GGJ_2019/Assets/FogVolume/Resources/SpeedTreeVertexDepth.cginc

#ifndef SPEEDTREE_VERTEX_INCLUDED
#define SPEEDTREE_VERTEX_INCLUDED

///////////////////////////////////////////////////////////////////////  
//  SpeedTree v6 Vertex Processing

///////////////////////////////////////////////////////////////////////  
//  struct SpeedTreeVB

// texcoord setup
//
//		BRANCHES						FRONDS						LEAVES
// 0	diffuse uv, branch wind xy		"							"
// 1	lod xyz, 0						lod xyz, 0					anchor xyz, lod scalar
// 2	detail/seam uv, seam amount, 0	frond wind xyz, 0			leaf wind xyz, leaf group

struct SpeedTreeVB 
{
	float4 vertex		: POSITION;
	float4 tangent		: TANGENT;
	float3 normal		: NORMAL;
	float4 texcoord		: TEXCOORD0;
	float4 texcoord1	: TEXCOORD1;
	float4 texcoord2	: TEXCOORD2;
	float2 texcoord3	: TEXCOORD3;
	half4 color			: COLOR;
	
	UNITY_VERTEX_INPUT_INSTANCE_ID
};


///////////////////////////////////////////////////////////////////////  
//  SpeedTree winds

#ifdef ENABLE_WIND

#define WIND_QUALITY_NONE		0
#define WIND_QUALITY_FASTEST	1
#define WIND_QUALITY_FAST		2
#define WIND_QUALITY_BETTER		3
#define WIND_QUALITY_BEST		4
#define WIND_QUALITY_PALM		5

uniform half _WindQuality;
uniform half _WindEnabled;

#include "SpeedTreeWind.cginc"

#endif

///////////////////////////////////////////////////////////////////////  
//  OffsetSpeedTreeVertex

void OffsetSpeedTreeVertex(inout SpeedTreeVB data, float lodValue)
{
	
	float3 finalPosition = data.vertex.xyz;
	
	#ifdef ENABLE_WIND
		half windQuality = _WindQuality * _WindEnabled;

		float3 rotatedWindVector, rotatedBranchAnchor;
		if (windQuality <= WIND_QUALITY_NONE)
		{
			rotatedWindVector = float3(0.0f, 0.0f, 0.0f);
			rotatedBranchAnchor = float3(0.0f, 0.0f, 0.0f);
		}
		else
		{
			// compute rotated wind parameters
			rotatedWindVector = normalize(mul(_ST_WindVector.xyz, (float3x3)unity_ObjectToWorld));
			rotatedBranchAnchor = normalize(mul(_ST_WindBranchAnchor.xyz, (float3x3)unity_ObjectToWorld)) * _ST_WindBranchAnchor.w;
		}
	#endif

	#if defined(GEOM_TYPE_BRANCH) || defined(GEOM_TYPE_FROND)

		// smooth LOD
		#ifdef LOD_FADE_PERCENTAGE
			finalPosition = lerp(finalPosition, data.texcoord1.xyz, lodValue);
		#endif

		// frond wind, if needed
		#if defined(ENABLE_WIND) && defined(GEOM_TYPE_FROND)
			if (windQuality == WIND_QUALITY_PALM)
				finalPosition = RippleFrond(finalPosition, data.normal, data.texcoord.x, data.texcoord.y, data.texcoord2.x, data.texcoord2.y, data.texcoord2.z);
		#endif

	#elif defined(GEOM_TYPE_LEAF)

		// remove anchor position
		finalPosition -= data.texcoord1.xyz;

		bool isFacingLeaf = data.color.a == 0;
		if (isFacingLeaf)
		{
			#ifdef LOD_FADE_PERCENTAGE
				finalPosition *= lerp(1.0, data.texcoord1.w, lodValue);
			#endif
			// face camera-facing leaf to camera
			float offsetLen = length(finalPosition);
			finalPosition = mul(finalPosition.xyz, (float3x3)UNITY_MATRIX_IT_MV); // inv(MV) * finalPosition
			finalPosition = normalize(finalPosition) * offsetLen; // make sure the offset vector is still scaled
		}
		else
		{
			#ifdef LOD_FADE_PERCENTAGE
				float3 lodPosition = float3(data.texcoord1.w, data.texcoord3.x, data.texcoord3.y);
				finalPosition = lerp(finalPosition, lodPosition, lodValue);
			#endif
		}

		#ifdef ENABLE_WIND
			// leaf wind
			if (windQuality > WIND_QUALITY_FASTEST && windQuality < WIND_QUALITY_PALM)
			{
				float leafWindTrigOffset = data.texcoord1.x + data.texcoord1.y;
				finalPosition = LeafWind(windQuality == WIND_QUALITY_BEST, data.texcoord2.w > 0.0, finalPosition, data.normal, data.texcoord2.x, float3(0,0,0), data.texcoord2.y, data.texcoord2.z, leafWindTrigOffset, rotatedWindVector);
			}
		#endif

		// move back out to anchor
		finalPosition += data.texcoord1.xyz;

	#endif

	#ifdef ENABLE_WIND
		float3 treePos = float3(unity_ObjectToWorld[0].w, unity_ObjectToWorld[1].w, unity_ObjectToWorld[2].w);

		#ifndef GEOM_TYPE_MESH
			if (windQuality >= WIND_QUALITY_BETTER)
			{
				// branch wind (applies to all 3D geometry)
				finalPosition = BranchWind(windQuality == WIND_QUALITY_PALM, finalPosition, treePos, float4(data.texcoord.zw, 0, 0), rotatedWindVector, rotatedBranchAnchor);
			}
		#endif

		if (windQuality > WIND_QUALITY_NONE)
		{
			// global wind
			finalPosition = GlobalWind(finalPosition, treePos, true, rotatedWindVector, _ST_WindGlobal.x);
		}
	#endif

	data.vertex.xyz = finalPosition;
}

#endif // SPEEDTREE_VERTEX_INCLUDED