basic1/games/lua_examples/air_hockey.lua

-- NAME: Air Hockey
-- DESC: Fast-paced 2-player hockey

-- Game states
local STATE_MENU = 0
local STATE_PLAYING = 1
local STATE_GAME_OVER = 2

-- Game constants
local PADDLE_WIDTH = 6
local PADDLE_HEIGHT = 35
local PUCK_RADIUS = 3
local MAX_SCORE = 7
local PUCK_SPEED = 4

function init()
    game.vars.state = STATE_MENU
    
    -- Left paddle (player 1)
    game.vars.paddle_left_y = (game.height() / 2) - (PADDLE_HEIGHT / 2)
    game.vars.paddle_left_score = 0
    
    -- Right paddle (player 2)
    game.vars.paddle_right_y = (game.height() / 2) - (PADDLE_HEIGHT / 2)
    game.vars.paddle_right_score = 0
    
    -- Puck
    game.vars.puck_x = game.width() / 2
    game.vars.puck_y = game.height() / 2
    game.vars.puck_vel_x = PUCK_SPEED
    game.vars.puck_vel_y = 1
    
    -- Enable continuous updates
    game.set_frame_updates(true)
    
    print("Air Hockey initialized")
end

function update(event)
    local state = game.vars.state
    
    if state == STATE_MENU then
        if event.type == INPUT.TOUCH_DOWN or event.type == INPUT.BUTTON_0 or event.type == INPUT.BUTTON_1 then
            reset_game()
            game.vars.state = STATE_PLAYING
            return true
        end
    
    elseif state == STATE_PLAYING then
        -- Handle paddle input via touch
        if event.type == INPUT.TOUCH_DOWN or event.type == INPUT.TOUCH_MOVE then
            if event.x < game.width() / 2 then
                -- Left paddle
                game.vars.paddle_left_y = math.max(0, math.min(game.height() - PADDLE_HEIGHT, event.y - PADDLE_HEIGHT / 2))
            else
                -- Right paddle
                game.vars.paddle_right_y = math.max(0, math.min(game.height() - PADDLE_HEIGHT, event.y - PADDLE_HEIGHT / 2))
            end
        end
        
        -- Update physics on frame tick
        if event.type == INPUT.FRAME_TICK then
            update_puck()
            check_collisions()
            
            -- Check win
            if game.vars.paddle_left_score >= MAX_SCORE or game.vars.paddle_right_score >= MAX_SCORE then
                game.vars.state = STATE_GAME_OVER
            end
            
            return true
        end
    
    elseif state == STATE_GAME_OVER then
        if event.type == INPUT.TOUCH_DOWN or event.type == INPUT.BUTTON_0 or event.type == INPUT.BUTTON_1 then
            game.vars.state = STATE_MENU
            return true
        end
    end
    
    return false
end

function draw()
    renderer.clear(false)  -- Black background
    
    local state = game.vars.state
    
    if state == STATE_MENU then
        renderer.text_scaled(game.width() / 2 - 35, game.height() / 2 - 30, "AIR HOCKEY", true, 2)
        renderer.text_scaled(game.width() / 2 - 50, game.height() / 2, "Tap to Start", true, 2)
        renderer.text_scaled(game.width() / 2 - 60, game.height() / 2 + 20, "First to " .. tostring(MAX_SCORE), true, 2)
    
    elseif state == STATE_PLAYING or state == STATE_GAME_OVER then
        -- Draw center line
        for y = 0, game.height(), 4 do
            renderer.pixel(game.width() / 2, y, true)
        end
        
        -- Draw goal areas (top/bottom highlights)
        renderer.line(0, 5, game.width(), 5, true, 1)
        renderer.line(0, game.height() - 5, game.width(), game.height() - 5, true, 1)
        
        -- Draw paddles
        renderer.rect(5, game.vars.paddle_left_y, PADDLE_WIDTH, PADDLE_HEIGHT, true, true)
        renderer.rect(game.width() - 5 - PADDLE_WIDTH, game.vars.paddle_right_y, PADDLE_WIDTH, PADDLE_HEIGHT, true, true)
        
