roamsphere.cpp

大型多人在线游戏开发,该书光盘上附带的源码

/*
[e-mail]
Copyright (c) 2000, Sean O'Neil
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice,
  this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.
* Neither the name of this project nor the names of its contributors
  may be used to endorse or promote products derived from this software
  without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/

#include "Master.h"
#include "ROAMSphere.h"


unsigned short CROAMSphere::m_nIndex[128*1024*3];
int CROAMSphere::m_nStart[6];
int CROAMSphere::m_nEnd[6];


void CROAMSphere::RebuildEdgeList()
{
	// Set up the edge pointers for all triangles
	for(int i=0; i<6; i++)
	{
		for(CROAMTriangle *p1 = m_llTriangle[i].GetHead(); p1->IsInList(); p1 = p1->GetNext())
		{
			for(int j=i; j<6; j++)
			{
				for(CROAMTriangle *p2 = m_llTriangle[j].GetHead(); p2->IsInList(); p2 = p2->GetNext())
				{
					if(p2 == p1)
						continue;
					bool bMatch = true;
					if(p2->HasVertex(p1->m_nVertex[0]) && p2->HasVertex(p1->m_nVertex[1]))
						p1->m_pEdge[0] = p2;
					else if(p2->HasVertex(p1->m_nVertex[1]) && p2->HasVertex(p1->m_nVertex[2]))
						p1->m_pEdge[1] = p2;
					else if(p2->HasVertex(p1->m_nVertex[2]) && p2->HasVertex(p1->m_nVertex[0]))
						p1->m_pEdge[2] = p2;
					else
						bMatch = false;
					if(bMatch)
					{
						if(!p1->HasVertex(p2->m_nVertex[2]))
							p2->m_pEdge[0] = p1;
						else if(!p1->HasVertex(p2->m_nVertex[0]))
							p2->m_pEdge[1] = p1;
						else
							p2->m_pEdge[2] = p1;
					}
				}
			}
		}
	}
}

void CROAMSphere::BuildCube()
{
	unsigned short nVertex[4];
	CROAMTriangle *pTriangle;

	// Create front face vertices and triangles
	nVertex[0] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[0]]->Init(CVector(-1, 1, 1));
	nVertex[1] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[1]]->Init(CVector(-1, -1, 1));
	nVertex[2] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[2]]->Init(CVector(1, -1, 1));
	nVertex[3] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[3]]->Init(CVector(1, 1, 1));
	pTriangle = new CROAMTriangle(nVertex[0], nVertex[1], nVertex[2]);
	pTriangle->SetTriangleFace(CPlanetaryMap::FrontFace);
	m_llTriangle[CPlanetaryMap::FrontFace].AddTail(pTriangle);
	pTriangle = new CROAMTriangle(nVertex[2], nVertex[3], nVertex[0]);
	pTriangle->SetTriangleFace(CPlanetaryMap::FrontFace);
	m_llTriangle[CPlanetaryMap::FrontFace].AddTail(pTriangle);

	// Create back face vertices and triangles
	nVertex[0] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[0]]->Init(CVector(1, 1, -1));
	nVertex[1] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[1]]->Init(CVector(1, -1, -1));
	nVertex[2] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[2]]->Init(CVector(-1, -1, -1));
	nVertex[3] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[3]]->Init(CVector(-1, 1, -1));
	pTriangle = new CROAMTriangle(nVertex[0], nVertex[1], nVertex[2]);
	pTriangle->SetTriangleFace(CPlanetaryMap::BackFace);
	m_llTriangle[CPlanetaryMap::BackFace].AddTail(pTriangle);
	pTriangle = new CROAMTriangle(nVertex[2], nVertex[3], nVertex[0]);
	pTriangle->SetTriangleFace(CPlanetaryMap::BackFace);
	m_llTriangle[CPlanetaryMap::BackFace].AddTail(pTriangle);

	// Create left face vertices and triangles
	nVertex[0] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[0]]->Init(CVector(-1, 1, -1));
	nVertex[1] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[1]]->Init(CVector(-1, -1, -1));
	nVertex[2] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[2]]->Init(CVector(-1, -1, 1));
	nVertex[3] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[3]]->Init(CVector(-1, 1, 1));
	pTriangle = new CROAMTriangle(nVertex[0], nVertex[1], nVertex[2]);
	pTriangle->SetTriangleFace(CPlanetaryMap::LeftFace);
	m_llTriangle[CPlanetaryMap::LeftFace].AddTail(pTriangle);
	pTriangle = new CROAMTriangle(nVertex[2], nVertex[3], nVertex[0]);
	pTriangle->SetTriangleFace(CPlanetaryMap::LeftFace);
	m_llTriangle[CPlanetaryMap::LeftFace].AddTail(pTriangle);

