lib/geometry/points_and_lines.nit

   1 # This file is part of NIT (http://www.nitlanguage.org).
   2 #
   3 # Copyright 2014 Alexis Laferrière <alexis.laf@xymus.net>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 # Provides interfaces and classes to represent basic geometry needs.
  18 module points_and_lines
  19
  20 # An abstract 2d point, strongly linked to its implementation `Point`
  21 interface IPoint[N: Numeric]
  22         # horizontal coordinate
  23         fun x: N is abstract
  24         # vertical coordinate
  25         fun y: N is abstract
  26
  27         redef fun to_s do return "({x}, {y})"
  28 end
  29
  30 # A 2d point and an implementation of `IPoint`
  31 class Point[N: Numeric]
  32         super IPoint[N]
  33
  34         redef var x: N
  35         redef var y: N
  36 end
  37
  38 # An abstract 3d point, strongly linked to its implementation `Point3d`
  39 interface IPoint3d[N: Numeric]
  40         super IPoint[N]
  41
  42         # depth coordinate
  43         fun z: N is abstract
  44
  45         redef fun to_s do return "({x}, {y}, {z})"
  46 end
  47
  48 # A 3d point and an implementation of `IPoint3d`
  49 class Point3d[N: Numeric]
  50         super IPoint3d[N]
  51         super Point[N]
  52
  53         redef var z: N
  54 end
  55
  56 # An abstract 2d line segment
  57 interface ILine[N: Numeric]
  58         # The type of points that ends the segment
  59         type P: IPoint[N]
  60
  61         # The point that is the left-end of the segment
  62         fun point_left: P is abstract
  63
  64         # The point that is the right-end of the segment
  65         fun point_right: P is abstract
  66
  67         redef fun to_s do return "{point_left}--{point_right}"
  68 end
  69
  70 # A 2d line segment
  71 class Line[N: Numeric]
  72         super ILine[N]
  73
  74         redef var point_left: P
  75         redef var point_right: P
  76
  77         init
  78         do
  79                 var a = point_left
  80                 var b = point_right
  81                 if a.x > b.x then
  82                         point_left = b
  83                         point_right = a
  84                 end
  85         end
  86
  87 end
  88
  89 # An abstract 3d line segment
  90 interface ILine3d[N: Numeric]
  91         super ILine[N]
  92
  93         redef type P: IPoint3d[N]
  94 end
  95
  96 # A 3d line segment
  97 class Line3d[N: Numeric]
  98         super Line[N]
  99         super ILine3d[N]
 100 end