transform.h

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 * VCLib                                                                     *
 * Visual Computing Library                                                  *
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 * Copyright(C) 2021-2025                                                    *
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#ifndef VCL_ALGORITHMS_MESH_UPDATE_TRANSFORM_H
#define VCL_ALGORITHMS_MESH_UPDATE_TRANSFORM_H
 
#include <vclib/mesh.h>
#include <vclib/space/core.h>
 
namespace vcl {
 
template<MeshConcept MeshType, typename ScalarM>
void applyTransformMatrix(
    MeshType&                mesh,
    const Matrix44<ScalarM>& matrix,
    bool                     updateNormals = true)
{
    using VertexType = MeshType::VertexType;
 
    multiplyPointsByMatrix(mesh.vertices() | vcl::views::positions, matrix);
 
    // TODO: automatize: for each element, check if it has normal and apply
    // the matrix to it
    if (updateNormals) {
        if constexpr (HasPerVertexNormal<MeshType>) {
            if (isPerVertexNormalAvailable(mesh)) {
                multiplyNormalsByMatrix(
                    mesh.vertices() | vcl::views::normals, matrix);
            }
        }
        if constexpr (HasPerFaceNormal<MeshType>) {
            if (isPerFaceNormalAvailable(mesh)) {
                multiplyNormalsByMatrix(
                    mesh.faces() | vcl::views::normals, matrix);
            }
        }
    }
}
 
template<MeshConcept MeshType, PointConcept PointType>
void translate(MeshType& mesh, const PointType& t)
{
    using VertexType = MeshType::VertexType;
    for (VertexType& v : mesh.vertices()) {
        v.position() += t;
    }
}
 
template<MeshConcept MeshType, PointConcept PointType>
void scale(MeshType& mesh, const PointType& s)
{
    using VertexType = MeshType::VertexType;
    for (VertexType& v : mesh.vertices()) {
        v.position()(0) *= s(0);
        v.position()(1) *= s(1);
        v.position()(2) *= s(2);
    }
}
 
template<MeshConcept MeshType, typename Scalar = double>
void scale(MeshType& mesh, const Scalar& s)
{
    using VertexType = MeshType::VertexType;
    for (VertexType& v : mesh.vertices()) {
        v.position() *= s;
    }
}
 
template<MeshConcept MeshType, typename Scalar>
void rotate(
    MeshType&               mesh,
    const Matrix33<Scalar>& m,
    bool                    updateNormals = true)
{
    for (auto& v : mesh.vertices()) {
        v.position() = m * v.position();
    }
 
    if (updateNormals) {
        if constexpr (HasPerVertexNormal<MeshType>) {
            if (isPerVertexNormalAvailable(mesh)) {
                for (auto& v : mesh.vertices()) {
                    v.normal() = m * v.normal();
                }
            }
        }
 
        if constexpr (HasPerFaceNormal<MeshType>) {
            if (isPerFaceNormalAvailable(mesh)) {
                for (auto& f : mesh.faces()) {
                    f.normal() = m * f.normal();
                }
            }
        }
    }
}
 
template<MeshConcept MeshType, PointConcept PointType, typename Scalar = double>
void rotate(
    MeshType&        mesh,
    const PointType& axis,
    const Scalar&    angleRad,
    bool             updateNormals = true)
{
    using ScalarType = MeshType::VertexType::PositionType::ScalarType;
 
    Matrix33<ScalarType> m;
    setTransformMatrixRotation(m, axis, angleRad);
 
    rotate(mesh, m, updateNormals);
}
 
template<MeshConcept MeshType, PointConcept PointType, typename Scalar = double>
void rotateDeg(
    MeshType&        mesh,
    const PointType& axis,
    const Scalar&    angleDeg,
    bool             updateNormals = true)
{
    rotate(mesh, axis, toRad(angleDeg), updateNormals);
}
 
} // namespace vcl
 
#endif // VCL_ALGORITHMS_MESH_UPDATE_TRANSFORM_H