Method: Mittsu::Geometry#merge_vertices

Defined in:

lib/mittsu/core/geometry.rb

#merge_vertices ⇒ Object

# File 'lib/mittsu/core/geometry.rb', line 405

def merge_vertices
  vertices_map = {} # Hashmap for looking up vertice by position coordinates (and making sure they are unique)
  unique = []; changes = []
  precision_points = 4 # number of decimal points, eg. 4 for epsilon of 0.0001
  precision = 10 ** precision_points
  @vertices.each_with_index do |v, i|
    key = "#{(v.x * precision).round}_#{(v.y * precision).round}_#{(v.z * precision).round}"
    if vertices_map[key].nil?
      vertices_map[key] = i
      unique << v
      changes[i] = unique.length - 1
    else
      #console.log('Duplicate vertex found. ', i, ' could be using ', vertices_map[key])
      changes[i] = changes[vertices_map[key]]
    end
  end
  # if faces are completely degenerate after merging vertices, we
  # have to remove them from the geometry.
  face_indices_to_remove = []
  @faces.each_with_index do |face, i|
    face.a = changes[face.a]
    face.b = changes[face.b]
    face.c = changes[face.c]
    indices = [face.a, face.b, face.c]
    dup_index = -1
    # if any duplicate vertices are found in a Face3
    # we have to remove the face as nothing can be saved
    3.times do |n|
      if indices[n] == indices[(n + 1) % 3]
        dup_index = n
        face_indices_to_remove << i
        break
      end
    end
  end
  face_indices_to_remove.reverse_each do |idx|
    idx = face_indices_to_remove[i]
    @faces.delete_at idx
    @face_vertex_uvs.each do |uv|
      uv.delete_at idx
    end
  end
  # Use unique set of vertices
  diff = @vertices.length - unique.length
  @vertices = unique
  diff
end