trimesh.cpp

3D赛车游戏源代码-用Visual Studio 2005

#include "StdAfx.h"
#include "TriMesh.h"
#include "OGLutil.h"

//-------------------------------------------------------------------------------
// 三角形网孔构造函数
//-------------------------------------------------------------------------------
TriMesh::TriMesh() 
{
	m_vertexCount = 0;
	m_vertexList = NULL;
	m_triCount = 0;
	m_triList = NULL;
	m_boundingBox.Empty();
}

//-------------------------------------------------------------------------------
// 析构函数，确定资源已经释放
//-------------------------------------------------------------------------------
TriMesh::~TriMesh() 
{
	FreeMemory();
}

//-------------------------------------------------------------------------------
// 为网孔数据分配内存
//-------------------------------------------------------------------------------
void TriMesh::AllocateMemory(int nVertexCount, int nTriCount) 
{
	FreeMemory();

	assert(nVertexCount <= 65536); 

	m_vertexCount = nVertexCount;
	m_vertexList = new RenderVertex[m_vertexCount];

	m_triCount = nTriCount;
	m_triList = new RenderTri[m_triCount];
}

//-------------------------------------------------------------------------------
// 释放内存以及把数据回复初始状态
//-------------------------------------------------------------------------------
void TriMesh::FreeMemory() 
{
	delete [] m_vertexList;
	delete [] m_triList;

	m_vertexList = NULL;
	m_triList = NULL;
	m_vertexCount = 0;
	m_triCount = 0;
}

//-------------------------------------------------------------------------------
// 根据当前的3D设备渲染这个网孔
//-------------------------------------------------------------------------------
void TriMesh::Render() const 
{
	g_Renderer.RenderTriMesh(m_vertexList, m_vertexCount, m_triList, m_triCount);
	// g_Renderer.RenderBox(m_boundingBox.min, m_boundingBox.max);
}

//-------------------------------------------------------------------------------
// 计算轴对齐盒子，依据顶点数据
//-------------------------------------------------------------------------------
void TriMesh::ComputeBoundingBox() 
{
	m_boundingBox.Empty();

	for (int i = 0 ; i < m_vertexCount ; ++i) 
	{
		m_boundingBox.Add(m_vertexList[i].p);
	}
}