101 lines
2.6 KiB
C++
101 lines
2.6 KiB
C++
// Lighting.cpp: implementation of the CLighting class.
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//
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//////////////////////////////////////////////////////////////////////
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#include "stdafx.h"
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#include "Test.h"
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#include "Lighting.h"
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#include "math.h"
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#define PI 3.14159265
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#define MIN(a,b) ((a<b)?(a):(b))
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#define MAX(a,b) ((a>b)?(a):(b))
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#ifdef _DEBUG
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#undef THIS_FILE
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static char THIS_FILE[]=__FILE__;
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#define new DEBUG_NEW
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#endif
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//////////////////////////////////////////////////////////////////////
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// Construction/Destruction
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//////////////////////////////////////////////////////////////////////
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CLighting::CLighting()
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{
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LightNum=1;
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Light=new CLight[LightNum];
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Ambient=CRGB(0.3,0.3,0.3);//环境光恒定不变
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}
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CLighting::~CLighting()
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{
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if(Light)
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{
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delete []Light;
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Light=NULL;
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}
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}
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void CLighting::SetLightNumber(int lnum)
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{
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if(Light)
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{
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delete []Light;
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}
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LightNum=lnum;
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Light=new CLight[lnum];
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}
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CLighting::CLighting(int lnum)
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{
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LightNum=lnum;
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Light=new CLight[lnum];
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Ambient=CRGB(0.3,0.3,0.3);
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}
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CRGB CLighting::Lighting(CP3 ViewPoint,CP3 Point,CVector Normal,CMaterial *pMaterial)
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{
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CRGB LastC=pMaterial->M_Emit;//材质自身发散色为初始值
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for(int i=0;i<LightNum;i++)//来自光源
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{
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if(Light[i].L_OnOff)
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{
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CRGB InitC;
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InitC.red=0,InitC.green=0,InitC.blue=0;
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CVector VL(Point,Light[i].L_Position);//VL为指向光源的矢量
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double d=VL.Mag();//d为光传播的距离，等于光矢量VL的模
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VL=VL.Normalize();//单位化光矢量
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CVector VN=Normal;
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VN=VN.Normalize();//单位化法矢量
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//第1步，加入漫反射光
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double CosTheta=MAX(Dot(VL,VN),0);
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InitC.red+=Light[i].L_Diffuse.red*pMaterial->M_Diffuse.red*CosTheta;
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InitC.green+=Light[i].L_Diffuse.green*pMaterial->M_Diffuse.green*CosTheta;
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InitC.blue+=Light[i].L_Diffuse.blue*pMaterial->M_Diffuse.blue*CosTheta;
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//第2步，加入镜面反射光
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CVector VV(Point,ViewPoint);//VV为视矢量
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VV=VV.Normalize();//单位化视矢量
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CVector VH=(VL+VV)/(VL+VV).Mag();//VH为平分矢量
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double nHN=pow(MAX(Dot(VH,VN),0),pMaterial->M_n);
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InitC.red+=Light[i].L_Specular.red*pMaterial->M_Specular.red*nHN;
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InitC.green+=Light[i].L_Specular.green*pMaterial->M_Specular.green*nHN;
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InitC.blue+=Light[i].L_Specular.blue*pMaterial->M_Specular.blue*nHN;
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//第3步，光强衰减
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double c0=Light[i].L_C0;//c0为常数衰减因子
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double c1=Light[i].L_C1;//c1线性衰减因子
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double c2=Light[i].L_C2;//c2二次衰减因子
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double f=(1.0/(c0+c1*d+c2*d*d));//光强衰减函数
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f=MIN(1.0,f);
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LastC+=InitC*f;
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}
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else
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{
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LastC+=Point.c;//物体自身颜色
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}
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}
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//第4步，加入环境光
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LastC+=Ambient*pMaterial->M_Ambient;
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//第5步，颜色归一化到[0,1]区间
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LastC.Normalize();
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//第6步，返回所计算顶点的光强颜色
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return LastC;
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}
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