// Not for redistribution without the author's express written permission
#ifndef MMDLIT_SURFACEEDGE_LIGHTING_INCLUDED
#define MMDLIT_SURFACEEDGE_LIGHTING_INCLUDED

#include "MMD4Mecanim-MMDLit-Surface-Tessellation.cginc"
#include "MMD4Mecanim-MMDLit-Compatible.cginc"

half _AmbientToDiffuse;
half4 _EdgeColor;
float _EdgeSize;

#define MMDLIT_GLOBALLIGHTING (0.6)
#define MMDLIT_EDGE_ZOFST (0.00001)

inline float MMDLit_GetEdgeSize()
{
	return _EdgeSize;
}

inline float4 MMDLit_GetEdgeVertex(float4 vertex, float3 normal)
{
#if 1
	float edge_size = MMDLit_GetEdgeSize();
#else
	// Adjust edge_size by distance & fovY
	float4 world_pos = mul(MMDLit_GetMatrixMV(), vertex);
	float r_proj_y = UNITY_MATRIX_P[1][1];
	float edge_size = abs(MMDLit_GetEdgeSize() / r_proj_y * world_pos.z) * 2.0;
#endif
	return vertex + float4(normal.xyz * edge_size, 0.0);
}

inline float4 MMDLit_TransformEdgeVertex(float4 vertex)
{
#if 0
	vertex = _UnityObjectToClipPos(vertex);
	vertex.z += MMDLIT_EDGE_ZOFST * vertex.w;
	return vertex;
#else
	return _UnityObjectToClipPos(vertex);
#endif
}

inline half3 MMDLit_GetAlbedo(out half alpha)
{
	alpha = _EdgeColor.a;
	return (half3)_EdgeColor;
}

inline half3 MMDLit_Lighting(half3 albedo, half atten, half3 globalAmbient)
{
	half3 color = (half3)_LightColor0 * MMDLIT_ATTEN(atten);
	color *= MMDLIT_GLOBALLIGHTING;
	#ifdef AMB2DIFF_ON
	color *= saturate(globalAmbient * _AmbientToDiffuse); // Feedback ambient for Unity5.
	#endif
	#ifdef UNITY_PASS_FORWARDADD
	// No Ambient.
	#else
	color += globalAmbient;
	#endif
	color *= albedo;
	return color;
}

#endif // MMDLIT_SURFACEEDGE_LIGHTING_INCLUDED