indexing

	description: "3D Component for the elfractal example"
	author: "Lars Krapf"
	date: "$Date$"
	revision: "$Revision$"

class EF_3D_DISPLAY

inherit

	EM_3D_COMPONENT
	EMGL_BASIC_RENDERER

	DOUBLE_MATH
		export {NONE} all end

create

	make_from_dimension

feature {NONE} -- Initialisation

	make_from_dimension(a_width: INTEGER; a_height: INTEGER) is
			-- Initialise default values.
		require
			valid_dimension: a_width > 0 and a_height > 0
		do
			make_3d_component
			set_max_view_distance(400.0)
			set_dimension(a_width, a_height)
			set_tooltip ("left-drag to rotate, right-drag to zoom")

			longitude := 10
			latitude := 20
			distance := 100
			angle := 0.6
			create l_system.make_empty

			-- Prepare Usercommands
			create user_commands_string.make_empty
			create user_commands.make (19)

			-- Event registration
			mouse_dragged_event.subscribe (agent handle_mouse_dragged)
			mouse_wheel_up_event.subscribe (agent handle_mouse_wheel_up)
			mouse_wheel_down_event.subscribe (agent handle_mouse_wheel_down)

		ensure
			system_exists: l_system /= Void
		end

feature -- Element Change
	set_user_commands_string(a_string: STRING) is
			-- Set the String representing the user definitions for the l-system
		require
			user_commands_valid: a_string /= Void
		do
			user_commands_string := a_string
			parse_user_commands
		ensure
			user_commands_set: user_commands_string /= Void
		end

	set_system_string(a_string: STRING) is
			-- Set the String representing the system to execute
		require
			a_string_not_void: a_string /= Void
		do
			l_system := a_string
		ensure
			system_valid: l_system /= Void
		end

	set_iterations(n: INTEGER) is
			-- Set the number of iterations
		require
			atleast_one_iteration: n >= 0
		do
			iterations := n
		ensure
			iterations_valid: iterations >= 0
		end

	set_simple_mode(mode: BOOLEAN) is
			-- Set simple mode
		do
			simple_mode := mode
		end

feature -- Access

	longitude: REAL
			-- Longitude of the eye (in degree) around center (0,0,0)

	latitude: REAL
			-- Latitude of the eye (in degree) around center (0,0,0)

	distance: REAL
			-- Distance of the eye to center (0,0,0)


feature -- Basic operations

	create_script is
			-- Create the GL_Script and redraw
		local
			state: EF_STATE
		do
			emgl_new_list(script, EM_GL_COMPILE)
			state := draw_lines(l_system, create {EF_STATE}.make,iterations)
			emgl_end_list
		end

	set_animated(status: BOOLEAN) is
			-- set animated status
		do
			animated := status
		end


feature -- Drawing

	draw is
			-- Draw the compiled GLList
		do
			if animated then
				angle := angle + 0.005
				create_script
			end

			-- Set up eye position
			emgl_translatef (0, 0, -distance)
			emgl_rotatef (-longitude, 0, 1, 0)
			emgl_rotatef (latitude, cosine (-longitude / 180 * pi),0,sine (-longitude / 180 * pi))

			-- Draw List
			emgl_begin(EM_GL_LINES)
			emgl_call_list(script)
			emgl_end

		end

feature {NONE} -- Mouse management


	handle_mouse_dragged (event: EM_MOUSEMOTION_EVENT) is
			-- Handle mouse dragged event.
		do
			if event.button_state_left then
				longitude := longitude - event.motion.x
				latitude := latitude + event.motion.y
				if latitude > 90 then
					latitude := 90
				elseif latitude < -90 then
					latitude := -90
				end
			end
			if event.button_state_right then
				distance := distance + event.motion.y
				if distance < 0 then
					distance := 0
				end
				if distance > 300 then
					distance := 300
				end
			end

		end

	handle_mouse_wheel_up is
			-- Handle mouse wheel up event.
		do
			angle := angle + 0.02
			create_script
		end

	handle_mouse_wheel_down is
			-- Handle mouse wheel down event.
		do
			angle := angle - 0.02
			create_script
		end

feature {NONE} -- Implementation

	parse_user_commands is
			-- Go to user definitions and fill hash_table
		local
			lines: LIST [STRING]
			line: LIST [STRING]
		do
			user_commands.clear_all

