indexing
	description: "[
					Small cubes for a big special effect.
					
					This class is part of the XAE Extended Adventure Engine Project.
				  ]"

	author: "Ralph Wiedemeier, ralphw@student.ethz.ch"
	date: "$Date$"
	revision: "$Revision$"

class
	GUI_SFX_SMALL_CUBE

inherit
	OPEN_GL_LIBRARY
		export {NONE} all end

	DOUBLE_MATH
		export {NONE} all
		undefine default_create end


create {GUI_TRANSITION}
	make_with_pos

feature -- Initialization

--	make_with_pos (a_row: INTEGER; a_src_col: INTEGER; a_dst_col: INTEGER; a_src_tex: INTEGER; a_dst_tex: INTEGER) is
	make_with_pos (a_row: INTEGER; a_src_col: INTEGER; a_dst_col: INTEGER; a_src_tex: EM3D_TEXTURE_2D[ EMGL_FORMAT_RGBA ]; a_dst_tex: EM3D_TEXTURE_2D[ EMGL_FORMAT_RGBA ]) is
			-- create new cube with given source and destination positions
		do
			row := a_row
			src_col := a_src_col
			dst_col := a_dst_col

--			src_texture_id := a_src_tex
--			dst_texture_id := a_dst_tex
			src_texture := a_src_tex
			dst_texture := a_dst_tex

			generate_gl_script
		end


feature -- Operation

	draw (time: DOUBLE) is
			-- draw cube (time from 0..1)
		local
			x, y, z: DOUBLE
		do
			x := smooth_05 (1 - time) * x_target
			y := y_target
			z := smooth_05 (time) * z_target

			emgl_push_matrix
			emgl_translated (x, y, z)
--			gl_call_list (script_id)
			display_list.call_list

			emgl_pop_matrix
		end

feature {NONE} -- Implementation

	generate_gl_script is
			--
		local
			tex_width, tex_height: DOUBLE
			src_tex_u, dst_tex_u, tex_v: DOUBLE
			cube_width, cube_height: DOUBLE
		do
			tex_width := 1 / columns
			tex_height := 1 / rows
			src_tex_u := src_col * tex_width
			dst_tex_u := 1 - dst_col * tex_width
			tex_v := row * tex_height

			cube_width := width / columns
			cube_height := height / rows

			x_target :=  cube_width * src_col
			y_target :=  cube_height * row
			z_target := -cube_width * dst_col

--			script_id := gl_gen_lists (1)
--			gl_new_list (script_id, EM_GL_COMPILE)
			create display_list
			display_list.new_list_compile

--			macro_bind_texture_antialiased_replace (src_texture_id)
			macro_bind_texture_antialiased_replace (src_texture)

			-- CHANGES em prepended
			emgl_begin (EM_gl_quads)
				-- Front Face (SOURCE)
				emgl_tex_coord2d (src_tex_u, tex_v)
				emgl_vertex3d (0, 0, 0)
				emgl_tex_coord2d (src_tex_u + tex_width, tex_v)
				emgl_vertex3d (cube_width, 0, 0)
				emgl_tex_coord2d (src_tex_u + tex_width, tex_v + tex_height)
				emgl_vertex3d (cube_width, cube_height, 0)
				emgl_tex_coord2d (src_tex_u, tex_v + tex_height)
				emgl_vertex3d (0, cube_height, 0)
				-- Back Face
				emgl_tex_coord2d (src_tex_u, tex_v)
				emgl_vertex3d (cube_width, 0, -cube_width)
				emgl_tex_coord2d (src_tex_u + tex_width, tex_v)
				emgl_vertex3d (0, 0, -cube_width)
				emgl_tex_coord2d (src_tex_u + tex_width, tex_v + tex_height)
				emgl_vertex3d (0, cube_height, -cube_width)
				emgl_tex_coord2d (src_tex_u, tex_v + tex_height)
				emgl_vertex3d (cube_width, cube_height, -cube_width)
			emgl_end
			src_texture.unbind

--			macro_bind_texture_antialiased_replace (dst_texture_id)
			macro_bind_texture_antialiased_replace (dst_texture)
			emgl_begin (EM_gl_quads)
				-- Left Face
				emgl_tex_coord2d (dst_tex_u, tex_v)
				emgl_vertex3d (0, 0, 0)
				emgl_tex_coord2d (dst_tex_u - tex_width, tex_v)
				emgl_vertex3d (0, 0, -cube_width)
				emgl_tex_coord2d (dst_tex_u - tex_width, tex_v + tex_height)
				emgl_vertex3d (0, cube_height, -cube_width)
				emgl_tex_coord2d (dst_tex_u, tex_v + tex_height)
				emgl_vertex3d (0,  cube_height, 0)
				-- Right Face (TARGET)
				emgl_tex_coord2d (dst_tex_u, tex_v)
				emgl_vertex3d (cube_width, 0, -cube_width)
				emgl_tex_coord2d (dst_tex_u - tex_width, tex_v)
				emgl_vertex3d (cube_width, 0, 0)
				emgl_tex_coord2d (dst_tex_u - tex_width, tex_v + tex_height)
				emgl_vertex3d (cube_width, cube_height, 0)
				emgl_tex_coord2d (dst_tex_u, tex_v + tex_height)
				emgl_vertex3d (cube_width,  cube_height, -cube_width)
			emgl_end
			dst_texture.unbind

			macro_disable_texture_mapping
			emgl_begin (EM_gl_quads)
				emgl_color4d (0.1, 0.1, 0.2, 1)
				-- Top Face
				emgl_vertex3d (0, cube_height, 0)
				emgl_vertex3d (cube_width, cube_height, 0)
				emgl_vertex3d (cube_width, cube_height, -cube_width)
				emgl_vertex3d (0, cube_height, -cube_width)
				-- Bottom Face
				emgl_vertex3d (0, 0, 0)
				emgl_vertex3d (cube_width, 0, 0)
				emgl_vertex3d (cube_width, 0, -cube_width)
				emgl_vertex3d (0, 0, -cube_width)
			emgl_end

			emgl_end_list
		end

	smooth (t: DOUBLE): DOUBLE is
			-- Get smooth transition (0..1)
		do
			result := 3*t*t - 2*t*t*t
		end

	smooth_05 (t: DOUBLE): DOUBLE is
			-- Get smooth transition (0..0.5)
		local
			s: DOUBLE
		do
			s := t * 2
			if s > 1 then s := 1 end
			result := 3*s*s - 2*s*s*s
		end



--	script_id: INTEGER
--	src_texture_id: INTEGER
--	dst_texture_id: INTEGER
	display_list: EMGL_DISPLAY_LIST
	src_texture: EM3D_TEXTURE_2D[ EMGL_FORMAT_RGBA ]
	dst_texture: EM3D_TEXTURE_2D[ EMGL_FORMAT_RGBA ]

	row: INTEGER
	src_col: INTEGER
	dst_col: INTEGER

	x_target: DOUBLE
	y_target: DOUBLE
	z_target: DOUBLE

	rows: INTEGER is 5
	columns: INTEGER is 10

	width: INTEGER is 1024
	height: INTEGER is 512

end -- class GUI_SFX_SMALL_CUBE