Emit this index once more (this is to turn around)
1243	*pIdx++ = _index( x[3], y[3] ); numIndexes++;
1244	}
1245	}
1246	}
1247	}
1248
1249
1250	indexData->indexBuffer->unlock();
1251	indexData->indexCount = numIndexes;
1252	indexData->indexStart = 0;
1253
1254	return indexData;
1255
1256	}
1257	//-----------------------------------------------------------------------
1258	IndexData* TerrainRenderable::generateTriListIndexes(unsigned int stitchFlags)
1259	{
1260
1261	int numIndexes = 0;
1262	/* msz: added for v1-2-0 compatibility */
1263	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
1264	int step = 1 << getRenderLevel();
1265	#else
1266	int step = 1 << mRenderLevel;
1267	#endif // GTP_VISIBILITY_MODIFIED_OGRE
1268	IndexData* indexData = 0;
1269
1270	int north = stitchFlags & STITCH_NORTH ? step : 0;
1271	int south = stitchFlags & STITCH_SOUTH ? step : 0;
1272	int east = stitchFlags & STITCH_EAST ? step : 0;
1273	int west = stitchFlags & STITCH_WEST ? step : 0;
1274
1275	int new_length = ( mOptions->tileSize / step ) * ( mOptions->tileSize / step ) * 2 * 2 * 2 ;
1276	//this is the maximum for a level. It wastes a little, but shouldn't be a problem.
1277
1278	indexData = new IndexData;
1279	indexData->indexBuffer =
1280	HardwareBufferManager::getSingleton().createIndexBuffer(
1281	HardwareIndexBuffer::IT_16BIT,
1282	new_length, HardwareBuffer::HBU_STATIC_WRITE_ONLY);//, false);
1283
1284	mSceneManager->_getIndexCache().mCache.push_back( indexData );
1285
1286	unsigned short* pIdx = static_cast<unsigned short*>(
1287	indexData->indexBuffer->lock(0,
1288	indexData->indexBuffer->getSizeInBytes(),
1289	HardwareBuffer::HBL_DISCARD));
1290
1291	// Do the core vertices, minus stitches
1292	for ( int j = north; j < mOptions->tileSize - 1 - south; j += step )
1293	{
1294	for ( int i = west; i < mOptions->tileSize - 1 - east; i += step )
1295	{
1296	//triangles
1297	*pIdx++ = _index( i, j ); numIndexes++;
1298	*pIdx++ = _index( i, j + step ); numIndexes++;
1299	*pIdx++ = _index( i + step, j ); numIndexes++;
1300
1301	*pIdx++ = _index( i, j + step ); numIndexes++;
1302	*pIdx++ = _index( i + step, j + step ); numIndexes++;
1303	*pIdx++ = _index( i + step, j ); numIndexes++;
1304	}
1305	}
1306
1307	// North stitching
1308	if ( north > 0 )
1309	{
1310	/* msz: added for v1-2-0 compatibility */
1311	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
1312	numIndexes += stitchEdge(NORTH, getRenderLevel(), mNeighbors[NORTH]->getRenderLevel(),
1313	west > 0, east > 0, &pIdx);
1314	#else
1315	numIndexes += stitchEdge(NORTH, mRenderLevel, mNeighbors[NORTH]->mRenderLevel,
1316	west > 0, east > 0, &pIdx);
1317	#endif // GTP_VISIBILITY_MODIFIED_OGRE
1318	}
1319	// East stitching
1320	if ( east > 0 )
1321	{
1322	/* msz: added for v1-2-0 compatibility */
1323	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
1324	numIndexes += stitchEdge(EAST, getRenderLevel(), mNeighbors[EAST]->getRenderLevel(),
1325	north > 0, south > 0, &pIdx);
1326	#else
1327	numIndexes += stitchEdge(EAST, mRenderLevel, mNeighbors[EAST]->mRenderLevel,
1328	north > 0, south > 0, &pIdx);
1329	#endif // GTP_VISIBILITY_MODIFIED_OGRE
1330	}
1331	// South stitching
1332	if ( south > 0 )
1333	{
1334	/* msz: added for v1-2-0 compatibility */
1335	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
1336	numIndexes += stitchEdge(SOUTH, getRenderLevel(), mNeighbors[SOUTH]->getRenderLevel(),
1337	east > 0, west > 0, &pIdx);
1338	#else
