Updated gitignore.

Lots of comments and changes in UI code in general.

.gitignore

@@ -111,4 +111,4 @@ flycheck_*.el
 # Swap Files #
 .*.kate-swp
 .swp.*
-
+.kateproject*

README.md

@@ -6,9 +6,12 @@ A dungeon crawler game made with LoveDOS for the DOSember Game Jam https://itch.
 
 ### Sprites 
 - [B&W Ornamental Cursor by qubodup](https://opengameart.org/content/bw-ornamental-cursor-19x19)
-- [Microchip texture by ZeptoBARS](https://opengameart.org/content/microchip-texture)
 - [Eris in colour by Stephen](https://openclipart.org/detail/329762/eris-in-colour)
 
+### Textures
+- [Microchip texture by ZeptoBARS](https://opengameart.org/content/microchip-texture)
+- [Assorted textures by Makkon](https://www.slipseer.com/index.php?resources/makkon-textures.28/)
+
 ### Sound effects
 - [Click.wav by frosty ham](https://opengameart.org/content/click-0)
 - [Sci-Fi Sound Effects Library by Little Robot Sound Factory](https://opengameart.org/content/sci-fi-sound-effects-library)

licenses/OFL.TXT

@@ -0,0 +1,97 @@
+Copyright (c) <dates>, <Copyright Holder> (<URL|email>),
+with Reserved Font Name <Reserved Font Name>.
+Copyright (c) <dates>, <additional Copyright Holder> (<URL|email>),
+with Reserved Font Name <additional Reserved Font Name>.
+Copyright (c) <dates>, <additional Copyright Holder> (<URL|email>).
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+https://openfontlicense.org
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded,
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.

main.lua

@@ -2,10 +2,10 @@
 -- Imports
 ------------------------------------------------------------------------------
 
-local love        = require 'love'
-local game_states = require 'src.states'
-local settings    = require 'src.utils.settings'
-local Fader       = require 'src.graphics.fader'
+local love           = require 'love'
+local game_states    = require 'src.states'
+local settings       = require 'src.utils.settings'
+local Fader          = require 'src.graphics.fader'
 
 
 ------------------------------------------------------------------------------
@@ -24,8 +24,8 @@ Debug         = false
 
 local function parse_args(args)
     for _, v in pairs(args) do
-        -- Enable debug mode.
-        if v == '-debug' then Debug = true end
+        if v == '-debug'      then Debug         = true end
+        if v == '-skip-intro' then Current_state = 2    end
     end
 end
 
@@ -74,7 +74,6 @@ function love.update(dt)
         if Change_state and Fade.done then
             game_states[Current_state]:unload(dt)
             Current_state = new_state
-            game_states[Current_state]:load()
             Change_state = false
             Fade:fade_in()
         end
@@ -88,13 +87,14 @@ function love.draw()
     Fade:draw()
 
     if Debug then
-        love.graphics.setColor(0, 0, 0)
-        love.graphics.rectangle('fill', 0, 0, 140, 50)
-        love.graphics.setColor()
+        -- love.graphics.setColor(0, 0, 0)
+        -- love.graphics.rectangle('fill', 0, 0, 140, 50)
+        love.graphics.setColor(255, 250, 0)
         love.graphics.print(string.format('OS: %s', love.system.getOS()), 5, 5)
         love.graphics.print(string.format('Love version: %s', love.getVersion()), 5, 15)
         love.graphics.print(string.format('Memory usage: %s KiB', love.system.getMemUsage()), 5, 25)
         love.graphics.print(string.format('FPS: %.2f', 1.0 / love.timer.getAverageDelta()), 5, 35)
+        love.graphics.setColor()
     end
 end
 
@@ -134,7 +134,7 @@ end
 function love.mousepressed(x, y, btn)
     -- Send events to the active game state if there is no fade active.
     if Fade.done then
-        game_states[Current_state]:mousemoved(x, y, btn)
+        game_states[Current_state]:mousepressed(x, y, btn)
     end
 end
 

src/graphics/drawable.lua

@@ -3,13 +3,13 @@
 ------------------------------------------------------------------------------
 
 local make_class = require 'src.utils.classes'
-local Asset      = require 'src.utils.asset'
 
 ------------------------------------------------------------------------------
 -- Class definitions
 ------------------------------------------------------------------------------
 
-local Drawable = make_class(Asset)
+---@class Drawable
+local Drawable = make_class()
 
 
 ------------------------------------------------------------------------------

src/graphics/sprite.lua

@@ -4,28 +4,41 @@
 
 local love       = require 'love'
 local make_class = require 'src.utils.classes'
+local Asset      = require 'src.utils.asset'
 local Drawable   = require 'src.graphics.drawable'
 
 ------------------------------------------------------------------------------
 -- Class definitions
 ------------------------------------------------------------------------------
 
-local Sprite = make_class(Drawable)
+local Sprite = make_class(Drawable, Asset)
 
 
 ------------------------------------------------------------------------------
 -- Class methods
 ------------------------------------------------------------------------------
 
-function Sprite:_init(sprite_name, x, y)
-    self.sprite_name = string.format('assets/%s', sprite_name)
+function Sprite:_init(file_name, x, y)
+    Asset._init(self, file_name)
     self.x = (x ~= nil and x) or 0
     self.y = (y ~= nil and y) or 0
 end
 
 
 function Sprite:load()
-    self.sprite = love.graphics.newImage(self.sprite_name)
+    if not self:is_loaded() then
+        self.sprite = love.graphics.newImage(self.file_name)
+    end
+end
+
+
+function Sprite:unload()
+    self.sprite = nil
+end
+
+
+function Sprite:is_loaded()
+    return self.sprite ~= nil
 end
 
 
@@ -36,11 +49,6 @@ function Sprite:draw()
 end
 
 
-function Sprite:unload()
-    self.sprite = nil
-end
-
-
 ------------------------------------------------------------------------------
 -- Module return
 ------------------------------------------------------------------------------

src/gstates/gstate.lua

@@ -3,8 +3,10 @@
 ------------------------------------------------------------------------------
 
 local make_class = require 'src.utils.classes'
+local assets     = require 'src.utils.asstmngr'
 local Drawable   = require 'src.graphics.drawable'
 
+
 ------------------------------------------------------------------------------
 -- Class definitions
 ------------------------------------------------------------------------------
@@ -18,13 +20,23 @@ local GameState = make_class(Drawable)
 
 function GameState:_init(name, index)
     Drawable._init(self)
-    self.name  = name
-    self.index = index
+    self.name       = name
+    self.index      = index
+    self.next_state = self.index
 end
 
 
 function GameState:update(_)
-    return self.index
+    return self.next_state
+end
+
+
+function GameState:load()
+end
+
+
+function GameState:unload()
+    assets:unload(self.name)
 end
 
 

src/gstates/menu.lua

@@ -2,92 +2,184 @@
 -- Imports
 ------------------------------------------------------------------------------
 
