游戏引擎

开发平台：
Visual C++

Heightmap.cpp：源码内容
							// Heightmap.cpp: implementation of the CHeightmap class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "Heightmap.h"
#include "stdio.h"
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
MOVE_VERTEX    * CHeightmap::m_pMovemap=NULL;
unsigned char  * CHeightmap::m_pTmap=NULL;
unsigned char  * CHeightmap::m_pCovermap=NULL;
VERTEX         * CHeightmap::m_pViewPos=NULL;
VERTEX         * CHeightmap::m_pSunPos =NULL;
float          * CHeightmap::m_pViewRotX=NULL;
float          * CHeightmap::m_pViewRotY=NULL;
bool             CHeightmap::m_bSunVisible=true;
int              CHeightmap::m_numUser=0;
BOUNDARY_2D      CHeightmap::m_rect=BOUNDARY_2D(0,0,0,0);
CHeightmap::CHeightmap()
{
	if(m_numUser==0)
	{
		/////////read terrain map
    	if(!ReadTerrainmapFile())
		{
		    MessageBox(0, "read heightmap failed", "Error", MB_OK | MB_ICONERROR);
		    return ;
		}
    	if(!ReadPlantmapFile())
		{
		    MessageBox(0, "read plantmap failed", "Error", MB_OK | MB_ICONERROR);
		    return ;
		}
		m_pMovemap =new MOVE_VERTEX [256*256];
        m_pViewPos =new VERTEX;
        m_pSunPos  =new VERTEX;
		m_pViewRotX=new float;
		m_pViewRotY=new float;
	}
	m_numUser++;
}
CHeightmap::~CHeightmap()
{
	m_numUser--;
	if(m_pTmap!=NULL && m_pCovermap!=NULL && (m_numUser==0))
	{
		delete [] m_pTmap;
		delete [] m_pCovermap;
		delete [] m_pMovemap;
		delete    m_pViewPos;
		delete    m_pSunPos;
		delete    m_pViewRotY;
		delete    m_pViewRotX;
		m_pTmap=NULL;
		m_pCovermap=NULL;
		m_pMovemap=NULL;
		m_pViewPos=NULL;
		m_pSunPos =NULL;
		m_pViewRotY=NULL;
		m_pViewRotX=NULL;
	}
}
unsigned char CHeightmap::GetHeightmapPointValue(VERTEX *checked)
{
	/*
	POINT point=ConvertToHeightmap(checked);
	return m_pTmap[256*point.y + point.x];*/
	return 0;
}
float CHeightmap::GetHeight(VERTEX *checked)
{
	POINT point=ConvertToHeightmap(checked);
	float Xpos,Zpos;
	if(checked->xpos<0)
	    Xpos=1+checked->xpos*0.1f-int(checked->xpos*0.1f);
	else
	    Xpos=checked->xpos*0.1f-int(checked->xpos*0.1f);
	if(checked->zpos<0)
	    Zpos=1+checked->zpos*0.1f-int(checked->zpos*0.1f);
	else 
		Zpos=checked->zpos*0.1f-int(checked->zpos*0.1f);
    ///////////////////////
	float ypos;
	float h11,h12,h22,h21;
	float ha,hb;
	//////////check Xpos and Zpos
	////////////////////////////
	int addx=point.x+1;
	int addy=point.y+1;
	if(addx==256)addx=0;
	if(addy==256)addy=0;
    h11=float(m_pTmap[256*(point.y+0) + (point.x+0)]);
    h12=float(m_pTmap[256*(addy) + (point.x+0)]);
    h21=float(m_pTmap[256*(point.y+0) + addx]);
    h22=float(m_pTmap[256*(addy) + addx]);
	ha=h11+Xpos*(h21-h11);
	hb=h12+Xpos*(h22-h12);	
    ypos=ha +Zpos*(hb-ha);
	return ypos;
}
float CHeightmap::GetHeight(float xpos,float zpos)
{
   VERTEX temp=VERTEX(xpos,0,zpos);
   float ypos=GetHeight(&temp);
   return ypos;
}
bool CHeightmap::CollideCheck(VERTEX viewPos,VERTEX objPos,float step)
{
	float dy=viewPos.ypos-objPos.ypos;
	float dx=viewPos.xpos-objPos.xpos;
	float dz=viewPos.zpos-objPos.zpos;
	int signx,signy,signz;
	if(dx<0)
	{dx=-dx; signx=-1;}
	else
        signx=1;
	if(dy<0)
	{dy=-dy; signy=-1;}
	else
        signy=1;
	if(dz<0)
	{dz=-dz; signz=-1;}
	else
        signz=1;
	float terrainHeight=GetHeight(&viewPos);
	float CurLineHeight=viewPos.ypos;
	
