game_terrain.cpp

自己写的一个D3D游戏Dome。实现了基本的游戏功能

#include "..\Include\Game_Terrain.h"

Game_Terrain::Game_Terrain(D3DXVECTOR3 pos,
						   LPCTSTR strTerrain,
						   float cellWidth,
						   float height,
						   float nTile){
	m_v3=pos;
	m_nCol=0;
	m_nRow=0;

	m_pTexture=NULL;
	m_nTile=nTile;
	m_CellWidth=cellWidth;
	m_maxHeight=height; 
	m_cStrTerrain=strTerrain;
}

Game_Terrain::~Game_Terrain(){
	SAFE_RELEASE(m_pTexture);
}

void Game_Terrain::InitObject(LPCTSTR strName){
	D3DXCreateTextureFromFile(g_sGlobal.g_pDevice,strName,&m_pTexture);
	
	//用GDI对象来读取位图，但是会转换成DIB位图
	long i=0,j=0;
	BITMAP  bmp;
	HBITMAP	hBmp;
	HDC		hDC;
	HBITMAP	oldBmp;
	hDC=CreateCompatibleDC(NULL); 
	hBmp=(HBITMAP)LoadImage(NULL,m_cStrTerrain,
		IMAGE_BITMAP,m_nCol,m_nRow,LR_LOADFROMFILE);
	oldBmp=(HBITMAP)SelectObject(hDC,hBmp);

	GetObject(hBmp,sizeof(bmp),&bmp);
	m_nCol=bmp.bmWidth;
	m_nRow=bmp.bmHeight; 
	m_pHeightData=new BYTE[m_nCol*m_nRow];
	DWORD color;

	for(i=0;i<m_nRow;i++){	
		for(j=0;j<m_nCol;j++){
			color=GetPixel(hDC,j,i);
			m_pHeightData[i*m_nCol+j]=*(BYTE*)&color;		//取红色通道 0xAABBGGRR
		}
	}
	DeleteObject(oldBmp);
	DeleteObject(hDC);
	DeleteObject(hBmp);
	m_dwNumOfVertices = m_nRow * m_nCol;
	m_dwNumOfPolygons = (m_nCol-1)*(m_nRow-1)*2;

	D3DXCreateMeshFVF(m_dwNumOfPolygons,m_dwNumOfVertices,D3DXMESH_MANAGED,D3DFVF_TERRAIN ,g_sGlobal.g_pDevice,&m_pMesh);

	TVertexBuffer* pVertices;
	m_pMesh->LockVertexBuffer(0,(void**)&pVertices);
	for(i=0;i<m_nCol*m_nRow;i++){
		pVertices[i].y=m_pHeightData[i];
		pVertices[i].x=float(i%m_nCol);
		pVertices[i].z=-float(i/m_nCol)+m_nRow;
		pVertices[i].nx=0;
		pVertices[i].ny=1;
		pVertices[i].nz=0;

		pVertices[i].tu=m_nTile*pVertices[i].x/m_nCol ;
		pVertices[i].tv=m_nTile*pVertices[i].z/m_nRow ;

	}

	m_pMesh->UnlockVertexBuffer();

	WORD* pIndex;
	m_pMesh->LockIndexBuffer(0,(void**)&pIndex);
	for(i=0,j=0;i<m_nCol*m_nRow;i++){
		if((i+1)%m_nCol && i/m_nCol!=m_nRow-1){
			pIndex[j+0]=(WORD)(i);
			pIndex[j+1]=(WORD)(i+1);
			pIndex[j+2]=(WORD)(i+m_nCol);
			pIndex[j+3]=(WORD)(i+m_nCol);
			pIndex[j+4]=(WORD)(i+1);
			pIndex[j+5]=(WORD)(i+1+m_nCol);
			j+=6;
		}
	}

	m_pMesh->UnlockIndexBuffer();


	//g_sGlobal.g_pDevice->SetRenderState(D3DRS_LIGHTING,TRUE);

	g_sGlobal.g_pDevice->SetRenderState(D3DRS_ZENABLE,TRUE);   
	g_sGlobal.g_pDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE);
	g_sGlobal.g_pDevice->SetRenderState(D3DRS_SRCBLEND,  D3DBLEND_SRCALPHA);
	g_sGlobal.g_pDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA);

	g_sGlobal.g_pDevice->SetSamplerState(0,D3DSAMP_ADDRESSU,D3DTADDRESS_MIRROR);
	g_sGlobal.g_pDevice->SetSamplerState(0,D3DSAMP_ADDRESSV,D3DTADDRESS_MIRROR);
	g_sGlobal.g_pDevice->SetTextureStageState(0,D3DTSS_COLOROP,D3DTOP_BLENDTEXTUREALPHA);