-local love        = require 'love'
-local make_class  = require 'src.utils.classes'
-local GameState   = require 'src.gstates.gstate'
-local Fader       = require 'src.graphics.fader'
-local Sprite      = require 'src.graphics.sprite'
-local Cursor      = require 'src.ui.cursor'
-local SoundEffect = require 'src.sound.sfx'
+local love           = require 'love'
+local assets         = require 'src.utils.asstmngr'
+local sound_manager  = require 'src.sound.sndmngr'
+local dialog_manager = require 'src.ui.dlgmngr'
+local make_class     = require 'src.utils.classes'
+local constants      = require 'src.gstates.menus.const'
+local GameState      = require 'src.gstates.gstate'
+local MainMenu       = require 'src.gstates.menus.mainmenu'
+local OptionsMenu    = require 'src.gstates.menus.options'
+local Fader          = require 'src.graphics.fader'
+local Cursor         = require 'src.ui.cursor'
+local Font           = require 'src.ui.font'
+local SoundEffect    = require 'src.sound.sfx'
 
 
 ------------------------------------------------------------------------------
 -- Class definitions
 ------------------------------------------------------------------------------
 
-local MainMenu = make_class(GameState)
+local Menu = make_class(GameState)
 
 
 ------------------------------------------------------------------------------
--- Class methods
+--  Class methods
 ------------------------------------------------------------------------------
 
-function MainMenu:_init(name, index)
+function Menu:_init(name, index)
     GameState._init(self, name, index)
-    self.skip  = false
-    self.fade  = Fader()
+    self.fade         = Fader()
+    self.current_menu = constants.MAIN_MENU
+    self.next_menu    = constants.MAIN_MENU
+    self.all_loaded   = false
 
     -- Create sprites and buttons.
-    self.background = Sprite('imgs/cpu.png')
+    self.btn_font   = Font('fonts/Concrete.ttf')
+    self.title_font = Font('fonts/BBrick.ttf', 35)
 
     -- Create a mouse cursor object at the current mouse position.
     local mx, my = love.mouse.getPosition()
-    self.cursor = Cursor(mx, my)
+    self.cursor  = Cursor(mx, my)
 
     -- Create sound effects.
     self.bgm = SoundEffect('bgm/eskisky.wav')
+
+    -- Create the sub-menus.
+    self.menus = { }
+    self.menus[constants.MAIN_MENU]    = MainMenu(self, self.title_font, self.btn_font)
+    self.menus[constants.OPTIONS_MENU] = OptionsMenu(self, self.title_font, self.btn_font)
+
+    -- Register all assets.
+    assets:register(self.name, self.btn_font)
+    assets:register(self.name, self.title_font)
+    assets:register(self.name, self.cursor)
+    assets:register(self.name, self.bgm)
 end
 
 
-function MainMenu:load()
-    -- Load sprites.
-    self.background:load()
-    self.cursor:load()
+function Menu:update(dt)
+    if not self.bgm:isPlaying() then sound_manager:play_music(self.bgm) end
 
-    -- Load sound effects and start playing the background music
-    self.bgm:load()
-    self.bgm:play()
+    if self.all_loaded then
+        self.menus[self.current_menu]:update(dt)
+        dialog_manager:update(dt)
+
+        -- If the game state changed then trigger a fade out.
+        if self.next_menu ~= self.current_menu and self.fade.done then
+            self.fade:fade_out()
+        end
+
+        self.fade:update(dt)
+
+        -- Update the game state.
+        if self.menus[self.next_menu] == nil then
+            error(string.format('%s: switched to unknown menu', self.next_menu))
+        else
+            -- If the new state exists then unload it's data and set the new state.
+            if self.next_menu ~= self.current_menu and self.fade.done then
+                self.current_menu = self.next_menu
+                self.fade:fade_in()
+            end
+        end
+    else
+        local done = true
+
+        assets:update(self.name)
+
+        for _, v in pairs(self.menus) do
+            assets:update(v.name)
+            done = done and assets:done(v.name)
+        end
+
+        self.all_loaded = assets:done(self.name) and done
+    end
+
+    return self.next_state
 end
 
 
-function MainMenu:update(dt)
-    -- Update the fader.
-    self.fade:update(dt)
-
-    -- Move on to the next game state if the user skipped the intro or all stages are complete.
-    if not self.skip then return self.index else return -1 end
+function Menu:draw()
+    if self.all_loaded then
+        self.menus[self.current_menu]:draw()
+        dialog_manager:draw()
+        self.cursor:draw()
+        self.fade:draw()
+    else
+        assets:draw()
+    end
 end
 
-
-function MainMenu:draw()
-    self.background:draw()
-    self.cursor:draw()
-    self.fade:draw()
-end
-
-
-function MainMenu:unload()
-    self.background:unload()
-    self.cursor:unload()
-    self.bgm:unload()
-end
-
-
-function MainMenu:keypressed(key)
-    -- Skip the intro on any key press.
-    if key == "escape" then
-        self.skip = true
+function Menu:keypressed(key, code, isrepeat)
+    -- Send events to the active game state if there is no fade active.
+    if Fade.done then
+        if dialog_manager:empty() then
+            self.menus[self.current_menu]:keypressed(key, code, isrepeat)
+        else
+            dialog_manager:keypressed(key, code, isrepeat)
+        end
     end
 end
 
 
-function MainMenu:mousemoved(x, y, dx, dy)
+function Menu:keyreleased(key, code)
+    -- Send events to the active game state if there is no fade active.
+    if Fade.done then
+        if dialog_manager:empty() then
+            self.menus[self.current_menu]:keyreleased(key, code)
+        else
+            dialog_manager:keyreleased(key, code)
+        end
+    end
+end
+
+
+function Menu:textinput(text)
+    -- Send events to the active game state if there is no fade active.
+    if Fade.done then
+        if dialog_manager:empty() then
+            self.menus[self.current_menu]:textinput(text)
+        else
+            dialog_manager:textinput(text)
+        end
+    end
+end
+
+function Menu:mousemoved(x, y, dx, dy)
+    if dialog_manager:empty() then
+        self.menus[self.current_menu]:mousemoved(x, y, dx, dy)
+    else
+        dialog_manager:mousemoved(x, y, dx, dy)
+    end
     self.cursor:mousemoved(x, y, dx, dy)
 end
 
 
+function Menu:mousepressed(x, y, btn)
+    if self.fade.done then
+        if dialog_manager:empty() then
+            self.menus[self.current_menu]:mousepressed(x, y, btn)
+        else
+            dialog_manager:mousepressed(x, y, btn)
+        end
+    end
+end
+
+
+function Menu:mousereleased(x, y, btn)
+    if self.fade.done then
+        if dialog_manager:empty() then
+            self.menus[self.current_menu]:mousereleased(x, y, btn)
+        else
+            dialog_manager:mousereleased(x, y, btn)
+        end
+    end
+end
+
+
 ------------------------------------------------------------------------------
 -- Module return
 ------------------------------------------------------------------------------
 
