【008-Shader-漫反射】

// Upgrade NOTE: replaced '_Object2World' with 'unity_ObjectToWorld'

// 漫反射
Shader "Study/08-DiffuseShader"
{
    
    
    Properties
    {
    
    
        _MatColor("Mat Color",Color) = (1,1,1,1)
    }
    SubShader
    {
    
    
        // 渲染模式
        Tags{
    
    
            "LightMode" = "ForwardBase"
        }

        Pass
        {
    
    
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            // 使用光照库
            #include "Lighting.cginc"
            #include "UnityCG.cginc"

            struct appdata
            {
    
    
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
    
    
                float4 vertex : SV_POSITION;

                float4 world_vertex: TEXCOORD8;
                // 法向量
                float3 world_normal: TEXCOORD9;
            };

            v2f vert (appdata_full v)
            {
    
    
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.world_vertex = mul(unity_ObjectToWorld,v.vertex);
                o.world_normal = UnityObjectToWorldNormal(v.normal);
                return o;
            }

            float3 _MatColor;

            fixed4 frag (v2f i) : SV_Target
            {
    
    
                // color = light_col * mat_col * cos<N,L>
                // N.L = |N|*|L|*cos<N,L>
                float3 N = normalize(i.world_normal);
                float3 L = normalize(UnityWorldSpaceLightDir(i.world_vertex));

                float3 col = _LightColor0 * _MatColor * max(0,dot(N,L));
                return fixed4(col,1);
            }
            ENDCG
        }
    }
}