mijin2/source/mijin/geo/tangent_generation.hpp

103 lines
3.6 KiB
C++

#pragma once
#if !defined(MIJIN_GEO_TANGENT_GENERATION_HPP_INCLUDED)
#define MIJIN_GEO_TANGENT_GENERATION_HPP_INCLUDED 1
#include <mikktspace.h>
#include "./geometry_traits.hpp"
namespace mijin
{
namespace impl
{
template<FullMesh3D TMesh>
struct MikktData
{
Mesh3DTraits<TMesh> traits;
Vector2Traits<typename TMesh::vector2_t> vec2Traits;
Vector3Traits<typename TMesh::vector3_t> vec3Traits;
Vector4Traits<typename TMesh::vector4_t> vec4Traits;
TMesh* mesh;
};
template<FullMesh3D TMesh>
int mikktGetNumFaces(const SMikkTSpaceContext* context)
{
const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
return static_cast<int>(data.traits.getNumFaces(*data.mesh));
}
template<FullMesh3D TMesh>
int mikktGetNumVerticesOfFace(const SMikkTSpaceContext* context, const int face)
{
const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
return static_cast<int>(data.traits.getFaceNumVertices(*data.mesh, face));
}
template<FullMesh3D TMesh>
void mikktGetPosition(const SMikkTSpaceContext* context, float posOut[], const int face, const int vert) // NOLINT
{
const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
const auto position = data.traits.getPosition(*data.mesh, face, vert);
posOut[0] = data.vec3Traits.getX(position);
posOut[1] = data.vec3Traits.getY(position);
posOut[2] = data.vec3Traits.getZ(position);
}
template<FullMesh3D TMesh>
void mikktGetNormal(const SMikkTSpaceContext* context, float normOut[], const int face, const int vert) // NOLINT
{
const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
const auto normal = data.traits.getNormal(*data.mesh, face, vert);
normOut[0] = data.vec3Traits.getX(normal);
normOut[1] = data.vec3Traits.getY(normal);
normOut[2] = data.vec3Traits.getZ(normal);
}
template<FullMesh3D TMesh>
void mikktGetTexCoord(const SMikkTSpaceContext* context, float texcOut[], const int face, const int vert) // NOLINT
{
const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
const auto texCoord = data.traits.getTexCoord(*data.mesh, face, vert);
texcOut[0] = data.vec2Traits.getX(texCoord);
texcOut[1] = data.vec2Traits.getY(texCoord);
}
template<FullMesh3D TMesh>
void mikktSetTSpaceBasic(const SMikkTSpaceContext* context, const float resultTangent[], const float sign, const int face, const int vert) // NOLINT
{
const MikktData<TMesh>& data = *static_cast<MikktData<TMesh>*>(context->m_pUserData);
typename Mesh3DTraits<TMesh>::vector4_t tangent;
data.vec4Traits.setX(tangent, resultTangent[0]);
data.vec4Traits.setY(tangent, resultTangent[1]);
data.vec4Traits.setZ(tangent, resultTangent[2]);
data.vec4Traits.setW(tangent, sign);
data.traits.setTangent(*data.mesh, face, vert, tangent);
}
}
template<FullMesh3D TMesh>
bool generateTangentsMikkt(TMesh& mesh)
{
SMikkTSpaceInterface mikktInterface = {
.m_getNumFaces = &impl::mikktGetNumFaces<TMesh>,
.m_getNumVerticesOfFace = &impl::mikktGetNumVerticesOfFace<TMesh>,
.m_getPosition = &impl::mikktGetPosition<TMesh>,
.m_getNormal = &impl::mikktGetNormal<TMesh>,
.m_getTexCoord = &impl::mikktGetTexCoord<TMesh>,
.m_setTSpaceBasic = &impl::mikktSetTSpaceBasic<TMesh>
};
impl::MikktData<TMesh> data = {
.mesh = &mesh
};
const SMikkTSpaceContext context = {
.m_pInterface = &mikktInterface,
.m_pUserData = &data
};
return genTangSpaceDefault(&context);
}
}
#endif // MIJIN_GEO_TANGENT_GENERATION_HPP_INCLUDED