/// <summary>
/// FragmentShader是结构体 值类型，MyColor是类类型，引用类型
/// </summary>
/// <param name="FS"></param>
/// <param name="mycolor"></param>
/// <returns></returns>
public static MyColor LightMode_BlinnPhong(a2v FS, MyColor mycolor, bool IsTexture, bool IsPointLighting, Light PointLight)
{
//----------------------所有颜色统一在0-1内计算----------------返回mycolor时，在回到0-255
//材质 光照 暂时写在这边 完成光照模型后，写在外部
//MyColor Ambient = new MyColor(0, 0, 0); //环境光 可以不和下面两个一样
MyColor Ambient = new MyColor(0.3, 0.3, 0.3);
//MyColor Diffuse = new MyColor(0, 0, 0);
MyColor Diffuse = new MyColor(0.3, 0.3, 0.3);
//MyColor Specular = new MyColor(0, 0, 0);
MyColor Specular = new MyColor(0.8, 0.8, 0.8);
Material material = new Material(Ambient, Diffuse, Specular);
//PointLight = new Light(new Vector(5, 10, 0, 1), new MyColor(1, 1, 1));
//读取纹理的颜色 先假设为mycolor
MyColor texture = new MyColor();
if (IsTexture)
{
texture = new MyColor(mycolor).Scale(1.0 / 255);
}
else
{
texture.r = 0.5;
texture.g = 0.5;
texture.b = 0.5;
}
if (IsPointLighting)
{
Vector normal = new Vector(FS.WorldNormal);
Vector ViewDir = FS.eye - FS.WorldPos;
ViewDir.NormalizedVector();
Vector LightDir = PointLight.LightPos - FS.WorldPos;
double distance = LightDir.Length();//光源与渲染点的距离
LightDir.NormalizedVector();
//----衰减计算----
double constant = 1;
double linear = 0.0009;
double quadratic = 0.000032;
double num = constant + linear * distance + quadratic * (distance * distance);
double attenuation = 0;
if (num != 0)
{
attenuation = 1.0 / num;
}
attenuation = MyStaticMethod.MaxNumber(attenuation, 0);
MyColor LightAmbient = texture * ((PointLight.LightColor + EnvironmentLight) * material.Ambient);
//漫反射系数计算
double diff = MyStaticMethod.MaxNumber(Vector.DotMultiply(normal, LightDir), 0);
MyColor LightDiffuse = texture * (PointLight.LightColor * material.Diffuse) * diff;
//反射计算 blinn-phong
Vector H = (LightDir + ViewDir).NormalizedVector();
double shininess = 256;//镜面反射系数
double reflect = Math.Pow(MyStaticMethod.MaxNumber(Vector.DotMultiply(H, normal), 0), shininess);
MyColor LightSpecular = texture * PointLight.LightColor * material.Specular * reflect;
//MyColor ret = LightAmbient + (LightDiffuse + LightSpecular);
MyColor ret = LightAmbient + (LightDiffuse + LightSpecular) * attenuation;
ret.Scale(255.0);
return(ret);
}
else
{
MyColor ret = texture.Scale(255.0);
return(ret);
}
}