-return MainMenu
+return Menu

src/gstates/menus/base.lua

@@ -0,0 +1,75 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love        = require 'love'
+local assets      = require 'src.utils.asstmngr'
+local make_class  = require 'src.utils.classes'
+local GameState   = require 'src.gstates.gstate'
+local Sprite      = require 'src.graphics.sprite'
+local VBox        = require 'src.ui.vbox'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local BaseMenu = make_class(GameState)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function BaseMenu:_init(parent, name, index, bckg)
+    GameState._init(self, name, index)
+
+    self.parent = parent
+
+    -- Create background sprite and container.
+    self.background = Sprite(bckg)
+    self.container  = VBox(15, 5, love.graphics.getWidth() - 15)
+
+    -- Register the background and container into the asset manager.
+    assets:register(self.name, self.background)
+    assets:register(self.name, self.container)
+end
+
+
+function BaseMenu:mousemoved(x, y, dx, dy)
+    self.container:mousemoved(x, y, dx, dy)
+end
+
+
+function BaseMenu:mousepressed(x, y, btn)
+    self.container:mousepressed(x, y, btn)
+end
+
+
+function BaseMenu:mousereleased(x, y, btn)
+    self.container:mousereleased(x, y, btn)
+end
+
+
+function BaseMenu:update()
+    if not assets:done(self.name) then
+        assets:update(self.name)
+    end
+end
+
+
+function BaseMenu:draw()
+    if assets:done(self.name) then
+        self.background:draw()
+        self.container:draw()
+    else
+        assets:draw()
+    end
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return BaseMenu

src/gstates/menus/const.lua

@@ -0,0 +1,17 @@
+------------------------------------------------------------------------------
+-- Constants
+------------------------------------------------------------------------------
+
+local constants = {
+    MAIN_MENU    = 1,
+    OPTIONS_MENU = 2,
+    STORY        = 3,
+    LOAD_MENU    = 4,
+}
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return constants

src/gstates/menus/mainmenu.lua

@@ -0,0 +1,41 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+local constants  = require 'src.gstates.menus.const'
+local BaseMenu   = require 'src.gstates.menus.base'
+local Color      = require 'src.utils.color'
+local Label      = require 'src.ui.label'
+local TextButton = require 'src.ui.textbtn'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local MainMenu = make_class(BaseMenu)
+
+
+------------------------------------------------------------------------------
+-- Main Menu Class methods
+------------------------------------------------------------------------------
+
+function MainMenu:_init(parent, title_font, button_font)
+    BaseMenu._init(self, parent, "Main Menu", constants.MAIN_MENU, 'imgs/concb03.png')
+
+    -- Create UI elements of the main menu.
+    self.container:add(Label(nil, nil, 'LoveDOS', title_font, Color(215, 0, 0), true))
+    self.container:add(TextButton('New Game', button_font))
+    self.container:add(TextButton('Load Game', button_font))
+    self.container:add(TextButton('Options', button_font, nil, nil, function() parent.next_menu = constants.OPTIONS_MENU end))
+    self.container:add(TextButton('Help & Story', button_font))
+    self.container:add(TextButton('Quit', button_font, nil, nil, function() parent.next_state = -1 end))
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return MainMenu

src/gstates/menus/options.lua

@@ -0,0 +1,178 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class    = require 'src.utils.classes'
+local constants     = require 'src.gstates.menus.const'
+local settings      = require 'src.utils.settings'
+local sound_manager = require 'src.sound.sndmngr'
+local assets        = require 'src.utils.asstmngr'
+local BaseMenu      = require 'src.gstates.menus.base'
+local Color         = require 'src.utils.color'
+local HBox          = require 'src.ui.hbox'
+local Label         = require 'src.ui.label'
+local TextButton    = require 'src.ui.textbtn'
+local TextInput     = require 'src.ui.textinpt'
+local Checkbox      = require 'src.ui.chkbox'
+local Bar           = require 'src.ui.bar'
+local Dialog        = require 'src.ui.dialog'
+local Font          = require 'src.ui.font'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local OptionsMenu = make_class(BaseMenu)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function OptionsMenu:_init(parent, title_font, button_font)
+    BaseMenu._init(self, parent, "Options Menu", constants.OPTIONS_MENU, 'imgs/cpu.png')
+
+    self.subtitle_font = Font('fonts/BBrick.ttf', 25)
+
+    -- Create UI elements of the menu.
+    self.container:add(Label(nil, nil, 'Options', title_font, Color(215, 0, 0), true))
+
+    -- Permadeath checkbox.
+    local box = HBox()
+
+    box:add(Label(nil, nil, 'Enable Permadeath: ', button_font))
+    box:add(Checkbox(
+        function()
+            settings.permadeath = not settings.permadeath
+        end,
+        function()
+            return settings.permadeath
+        end,
+        17,
+        15))
+
+    self.container:add(box)
+
+    -- Control binding dialog.
+    local dlg = Dialog('imgs/tchcmp1.png', nil, 15, nil, nil, button_font)
+
+    dlg:add(Label(nil, nil, 'Set Controls', self.subtitle_font, Color(215, 0, 0), true))
+
+    box = HBox()
+    box.spacing = 30
+    -- text, font, x, y, callback, value, float, base_col, sel_color, press_col
+    box:add(TextInput('Step Forw.',
+                      button_font,
+                      nil, nil,
+                      function(v) settings.forward = v end,
+                      function() return settings.forward end))
+    box:add(TextInput('Step Back',
+                      button_font,
+                      nil, nil,
+                      function(v) settings.backward = v end,
+                      function() return settings.backward end))
+
+    dlg:add(box)
+
+    box = HBox()
+    box.spacing = 40
+    box:add(TextInput('Step Left',
+                      button_font,
+                      nil, nil,
+                      function(v) settings.stepleft = v end,
+                      function() return settings.stepleft end))
+    box:add(TextInput('Step Right',
+                      button_font,
+                      nil, nil,
+                      function(v) settings.stepright = v end,
+                      function() return settings.stepright end))
+
+    dlg:add(box)
+
+    box = HBox()
+    box.spacing = 42
+    box:add(TextInput('Turn Left',
+                      button_font,
+                      nil, nil,
+                      function(v) settings.turnleft = v end,
+                      function() return settings.turnleft end))
+    box:add(TextInput('Turn Right',
+                      button_font,
+                      nil, nil,
+                      function(v) settings.turnright = v end,
+                      function() return settings.turnright end))
+
+    dlg:add(box)
+
+    box = HBox()
+
+    box:add(TextButton(
+        'Set Controls',
+        button_font,
+        nil,
+        nil,
+        function()
+            dlg:show()
+        end))
+
+    self.container:add(box)
+
+    -- Sound volume bar.
+    box = HBox()
+
+    box:add(Label(nil, nil, 'Sound Volume: ', button_font))
+    box:add(Bar(
+        function(v)
+            settings.soundvol = math.ceil(v)
+        end,
+        function()
+            return settings.soundvol
+        end,
+        0, 100,
+        170, 15))
+
+    self.container:add(box)
+
+    -- Music volume bar.
+    box = HBox()
+    box.spacing = 13
+
+    box:add(Label(nil, nil, 'Music Volume: ', button_font))
+    box:add(Bar(
+        function(v)
+            settings.musicvol = math.ceil(v)
+            sound_manager:update_volumes()
+        end,
+        function()
+            return settings.musicvol
+        end,
+        0, 100,
+        170, 15))
+
+    self.container:add(box)
+
+    -- Back button.
+    box = HBox()
+    box:add(TextButton(
+        'Go Back',
+        button_font,
+        nil,
+        nil,
+        function()
+            settings:save_settings()
+            parent.next_menu = constants.MAIN_MENU
+        end))
+    self.container:add(box)
+
+    -- Register the dialog with the asset manager.
+    assets:register(self.name, dlg)
+    assets:register(self.name, self.subtitle_font)
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return OptionsMenu

src/sound/sfx.lua

@@ -11,7 +11,7 @@ local Asset      = require 'src.utils.asset'
 ------------------------------------------------------------------------------
 
