Class: CP::Shape::Poly

Inherits:
Object
  • Object
show all
Includes:
CP::Shape
Defined in:
lib/chipmunk-ffi/shape.rb,
lib/chipmunk-ffi/unsafe.rb

Instance Attribute Summary

Attributes included from CP::Shape

#struct

Class Method Summary collapse

Instance Method Summary collapse

Methods included from CP::Shape

#bb, #body, #body=, #cache_bb, #collision_type, #collision_type=, #data, #data=, #e, #e=, #group, #group=, #layers, #layers=, #point_query, reset_id_counter, #segment_query, #sensor=, #sensor?, #set_data_pointer, #surface_v, #surface_v=, #u, #u=

Constructor Details

#initialize(body, verts, offset_vec) ⇒ Poly

Returns a new instance of Poly.



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# File 'lib/chipmunk-ffi/shape.rb', line 202

def initialize(body, verts, offset_vec)
  @body = body
  verts = CP::Shape::Poly.make_vertices_valid(verts)
  mem_pointer = CP::Shape::Poly.pointer_for_verts(verts)
  
  ptr = CP.cpPolyShapeNew body.struct.pointer, verts.size, mem_pointer, offset_vec.struct
  @struct = ShapeStruct.new ptr
  set_data_pointer
end

Class Method Details

.make_vertices_valid(verts) ⇒ Object 



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# File 'lib/chipmunk-ffi/shape.rb', line 236

def self.make_vertices_valid(verts)
  if CP::Shape::Poly.strictly_valid_vertices?(verts)
    return verts
  elsif CP::Shape::Poly.strictly_valid_vertices?(verts.reverse)
    return verts.reverse
  else
    raise "Chipmunk-FFI Error: Vertices do not form convex polygon."
  end
end

.pointer_for_verts(verts) ⇒ Object 



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# File 'lib/chipmunk-ffi/shape.rb', line 212

def self.pointer_for_verts(verts)
  mem_pointer = FFI::MemoryPointer.new Vect, verts.size
  vert_structs = verts.collect{|s|s.struct}

  size = Vect.size
  tmp = mem_pointer
  vert_structs.each_with_index {|i, j|
    tmp.send(:put_bytes, 0, i.to_bytes, 0, size)
    tmp += size unless j == vert_structs.length-1 # avoid OOB
  }
  return mem_pointer
end

.strictly_valid_vertices?(verts) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/chipmunk-ffi/shape.rb', line 225

def self.strictly_valid_vertices?(verts)
  mem_pointer = CP::Shape::Poly.pointer_for_verts(verts)
  result = CP.cpPolyValidate(mem_pointer,verts.size)
  return (result != 0)
end

.valid_vertices?(verts) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/chipmunk-ffi/shape.rb', line 231

def self.valid_vertices?(verts)
  CP::Shape::Poly.strictly_valid_vertices?(verts) || 
  CP::Shape::Poly.strictly_valid_vertices?(verts.reverse)
end

Instance Method Details

#verts=(new_verts_and_offset) ⇒ Object 



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# File 'lib/chipmunk-ffi/unsafe.rb', line 31

def verts=(new_verts_and_offset)
  new_verts, new_offset = *new_verts_and_offset
  
  new_verts_pointer = FFI::MemoryPointer.new Vect, new_verts.count
  
  size = Vect.size
  tmp = new_verts_pointer
  new_verts.each_with_index  do |vert, i|
    tmp.send(:put_bytes, 0, vert.struct.to_bytes, 0, size)
    tmp += size unless i == new_verts.length - 1 # avoid OOB
  end
  
  CP.cpPolyShapeSetVerts(@struct.pointer, new_verts.count, new_verts_pointer, new_offset.struct)
end