tornavis/source/blender/blenkernel/BKE_mesh.hh

382 lines
14 KiB
C++

/* SPDX-FileCopyrightText: 2023 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#pragma once
/** \file
* \ingroup bke
*/
#include "BLI_index_mask.hh"
#include "BKE_mesh.h"
#include "BKE_mesh_types.hh"
namespace blender::bke {
namespace mesh {
/* -------------------------------------------------------------------- */
/** \name Polygon Data Evaluation
* \{ */
/** Calculate the up direction for the face, depending on its winding direction. */
float3 face_normal_calc(Span<float3> vert_positions, Span<int> face_verts);
/**
* Calculate tessellation into #MLoopTri which exist only for this purpose.
*/
void looptris_calc(Span<float3> vert_positions,
OffsetIndices<int> faces,
Span<int> corner_verts,
MutableSpan<MLoopTri> looptris);
/**
* A version of #looptris_calc which takes pre-calculated face normals
* (used to avoid having to calculate the face normal for NGON tessellation).
*
* \note Only use this function if normals have already been calculated, there is no need
* to calculate normals just to use this function.
*/
void looptris_calc_with_normals(Span<float3> vert_positions,
OffsetIndices<int> faces,
Span<int> corner_verts,
Span<float3> face_normals,
MutableSpan<MLoopTri> looptris);
void looptris_calc_face_indices(OffsetIndices<int> faces, MutableSpan<int> looptri_faces);
/** Calculate the average position of the vertices in the face. */
float3 face_center_calc(Span<float3> vert_positions, Span<int> face_verts);
/** Calculate the surface area of the face described by the indexed vertices. */
float face_area_calc(Span<float3> vert_positions, Span<int> face_verts);
/** Calculate the angles at each of the faces corners. */
void face_angles_calc(Span<float3> vert_positions,
Span<int> face_verts,
MutableSpan<float> angles);
/** \} */
/* -------------------------------------------------------------------- */
/** \name Medium-Level Normals Calculation
* \{ */
/**
* Calculate face normals directly into a result array.
*
* \note Usually #Mesh::face_normals() is the preferred way to access face normals,
* since they may already be calculated and cached on the mesh.
*/
void normals_calc_faces(Span<float3> vert_positions,
OffsetIndices<int> faces,
Span<int> corner_verts,
MutableSpan<float3> face_normals);
/**
* Calculate vertex normals directly into the result array.
*
* \note Vertex and face normals can be calculated at the same time with
* #normals_calc_faces_and_verts, which can have performance benefits in some cases.
*
* \note Usually #Mesh::vert_normals() is the preferred way to access vertex normals,
* since they may already be calculated and cached on the mesh.
*/
void normals_calc_verts(Span<float3> vert_positions,
OffsetIndices<int> faces,
Span<int> corner_verts,
Span<float3> face_normals,
MutableSpan<float3> vert_normals);
/** \} */
/* -------------------------------------------------------------------- */
/** \name Face Corner Normal Calculation
* \{ */
/**
* Combined with the automatically calculated face corner normal, this gives a dimensional
* coordinate space used to convert normals between the "custom normal" #short2 representation and
* a regular #float3 format.
*/
struct CornerNormalSpace {
/** The automatically computed face corner normal, not including influence of custom normals. */
float3 vec_lnor;
/** Reference vector, orthogonal to #vec_lnor. */
float3 vec_ref;
/** Third vector, orthogonal to #vec_lnor and #vec_ref. */
float3 vec_ortho;
/** Reference angle around #vec_ortho, in [0, pi] range (0.0 marks space as invalid). */
float ref_alpha;
/** Reference angle around #vec_lnor, in [0, 2pi] range (0.0 marks space as invalid). */
float ref_beta;
};
/**
* Storage for corner fan coordinate spaces for an entire mesh.
*/
struct CornerNormalSpaceArray {
/**
* The normal coordinate spaces, potentially shared between multiple face corners in a smooth fan
* connected to a vertex (and not per face corner). Depending on the mesh (the amount of sharing
* / number of sharp edges / size of each fan), there may be many fewer spaces than face corners,
* so they are stored in a separate array.
