indexing

	description: "[

		An example scene representing a nice OpenGl Scene with some fog, light and nice cubes

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

class CUBE

inherit

	EM_3D_COMPONENT
--		redefine
--			prepare_drawing
--		end

	EM_SHARED_BITMAP_FACTORY

	EM_TIME_SINGLETON

	EMGL_BASIC_RENDERER

	EMGL_TEXGEN

	SINGLE_MATH
		export {NONE} all end

create

	make

feature {NONE} -- Initialisation

	make is
			-- Initialise default values.
		do
			make_3d_component

			create source_pos.make_xyz (0,0,0)
			create destination_pos.make_xyz (0,0,0)
			create direction.make_xyz (1,0,0)

			init_shapes

			emgl_line_width (2.0)

			-- init fog
			emgl_enable (em_gl_fog)
			emgl_fogi (em_gl_fog_mode, em_gl_exp2)
			emgl_fogf (Em_gl_fog_density, 0.35)
			emgl_fogf (em_gl_fog_start, 2.0)
			emgl_fogf (em_gl_fog_end, 6.0)
			emgl_hint (Em_gl_fog_hint, Em_gl_nicest)

			-- init lightning
			emgl_enable (em_gl_light0)
			emgl_enable (em_gl_lighting)

			emgl_enable (em_gl_blend)
			emgl_blend_func (em_gl_src_alpha, em_gl_one)

			-- init textures
			emgl_enable (em_gl_texture_2d)
			emgl_enable (em_gl_color_material)

			-- init environment mapping
			emgl_enable (em_gl_texture_gen_s)
			emgl_enable (em_gl_texture_gen_t)
			emgl_tex_geni (em_gl_s, em_gl_texture_gen_mode, em_gl_sphere_map)
			emgl_tex_geni (em_gl_t, em_gl_texture_gen_mode, em_gl_sphere_map)

			emgl_hint (em_gl_perspective_correction_hint, em_gl_nicest)
			emgl_shade_model (em_gl_smooth)

			-- init depth buffer
			emgl_shade_model (em_gl_depth_test)
			emgl_depth_func (em_gl_lequal)

			-- set perspective
			set_field_of_view (60)
			set_min_view_distance (0.1)
			set_max_view_distance (100.0)
		end

feature -- Initialization

	init_shapes is
			-- Init drawing list
		local
			pos_x, pos_y, pos_z: INTEGER
		do
			-- create display list
			display_list := emgl_gen_lists (1)
			emgl_new_list (display_list, em_gl_compile)

			-- put cubes into the list
			from
				pos_x := 0
			until
				pos_x = max_cube
			loop
				from
					pos_y := 0
				until
					pos_y = max_cube
				loop
					from
						pos_z := 0
					until
						pos_z = max_cube
					loop
						emgl_push_matrix
						emgl_translatef (pos_x, pos_y, pos_z)
						emgl_translatef (-4.5, -4.5, -4.5)

						render_cube
						emgl_pop_matrix

						pos_z := pos_z + 1
					end

					pos_y := pos_y + 1
				end

				pos_x := pos_x + 1
			end

			emgl_end_list
		end

feature -- Drawing

--	prepare_drawing is
			-- Prepare for drawing `Current'.
--		do
--			if width > 0 and height > 0 then
				-- Reset depth buffer
--				emgl_clear (Em_gl_depth_buffer_bit)

				-- Opengl settings
--				emgl_enable (Em_gl_depth_test)

				-- Enable antialiasing
--				emgl_enable (Em_gl_line_smooth)
--				emgl_hint (Em_gl_line_smooth, Em_gl_nicest)

				-- Setup the projection matrix
--				emgl_matrix_mode (Em_gl_projection)
--				emgl_load_identity
--				emglu_perspective (field_of_view, width/height, min_view_distance, max_view_distance)

				-- Setup the model view matrix
--				emgl_matrix_mode (Em_gl_modelview)
--				emgl_load_identity
--			end
--		end

	draw is
			-- Draw Scene
		do
			last_redraw_time := actual_redraw_time
			actual_redraw_time := time.ticks / 2000

			emgl_rotatef (actual_redraw_time * 7.0, 1, 0, 0)
			emgl_rotatef (actual_redraw_time * 8.0, 0, 1, 0)
			emgl_rotatef (actual_redraw_time * 9.0, 0, 0, 1)

