Shader "MY/PBR/VertexLit"
{
	Properties
	{
		_Color("Color", Color) = (1,1,1,1)
		_MainTex("主贴图", 2D) = "white"{}
		_NormalTex("法线", 2D) = "bump"{}
		_MetalnessTex("金属遮罩", 2D) = "black"{}
		_Metalness("金属系数", Range(0,1)) = 0.35
		_Smoothness("Smoothness", Range(0,1)) = 0.35
	}

		SubShader
		{
			Tags{ "RenderType" = "Geometry" "IgnoreProjector" = "False" }
			ColorMask RGB
			Pass
			{
				Name "FORWARD"
				Tags{ "LightMode" = "ForwardBase" }
				ColorMask RGB
				CGPROGRAM
				#pragma vertex vert_surf
				#pragma fragment frag_surf

				#include "HLSLSupport.cginc"
				#include "UnityCG.cginc"
				#include "Lighting.cginc"
				#include "AutoLight.cginc"

				uniform sampler2D _MainTex;
				uniform half4 _MainTex_ST;
				uniform sampler2D _NormalTex;
				uniform sampler2D _MetalnessTex;

				uniform fixed4 _Color;
				uniform fixed _Reflect;
				uniform fixed _Metalness;
				uniform fixed _Smoothness;
				uniform fixed _MatCapPower;

				struct v2f_surf
				{
					UNITY_POSITION(pos);
					half4 uv : TEXCOORD0;
					half4 tSpace0 : TEXCOORD1;
					half4 tSpace1 : TEXCOORD2;
					half4 tSpace2 : TEXCOORD3;
					half3 sh : TEXCOORD4;
					LIGHTING_COORDS(5, 6)
					half4 uv1 : TEXCOORD7;
				};

				struct PBROutput
				{
					fixed3 Albedo;
					fixed3 Normal;
					fixed3 Emission;
					fixed Metallic;
					fixed Smoothness;
					fixed Alpha;
				};

				inline fixed3 BRDF_PBS(PBROutput s, fixed3 viewDir, UnityGI gi)
				{
					fixed reflect;
					fixed3 specColor;
					fixed3 Albedo = s.Albedo;
					s.Albedo = DiffuseAndSpecularFromMetallic(s.Albedo, s.Metallic, specColor, reflect);
					fixed3 normal = normalize(s.Normal);
					fixed3 lightdir = gi.light.dir;
					fixed3 lightcolor = gi.light.color;

					fixed Roughness = 1 - s.Smoothness;
					fixed3 halfDir = normalize(lightdir + viewDir);
					fixed nv = abs(dot(normal, viewDir));
					fixed nl = saturate(dot(normal, lightdir));
					fixed nh = saturate(dot(normal, halfDir));
					fixed lv = saturate(dot(lightdir, viewDir));
					fixed lh = saturate(dot(lightdir, halfDir));

					fixed diffuseTerm = DisneyDiffuse(nv, nl, lh, Roughness) * nl;
					fixed roughness = Roughness * Roughness;

					roughness = max(roughness, 0.002);
					fixed V = SmithJointGGXVisibilityTerm(nl, nv, roughness);
					fixed D = GGXTerm(nh, roughness);

					fixed specularTerm = V * D * UNITY_PI;
					specularTerm = sqrt(max(1e-4h, specularTerm));
					specularTerm = max(0, specularTerm * nl);

					return s.Albedo * (gi.indirect.diffuse + lightcolor * diffuseTerm) + specularTerm * lightcolor * FresnelTerm(specColor, lh);
				}


				v2f_surf vert_surf(appdata_full v)
				{
					v2f_surf o = (v2f_surf)0;
					o.pos = UnityObjectToClipPos(v.vertex);
					o.uv.xy = TRANSFORM_TEX(v.texcoord, _MainTex);
					half3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
					fixed3 worldNormal = UnityObjectToWorldNormal(v.normal);
					fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);
					fixed tangentSign = v.tangent.w * unity_WorldTransformParams.w;
					fixed3 worldBinormal = cross(worldNormal, worldTangent) * tangentSign;
					o.tSpace0 = half4(worldTangent.x, worldBinormal.x, worldNormal.x, worldPos.x);
					o.tSpace1 = half4(worldTangent.y, worldBinormal.y, worldNormal.y, worldPos.y);
					o.tSpace2 = half4(worldTangent.z, worldBinormal.z, worldNormal.z, worldPos.z);
					o.sh = ShadeSHPerVertex(worldNormal, o.sh);
					return o;
				}

				fixed4 frag_surf(v2f_surf IN) : SV_Target
				{
					fixed4 albedo = tex2D(_MainTex, IN.uv.xy);
					fixed4 c = albedo;
					fixed3 normal = UnpackNormal(tex2D(_NormalTex, IN.uv.xy));
					fixed2 metalnessTexed = tex2D(_MetalnessTex, IN.uv.xy).ra * _Metalness;
					metalnessTexed.g *= _Smoothness;
					fixed metallic = metalnessTexed.r;

					//边缘光
					half3 worldPos = half3(IN.tSpace0.w, IN.tSpace1.w, IN.tSpace2.w);
					fixed3 worldViewDir = normalize(UnityWorldSpaceViewDir(worldPos));

					PBROutput o = (PBROutput)0;
					o.Albedo = albedo.rgb * _Color.rgb;
					o.Normal = normal;
					o.Metallic = metallic;
					o.Smoothness = metalnessTexed.g;
					o.Emission = 0;

					fixed3 worldN;
					worldN.x = dot(IN.tSpace0.xyz, o.Normal);
					worldN.y = dot(IN.tSpace1.xyz, o.Normal);
					worldN.z = dot(IN.tSpace2.xyz, o.Normal);
					worldN = normalize(worldN);
					o.Normal = worldN;

					UnityGI gi;
					gi.indirect.diffuse = ShadeSHPerPixel(o.Normal, IN.sh, worldPos);
					gi.indirect.specular = 0;
					gi.light.color = _LightColor0.rgb;
					gi.light.dir = normalize(UnityWorldSpaceLightDir(worldPos));

					c.rgb = BRDF_PBS(o, worldViewDir, gi);
					c.rgb += o.Emission;
					c.a *= _Color.a;
					return c;
				}
				ENDCG
			}
		}
}