 -- SoundEffect is a simple wrapper around Löve's Source class to allow for
--- easy loading/unloading and automatically hecking if a sound effect is valid
+-- easy loading/unloading and automatically checking if a sound effect is valid
 -- before using it.
 local SoundEffect = make_class(Asset)
 
@@ -21,12 +21,14 @@ local SoundEffect = make_class(Asset)
 ------------------------------------------------------------------------------
 
 function SoundEffect:_init(file_name)
-    self.file_name = string.format('assets/%s', file_name)
+    Asset._init(self, file_name)
 end
 
 
 function SoundEffect:load()
-    self.sfx = love.audio.newSource(self.file_name)
+    if not self:is_loaded() then
+        self.sfx = love.audio.newSource(self.file_name)
+    end
 end
 
 
@@ -36,6 +38,11 @@ function SoundEffect:unload()
 end
 
 
+function SoundEffect:is_loaded()
+    return self.sfx ~= nil
+end
+
+
 function SoundEffect:setVolume(volume)
     if self.sfx ~= nil then self.sfx:setVolume(volume) end
 end

src/sound/sndmngr.lua

@@ -0,0 +1,57 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+local settings   = require 'src.utils.settings'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local SoundManager = make_class()
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function SoundManager:_init()
+    self.active_bgm = nil
+end
+
+
+function SoundManager:play_sound(sfx)
+    local vol = math.max(math.min(settings.soundvol / 100, 1.0), 0.0)
+    sfx:setVolume(vol)
+    sfx:play()
+end
+
+
+function SoundManager:play_music(bgm)
+    local vol = math.max(math.min(settings.musicvol / 100, 1.0), 0.0)
+
+    if self.active_bgm ~= nil then
+        self.active_bgm:stop()
+    end
+
+    self.active_bgm = bgm
+    self.active_bgm:setVolume(vol)
+    self.active_bgm:play()
+end
+
+
+function SoundManager:update_volumes()
+    if self.active_bgm ~= nil then
+        local vol = math.max(math.min(settings.musicvol / 100, 1.0), 0.0)
+        self.active_bgm:setVolume(vol)
+    end
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return SoundManager()

src/states.lua

@@ -2,8 +2,8 @@
 -- Imports
 ------------------------------------------------------------------------------
 
-local Intro    = require 'src.gstates.intro'
-local MainMenu = require 'src.gstates.menu'
+local Intro = require 'src.gstates.intro'
+local Menu  = require 'src.gstates.menu'
 
 
 ------------------------------------------------------------------------------
@@ -13,7 +13,7 @@ local MainMenu = require 'src.gstates.menu'
 -- Table of all valid game states.
 local states = {
     Intro('intro', 1),
-    MainMenu('menu', 2),
+    Menu('menu', 2),
 }
 
 

src/ui/bar.lua

@@ -0,0 +1,121 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love       = require 'love'
+local make_class = require 'src.utils.classes'
+local collisions = require 'src.utils.colls'
+local UIElement  = require 'src.ui.element'
+local Color      = require 'src.utils.color'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local Bar = make_class(UIElement)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function Bar:_init(callback, val_fn, min, max, w, h, color, sel_color, press_col, float, x, y)
+    UIElement._init(self, x, y, float, false)
+    self.callback  = callback
+    self.val_fn    = val_fn
+    self.min       = min
+    self.max       = max
+    self.w         = w
+    self.h         = h
+    self.base_col  = color  ~= nil and color  or Color(255, 255, 255)
+    self.sel_color = sel_color ~= nil and sel_color or Color(215, 0, 0)
+    self.press_col = press_col ~= nil and press_col or Color(99, 99, 139)
+    self.disbl_col = Color(95, 63, 75)
+end
+
+
+function Bar:set_dimensions()
+    self.w = self.w
+    self.h = self.h
+end
+
+
+function Bar:draw()
+    local color = self.callback == nil and self.disbl_col or ((self.pressed and self.press_col) or ((self.selected and self.sel_color) or self.base_col))
+
+    -- Convert the variable's value to the [0, 1] space.
+    local v = (self.val_fn() + math.abs(self.min)) / (self.max + math.abs(self.min))
+
+    love.graphics.setColor(color.r, color.g, color.b)
+
+    -- Render the bar's outline.
+    love.graphics.rectangle('line', self.x, self.y, self.w, self.h)
+
+    -- Render the bar's content using the [0, 1] value as a proportion of the bar's width.
+    love.graphics.rectangle('fill', self.x, self.y, self.w * v, self.h)
+    love.graphics.setColor()
+end
+
+
+function Bar:_mouse2bar(x)
+    -- Take the x coord to the [0, 1] space, with clamping.
+    local v = math.max(math.min(((x - self.x) / self.w), 1.0), 0.0)
+
+    -- Convert the value to a horizontal bar coordinate and return it.
+    return (v * (self.max + math.abs(self.min))) - self.min
+end
+
+
+function Bar:mousemoved(x, y)
+    -- Select if the pointer is inside the button's bounding rect.
+    self.selected = collisions.point_in_square(x, y, self.x, self.y, self.w, self.h)
+
+    -- If the button was pressed then check if the pointer is no longer inside the button.
+    if self.pressed then
+        -- If it's not, then mark the button as "was pressed".
+        self.pressed     = collisions.point_in_square(x, y, self.x, self.y, self.w, self.h)
+        self.was_pressed = true
+        self.callback(self:_mouse2bar(x))
+    end
+
+    -- If the button was pressed and the pointer is inside the button right now.
+    if self.was_pressed and collisions.point_in_square(x, y, self.x, self.y, self.w, self.h) then
+        -- Then mark the button as pressed again.
+        self.pressed     = true
+        self.was_pressed = false
+        self.callback(self:_mouse2bar(x))
+    end
+end
+
+
+function Bar:mousepressed(x, y, btn)
+    -- If the pointer was inside the button when it was pressed then mark the button as pressed.
+    if btn == 0 then
+        self.pressed = collisions.point_in_square(x, y, self.x, self.y, self.w, self.h)
+    end
+end
+
+
+function Bar:mousereleased(x, _, btn)
+    if btn == 0 then
+        if self.pressed then
+            -- If the button was pressed then execute the callback if any and unmark as pressed.
+            if self.callback ~= nil then
+                self.callback(self:_mouse2bar(x))
+            end
+
+            self.pressed = false
+        end
+
+        -- The button no longer was pressed.
+        self.was_pressed = false
+    end
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Bar

