#include "CSkinRules.hpp"
#include "CToken.hpp"
#include "Graphics/CModel.hpp"
#include "CPoseAsTransforms.hpp"

namespace urde
{

CSkinRules::CSkinRules(CInputStream& in)
{
    u32 bankCount = in.readUint32Big();
    x0_skinBanks.reserve(bankCount);
    for (u32 i=0 ; i<bankCount ; ++i)
        x0_skinBanks.emplace_back(in);

    u32 virtualBoneCount = in.readUint32Big();
    m_virtualBones.reserve(virtualBoneCount);
    for (u32 i=0 ; i<virtualBoneCount ; ++i)
        m_virtualBones.emplace_back(in);

    u32 poolSz = in.readUint32Big();
    m_poolToSkinIdx.reserve(poolSz);
    for (u32 i=0 ; i<poolSz ; ++i)
        m_poolToSkinIdx.push_back(in.readUint32Big());
}

void CSkinRules::TransformVerticesCPU(std::vector<std::pair<zeus::CVector3f, zeus::CVector3f>>& vnOut,
                                      const CPoseAsTransforms& pose, const CModel& model) const
{
    vnOut.resize(m_poolToSkinIdx.size());
    for (size_t i=0 ; i<m_poolToSkinIdx.size() ; ++i)
    {
        const CVirtualBone& vb = m_virtualBones[m_poolToSkinIdx[i]];
        zeus::CVector3f origVertex = model.GetPoolVertex(i);
        zeus::CVector3f vertex;
        zeus::CVector3f origNormal = model.GetPoolNormal(i);
        zeus::CVector3f normal;
        for (const SSkinWeighting& w : vb.GetWeights())
        {
            const zeus::CTransform& xf = pose.GetRestToAccumTransform(w.m_id);
            vertex += (xf * origVertex) * w.m_weight;
            normal += (xf.basis.inverted().transposed() * origNormal) * w.m_weight;
        }
        vnOut[i] = std::make_pair(vertex, normal.normalized());
    }
}

CFactoryFnReturn FSkinRulesFactory(const SObjectTag& tag, CInputStream& in, const CVParamTransfer& params,
                                   CObjectReference* selfRef)
{
    return TToken<CSkinRules>::GetIObjObjectFor(std::make_unique<CSkinRules>(in));
}

}