	// Create right face vertices and triangles
	nVertex[0] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[0]]->Init(CVector(1, 1, 1));
	nVertex[1] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[1]]->Init(CVector(1, -1, 1));
	nVertex[2] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[2]]->Init(CVector(1, -1, -1));
	nVertex[3] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[3]]->Init(CVector(1, 1, -1));
	pTriangle = new CROAMTriangle(nVertex[0], nVertex[1], nVertex[2]);
	pTriangle->SetTriangleFace(CPlanetaryMap::RightFace);
	m_llTriangle[CPlanetaryMap::RightFace].AddTail(pTriangle);
	pTriangle = new CROAMTriangle(nVertex[2], nVertex[3], nVertex[0]);
	pTriangle->SetTriangleFace(CPlanetaryMap::RightFace);
	m_llTriangle[CPlanetaryMap::RightFace].AddTail(pTriangle);

	// Create top face vertices and triangles
	nVertex[0] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[0]]->Init(CVector(-1, 1, -1));
	nVertex[1] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[1]]->Init(CVector(-1, 1, 1));
	nVertex[2] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[2]]->Init(CVector(1, 1, 1));
	nVertex[3] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[3]]->Init(CVector(1, 1, -1));
	pTriangle = new CROAMTriangle(nVertex[0], nVertex[1], nVertex[2]);
	pTriangle->SetTriangleFace(CPlanetaryMap::TopFace);
	m_llTriangle[CPlanetaryMap::TopFace].AddTail(pTriangle);
	pTriangle = new CROAMTriangle(nVertex[2], nVertex[3], nVertex[0]);
	pTriangle->SetTriangleFace(CPlanetaryMap::TopFace);
	m_llTriangle[CPlanetaryMap::TopFace].AddTail(pTriangle);

	// Create bottom face vertices and triangles
	nVertex[0] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[0]]->Init(CVector(-1, -1, 1));
	nVertex[1] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[1]]->Init(CVector(-1, -1, -1));
	nVertex[2] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[2]]->Init(CVector(1, -1, -1));
	nVertex[3] = CVertex::Array.LockElement();
	CVertex::Array[nVertex[3]]->Init(CVector(1, -1, 1));
	pTriangle = new CROAMTriangle(nVertex[0], nVertex[1], nVertex[2]);
	pTriangle->SetTriangleFace(CPlanetaryMap::BottomFace);
	m_llTriangle[CPlanetaryMap::BottomFace].AddTail(pTriangle);
	pTriangle = new CROAMTriangle(nVertex[2], nVertex[3], nVertex[0]);
	pTriangle->SetTriangleFace(CPlanetaryMap::BottomFace);
	m_llTriangle[CPlanetaryMap::BottomFace].AddTail(pTriangle);

	RebuildEdgeList();
}

void CROAMSphere::UpdateTriangleOffset(CROAMTriangle *pTriangle)
{
	pTriangle->m_vMidpoint = pTriangle->Vertex(0)->m_vPosition.Midpoint(pTriangle->Vertex(2)->m_vPosition);
	pTriangle->m_fOffset = m_pHeightMap->GetHeightOffset(pTriangle->m_vMidpoint);
	pTriangle->m_fLength = pTriangle->Vertex(0)->m_vPosition.DistanceSquared(pTriangle->Vertex(2)->m_vPosition);
}

bool CROAMSphere::Split(CROAMTriangle *pTriangle)
{
	// If the opposite triangle is not ready to split with this one, then it must be split first.
	// After that, it should always be ready to split with this one.
	static CROAMTriangle *pOpposite;
	if(pTriangle->m_pEdge[2]->m_pEdge[2] != pTriangle)
		if(!Split(pTriangle->m_pEdge[2]))
			return false;
	pOpposite = pTriangle->m_pEdge[2];
	ASSERT(pOpposite->m_pEdge[2] == pTriangle);

	// Now split edge 2-0 by getting its midpoint and creating a new vertex
	static unsigned short nTriangleVertex, nOppositeVertex;
	static CVertex *pTriangleVertex, *pOppositeVertex;
	nTriangleVertex = CVertex::Array.LockElement();
	if(nTriangleVertex == 65535)
		return false;
	pTriangleVertex = CVertex::Array[nTriangleVertex];

	pTriangleVertex->m_vPosition = pTriangle->m_vMidpoint;
	float fHeight = pTriangleVertex->m_vPosition.Magnitude();
	pTriangleVertex->m_vPosition *= (fHeight + pTriangle->m_fOffset) / fHeight;
	if(m_pSurfaceMap)
	{
		m_pSurfaceMap->GetRawTextureCoordinates(pTriangleVertex->m_vPosition, fHeight + pTriangle->m_fOffset, pTriangleVertex->m_fTexCoord[0], pTriangleVertex->m_fTexCoord[1]);
		m_pSurfaceMap->GetTextureCoordinates(pTriangleVertex->m_vPosition, pTriangle->GetTriangleFace(), pTriangleVertex->m_fTexCoord[2], pTriangleVertex->m_fTexCoord[3]);
	}

	// If the triangles are on different faces, create distinct vertices for unique texture coordinates
	nOppositeVertex = nTriangleVertex;
	pOppositeVertex = pTriangleVertex;
	if(pTriangle->GetTriangleFace() != pOpposite->GetTriangleFace())
	{
		nOppositeVertex = CVertex::Array.LockElement();