function _init()
	player = {x=64, y=64}

end

function _update()
 local move_x, move_y = 0, 0
 if btn(0) then move_x = -1 end
 if btn(1) then move_x = 1 end
 if btn(2) then move_y = -1 end
 if btn(3) then move_y = 1 end

 -- update player position and animation
 if move_x != 0 or move_y != 0 then
     player.x += move_x
     player.y += move_y 
	end
	update_ball()

end

function _draw()
	cls()
	rectfill(player.x,
		player.y,
		player.x+8,
		player.y+8,
		8)
	draw_ball()

end

--ball

ball = {x=80, y=80, vx=0, vy=0, length=24, friction=0.9, mass=5, pull_force=0.2}

ball.hitbox = {2,2,6,6}
ball.name = "ball"
ball.radius = 5

-- in ball initialization
ball.light_pos = {x = ball.x, y = ball.y}

function distance(x1, y1, x2, y2)
    return sqrt((x2-x1)^2 + (y2-y1)^2)
end

function update_ball()
    local dx = ball.x - player.x
    local dy = ball.y - player.y 
    local dist = distance(ball.x, ball.y, player.x, player.y)

    if dist > ball.length then
        local angle = atan2(dx, dy)
        local pull_strength = (dist - ball.length) * ball.pull_force

        ball.vx -= cos(angle) * pull_strength
        ball.vy -= sin(angle) * pull_strength
    end
    ball.vx *= ball.friction
    ball.vy *= ball.friction
    ball.x += ball.vx
    ball.y += ball.vy

    if ball.vx != 0 or ball.vy != 0 then
        local move_dir_x = ball.vx > 0 and 1 or (ball.vx < 0 and -1 or 0)
        local move_dir_y = ball.vy > 0 and 1 or (ball.vy < 0 and -1 or 0)

        ball.light_pos.x += move_dir_x * 0.5
        ball.light_pos.y += move_dir_y * 0.5

        -- check if light has reached ball edge
        local light_dist = distance(ball.x, ball.y, ball.light_pos.x, ball.light_pos.y)

        if light_dist >= ball.radius+1 then
             -- move light along the direction of movement
             ball.rolled_under = true
            ball.roll_under_timer = ball.roll_under_frames

            -- reposition light on opposite side of ball and continue moving
            ball.light_pos.x = ball.x - move_dir_x * ball.radius
            ball.light_pos.y = ball.y - move_dir_y * ball.radius

            -- immediately continue moving in the same direction
            ball.light_pos.x += move_dir_x * 0.5
            ball.light_pos.y += move_dir_y * 0.5
        end

    end

end

function draw_ball()
    line(player.x+4, player.y+4, ball.x, ball.y, 13)
    circfill(ball.x, ball.y, 5, 1)

    -- light spot
    circfill(ball.light_pos.x, ball.light_pos.y, 1, 7)

end

--ball

ball = {x=80, y=80, vx=0, vy=0, length=24, friction=0.75, mass=5, pull_force=0.2}

ball.hitbox = {2,2,6,6}
ball.name = "ball"
ball.radius = 5
ball.light_travel =0
-- in ball initialization
ball.light_pos = {x = ball.x, y = ball.y}

function distance(x1, y1, x2, y2)
    return sqrt((x2-x1)^2 + (y2-y1)^2)
end

function update_ball()
    local dx = ball.x - player.x
    local dy = ball.y - player.y 
    local dist = distance(ball.x, ball.y, player.x, player.y)

    if dist > ball.length then
        local angle = atan2(dx, dy)
        local pull_strength = (dist - ball.length) * ball.pull_force

        ball.vx -= cos(angle) * pull_strength
        ball.vy -= sin(angle) * pull_strength
    end
    ball.vx *= ball.friction
    ball.vy *= ball.friction
    ball.x += ball.vx
    ball.y += ball.vy

     -- calculate movement angle
    if ball.vx != 0 or ball.vy != 0 then
        local angle = atan2(ball.vy, ball.vx)

        -- move light along the ball's movement trajectory
        ball.light_pos.x = ball.x + cos(angle) * ball.light_travel
        ball.light_pos.y = ball.y + sin(angle) * ball.light_travel

        -- when light reaches edge, reset travel
        ball.light_travel += 0.1
        if ball.light_travel >= ball.radius then
            ball.light_travel = -ball.radius
        end
    end

end

function draw_ball()
    line(player.x+4, player.y+4, ball.x, ball.y, 13)
    circfill(ball.x, ball.y, 5, 7)

    -- light spot
    --circfill(ball.light_pos.x, ball.light_pos.y, 1, 7)
    pset(ball.light_pos.x, ball.light_pos.y,1) 

end