			-- go through user_command_string line by line
			lines := user_commands_string.split('%N')
			from
				lines.start
			until
				lines.after
			loop
				-- split definition on '=' and store it into hashtable
				line := lines.item.split('=')
				if line.count = 2 then
					user_commands.put (line.i_th(2), line.i_th(1))
				end
				lines.forth
			end
		end

	is_builtin(a_char: CHARACTER):BOOLEAN is
			-- check if a_char is a special character
		do
			Result := a_char.is_equal('[') or a_char.is_equal(']')
		end

	draw_lines(system: STRING; a_state: EF_STATE; iteration: INTEGER):EF_STATE is
		local
			i,j: INTEGER
			state, old_state: EF_STATE
			token: STRING
		do
			state := a_state.twin
			-- Go through Systemstring, char by char and parse tokens
			from
				i := 2
				j := 1
			until
				j > system.count
			loop
				-- found end of current token?
				if i > system.count or system.item(i).is_upper or is_builtin(system.item(i)) then
					token := system.substring(j,i-1)
					j := i

					-- token recognized?
					if user_commands.has(token) then
						if iteration > 0 then
							-- execute user defined command
							state := draw_lines(user_commands[token], state, iteration-1)
						else
							if simple_mode then
								-- use colors based on current coordinates
								emgl_color3f(1-state.x*0.02,1-state.y*0.02,1-state.z*0.02)
							else
								-- use colors from state
								emgl_color3f(state.r, state.g, state.b)
							end
							-- draw a line in current direction
							emgl_vertex3f(state.x, state.y, state.z)
							state.set_coordinates(state.x-sine(state.phi)*cosine(state.rho),state.y+sine(state.rho),state.z+cosine(state.rho)*cosine(state.phi))
							emgl_vertex3f(state.x, state.y, state.z)

						end
					end

					-- color Builtins
					if token.is_equal("Red+") then state.set_colors(state.r + 0.1, state.g, state.b) end
					if token.is_equal("Red-") then state.set_colors(state.r - 0.1, state.g, state.b) end
					if token.is_equal("Green+") then state.set_colors(state.r, state.g + 0.1, state.b) end
					if token.is_equal("Green-") then state.set_colors(state.r, state.g - 0.1, state.b) end
					if token.is_equal("Blue+") then state.set_colors(state.r, state.g, state.b + 0.1) end
					if token.is_equal("Blue-") then state.set_colors(state.r, state.g, state.b - 0.1) end


					-- step forward
					if token.is_equal("F") then
						if iteration = 0 then
							-- if no more iterations left
							if simple_mode then
								-- use colors based on current coordinates
								emgl_color3f(1-state.x*0.02,1-state.y*0.02,1-state.z*0.02)
							else
								-- use colors from state
								emgl_color3f(state.r, state.g, state.b)
							end
							-- draw a line in current direction
							emgl_vertex3f(state.x, state.y, state.z)
							state.set_coordinates(state.x-sine(state.phi)*cosine(state.rho),state.y+sine(state.rho),state.z+cosine(state.rho)*cosine(state.phi))
							emgl_vertex3f(state.x, state.y, state.z)
						else
							-- otherwise reiterate into current system
							state := draw_lines(l_system, state, iteration-1)
						end
					end

					-- directional builtins
					if token.is_equal("D") then state.set_angles(state.phi+angle, state.rho) end
					if token.is_equal("U") then state.set_angles(state.phi-angle, state.rho) end
					if token.is_equal("R") then state.set_angles(state.phi, state.rho+angle) end
					if token.is_equal("L") then state.set_angles(state.phi, state.rho-angle) end

					-- special builtins
					if token.is_equal("[") then
						-- store current state
						old_state := state.twin
					end
					if token.is_equal("]") then
						-- restore state
						if old_state /= Void then
							state := old_state.twin
						end
					end
				end
				i := i + 1
			end
			Result := state
		end


	iterations: INTEGER
		-- the number of iterations

	angle: DOUBLE
		-- the default angle of commands U,D,L and R

	script: INTEGER is 1
		-- the opengl list to use

	l_system: STRING
		-- a string representation of the l-type system

	user_commands_string: STRING
		-- string representation of the user commands

	user_commands: HASH_TABLE [STRING, STRING]
		-- a hashtable containing user-defined commands

	animated: BOOLEAN
		-- animate angles?

	simple_mode: BOOLEAN
		-- simple mode?
end