collinear.rb

#For answering question on Shoes mailing list dmonroe
Shoes.app(:title => "Coplanar Points", :width => 550, :height => 400) do    

	def calculate
		@beex = (@betax.text.to_f-@alphax.text.to_f)
		@beey = (@betay.text.to_f-@alphay.text.to_f)
		@beez = (@betaz.text.to_f-@alphaz.text.to_f)
		@ceex = (@gammax.text.to_f-@alphax.text.to_f)
		@ceey = (@gammay.text.to_f-@alphay.text.to_f)
		@ceez = (@gammaz.text.to_f-@alphaz.text.to_f)
		@deex = (@deltax.text.to_f-@alphax.text.to_f)
		@deey = (@deltax.text.to_f-@alphay.text.to_f)
		@deez = (@deltax.text.to_f-@alphaz.text.to_f)


		((@beex*((@ceey*@deez)-(@ceez*@deey)))-(@beey*((@ceex*@deez)-(@ceez*@deex)))+(@beez*((@ceex*@deey))-(@ceey*@deex)))
	end
	stack(:width => '100%', :margin => 20) do
		para('Calculate Coplanar Points') 
		para('                           x                  y                       z')   
	end    

	flow(:width => '100%' ) do
		para('Point A: ')
		@alphax = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
		@alphay = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
		@alphaz = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
	end
	flow(:width => '100%' ) do
		para('Point B: ')
		@betax = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
		@betay = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
		@betaz = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
	end
	flow(:width => '100%' ) do
		para('Point C: ')
		@gammax = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
		@gammay = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
		@gammaz = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
	end
	flow(:width => '100%' ) do
		para('Point D: ')
		@deltax = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
		@deltay = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}
		@deltaz = edit_line(:width => 100, height => 35) {@coplanar.text = calculate}

		@button = button "Configure" do
			c = calculate==0
			case c
			when true
				alert("Points are coplanar, equation is")
			when false
				alert("Points are NOT coplanar")

			end
		end
	end
end