	--		gl_translatef (0, 0, (actual_redraw_time - 0.5) * 3.0)

			emgl_translatef (vx,vy,0)

			emgl_color4f (0.0, 0.5, 1.0, 0.4)
			gl_bind_texture_external (em_gl_texture_2d, 0)

			emgl_call_list (display_list)

			emgl_color4f (0.0, 0.8, 0.8, 0.1);
			emgl_polygon_mode (em_gl_front_and_back, em_gl_line)

			emgl_call_list (display_list)

			emgl_polygon_mode (em_gl_front_and_back, em_gl_fill)
		end

feature {NONE} -- Implementation

	vx, vy: DOUBLE

	render_cube is
			-- Render a single cube with normals
		do
			emgl_begin (em_gl_quads)

		    emgl_normal3f (1.0, 0.0, 0.0)
		    emgl_tex_coord2f (0.0, 0.0); emgl_vertex3f ( 0.25, -0.25, -0.25)
		    emgl_tex_coord2f (1.0, 0.0); emgl_vertex3f ( 0.25,  0.25, -0.25)
		    emgl_tex_coord2f (1.0, 1.0); emgl_vertex3f ( 0.25,  0.25,  0.25)
		    emgl_tex_coord2f (0.0, 1.0); emgl_vertex3f ( 0.25, -0.25,  0.25)

		    emgl_normal3f (-1.0, 0.0, 0.0)
		    emgl_tex_coord2f (0.0, 1.0); emgl_vertex3f (-0.25, -0.25,  0.25)
		    emgl_tex_coord2f (0.0, 0.0); emgl_vertex3f (-0.25, -0.25, -0.25)
		    emgl_tex_coord2f (1.0, 0.0); emgl_vertex3f (-0.25,  0.25, -0.25)
		    emgl_tex_coord2f (1.0, 1.0); emgl_vertex3f (-0.25,  0.25,  0.25)

		    emgl_normal3f (0.0, 0.0, -1.0)
		    emgl_tex_coord2f (0.0, 1.0); emgl_vertex3f (-0.25,  0.25,  -0.25)
		    emgl_tex_coord2f (1.0, 1.0); emgl_vertex3f ( 0.25,  0.25,  -0.25)
		    emgl_tex_coord2f (1.0, 0.0); emgl_vertex3f ( 0.25, -0.25,  -0.25)
		    emgl_tex_coord2f (0.0, 0.0); emgl_vertex3f (-0.25, -0.25,  -0.25)

		    emgl_normal3f (0.0, 0.0, 1.0)
		    emgl_tex_coord2f (0.0, 0.0); emgl_vertex3f (-0.25, -0.25,  0.25)
		    emgl_tex_coord2f (0.0, 1.0); emgl_vertex3f (-0.25,  0.25,  0.25)
		    emgl_tex_coord2f (1.0, 1.0); emgl_vertex3f ( 0.25,  0.25,  0.25)
		    emgl_tex_coord2f (1.0, 0.0); emgl_vertex3f ( 0.25, -0.25,  0.25)

		    emgl_normal3f (0.0, 1.0, 0.0)
		    emgl_tex_coord2f (0.0, 1.0); emgl_vertex3f ( 0.25,  0.25, -0.25)
		    emgl_tex_coord2f (1.0, 1.0); emgl_vertex3f ( 0.25,  0.25,  0.25)
		    emgl_tex_coord2f (1.0, 0.0); emgl_vertex3f (-0.25,  0.25,  0.25)
		    emgl_tex_coord2f (0.0, 0.0); emgl_vertex3f (-0.25,  0.25, -0.25)

		    emgl_normal3f (0.0, -1.0, 0.0)
		    emgl_tex_coord2f (1.0, 1.0); emgl_vertex3f ( 0.25, -0.25,  0.25)
		    emgl_tex_coord2f (1.0, 0.0); emgl_vertex3f (-0.25, -0.25,  0.25)
		    emgl_tex_coord2f (0.0, 0.0); emgl_vertex3f (-0.25, -0.25, -0.25)
		    emgl_tex_coord2f (0.0, 1.0); emgl_vertex3f ( 0.25, -0.25, -0.25)
		    emgl_end
		end

	display_list: INTEGER
			-- Identifier for display list

	max_cube: INTEGER is 10
			-- maximal number of cubes to be drawn

	last_redraw_time, actual_redraw_time: DOUBLE
			-- tariable for time

	step: DOUBLE
			-- for camera position

	source_pos, destination_pos: GL_VECTOR_3D [DOUBLE]
			-- source and destionation position

	direction: GL_VECTOR_3D [DOUBLE]
			-- direction the camera is looking
end