src/ui/button.lua

@@ -0,0 +1,90 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+local collisions = require 'src.utils.colls'
+local UIElement  = require 'src.ui.element'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+---@class Button: UIElement
+local Button = make_class(UIElement)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+---@param x number
+---@param y number
+---@param callback function
+---@param float boolean
+function Button:_init(x, y, callback, float)
+    UIElement._init(self, x, y, float, false)
+    self.selected    = false
+    self.pressed     = false
+    self.was_pressed = false
+    self.callback    = callback
+end
+
+
+function Button:set_dimensions()
+    self.w = 0
+    self.h = 0
+end
+
+
+function Button:mousemoved(x, y)
+    -- Select if the pointer is inside the button's bounding rect.
+    self.selected = collisions.point_in_square(x, y, self.x, self.y, self.w, self.h)
+
+    -- If the button was pressed then check if the pointer is no longer inside the button.
+    if self.pressed then
+        -- If it's not, then mark the button as "was pressed".
+        self.pressed     = collisions.point_in_square(x, y, self.x, self.y, self.w, self.h)
+        self.was_pressed = true
+    end
+
+    -- If the button was pressed and the pointer is inside the button right now.
+    if self.was_pressed and collisions.point_in_square(x, y, self.x, self.y, self.w, self.h) then
+        -- Then mark the button as pressed again.
+        self.pressed     = true
+        self.was_pressed = false
+    end
+end
+
+
+function Button:mousepressed(x, y, btn)
+    -- If the pointer was inside the button when it was pressed then mark the button as pressed.
+    if btn == 0 then
+        self.pressed = collisions.point_in_square(x, y, self.x, self.y, self.w, self.h)
+    end
+end
+
+
+function Button:mousereleased(_, _, btn)
+    if btn == 0 then
+        if self.pressed then
+            -- If the button was pressed then execute the callback if any and unmark as pressed.
+            if self.callback ~= nil then
+                self.callback()
+            end
+
+            self.pressed = false
+        end
+
+        -- The button no longer was pressed.
+        self.was_pressed = false
+    end
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Button

src/ui/chkbox.lua

@@ -0,0 +1,55 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love       = require 'love'
+local make_class = require 'src.utils.classes'
+local Button     = require 'src.ui.button'
+local Color      = require 'src.utils.color'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local Checkbox = make_class(Button)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function Checkbox:_init(callback, value, w, h, color, sel_color, press_col, float, x, y)
+    Button._init(self, x, y, callback, float)
+    self.value = value
+    self.w     = w ~= nil and w or 20
+    self.h     = h ~= nil and h or 20
+    self.base_col  = color  ~= nil and color  or Color(255, 255, 255)
+    self.sel_color = sel_color ~= nil and sel_color or Color(215, 0, 0)
+    self.press_col = press_col ~= nil and press_col or Color(99, 99, 139)
+    self.disbl_col = Color(95, 63, 75)
+end
+
+
+function Checkbox:set_dimensions()
+    self.w = self.w
+    self.h = self.h
+end
+
+
+function Checkbox:draw()
+    local color = self.callback == nil and self.disbl_col or ((self.pressed and self.press_col) or ((self.selected and self.sel_color) or self.base_col))
+    local mode = nil
+    if self.value() then mode = 'fill' else mode = 'line' end
+
+    love.graphics.setColor(color.r, color.g, color.b)
+    love.graphics.rectangle(mode, self.x, self.y, self.w, self.h)
+    love.graphics.setColor()
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Checkbox

src/ui/dialog.lua

@@ -0,0 +1,117 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love           = require 'love'
+local make_class     = require 'src.utils.classes'
+local dialog_manager = require 'src.ui.dlgmngr'
+local VBox           = require 'src.ui.vbox'
+local Sprite         = require 'src.graphics.sprite'
+local TextButton     = require 'src.ui.textbtn'
+local HBox           = require 'src.ui.hbox'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local Dialog = make_class(VBox)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function Dialog:_init(bckg, spacing, padding, close_btn, accept_btn, font)
+    VBox._init(self, nil, nil, nil, nil, spacing, false)
+    self.spacing    = spacing ~= nil and spacing or 10
+    self.padding    = padding ~= nil and padding or 15
+    self.background = Sprite(bckg)
+    self.shown      = false
+
+    local close = nil
+
+    if close_btn ~= nil then
+        close = close_btn
+    else
+        close = TextButton(
+            'Close',
+            font,
+            nil,
+            nil,
+            function()
+                self:hide()
+            end)
+    end
+
+    local accept = nil
+    if accept_btn ~= nil then accept = accept_btn end
+
+    -- Create a container for the close and accept button and add them.
+    local box = HBox(nil, nil, nil, nil, 10, true)
+    box:add(close)
+
+    if accept ~= nil then box:add(accept) end
+
+    self.elements[9001] = box
+end
+
+
+function Dialog:add(element)
+    table.insert(self.elements, element)
+end
+
+
+function Dialog:load()
+    self.background:load()
+    self:set_dimensions()
+    VBox.load(self)
+end
+
+
+function Dialog:set_dimensions()
+    self.w = self.background.sprite:getWidth()
+    self.h = self.background.sprite:getHeight()
+
+    -- Center the dialog on the screen.
+    self.x = (320 - self.w) / 2
+    self.y = (200 - self.h) / 2
+
+    self.background.x = self.x
+    self.background.y = self.y
+
+    -- Add padding.
+    self.x = self.x + self.padding
+    self.y = self.y + self.padding / 2
+end
+
+
+function Dialog:draw()
+    love.graphics.setColor(0, 0, 0)
+    love.graphics.rectangle('line', self.x - self.padding - 1, self.y - (self.padding / 2) - 1, self.w + 2, self.h + 2)
+    love.graphics.setColor()
+
+    self.background:draw()
+    VBox.draw(self)
+end
+
+
+function Dialog:show()
+    if not self.shown then
+        dialog_manager:add(self)
+        self.shown = true
+    end
+end
+
+
+function Dialog:hide()
+    dialog_manager:remove(self)
+    self.shown = false
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Dialog

src/ui/dlgmngr.lua

@@ -0,0 +1,104 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+local Drawable   = require 'src.graphics.drawable'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local DialogManager = make_class(Drawable)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function DialogManager:_init()
+    Drawable._init(self)
+    self.dialogs = {}
+    self.count   = 0
+end
+
+
+function DialogManager:add(dialog)
+    self.dialogs[dialog] = true
+    self.count           = self.count + 1
+end
+
+
+function DialogManager:remove(dialog)
+    self.dialogs[dialog] = nil
+    self.count           = math.max(self.count - 1, 0)
+end
+
+
+function DialogManager:empty()
+    return self.count == 0
+end
+
+
+function DialogManager:update(dt)
+    for d, _ in pairs(self.dialogs) do
+        d:update(dt)
+    end
+end
+
+
+function DialogManager:draw()
+    for d, _ in pairs(self.dialogs) do
+        d:draw()
+    end
+end
+
+
+function DialogManager:keypressed(key, code, isrepeat)
+    for d, _ in pairs(self.dialogs) do
+        d:keypressed(key, code, isrepeat)
+    end
+end
+
+
+function DialogManager:textinput(text)
+    for d, _ in pairs(self.dialogs) do
+        d:textinput(text)
+    end
+end
+
+
+function DialogManager:keyreleased(key, code)
+    for d, _ in pairs(self.dialogs) do
+        d:keyreleased(key, code)
+    end
+end
+
+
+function DialogManager:mousemoved(x, y, dx, dy)
+    for d, _ in pairs(self.dialogs) do
+        d:mousemoved(x, y, dx, dy)
+    end
+end
+
+
+function DialogManager:mousepressed(x, y, btn)
+    for d, _ in pairs(self.dialogs) do
+        d:mousepressed(x, y, btn)
+    end
+end
+
+
+function DialogManager:mousereleased(x, y, btn)
+    for d, _ in pairs(self.dialogs) do
+        d:mousereleased(x, y, btn)
+    end
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return DialogManager()