1339	numIndexes += stitchEdge(SOUTH, mRenderLevel, mNeighbors[SOUTH]->mRenderLevel,
1340	east > 0, west > 0, &pIdx);
1341	#endif // GTP_VISIBILITY_MODIFIED_OGRE
1342	}
1343	// West stitching
1344	if ( west > 0 )
1345	{
1346	/* msz: added for v1-2-0 compatibility */
1347	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
1348	numIndexes += stitchEdge(WEST, getRenderLevel(), mNeighbors[WEST]->getRenderLevel(),
1349	south > 0, north > 0, &pIdx);
1350	#else
1351	numIndexes += stitchEdge(WEST, mRenderLevel, mNeighbors[WEST]->mRenderLevel,
1352	south > 0, north > 0, &pIdx);
1353	#endif // GTP_VISIBILITY_MODIFIED_OGRE
1354	}
1355
1356
1357	indexData->indexBuffer->unlock();
1358	indexData->indexCount = numIndexes;
1359	indexData->indexStart = 0;
1360
1361	return indexData;
1362	}
1363	//-----------------------------------------------------------------------
1364	HardwareVertexBufferSharedPtr TerrainRenderable::createDeltaBuffer(void)
1365	{
1366	// Delta buffer is a 1D float buffer of height offsets
1367	HardwareVertexBufferSharedPtr buf =
1368	HardwareBufferManager::getSingleton().createVertexBuffer(
1369	VertexElement::getTypeSize(VET_FLOAT1),
1370	mOptions->tileSize * mOptions->tileSize,
1371	HardwareBuffer::HBU_STATIC_WRITE_ONLY);
1372	// Fill the buffer with zeros, we will only fill in delta
1373	void* pVoid = buf->lock(HardwareBuffer::HBL_DISCARD);
1374	memset(pVoid, 0, mOptions->tileSize * mOptions->tileSize * sizeof(float));
1375	buf->unlock();
1376
1377	return buf;
1378
1379	}
1380	//-----------------------------------------------------------------------
1381	void TerrainRenderable::_updateCustomGpuParameter(
1382	const GpuProgramParameters::AutoConstantEntry& constantEntry,
1383	GpuProgramParameters* params) const
1384	{
1385	if (constantEntry.data == MORPH_CUSTOM_PARAM_ID)
1386	{
1387	// Update morph LOD factor
1388	params->setConstant(constantEntry.index, mLODMorphFactor);
1389	}
1390	else
1391	{
1392	Renderable::_updateCustomGpuParameter(constantEntry, params);
1393	}
1394
1395	}
1396	//-----------------------------------------------------------------------
1397	int TerrainRenderable::stitchEdge(Neighbor neighbor, int hiLOD, int loLOD,
1398	bool omitFirstTri, bool omitLastTri, unsigned short** ppIdx)
1399	{
1400	assert(loLOD > hiLOD);
1401	/*
1402	Now do the stitching; we can stitch from any level to any level.
1403	The stitch pattern is like this for each pair of vertices in the lower LOD
1404	(excuse the poor ascii art):
1405
1406	lower LOD
1407	-----------
1408	\|\ \ 3 / /\|
1409	\|1\2 \ / 4/5\|
1410	--------*
1411	higher LOD
1412
1413	The algorithm is, for each pair of lower LOD vertices:
1414	1. Iterate over the higher LOD vertices, generating tris connected to the
1415	first lower LOD vertex, up to and including 1/2 the span of the lower LOD
1416	over the higher LOD (tris 1-2). Skip the first tri if it is on the edge
1417	of the tile and that edge is to be stitched itself.
1418	2. Generate a single tri for the middle using the 2 lower LOD vertices and
1419	the middle vertex of the higher LOD (tri 3).
1420	3. Iterate over the higher LOD vertices from 1/2 the span of the lower LOD
1421	to the end, generating tris connected to the second lower LOD vertex
1422	(tris 4-5). Skip the last tri if it is on the edge of a tile and that
1423	edge is to be stitched itself.
1424
1425	The same algorithm works for all edges of the patch; stitching is done
1426	clockwise so that the origin and steps used change, but the general
1427	approach does not.
