#Material
Name        BlinnPhong+HalfLambert shading model only color
Reference   https://zhuanlan.zhihu.com/p/442023993
Base        Std3D/BlinnPhong

//某些Require并不真的存在.ubo文件，写成一行一个是为了方便未来改成带路径的
Require     LocalToWorld
Require     Camera

define      HAVE_SPECULAR   off     //默认不定义HAVE_SPECULAR

UBO
{
    File    BlinnPhongSun.ubo   //文件名,如果/开头表示从ShaderLibrary根目录开始，没有则表示同一目录
    Struct  BlinnPhongSun       //结构名称
    Name    sun                 //在代码中的变量名
    Stage   Fragment            //会引用的shader
    Set     Global              //Descriptor Set
}

#MaterialInstance
Length 16
Stage  Fragment
Code
{
    vec3 Color;
    float Gloss;
}

#VertexInput
vec3 Normal

#Vertex
Output
{
    vec4 Position;
    vec3 Normal;
}

Code
{
    mat3 GetNormalMatrix()
    {
        return mat3(camera.view*GetLocalToWorld());
    }

    vec3 GetNormal(mat3 normal_matrix,vec3 normal)
    {
        return normalize(normal_matrix*normal);
    }

    void main()
    {
        mat3 normal_matrix=GetNormalMatrix();

        Output.Normal   =GetNormal(normal_matrix,Normal);
        Output.Position =GetPosition3D();
        
        HandoverMI();

        gl_Position     =Output.Position;
    }
}

#Fragment
Output
{
    vec4 FragColor;
}

Code
{
    void main()
    {
        MaterialInstance mi=GetMI();

        //将法线归一化
//        vec3 world_normal           =normalize(Input.Normal);

        //对世界坐标下的灯光方法归一化
//        vec3 world_light_direction  =normalize(sun.direction.xyz);

        //点乘法线和光照
        float intensity=0.5*max(dot(Input.Normal,sun.direction.xyz),0.0)+0.5;

        //直接光颜色
        vec3 direct_color           =intensity*sun.color.rgb*mi.Color.rgb;

//    #ifndef HAVE_SPECULAR
//        FragColor=vec4(direct_color,1.0);
//     #else

        vec3 spec_color=vec3(0.0);

        if(intensity>0.0)
        {
            vec3 half_vector=normalize(sun.direction.xyz+normalize(Input.Position.xyz+camera.pos));

            float specular=max(dot(half_vector,Input.Normal),0.0);

            spec_color=specular*pow(specular,mi.Gloss)*sun.color.rgb;
        }
        
        FragColor=vec4(direct_color+spec_color,1.0);
//     #endif//HAVE_SPECULAR
    }
}