src/ui/element.lua

@@ -0,0 +1,84 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+local Asset      = require 'src.utils.asset'
+local Drawable   = require 'src.graphics.drawable'
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local focused_element = nil
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+---@class UIElement: Drawable, Asset
+local UIElement = make_class(Drawable, Asset)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+---@param x integer
+---@param y integer
+---@param float boolean
+---@param focusable boolean
+function UIElement:_init(x, y, float, focusable)
+    Asset._init(self)
+    self.x           = x
+    self.y           = y
+    self.w           = nil
+    self.h           = nil
+    self.float_right = float and float or false
+    self.focusable   = focusable ~= nil and focusable or false
+end
+
+
+function UIElement:set_dimensions()
+    self.w = 0
+    self.h = 0
+end
+
+
+function UIElement:load()
+end
+
+
+function UIElement:unload()
+end
+
+
+function UIElement:is_loaded()
+    return true
+end
+
+
+function UIElement:focus()
+    if self.focusable then
+        focused_element = self
+    end
+end
+
+
+function UIElement:blur()
+    if self.focusable and focused_element == self then
+        focused_element = nil
+    end
+end
+
+
+function UIElement:is_focused()
+    return self.focusable and focused_element == self
+end
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return UIElement

src/ui/font.lua

@@ -0,0 +1,73 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love       = require 'love'
+local make_class = require 'src.utils.classes'
+local Asset      = require 'src.utils.asset'
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+---@class Font: Asset
+-- Font is a simple wrapper around Löve's own Font class to allow for
+-- easy loading/unloading and automatically checking if it's is valid
+-- before using it.
+local Font = make_class(Asset)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+---@param file_name string
+---@param size number
+function Font:_init(file_name, size)
+    self.file_name = string.format('assets/%s', file_name)
+    self.size = (size ~= nil and size) or 20
+end
+
+
+function Font:load()
+    if not self:is_loaded() then
+        self.f = love.graphics.newFont(self.file_name, self.size)
+    end
+end
+
+
+function Font:unload()
+    self.f = nil
+end
+
+
+function Font:is_loaded()
+    return self.f ~= nil
+end
+
+
+function Font:set()
+    if self.f ~= nil then love.graphics.setFont(self.f) end
+end
+
+
+function Font:unset()
+    love.graphics.setFont()
+end
+
+
+function Font:get_width(text)
+    if self.f ~= nil then return self.f:getWidth(text) else return nil end
+end
+
+
+function Font:get_height(text)
+    if self.f ~= nil then return self.f:getHeight(text) else return nil end
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Font

src/ui/hbox.lua

@@ -0,0 +1,63 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+local Layout     = require 'src.ui.layout'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+---@class HBox: Layout
+local HBox = make_class(Layout)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function HBox:_init(x, y, w, h, spacing, float)
+    Layout._init(self, x, y, w, h, spacing, float)
+end
+
+
+function HBox:load()
+    Layout.load(self)
+
+    local _x = self.x
+
+    -- Load required assets if needed and then compute the coordinates of each button.
+    for _, v in pairs(self.elements) do
+        v.y = self.y
+
+        v.x = _x
+        _x = _x + v.w + self.spacing
+    end
+end
+
+
+function HBox:set_dimensions()
+    if self.w == nil then
+        self.w = 0
+        for i, v in pairs(self.elements) do
+            self.w = self.w + v.w
+            if i < #self.elements then self.w = self.w + self.spacing end
+        end
+    end
+
+    if self.h == nil then
+        self.h = 0
+        for _, v in pairs(self.elements) do
+            if v.h > self.h then self.h = v.h end
+        end
+    end
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return HBox

src/ui/label.lua

@@ -0,0 +1,74 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love       = require 'love'
+local make_class = require 'src.utils.classes'
+local UIElement  = require 'src.ui.element'
+local Color      = require 'src.utils.color'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+---@class Label: UIElement
+local Label = make_class(UIElement)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+---@param x number
+---@param y number
+---@param text string
+---@param font Font
+---@param color Color
+---@param float boolean
+function Label:_init(x, y, text, font, color, float)
+    UIElement._init(self, x, y, float, false)
+    self.text  = text
+    self.font  = font
+    self.color = color ~= nil and color or Color(255, 255, 255)
+end
+
+
+function Label:set_dimensions()
+    self.w = self.font:get_width(self.text)
+    self.h = self.font:get_height(self.text)
+end
+
+
+function Label:load()
+    self.font:load()
+
+    -- If the label's size has not been computed then do it.
+    if self.w == nil or self.h == nil then self:set_dimensions() end
+end
+
+
+function Label:unload()
+    self.font:unload()
+end
+
+
+function Label:is_loaded()
+    return self.font:is_loaded() and self.w ~= nil and self.h ~= nil
+end
+
+
+function Label:draw()
+    love.graphics.setColor(self.color.r, self.color.g, self.color.b)
+    self.font:set()
+    love.graphics.print(self.text, self.x, self.y)
+    self.font:unset()
+    love.graphics.setColor()
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Label

src/ui/layout.lua

@@ -0,0 +1,118 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+local UIElement  = require 'src.ui.element'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+---@class Layout: UIElement
+local Layout = make_class(UIElement)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function Layout:_init(x, y, w, h, spacing, float)
+    UIElement._init(self, x, y, float, false)
+    self.x        = x ~= nil and x or 0
+    self.y        = y ~= nil and y or 0
+    self.w        = w
+    self.h        = h
+    self.spacing  = spacing ~= nil and spacing or 10
+    self.elements = {}
+end
+
+
+function Layout:add(element)
+    table.insert(self.elements, element)
+end
+
+
+function Layout:load()
+    -- Load required assets if needed and then compute the coordinates of each button.
+    for _, v in pairs(self.elements) do
+        if v.is_a[UIElement] then
+            v:load()
+        end
+    end
+
+    self:set_dimensions()
+end
+
+
+function Layout:unload()
+    for _, v in pairs(self.elements) do
+        if v.is_a[UIElement] then
+            v:unload()
+        end
+    end
+end
+
+
+function Layout:update(dt)
+    for _, v in pairs(self.elements) do
+        v:update(dt)
+    end
+end
+
+
+function Layout:draw()
+    for _, v in pairs(self.elements) do
+        v:draw()
+    end
+end
+
+
+function Layout:keypressed(key, code, isrepeat)
+    for _, v in pairs(self.elements) do
+        v:keypressed(key, code, isrepeat)
+    end
+end
+
+
+function Layout:textinput(text)
+    for _, v in pairs(self.elements) do
+        v:textinput(text)
+    end
+end
+
+
+function Layout:keyreleased(key, code)
+    for _, v in pairs(self.elements) do
+        v:keyreleased(key, code)
+    end
+end
+
+
+function Layout:mousemoved(x, y, dx, dy)
+    for _, v in pairs(self.elements) do
+        v:mousemoved(x, y, dx, dy)
+    end
+end
+
+
+function Layout:mousepressed(x, y, btn)
+    for _, v in pairs(self.elements) do
+        v:mousepressed(x, y, btn)
+    end
+end
+
+
+function Layout:mousereleased(x, y, btn)
+    for _, v in pairs(self.elements) do
+        v:mousereleased(x, y, btn)
+    end
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Layout