*/
Array<CornerNormalSpace> spaces;
/**
* The index of the data in the #spaces array for each face corner (the array size is the
* same as #Mesh::totloop). Rare -1 values define face corners without a coordinate space.
*/
Array<int> corner_space_indices;
/**
* A map containing the face corners that make up each space,
* in the order that they were processed (winding around a vertex).
*/
Array<Array<int>> corners_by_space;
/** Whether to create the above map when calculating normals. */
bool create_corners_by_space = false;
};
short2 lnor_space_custom_normal_to_data(const CornerNormalSpace &lnor_space,
const float3 &custom_lnor);
/**
* Compute split normals, i.e. vertex normals associated with each face (hence 'loop normals').
* Useful to materialize sharp edges (or non-smooth faces) without actually modifying the geometry
* (splitting edges).
*
* \param sharp_edges: Optional array of sharp edge tags, used to split the evaluated normals on
* each side of the edge.
* \param r_lnors_spacearr: Optional return data filled with information about the custom
* normals spaces for each grouped fan of face corners.
*/
void normals_calc_loop(Span<float3> vert_positions,
Span<int2> edges,
OffsetIndices<int> faces,
Span<int> corner_verts,
Span<int> corner_edges,
Span<int> loop_to_face_map,
Span<float3> vert_normals,
Span<float3> face_normals,
const bool *sharp_edges,
const bool *sharp_faces,
const short2 *clnors_data,
bool use_split_normals,
float split_angle,
CornerNormalSpaceArray *r_lnors_spacearr,
MutableSpan<float3> r_loop_normals);
void normals_loop_custom_set(Span<float3> vert_positions,
Span<int2> edges,
OffsetIndices<int> faces,
Span<int> corner_verts,
Span<int> corner_edges,
Span<float3> vert_normals,
Span<float3> face_normals,
const bool *sharp_faces,
MutableSpan<bool> sharp_edges,
MutableSpan<float3> r_custom_loop_normals,
MutableSpan<short2> r_clnors_data);
void normals_loop_custom_set_from_verts(Span<float3> vert_positions,
Span<int2> edges,
OffsetIndices<int> faces,
Span<int> corner_verts,
Span<int> corner_edges,
Span<float3> vert_normals,
Span<float3> face_normals,
const bool *sharp_faces,
MutableSpan<bool> sharp_edges,
MutableSpan<float3> r_custom_vert_normals,
MutableSpan<short2> r_clnors_data);
/**
* Define sharp edges as needed to mimic 'autosmooth' from angle threshold.
*
* Used when defining an empty custom loop normals data layer,
* to keep same shading as with auto-smooth!
*
* \param sharp_faces: Optional array used to mark specific faces for sharp shading.
*/
void edges_sharp_from_angle_set(OffsetIndices<int> faces,
Span<int> corner_verts,
Span<int> corner_edges,
Span<float3> face_normals,
Span<int> loop_to_face,
const bool *sharp_faces,
const float split_angle,
MutableSpan<bool> sharp_edges);
/** \} */
/* -------------------------------------------------------------------- */
/** \name Topology Queries
* \{ */
/**
* Find the index of the next corner in the face, looping to the start if necessary.
* The indices are into the entire corners array, not just the face's corners.
*/
inline int face_corner_prev(const IndexRange face, const int corner)
{
return corner - 1 + (corner == face.start()) * face.size();
}
/**
* Find the index of the previous corner in the face, looping to the end if necessary.
* The indices are into the entire corners array, not just the face's corners.
*/
inline int face_corner_next(const IndexRange face, const int corner)
{
if (corner == face.last()) {
return face.start();
}
return corner + 1;
}
/**
* Find the index of the corner in the face that uses the given vertex.
* The index is into the entire corners array, not just the face's corners.
*/
inline int face_find_corner_from_vert(const IndexRange face,
const Span<int> corner_verts,
const int vert)
{
return face[corner_verts.slice(face).first_index(vert)];
}
/**
* Return the vertex indices on either side of the given vertex, ordered based on the winding
* direction of the face. The vertex must be in the face.
