i-mic-fps/lib/math/bounding_box.rb

class IMICFPS
  class BoundingBox
    attr_accessor :min, :max

    def initialize
      @min = Vector.new
      @max = Vector.new
    end

    def ==(other)
      @min == other.min &&
      @max == other.max
    end

    # returns a new bounding box that includes both bounding boxes
    def union(other)
      temp = BoundingBox.new
      temp.min.x = [@min.x, other.min.x].min
      temp.min.y = [@min.y, other.min.y].min
      temp.min.z = [@min.z, other.min.z].min

      temp.max.x = [@max.x, other.max.x].max
      temp.max.y = [@max.y, other.max.y].max
      temp.max.z = [@max.z, other.max.z].max

      return temp
    end

    # returns boolean
    def intersect(other)
      (@min.x <= other.max.x && @max.x >= other.min.x) &&
      (@min.y <= other.max.y && @max.y >= other.min.y) &&
      (@min.z <= other.max.z && @max.z >= other.min.z)
    end

    def difference(other)
      temp = BoundingBox.new
      temp.min = @min - other.min
      temp.max = @max - other.max

      return temp
    end

    def volume
      width * height * depth
    end

    def width
      @max.x - @min.x
    end

    def height
      @max.y - @min.y
    end

    def depth
      @max.z - @min.z
    end

    def normalize(entity)
      temp = BoundingBox.new
      temp.min.x = @min.x.to_f * entity.scale
      temp.min.y = @min.y.to_f * entity.scale
      temp.min.z = @min.z.to_f * entity.scale

      temp.max.x = @max.x.to_f * entity.scale
      temp.max.y = @max.y.to_f * entity.scale
      temp.max.z = @max.z.to_f * entity.scale

      return temp
    end

    def normalize_with_offset(entity)
      temp = BoundingBox.new
      temp.min.x = @min.x.to_f * entity.scale + entity.position.x
      temp.min.y = @min.y.to_f * entity.scale + entity.position.y
      temp.min.z = @min.z.to_f * entity.scale + entity.position.z

      temp.max.x = @max.x.to_f * entity.scale + entity.position.x
      temp.max.y = @max.y.to_f * entity.scale + entity.position.y
      temp.max.z = @max.z.to_f * entity.scale + entity.position.z

      return temp
    end
  end
end