src/ui/textbtn.lua

@@ -0,0 +1,74 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love       = require 'love'
+local make_class = require 'src.utils.classes'
+local Button     = require 'src.ui.button'
+local Color      = require 'src.utils.color'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local TextButton = make_class(Button)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function TextButton:_init(text, font, x, y, callback, float, base_col, sel_color, press_col)
+    Button._init(self, x, y, callback, float)
+    self.font      = font
+    self.text      = text
+    self.base_col  = base_col  ~= nil and base_col  or Color(255, 255, 255)
+    self.sel_color = sel_color ~= nil and sel_color or Color(215, 0, 0)
+    self.press_col = press_col ~= nil and press_col or Color(99, 99, 139)
+    self.disbl_col = Color(95, 63, 75)
+end
+
+
+function TextButton:load()
+    if not self.font:is_loaded() then
+        self.font:load()
+    end
+
+    -- If the label's size has not been computed then do it.
+    if self.w == nil or self.h == nil then self:set_dimensions() end
+end
+
+
+function TextButton:unload()
+    self.font:unload()
+end
+
+
+function TextButton:is_loaded()
+    return self.font:is_loaded() and self.w ~= nil and self.h ~= nil
+end
+
+
+function TextButton:set_dimensions()
+    self.w = self.font:get_width(self.text)
+    self.h = self.font:get_height(self.text)
+end
+
+
+function TextButton:draw()
+    local color = self.callback == nil and self.disbl_col or ((self.pressed and self.press_col) or ((self.selected and self.sel_color) or self.base_col))
+
+    love.graphics.setColor(color.r, color.g, color.b)
+    self.font:set()
+    love.graphics.print(self.text, self.x, self.y)
+    self.font:unset()
+    love.graphics.setColor()
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return TextButton

src/ui/textinpt.lua

@@ -0,0 +1,118 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love       = require 'love'
+local make_class = require 'src.utils.classes'
+local collisions = require 'src.utils.colls'
+local UIElement  = require 'src.ui.element'
+local Color      = require 'src.utils.color'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+---@class CharInput: UIElement
+local TextInput = make_class(UIElement)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+---@param text string
+---@param font Font
+---@param x number
+---@param y number
+---@param callback function
+---@param value function
+---@param float boolean
+---@param base_col Color
+---@param sel_color Color
+---@param press_col Color
+function TextInput:_init(text, font, x, y, callback, value, float, base_col, sel_color, press_col)
+    UIElement._init(self, x, y, float, true)
+    self.callback  = callback
+    self.value     = value
+    self.font      = font
+    self.text      = text
+    self.base_col  = base_col  ~= nil and base_col  or Color(255, 255, 255)
+    self.sel_color = sel_color ~= nil and sel_color or Color(215, 0, 0)
+    self.press_col = press_col ~= nil and press_col or Color(99, 99, 139)
+    self.disbl_col = Color(95, 63, 75)
+    self.selected  = false
+    self.pressed   = false
+end
+
+
+function TextInput:load()
+    self.font:load()
+
+    -- If the label's size has not been computed then do it.
+    if self.w == nil or self.h == nil then self:set_dimensions() end
+end
+
+
+function TextInput:unload()
+    self.font:unload()
+end
+
+
+function TextInput:is_loaded()
+    return self.font:is_loaded() and self.w ~= nil and self.h ~= nil
+end
+
+
+function TextInput:set_dimensions()
+    self.w = self.font:get_width(self.text .. 'm')
+    self.h = self.font:get_height(self.text)
+end
+
+
+function TextInput:draw()
+    local color = self.callback == nil and self.disbl_col or (((self.pressed or self:is_focused()) and self.press_col) or ((self.selected and self.sel_color) or self.base_col))
+
+    love.graphics.setColor(color.r, color.g, color.b)
+    self.font:set()
+
+    if self:is_focused() then
+        love.graphics.print(self.text .. ': ?', self.x, self.y)
+    else
+        love.graphics.print(self.text .. ': ' .. self.value(), self.x, self.y)
+    end
+
+    self.font:unset()
+    love.graphics.setColor()
+end
+
+
+function TextInput:mousemoved(x, y)
+    -- Select if the pointer is inside the button's bounding rect.
+    self.selected = collisions.point_in_square(x, y, self.x, self.y, self.w, self.h)
+end
+
+
+function TextInput:mousepressed(_, _, btn)
+    -- If the pointer was inside the button when it was pressed then mark the button as pressed.
+    if btn == 0 and self.selected then
+        self:focus()
+    end
+end
+
+
+function TextInput:keypressed(key)
+    if self:is_focused() then
+        if #key == 1 then
+            if self.callback ~= nil then self.callback(key) end
+            self:blur()
+        end
+    end
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return TextInput

src/ui/vbox.lua

@@ -0,0 +1,66 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+local Layout     = require 'src.ui.layout'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+---@class VBox: Layout
+local VBox = make_class(Layout)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function VBox:_init(x, y, w, h, spacing, float)
+    Layout._init(self, x, y, w, h, spacing, float)
+end
+
+
+function VBox:load()
+    Layout.load(self)
+
+    local _y = self.y
+
+    -- Load required assets if needed and then compute the coordinates of each button.
+    for _, v in pairs(self.elements) do
+        if v.float_right then
+            v.x = self.w - v.w
+        else
+            v.x = self.x
+        end
+
+        v.y = _y
+        _y = _y + v.h + self.spacing
+    end
+end
+
+
+function VBox:set_dimensions()
+    if self.w == nil then
+        self.w = 0
+        for _, v in pairs(self.elements) do
+            if v.w > self.w then self.w = v.w end
+        end
+    end
+
+    if self.h == nil then
+        self.h = 0
+        for i, v in pairs(self.elements) do
+            self.h = self.h + v.h
+            if i < #self.elements then self.h = self.h + self.spacing end
+        end
+    end
+end
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return VBox

src/utils/asset.lua

@@ -9,6 +9,7 @@ local make_class = require 'src.utils.classes'
 -- Class definitions
 ------------------------------------------------------------------------------
 
+---@class Asset
 local Asset = make_class()
 
 
@@ -16,15 +17,23 @@ local Asset = make_class()
 -- Class methods
 ------------------------------------------------------------------------------
 
-function Asset:_init()
+function Asset:_init(file_name)
+    self.file_name = string.format('assets/%s', file_name)
 end
 
 
 function Asset:load()
+    error 'Attempted to load unimplemented asset.'
 end
 
 
 function Asset:unload()
+    error 'Attempted to unload unimplemented asset.'
+end
+
+
+function Asset:is_loaded()
+    return false
 end
 