	float CurZ=viewPos.zpos;
	float CurX=viewPos.xpos;
	if(dz>dx)
	{
		int times=int(dz/step);
		float deltaH=dy/times;
		float deltax=signx*dx*step/dz;
        for(int i=0;i<times;i++)
		{
			if(terrainHeight>CurLineHeight)return true;
            CurLineHeight -= signy*deltaH;
			terrainHeight=GetHeight(CurX,CurZ);
			CurX-=deltax;
			CurZ-=signz*step;
		}
	}
	else
	{
		int times=int(dx/step);
		float deltaH=dy/times;
		float deltaz=signz*dz*step/dx;
        for(int i=0;i<times;i++)
		{
			if(terrainHeight>CurLineHeight)return true;
            CurLineHeight -= signy*deltaH;
			terrainHeight=GetHeight(CurX,CurZ);
			CurZ-=deltaz;
			CurX-=signx*step;
		}
	}
    return false;
}
bool CHeightmap::IsInFrustum(VERTEX checked)
{
	POINT point=ConvertToMovemap(checked);
	if(point.x==0 && point.y==0)return false;
	return true;
}
bool CHeightmap::CheckSunVisible()
{
	if(!m_bSunVisible)return false;
	float dx=m_pViewPos->xpos-m_pSunPos->xpos ;
	float dz=m_pViewPos->zpos-m_pSunPos->zpos ;
	float dy=m_pViewPos->ypos-m_pSunPos->ypos ;
    
	float absx=dx;
	if(absx<0)absx=-absx;
	float absz=dz;
	if(absz<0)absz=-absz;
	float max=absz;
	if(absx>max)max=absx;
	max=200/max;
	dx=dx*max;
	dz=dz*max;
	dy=dy*max*0.85f;
	VERTEX checkPos=VERTEX(m_pViewPos->xpos-dx,m_pViewPos->ypos-dy,m_pViewPos->zpos-dz);
	return !CollideCheck(*m_pViewPos,checkPos,2);
}
POINT CHeightmap::ConvertToHeightmap(VERTEX *pos)
{
	POINT point;
	if(pos->xpos<0)
	    point.x=255+int(pos->xpos*0.1f)%256;
	else
		point.x=int(pos->xpos*0.1f)%256;
	if(pos->zpos<0)
	    point.y=255+int(pos->zpos*0.1f)%256;
	else 
		point.y=int(pos->zpos*0.1f)%256;
	return point;
}
POINT CHeightmap::ConvertToMovemap(VERTEX pos)
{
 	POINT point;
    
	point.x=int((pos.xpos-m_pViewPos->xpos)*0.05f)+128;
	point.y=int((pos.zpos-m_pViewPos->zpos)*0.05f)+128;
	if(point.x<m_rect.minx || point.x>m_rect.maxx )
	{   
		POINT p;
	    p.x=p.y=0;
		return p;
	}
	if(point.y<m_rect.minz || point.y>m_rect.maxz )
	{   
		POINT p;
	    p.x=p.y=0;
		return p;
	}
 
	return point;
}
bool CHeightmap::ReadTerrainmapFile()
{
	FILE *fp;
	fp=fopen("Terrains/ter256.bmp","rb");
	if(!fp)return false;
	BITMAPFILEHEADER fileheader;
	fread(&fileheader,sizeof(BITMAPFILEHEADER),1,fp);
	if(fileheader.bfType!=19778)return false;
    m_pTmap=new unsigned char[256*256];
	if(m_pTmap==NULL)return false;
    fseek(fp,1078,SEEK_SET);
	for(int z=255;z>-1;z--)
		for(int x=0;x<256;x++)
		{
			fread(&m_pTmap[256*z+x],sizeof(unsigned char),1,fp);	
		}	
	fclose(fp);
    return true;
}
bool CHeightmap::ReadPlantmapFile()
{
	FILE *fp;
	fp=fopen("plants/plantmap.bmp","rb");
	if(!fp)return false;
	BITMAPFILEHEADER fileheader;
	fread(&fileheader,sizeof(BITMAPFILEHEADER),1,fp);
	if(fileheader.bfType!=19778)return false;
    m_pCovermap=new unsigned char[256*256];
	if(m_pCovermap==NULL)return false;
    fseek(fp,1078,SEEK_SET);
	for(int z=255;z>-1;z--)
		for(int x=0;x<256;x++)
		{
			fread(&m_pCovermap[256*z+x],sizeof(unsigned char),1,fp);	
		}	
	fclose(fp);
    return true;
}
int  CHeightmap::GetPosInMovemap(int x,int z)
{
    return m_pMovemap[(128+z)*256+128+x].zpos*256+m_pMovemap[(128+z)*256+128+x].xpos;
}

						