Line data    Source code

       1           2 : Base.angle(g::AbstractGeometry, h::HHnd) =
       2             :     anglenext(g::AbstractGeometry, h::HHnd)
       3             : 
       4           1 : Base.angle(mesh::Mesh, x, h::HHnd) =
       5             :     Base.angle(geometry(mesh, position=x), h)
       6             : 
       7             : """
       8             :     g = geometry(mesh, position=x)
       9             : 
      10             :     α = angle(g, h::Hnd)
      11             :     α = angle(mesh, x, h::Hnd)
      12             : 
      13             : Synonym for [`anglenext`](@ref).
      14             : 
      15             : See also [`anglenext`](@ref), [`angleprev`](@ref)
      16             : """ Base.angle
      17             : 
      18             : """
      19             :     g = geometry(mesh, position=x)
      20             : 
      21             :     α = anglenext(g, h::Hnd)
      22             :     α = anglenext(mesh, x, h::Hnd)
      23             : 
      24             : Compute angle `α` enclosed by half-edge `h` and its successor
      25             : `next(mesh, h)` within their common face.
      26             : 
      27             : See also [`angle`](@ref), [`next`](@ref), [`angleprev`](@ref)
      28             : """
      29           2 : anglenext(g::AbstractGeometry, h::HHnd) =
      30             :     _angle(g::AbstractGeometry, h, next(tessellation(g), h))
      31             : 
      32           0 : anglenext(mesh::Mesh, x, h::HHnd) =
      33             :     anglenext(geometry(mesh, position=x), h)
      34             : 
      35             : """
      36             :     g = geometry(mesh, position=x)
      37             : 
      38             :     α = angleprev(g, h::Hnd)
      39             :     α = angleprev(mesh, x, h::Hnd)
      40             : 
      41             : Compute angle `α` enclosed by half-edge `h` and its predecessor
      42             : `pred(mesh, h)` within their common face.
      43             : 
      44             : See also [`prev`](@ref), [`anglenext`](@ref), [`angle`](@ref),
      45             : """
      46           2 : angleprev(g::AbstractGeometry, h::HHnd) =
      47             :     _angle(g::AbstractGeometry, prev(tessellation(g), h), h)
      48             : 
      49           1 : angleprev(mesh::Mesh, x, h::HHnd) =
      50             :     angleprev(geometry(mesh, position=x), h)
      51             : 
      52           4 : function _angle(g::AbstractGeometry, h1::HHnd, h2::HHnd)
      53           4 :     v1 = edgevector(g, h1)
      54           4 :     v2 = edgevector(g, h2)
      55             : 
      56           4 :     angle(-v1, v2)
      57             : end
      58             : 
      59             : """
      60             :     α = angle(v1, v2)
      61             : 
      62             : Compute angle (rad) enclosed by vectors `v1` and `v2`.
      63             : 
      64             : !!! warn "precondition"
      65             :     Both vectors `v1, v2` must have positive length.
      66             : 
      67             : """
      68          77 : function Base.angle(v1::AbstractVector, v2::AbstractVector)
      69          77 :     cs = dot(v1, v2) / (norm(v1) * norm(v2))
      70         154 :     cs = clamp(cs, -one(cs), +one(cs))
      71             : 
      72          77 :     acos(cs)
      73             : end
      74             : 
      75          73 : function dihedralangle(g::AbstractGeometry, h::Union{HHnd, EHnd})
      76          73 :     mesh = tessellation(g)
      77         219 :     f1, f2 = map(h -> face(mesh, h), halfedges(mesh, h))
      78             : 
      79          73 :     angle(normal(g, f1), normal(g, f2))
      80             : end
      81             : 
      82          37 : dihedralangle(mesh::Mesh, x, h::Union{HHnd, EHnd}) =
      83             :     dihedralangle(geometry(mesh, position=x), h)
      84             : 
      85             : """
      86             :     g = geometry(mesh, position=x, ...)
      87             : 
      88             :     α = dihedralangle(g, h::HHnd)
      89             :     α = dihedralangle(g, e::EHnd)
      90             : 
      91             :     α = dihedralangle(mesh, x, ...)
      92             : 
      93             : Compute *dihedral angle* enclosed by the faces that share half-edge
      94             : `h` (or edge `e`).
      95             : 
      96             : !!! warn "precondition"
      97             :     `h` and `e` must denote an **inner** (half-)edge, i.e., both faces
      98             :     are well-defined.
      99             : 
     100             : !!! note
     101             :     The face normals of `g::AbstractGeometry` are determined by
     102             :     [`normal`](@ref), i.e., the normal vector is read from the *face
     103             :     attribute* if present (and computed otherwise).
     104             : 
     105             : See also [`angle`](@ref), [`computedihedralangle`](@ref)
     106             : """ dihedralangle
     107             : 
     108             : """
     109             :     g = geometry(mesh, position=x, ...)
     110             : 
     111             :     α = computedihedralangle(g, h::HHnd)
     112             :     α = computedihedralangle(g, e::EHnd)
     113             : 
     114             : Same as [`dihedralangle`](@ref) but enforce computation of face
     115             : normals, i.e., **do not** lookup face attribute if present.
     116             : 
     117             : See also [`dihedralangle`](@ref)
     118             : """
     119          37 : computedihedralangle(g::AbstractGeometry, h::Union{HHnd, EHnd}) =
     120             :     dihedralangle(tessellation(g), position(g), h)