 

src/utils/asstmngr.lua

@@ -0,0 +1,135 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love       = require 'love'
+local make_class = require 'src.utils.classes'
+local Drawable   = require 'src.graphics.drawable'
+local Asset      = require 'src.utils.asset'
+local Sprite     = require 'src.graphics.sprite'
+local Font       = require 'src.ui.font'
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local AssetManager = make_class(Drawable)
+
+
+------------------------------------------------------------------------------
+-- Helper functions
+------------------------------------------------------------------------------
+
+local function _load(manager, owner)
+    if manager.assets[owner] ~= nil then
+        for k, _ in pairs(manager.assets[owner]) do
+            if k.is_a ~= nil and k.is_a[Asset] then
+                k:load()
+            end
+            coroutine.yield(false)
+        end
+    end
+
+    return true
+end
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function AssetManager:_init()
+    Drawable._init(self)
+    self.assets = {}
+    self.bckg   = Sprite('imgs/floppy.png')
+    self.font   = Font('fonts/BBrick.ttf', 40)
+    self.co     = nil
+
+    self.bckg:load()
+    self.font:load()
+end
+
+
+function AssetManager:unload(owner)
+    -- If the owner is known...
+    if self.assets[owner] ~= nil then
+        -- Iterate over it's asset set and unload everything.
+        for k, _ in pairs(self.assets[owner]) do
+            if k.is_a ~= nil and k.is_a[Asset] then
+                k:unload()
+            end
+        end
+    end
+end
+
+
+function AssetManager:update(owner)
+    if self.assets[owner] ~= nil then
+        if self.assets[owner].co == nil then
+            self.assets[owner].co = coroutine.create(_load)
+        end
+
+        local errorfree, retval = coroutine.resume(self.assets[owner].co, self, owner)
+
+        if errorfree then
+            self.assets[owner].done = retval
+
+            if retval then
+                self.assets[owner].co   = nil
+            end
+        else
+            error(retval)
+        end
+    end
+end
+
+
+function AssetManager:draw()
+    self.bckg:draw()
+
+    love.graphics.setColor(195, 147, 123)
+    self.font:set()
+    love.graphics.print('Loading...', 5, 150)
+    self.font:unset()
+    love.graphics.setColor()
+end
+
+
+function AssetManager:register(owner, asset)
+    -- If the owner is new, then create an asset set for it.
+    if self.assets[owner] == nil then
+        self.assets[owner] = {
+            done = false,
+            co   = nil,
+        }
+    end
+
+    -- Store the asset in the set.
+    self.assets[owner][asset] = true
+end
+
+
+function AssetManager:remove(owner, asset)
+    -- If the owner is new, then create an asset set for it.
+    if self.assets[owner] ~= nil then
+        -- Unload the asset just in case.
+        if self.assets[owner][asset] ~= nil then
+            self.assets[owner][asset]:unload()
+        end
+
+        -- Then remove it from the set.
+        self.assets[owner][asset] = nil
+    end
+end
+
+
+function AssetManager:done(owner)
+    return self.assets[owner] ~= nil and self.assets[owner].done
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return AssetManager()

src/utils/classes.lua

@@ -2,15 +2,16 @@
 -- Methods
 ------------------------------------------------------------------------------
 
--- Single inheritance version of the sample code from
--- http://lua-users.org/wiki/ObjectOrientationTutorial
-local function make_class(BaseClass)
+--- Code from http://lua-users.org/wiki/ObjectOrientationTutorial
+---@param ... table Optional base classes
+---@return table cls A class definition
+local function make_class(...)
     -- "cls" is the new class
-    local cls = {}
+    local cls, bases = {}, {...}
 
     -- copy base class contents into the new class
-    if BaseClass ~= nil then
-        for k, v in pairs(BaseClass) do
+    for _, base in ipairs(bases) do
+        for k, v in pairs(base) do
             cls[k] = v
         end
     end
@@ -19,8 +20,11 @@ local function make_class(BaseClass)
     -- so you can do an "instance of" check using my_instance.is_a[MyClass]
     cls.__index, cls.is_a = cls, {[cls] = true}
 
-    if BaseClass ~= nil then
-        cls.is_a[BaseClass] = true
+    for _, base in ipairs(bases) do
+        for c in pairs(base.is_a) do
+            cls.is_a[c] = true
+        end
+        cls.is_a[base] = true
     end
 
     -- the class's __call metamethod

src/utils/colls.lua

@@ -0,0 +1,17 @@
+------------------------------------------------------------------------------
+-- Module definitions
+------------------------------------------------------------------------------
+
+local collisions = {
+    -- Default setting values.
+    point_in_square = function(x, y, ox, oy, w, h)
+        return x >= ox and x <= ox + w and y >= oy and y <= oy + h
+    end,
+}
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return collisions

src/utils/color.lua

@@ -0,0 +1,31 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+---@class Color
+local Color = make_class()
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function Color:_init(r, g, b)
+    self.r = r ~= nil and r or 255
+    self.g = g ~= nil and g or 255
+    self.b = b ~= nil and b or 255
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Color

src/utils/settings.lua

@@ -4,6 +4,7 @@
 
 local love       = require 'love'
 local magiclines = require 'src.utils.mgclines'
+local make_class = require 'src.utils.classes'
 
 
 ------------------------------------------------------------------------------
@@ -17,25 +18,29 @@ local SETTINGS_PATH = 'settings.ini'
 -- Module definitions
 ------------------------------------------------------------------------------
 
-local settings = {
-    -- Default setting values.
-    permadeath = true,
-    forward    = 'w',
-    backward   = 's',
-    stepleft   = 'a',
-    stepright  = 'd',
-    turnleft   = 'q',
-    turnright  = 'e',
-    musicvol   = 75,
-    soundvol   = 100,
-}
+---@class Settings
+local Settings = make_class()
 
 
 ------------------------------------------------------------------------------
 -- Private module methods
 ------------------------------------------------------------------------------
 
-function settings:_parse_settings_str(s)
+function Settings:_init()
+    -- Default setting values.
+    self.permadeath = true
+    self.forward    = 'w'
+    self.backward   = 's'
+    self.stepleft   = 'a'
+    self.stepright  = 'd'
+    self.turnleft   = 'q'
+    self.turnright  = 'e'
+    self.musicvol   = 75
+    self.soundvol   = 100
+end
+
+
+function Settings:_parse_settings_str(s)
     -- For each line in the data string.
     for line in magiclines(s) do
         -- Check if the line matches a key=value pair
@@ -67,7 +72,7 @@ function settings:_parse_settings_str(s)
 end
 
 
-function settings:_get_settings_str()
+function Settings:_get_settings_str()
     -- Start with the settings category.
     local s = '[settings]\n'
 
@@ -84,7 +89,7 @@ function settings:_get_settings_str()
 end
 
 
-function settings:_open_or_create()
+function Settings:_open_or_create()
     if not love.filesystem.exists(SETTINGS_PATH) then
         -- If the settings file doesn't exist then create it with the default values.
         local setts = self:_get_settings_str()
@@ -106,14 +111,14 @@ end
 -- Public module methods
 ------------------------------------------------------------------------------
 
-function settings:load_settings()
+function Settings:load_settings()
     -- Obtain the settings data and parse it.
     local s = self:_open_or_create()
     self:_parse_settings_str(s)
 end
 
 
-function settings:save_settings()
+function Settings:save_settings()
     if not love.filesystem.exists(SETTINGS_PATH) or love.filesystem.isFile(SETTINGS_PATH) then
         -- If the settings file doesn't exist or it exists and is a file then save the current data.
         love.filesystem.write(SETTINGS_PATH, self:_get_settings_str())
@@ -128,4 +133,4 @@ end
 -- Module return
 ------------------------------------------------------------------------------
 
-return settings
+return Settings()