1428	*/
1429
1430	// Get pointer to be updated
1431	unsigned short* pIdx = *ppIdx;
1432
1433	// Work out the steps ie how to increment indexes
1434	// Step from one vertex to another in the high detail version
1435	int step = 1 << hiLOD;
1436	// Step from one vertex to another in the low detail version
1437	int superstep = 1 << loLOD;
1438	// Step half way between low detail steps
1439	int halfsuperstep = superstep >> 1;
1440
1441	// Work out the starting points and sign of increments
1442	// We always work the strip clockwise
1443	int startx, starty, endx, rowstep;
1444	bool horizontal;
1445	switch(neighbor)
1446	{
1447	case NORTH:
1448	startx = starty = 0;
1449	endx = mOptions->tileSize - 1;
1450	rowstep = step;
1451	horizontal = true;
1452	break;
1453	case SOUTH:
1454	// invert x AND y direction, helps to keep same winding
1455	startx = starty = mOptions->tileSize - 1;
1456	endx = 0;
1457	rowstep = -step;
1458	step = -step;
1459	superstep = -superstep;
1460	halfsuperstep = -halfsuperstep;
1461	horizontal = true;
1462	break;
1463	case EAST:
1464	startx = 0;
1465	endx = mOptions->tileSize - 1;
1466	starty = mOptions->tileSize - 1;
1467	rowstep = -step;
1468	horizontal = false;
1469	break;
1470	case WEST:
1471	startx = mOptions->tileSize - 1;
1472	endx = 0;
1473	starty = 0;
1474	rowstep = step;
1475	step = -step;
1476	superstep = -superstep;
1477	halfsuperstep = -halfsuperstep;
1478	horizontal = false;
1479	break;
1480	};
1481
1482	int numIndexes = 0;
1483
1484	for ( int j = startx; j != endx; j += superstep )
1485	{
1486	int k;
1487	for (k = 0; k != halfsuperstep; k += step)
1488	{
1489	int jk = j + k;
1490	//skip the first bit of the corner?
1491	if ( j != startx \|\| k != 0 \|\| !omitFirstTri )
1492	{
1493	if (horizontal)
1494	{
1495	*pIdx++ = _index( j , starty ); numIndexes++;
1496	*pIdx++ = _index( jk, starty + rowstep ); numIndexes++;
1497	*pIdx++ = _index( jk + step, starty + rowstep ); numIndexes++;
1498	}
1499	else
1500	{
1501	*pIdx++ = _index( starty, j ); numIndexes++;
1502	*pIdx++ = _index( starty + rowstep, jk ); numIndexes++;
1503	*pIdx++ = _index( starty + rowstep, jk + step); numIndexes++;
1504	}
1505	}
1506	}
1507
1508	// Middle tri
1509	if (horizontal)
1510	{
1511	*pIdx++ = _index( j, starty ); numIndexes++;
1512	*pIdx++ = _index( j + halfsuperstep, starty + rowstep); numIndexes++;
1513	*pIdx++ = _index( j + superstep, starty ); numIndexes++;
1514	}
1515	else
1516	{
1517	*pIdx++ = _index( starty, j ); numIndexes++;
1518	*pIdx++ = _index( starty + rowstep, j + halfsuperstep ); numIndexes++;
1519	*pIdx++ = _index( starty, j + superstep ); numIndexes++;
1520	}
1521
1522	for (k = halfsuperstep; k != superstep; k += step)
1523	{
1524	int jk = j + k;
1525	if ( j != endx - superstep \|\| k != superstep - step \|\| !omitLastTri )
1526	{
1527	if (horizontal)
1528	{
1529	*pIdx++ = _index( j + superstep, starty ); numIndexes++;
1530	*pIdx++ = _index( jk, starty + rowstep ); numIndexes++;
1531	*pIdx++ = _index( jk + step, starty + rowstep ); numIndexes++;
1532	}
1533	else
1534	{
1535	*pIdx++ = _index( starty, j + superstep ); numIndexes++;
1536	*pIdx++ = _index( starty + rowstep, jk ); numIndexes++;
1537	*pIdx++ = _index( starty + rowstep, jk + step ); numIndexes++;
1538	}
1539	}
1540	}
1541	}
1542
1543	*ppIdx = pIdx;
1544
1545	return numIndexes;
1546
1547	}
1548
1549	#ifdef GTP_VISIBILITY_MODIFIED_OGRE
1550	//-----------------------------------------------------------------------
1551	void TerrainRenderable::ResetRenderLevelIndex()
1552	{
1553	msCurrentRenderLevelIndex = 0;
1554	}
1555	//-----------------------------------------------------------------------
1556	void TerrainRenderable::NextRenderLevelIndex()
1557	{
1558	if ((++ msCurrentRenderLevelIndex) > MAX_RENDERLEVEL_INDEX)
1559	msCurrentRenderLevelIndex = 0;
1560	}
1561	#endif // GTP_VISIBILITY_MODIFIED_OGRE
1562
1563	} //namespace

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