// Shave and a Haircut
// (c) 2019 Epic Games
// US Patent 6720962

#include "shaveVrayTriShadeData.h"
#include "shaveVrayInstanceI.h"
#include "shaveVrayTriVoxelPrim.h"
#include "shaveVrayStaticTriVoxelPrim.h"
#include "misc_ray.h"


shaveVrayTriShadeData::shaveVrayTriShadeData(shaveVrayInstanceI *instance) 
	: BaseShadeData(instance) 
{
}

void shaveVrayTriShadeData::init(const VR::TraceTransform &itm) 
{
	this->itm=itm*0.01f;
}

bool shaveVrayTriShadeData::getUVWTriVerts(const VR::VRayContext &rc, VR::ShadeVec &t0, VR::ShadeVec &t1, VR::ShadeVec &t2)
{
	shaveVrayInstanceI* I = static_cast<shaveVrayInstanceI*>(instance);
	const VR::RayResult& rres = rc.rayresult;

	assert(PRIM_TYPE_STATIC_TRIANGLE == rres.primitive->type() || 
		   PRIM_TYPE_MOVING_TRIANGLE == rres.primitive->type());

	if(PRIM_TYPE_STATIC_TRIANGLE != rres.primitive->type() &&
	   PRIM_TYPE_MOVING_TRIANGLE != rres.primitive->type())
		return false;
	
	int fidx = rres.faceIndex;
	if(I->GetNumFacesPerInst() == 0)
		return false;
	
	int tidx = fidx % I->GetNumFacesPerInst();
	int i0 = tidx*3;
	int i1 = i0 + 1;
	int i2 = i1 + 1;
	t0 = toShadeVec(I->GetUV(i0));
	t1 = toShadeVec(I->GetUV(i1)); 
	t2 = toShadeVec(I->GetUV(i2));
	return true;
}

#if defined(VRAY30)
VR::Transform shaveVrayTriShadeData::getLocalUVWTransform(const VR::VRayContext &rc, int channel) 
{
	(void) channel; //unused
	VR::Transform result(1);
	VR::Vector t0, t1, t2;
	if (!getUVWTriVerts(rc, t0, t1, t2)) {
		return result;
	}
	const VR::RayResult& rres = rc.rayresult;
	const VR::Vector& bary = rres.bary;
	result.offs = bary.x*t0 + bary.y*t1 + bary.z*t2;
	VR::Vector dt0 = t1 - t0;
	VR::Vector dt1 = t2 - t0;

	if(!computeUVWMatrix(rres.faceEdge0, rres.faceEdge1, dt0, dt1, result.m))
		result.m = VR::Matrix(1);
	
	return result;
}

VR::Vector shaveVrayTriShadeData::getLocalUVWCoordinates(const VR::VRayContext &rc, int channel) 
{
	(void) channel; //unused
	VR::Vector t0, t1, t2;
	if (!getUVWTriVerts(rc, t0, t1, t2)) {
		return VR::Vector();
	}
	const VR::RayResult& rres = rc.rayresult;
	const VR::Vector& bary = rres.bary;
	VR::Vector t = bary.x*t0 + bary.y*t1 + bary.z*t2;
	return t;
}
#elif defined(VRAY40)
void shaveVrayTriShadeData::getLocalUVWTransform(const VR::VRayContext &rc, int channel, VR::ShadeTransform &result)
{
	(void) channel; //unused
	VR::ShadeVec t0, t1, t2;
	if (!getUVWTriVerts(rc, t0, t1, t2)) {
		result.makeIdentity();
		return;
	}
	const VR::RayResult& rres = rc.rayresult;
	const VR::ShadeVec& bary = rres.bary;
	result.offs = VR::x(bary)*t0 + VR::y(bary)*t1 + VR::z(bary)*t2;
	VR::ShadeVec dt0 = t1 - t0;
	VR::ShadeVec dt1 = t2 - t0;

	if(!VUtils::computeUVWMatrix(rres.faceEdge0, rres.faceEdge1, dt0, dt1, result.m))
		result.m.makeIdentity();
}

void shaveVrayTriShadeData::getLocalUVWCoordinates(const VR::VRayContext &rc, int channel, VR::ShadeVec &result)
{
	(void) channel; //unused
	VR::ShadeVec t0, t1, t2;
	if (!getUVWTriVerts(rc, t0, t1, t2)) {
		result.makeZero();
	}
	const VR::RayResult& rres = rc.rayresult;
	const VR::ShadeVec& bary = rres.bary;
	result = VR::x(bary)*t0 + VR::y(bary)*t1 + VR::z(bary)*t2;
}

int shaveVrayTriShadeData::getLocalUVWTransformByName(const VR::VRayContext &rc, const VR::StringID &channelName, VR::ShadeTransform &result)
{
	(void) rc;
	(void) channelName;
	(void) result;
	return channelNotFound;
}

int shaveVrayTriShadeData::getUVWCoordinatesByName(const VR::VRayContext &rc, const VR::StringID &channelName, VR::ShadeVec &result)
{
	(void) rc;
	(void) channelName;
	(void) result;
	return channelNotFound;
}

VR::ShadeVec shaveVrayTriShadeData::getMapChannelVertexVector(int mapChannelIdx, int vertexIdx)
{
	(void)mapChannelIdx;
	(void)vertexIdx;
	return VR::ShadeVec(0.0f);
}

VR::ShadeVec shaveVrayTriShadeData::getUVWcoords(const VR::VRayContext &rc, int channel) {
	return getMappedUVWcoords(rc, *this, channel);
}

void shaveVrayTriShadeData::getUVWderivs(const VR::VRayContext &rc, int channel, VR::ShadeVec derivs[2]) {
	getMappedUVWderivs(rc, *this, channel, derivs);
}

void shaveVrayTriShadeData::getUVWbases(const VR::VRayContext &rc, int channel, VR::ShadeVec bases[3]) {
	getMappedUVWbases(rc, *this, channel, bases);
}

VR::ShadeVec shaveVrayTriShadeData::getUVWnormal(const VR::VRayContext &rc, int channel) {
	return getMappedUVWnormal(rc, *this, channel);
}

#endif