*/
inline int2 face_find_adjecent_verts(const IndexRange face,
const Span<int> corner_verts,
const int vert)
{
const int corner = face_find_corner_from_vert(face, corner_verts, vert);
return {corner_verts[face_corner_prev(face, corner)],
corner_verts[face_corner_next(face, corner)]};
}
/**
* Return the number of triangles needed to tessellate a face with \a face_size corners.
*/
inline int face_triangles_num(const int face_size)
{
BLI_assert(face_size > 2);
return face_size - 2;
}
/**
* Return the index of the edge's vertex that is not the \a vert.
* If neither edge vertex is equal to \a v, returns -1.
*/
inline int edge_other_vert(const int2 &edge, const int vert)
{
if (edge[0] == vert) {
return edge[1];
}
if (edge[1] == vert) {
return edge[0];
}
return -1;
}
/** \} */
} // namespace mesh
void mesh_flip_faces(Mesh &mesh, const IndexMask &selection);
/** Set mesh vertex normals to known-correct values, avoiding future lazy computation. */
void mesh_vert_normals_assign(Mesh &mesh, Span<float3> vert_normals);
/** Set mesh vertex normals to known-correct values, avoiding future lazy computation. */
void mesh_vert_normals_assign(Mesh &mesh, Vector<float3> vert_normals);
} // namespace blender::bke
/* -------------------------------------------------------------------- */
/** \name Inline Mesh Data Access
* \{ */
inline blender::Span<blender::float3> Mesh::vert_positions() const
{
return {static_cast<const blender::float3 *>(
CustomData_get_layer_named(&this->vert_data, CD_PROP_FLOAT3, "position")),
this->totvert};
}
inline blender::MutableSpan<blender::float3> Mesh::vert_positions_for_write()
{
return {static_cast<blender::float3 *>(CustomData_get_layer_named_for_write(
&this->vert_data, CD_PROP_FLOAT3, "position", this->totvert)),
this->totvert};
}
inline blender::Span<blender::int2> Mesh::edges() const
{
return {static_cast<const blender::int2 *>(
CustomData_get_layer_named(&this->edge_data, CD_PROP_INT32_2D, ".edge_verts")),
this->totedge};
}
inline blender::MutableSpan<blender::int2> Mesh::edges_for_write()
{
return {static_cast<blender::int2 *>(CustomData_get_layer_named_for_write(
&this->edge_data, CD_PROP_INT32_2D, ".edge_verts", this->totedge)),
this->totedge};
}
inline blender::OffsetIndices<int> Mesh::faces() const
{
return blender::Span(this->face_offset_indices, this->faces_num + 1);
}
inline blender::Span<int> Mesh::face_offsets() const
{
if (this->faces_num == 0) {
return {};
}
return {this->face_offset_indices, this->faces_num + 1};
}
inline blender::Span<int> Mesh::corner_verts() const
{
return {static_cast<const int *>(
CustomData_get_layer_named(&this->loop_data, CD_PROP_INT32, ".corner_vert")),
this->totloop};
}
inline blender::MutableSpan<int> Mesh::corner_verts_for_write()
{
return {static_cast<int *>(CustomData_get_layer_named_for_write(
&this->loop_data, CD_PROP_INT32, ".corner_vert", this->totloop)),
this->totloop};
}
inline blender::Span<int> Mesh::corner_edges() const
{
return {static_cast<const int *>(
CustomData_get_layer_named(&this->loop_data, CD_PROP_INT32, ".corner_edge")),
this->totloop};
}
inline blender::MutableSpan<int> Mesh::corner_edges_for_write()
{
return {static_cast<int *>(CustomData_get_layer_named_for_write(
&this->loop_data, CD_PROP_INT32, ".corner_edge", this->totloop)),
this->totloop};
}
inline blender::Span<MDeformVert> Mesh::deform_verts() const
{
const MDeformVert *dverts = BKE_mesh_deform_verts(this);
if (!dverts) {
return {};
}
return {dverts, this->totvert};
}
inline blender::MutableSpan<MDeformVert> Mesh::deform_verts_for_write()
{
return {BKE_mesh_deform_verts_for_write(this), this->totvert};
}
/** \} */