	g_sGlobal.g_pDevice->SetSamplerState(0,D3DSAMP_MAGFILTER,D3DTEXF_LINEAR);
	g_sGlobal.g_pDevice->SetSamplerState(0,D3DSAMP_MIPFILTER, D3DTEXF_LINEAR);
	g_sGlobal.g_pDevice->SetSamplerState(0,D3DSAMP_MINFILTER, D3DTEXF_LINEAR);
}

void Game_Terrain::FrameMove(){
	ZeroMemory(&m_matWorld,sizeof(m_matWorld));
	m_matWorld._11=m_CellWidth;
	m_matWorld._22=m_maxHeight/255.0f;
	m_matWorld._33=m_CellWidth;
	m_matWorld._44=1;

	m_matWorld._41=m_v3.x-m_nCol*m_CellWidth/2;	//地形中心在m_vPos
	m_matWorld._42=m_v3.y;  
	m_matWorld._43=m_v3.z-m_nRow*m_CellWidth/2;		//地形中心在m_vPos
	g_sGlobal.g_pDevice->SetTransform(D3DTS_WORLD,&m_matWorld);
}

void Game_Terrain::Render(){
	/*if ( m_bHide )
	return;*/
	g_sGlobal.g_pDevice->SetTexture(0,m_pTexture);
	FrameMove();
	m_pMesh->DrawSubset(0);
}

FLOAT Game_Terrain::GetHeight(float x,float z){
	D3DXVECTOR3 vPos(0,0,0);
	x+=vPos.x+m_CellWidth*m_nCol/2.0f;
	z+=vPos.z+m_CellWidth*m_nRow/2.0f;

	float rx,rz;
	rx=x/m_CellWidth;
	rz=m_nRow-z/m_CellWidth;

	long col1,row1,col2,row2;
	float h1,h2,h3,h4,ha,hb;
	col1=DWORD(rx);
	row1=DWORD(rz);

	if(col1>m_nCol || col1<0 ||row1>m_nRow || row1<0) return 0;
	else {	//双线性插值
		col2=(col1==m_nCol)?col1:col1+1;
		row2=(row1==m_nRow)?row1:row1+1;
		h1=(m_pHeightData[row1*m_nCol+col1]*m_maxHeight/255.0f);	
		h2=(m_pHeightData[row1*m_nCol+col2]*m_maxHeight/255.0f);	
		h3=(m_pHeightData[row2*m_nCol+col1]*m_maxHeight/255.0f);	
		h4=(m_pHeightData[row2*m_nCol+col2]*m_maxHeight/255.0f);	
		ha=(h2*(rx-col1)+h1*(col2-rx));
		hb=(h4*(rx-col1)+h3*(col2-rx));
		return (hb*(rz-row1)+ha*(row2-rz));
	}
}

HRESULT Game_Terrain::GetTerrainVertex(D3DXVECTOR3 *cross,DWORD index,float u,float v){
	WORD* pIndices;
	WORD index1,index2,index3;
	D3DXVECTOR3 v1,v2,v3;
	m_pMesh->LockIndexBuffer(0,(void**)&pIndices);

	index1=pIndices[index*3];
	index2=pIndices[index*3+1];
	index3=pIndices[index*3+2];
	m_pMesh->UnlockIndexBuffer();

	TVertexBuffer* pcvVertices;
	m_pMesh->LockVertexBuffer (0,(void**)&pcvVertices);

	v1.x=pcvVertices[index1].x;
	v1.y=pcvVertices[index1].y;
	v1.z=pcvVertices[index1].z;

	v2.x=pcvVertices[index2].x;
	v2.y=pcvVertices[index2].y;
	v2.z=pcvVertices[index2].z;

	v3.x=pcvVertices[index3].x;
	v3.y=pcvVertices[index3].y;
	v3.z=pcvVertices[index3].z;
	m_pMesh->UnlockVertexBuffer();

	*cross = v1 + u * (v2 - v1) + v * (v3 - v1);
	cross->x=cross->x*m_matWorld._11+cross->y*m_matWorld._21+cross->z*m_matWorld._31+m_matWorld._41;
	cross->y=cross->x*m_matWorld._12+cross->y*m_matWorld._22+cross->z*m_matWorld._32+m_matWorld._42;
	cross->z=cross->x*m_matWorld._13+cross->y*m_matWorld._23+cross->z*m_matWorld._33+m_matWorld._43;
	return S_OK;
}