UI button and main menu beginning

button.lua

@@ -0,0 +1,83 @@
+require 'point'
+
+-- Clickable UI button
+---@class Button
+---@field position Point
+---@field size Point
+---@field prevPressed boolean
+---@field lastPressed boolean
+Button = {
+    position = Point:new( 1, 1 ),
+    size = Point:new( 1, 1 ),
+    prevPressed = false,
+    lastPressed = false
+}
+
+-- Factory function
+---@param position Point | nil
+---@param size Point | nil
+---@param pressed function | nil
+---@param held function | nil
+---@param released function | nil
+---@return Button
+function Button:new( position, size, pressed, held, released )
+    local button = {
+        position = position or Button.position,
+        size = size or Button.size,
+        prevPressed = false,
+        lastPressed = false,
+        pressed = pressed or Button.pressed,
+        held = held or Button.held,
+        released = released or Button.released
+    }
+
+    setmetatable( button, { __index = self } )
+
+    return button
+end
+
+-- Called when button just clicked
+function Button:pressed() end
+-- Called when button is held
+---@param dt number
+function Button:held( dt ) dt = dt end
+-- Called when button is just unclicked
+function Button:released() end
+
+-- Drawing function
+function Button:draw()
+    local x, y = self.position:coords()
+    local w, h = self.size:coords()
+    love.graphics.rectangle( 'line', x, y, w, h )
+end
+
+-- Check if given point is in bounds of button
+---@param point Point
+---@return boolean
+function Button:checkPoint( point )
+    local px, py = point:coords()
+    local sx, sy = self.position:coords()
+    local ex, ey = self.position:coords()
+    ex = ex + sx
+    ey = ey + sy
+    return px >= sx and px <= ex and py >= sy and py <= ey
+end
+
+-- Changing states and calls appropriate functions
+---@param dt number
+---@param point Point
+function Button:update( dt, point, pressed )
+    self.prevPressed = self.lastPressed
+    self.lastPressed = pressed
+
+    if self.lastPressed and not self.prevPressed then
+        local inBounds = self:checkPoint( point )
+        if inBounds then
+            self:pressed()
+        end
+    elseif self.lastPressed and self.prevPressed then
+        self:held( dt )
+    elseif not self.lastPressed and self.prevPressed then
+        self:released()
+    end
+end

grid.lua

@@ -12,7 +12,7 @@ Grid = {
 
 -- Factory function
 ---@param size Point
----@returns Grid
+---@return Grid
 function Grid:new( size )
     local grid = {
         lines = {},

main.lua

@@ -3,8 +3,11 @@ require 'point'
 require 'line'
 require 'mouse'
 require 'levelhandler'
+require 'button'
 Input = require 'input'
 
+InMenu = true
+
 local function updateCellSize()
     local width, height = love.graphics.getDimensions()
     local gridX, gridY = GameGrid.size:coords();
@@ -14,8 +17,16 @@ local function updateCellSize()
 end
 
 function love.load()
-    GameGrid = LevelHandler:first()
-    updateCellSize()
+    love.window.setMode( 800, 480 )
+
+    local menuButtonReleased = function()
+        InMenu = false
+        GameGrid = LevelHandler:first()
+        updateCellSize()
+    end
+
+    MenuStartButton = Button:new( Point:new( 240, 120 ), Point:new( 320, 80 ), nil, nil, menuButtonReleased )
+
 
     love.graphics.setLineStyle( Config.lineStyle )
 end
@@ -23,33 +34,40 @@ end
 function love.update( dt )
     Mouse:update()
     Input:update()
+    if InMenu then
+        MenuStartButton:update( dt, Point:new( Mouse.x, Mouse.y ), Mouse.pressed )
+    else
+        if Input:actionReleased( 'exit' ) then
+            love.event.quit()
+        end
 
-    if Input:actionReleased( 'exit' ) then
-        love.event.quit()
-    end
-
-    if Input:actionReleased( 'nextlevel' ) then
-        if GameGrid:isCompleted() then
-            GameGrid = LevelHandler:next()
-            updateCellSize()
+        if Input:actionReleased( 'nextlevel' ) then
+            if GameGrid:isCompleted() then
+                GameGrid = LevelHandler:next()
+                updateCellSize()
+            end
         end
     end
 end
 
 function love.draw()
-    GameGrid:draw()
+    if InMenu then
+        MenuStartButton:draw()
+    else
+        GameGrid:draw()
 
-    local text = string.format( "%d:%d global\n%d:%d local\n%d:%d from start", Mouse.x, Mouse.y, Mouse.point.x, Mouse.point.y, Mouse.startX - Mouse.x, Mouse.startY - Mouse.y )
-    love.graphics.print( text, 64, 256 )
+        local text = string.format( "%d:%d global\n%d:%d local\n%d:%d from start", Mouse.x, Mouse.y, Mouse.point.x, Mouse.point.y, Mouse.startX - Mouse.x, Mouse.startY - Mouse.y )
+        love.graphics.print( text, 64, 256 )
 
-    if Mouse.dragged then
-        love.graphics.print( "drag", 64, 300 )
-    end
-    if Mouse.lastLine ~= nil then
-        love.graphics.print( tostring( Mouse.lastLine ), 128, 300 )
-    end
+        if Mouse.dragged then
+            love.graphics.print( "drag", 64, 300 )
+        end
+        if Mouse.lastLine ~= nil then
+            love.graphics.print( tostring( Mouse.lastLine ), 128, 300 )
+        end
 
-    if GameGrid:isCompleted() then
-        love.graphics.print( "Grid completed. Press space to proceed to next", 64, 320 )
+        if GameGrid:isCompleted() then
+            love.graphics.print( "Grid completed. Press space to proceed to next", 64, 320 )
+        end
     end
 end

mouse.lua

@@ -31,6 +31,11 @@ function Mouse:update()
     Mouse.lastPoint = Mouse.point
     Mouse.lastPressed = Mouse.pressed
     Mouse.pressed = love.mouse.isDown( 1 )
+
+    if InMenu then
+        return
+    end
+
     Mouse.point = GridPoint.snapCoords( Point:new( Mouse.x, Mouse.y ) )
     if Mouse.lastLine ~= nil then
         local pointsLen = #Mouse.lastLine.points