indexing

	description: "[

		Example component to show implementation of a 3D scene component.
		
		Drawing:
			Implement 'draw' and put your OpenGL code there.
		
		Events:
			See EM_COMPONENT

	]"
	date: "$Date$"
	revision: "$Revision$"

class SIERPINSKI_SCENE

inherit

	EM_COMPONENT_SCENE

create

	make

feature {NONE} -- Initialisation

	make is
			-- Initialise default values.
		do
			make_component_scene
			show_opengl_demo

			-- we need this to reset some setting to draw this scene correctly
			-- if cube was shown before
			if Video_subsystem.video_surface.is_opengl_blitting_enabled then
				Video_subsystem.video_surface.disable_opengl_blitting
				gl_tex_envi (Em_gl_texture_env, Em_gl_texture_env_mode, Em_gl_modulate)
			end
		end

	show_opengl_demo is
			-- Show OpenGL demo.
		local
			text: STRING
			label: EM_LABEL
			button: EM_BUTTON
			checkbox: EM_CHECKBOX
		do
			if sierpinski_display = Void then
				-- Help text
				create sierpinski_help_panel.make_from_dimension (width, 100)
				sierpinski_help_panel.set_position (0, 0)

				create text.make_empty
				text.append_string ("To display 3D content together with widgets, use an EM_3D_COMPONENT.%N")
				text.append_string ("Basic approach:%N")
				text.append_string (" - inherit from EM_3D_COMPONENT%N")
				text.append_string (" - place OpenGL code in 'draw'%N")
				text.append_string (" - subscribe on desired event types to react on input events")

				create label.make_from_text (text)
				label.set_position (0, 10)
				label.set_dimension (570, 90)
				label.enable_multilined
				label.align_top
				sierpinski_help_panel.add_widget (label)

				-- Sierpinski pyramid
				create sierpinski_display.make
				sierpinski_display.set_position (0, 100)
				sierpinski_display.set_dimension (width, height-140)

				-- Usage text
				create sierpinski_control_panel.make_from_dimension (width, 40)
				sierpinski_control_panel.set_position (0, height-40)

				create label.make_from_text ("Level: ")
				label.set_dimension (50, 20)
				label.align_right
				sierpinski_control_panel.add_widget (label)

				create button.make_from_text ("+")
				button.set_dimension (20, 20)
				button.set_position (50, 0)
				button.clicked_event.subscribe (agent sierpinski_display.increase_subdivisions)
				sierpinski_control_panel.add_widget (button)

				create button.make_from_text ("-")
				button.set_dimension (20, 20)
				button.set_position (70, 0)
				button.clicked_event.subscribe (agent sierpinski_display.decrease_subdivisions)
				sierpinski_control_panel.add_widget (button)

				create label.make_from_text ("Zoom: ")
				label.set_position (100, 0)
				label.set_dimension (50, 20)
				label.align_right
				sierpinski_control_panel.add_widget (label)

				create button.make_from_text ("+")
				button.set_dimension (20, 20)
				button.set_position (150, 0)
				button.clicked_event.subscribe (agent sierpinski_display.decrease_distance)
				sierpinski_control_panel.add_widget (button)

				create button.make_from_text ("-")
				button.set_dimension (20, 20)
				button.set_position (170, 0)
				button.clicked_event.subscribe (agent sierpinski_display.increase_distance)
				sierpinski_control_panel.add_widget (button)

				create checkbox.make_from_text ("Lighting")
				checkbox.set_position (200, 0)
				checkbox.set_dimension (100, 20)
				checkbox.checked_event.subscribe (agent sierpinski_display.enable_lighting)
				checkbox.unchecked_event.subscribe (agent sierpinski_display.disable_lighting)
				sierpinski_control_panel.add_widget (checkbox)

				create checkbox.make_from_text ("Fog")
				checkbox.set_position (300, 0)
				checkbox.set_dimension (100, 20)
				checkbox.checked_event.subscribe (agent sierpinski_display.enable_fog)
				checkbox.unchecked_event.subscribe (agent sierpinski_display.disable_fog)
				sierpinski_control_panel.add_widget (checkbox)

				create label.make_from_text ("drag to rotate  -  mouse wheel to zoom  -  left click increase level  -  right click decrease level")
				label.set_dimension (width, 20)
				label.set_position (0, 20)
				label.align_center
				sierpinski_control_panel.add_widget (label)
			end

			add_component (sierpinski_display)
			add_component (sierpinski_control_panel)
			add_component (sierpinski_help_panel)
		end

	sierpinski_display: SIERPINSKI_DISPLAY
			-- Sierpinski piramyd display

	sierpinski_control_panel: EM_PANEL
			-- Panel with controls for sierpinski display

	sierpinski_help_panel: EM_PANEL
			-- Panel to display help text
end