        -- Draw puck (convert to integers)
        renderer.circle(math.floor(game.vars.puck_x + 0.5), math.floor(game.vars.puck_y + 0.5), PUCK_RADIUS, true, true)
        
        -- Draw scores
        renderer.text_scaled(game.width() / 2 - 30, 5, tostring(game.vars.paddle_left_score), true, 2)
        renderer.text_scaled(game.width() / 2 + 20, 5, tostring(game.vars.paddle_right_score), true, 2)
        
        if state == STATE_GAME_OVER then
            local winner = game.vars.paddle_left_score > game.vars.paddle_right_score and "Player 1" or "Player 2"
            renderer.text_scaled(game.width() / 2 - 50, game.height() / 2 - 20, "GAME OVER", true, 2)
            renderer.text_scaled(game.width() / 2 - 40, game.height() / 2, winner .. " Wins!", true, 2)
            renderer.text_scaled(game.width() / 2 - 60, game.height() / 2 + 20, "Tap to Menu", true, 2)
        end
    end
end

function update_puck()
    -- Move puck
    game.vars.puck_x = game.vars.puck_x + game.vars.puck_vel_x
    game.vars.puck_y = game.vars.puck_y + game.vars.puck_vel_y
    
    -- Bounce off top/bottom
    if game.vars.puck_y - PUCK_RADIUS < 0 or game.vars.puck_y + PUCK_RADIUS > game.height() then
        game.vars.puck_vel_y = -game.vars.puck_vel_y
        game.vars.puck_y = math.max(PUCK_RADIUS, math.min(game.height() - PUCK_RADIUS, game.vars.puck_y))
    end
    
    -- Goal: left side
    if game.vars.puck_x < 0 then
        game.vars.paddle_right_score = game.vars.paddle_right_score + 1
        reset_puck()
    end
    
    -- Goal: right side
    if game.vars.puck_x > game.width() then
        game.vars.paddle_left_score = game.vars.paddle_left_score + 1
        reset_puck()
    end
end

function check_collisions()
    -- Left paddle collision
    if game.vars.puck_x - PUCK_RADIUS < 5 + PADDLE_WIDTH then
        if game.vars.puck_y > game.vars.paddle_left_y and game.vars.puck_y < game.vars.paddle_left_y + PADDLE_HEIGHT then
            if game.vars.puck_vel_x < 0 then
                game.vars.puck_vel_x = -game.vars.puck_vel_x + 0.5  -- Speed up slightly
                
                -- Add spin
                local hit_pos = (game.vars.puck_y - game.vars.paddle_left_y) / PADDLE_HEIGHT
                game.vars.puck_vel_y = (hit_pos - 0.5) * 6
            end
        end
    end
    
    -- Right paddle collision
    if game.vars.puck_x + PUCK_RADIUS > game.width() - 5 - PADDLE_WIDTH then
        if game.vars.puck_y > game.vars.paddle_right_y and game.vars.puck_y < game.vars.paddle_right_y + PADDLE_HEIGHT then
            if game.vars.puck_vel_x > 0 then
                game.vars.puck_vel_x = -game.vars.puck_vel_x - 0.5  -- Speed up slightly
                
                -- Add spin
                local hit_pos = (game.vars.puck_y - game.vars.paddle_right_y) / PADDLE_HEIGHT
                game.vars.puck_vel_y = (hit_pos - 0.5) * 6
            end
        end
    end
end

function reset_puck()
    game.vars.puck_x = game.width() / 2
    game.vars.puck_y = game.height() / 2
    game.vars.puck_vel_x = PUCK_SPEED * (math.random() > 0.5 and 1 or -1)
    game.vars.puck_vel_y = (math.random() - 0.5) * 2
end

function reset_game()
    game.vars.paddle_left_y = (game.height() / 2) - (PADDLE_HEIGHT / 2)
    game.vars.paddle_left_score = 0
    game.vars.paddle_right_y = (game.height() / 2) - (PADDLE_HEIGHT / 2)
    game.vars.paddle_right_score = 0
    reset_puck()
end