xabina/core.adb

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-- Copyright (c) 2023 - Ognjen 'xolatile' Milan Robovic
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-- Xabina is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either
-- version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
-- implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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-- Experimental minimal terminal rogue-like game in Ada programming language. I used to write a lot of Ada programs some time ago, then went in full C and assembly mode, and came
-- back to Ada, but realized that I keep my folders messy... Since it's bothersome to find my old Ada projects and share them here, I decided that the most easy thing to do is to
-- write a new program in Ada, a tiny game. Work in progress, it's messy and ugly for now...
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package body core is

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	procedure bind (symbol : character         := CANCEL;
	                action : procedure_pointer := action_idle'access) is
	begin
		action_list (character'pos (symbol)) := action;
	end bind;

	procedure unbind (symbol : character := CANCEL) is
	begin
		action_list (character'pos (symbol)) := action_idle'access;
	end unbind;

	procedure action_idle is begin null;            end action_idle;
	procedure action_exit is begin active := false; end action_exit;

	procedure action_move_up    is begin player.y := player.y - 1; end action_move_up;
	procedure action_move_down  is begin player.y := player.y + 1; end action_move_down;
	procedure action_move_left  is begin player.x := player.x - 1; end action_move_left;
	procedure action_move_right is begin player.x := player.x + 1; end action_move_right;

	procedure render_screen_delete is begin put (ESCAPE & "[2J");              end render_screen_delete;
	procedure render_screen_offset is begin put (ESCAPE & "[H");               end render_screen_offset;
	procedure render_cursor_hide   is begin put (ESCAPE & "[?25l");            end render_cursor_hide;
	procedure render_cursor_show   is begin put (ESCAPE & "[?25h");            end render_cursor_show;
	procedure render_realignment   is begin put (CARRIAGE_RETURN & LINE_FEED); end render_realignment;

	procedure render_character (symbol : character     := ' ';
	                            colour : character     := '7';
	                            effect : character     := '0';
	                            y      : screen_height := 0;
	                            x      : screen_width  := 0) is
	begin
		screen_symbol (y, x) := symbol;
		screen_colour (y, x) := colour;
		screen_effect (y, x) := effect;
	end render_character;

	procedure render_screen is
		format : string (1 .. 12) := ESCAPE & "[E;3CmS" & ESCAPE & "[0m";
	begin
		render_screen_offset;
		for y in screen_height
		loop
			for x in screen_width
			loop
				format (8) := screen_symbol (y, x);
				format (6) := screen_colour (y, x);
				format (3) := screen_effect (y, x);
				put (format);
			end loop;
			render_realignment;
		end loop;
	end render_screen;

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-- Player
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	procedure render_player is
	begin
		render_character ('@', core.colour.cyan, core.effect.bold, screen_height (player.y), screen_width (player.x));
	end render_player;

end core;