Animation and movement troubles (SOLVED)

Questions
#1

Greetings to the Defold community!

I’m new to programming and just starting to learn the Defold engine, so my question may seem silly. I’m sorry about that.
I am trying to make a simple clone of the Vampire Survivors game and am currently working on the mechanics of movement and animation of the player. My character has two animations: "player_idle and “player_walk”. Keyboard input control.
I studied numerous tutorials and wrote such a player.script

local ACTION_RIGHT = hash("right")
local ACTION_LEFT = hash("left")
local ACTION_UP = hash("up")
local ACTION_DOWN = hash("down")

function init(self)
	msg.post("#", "acquire_input_focus")
	self.direction = vmath.vector3(0, 0, 0)
	self.current_animation = nil
	self.speed = 100.0
end

local function walk(self, dt)
	local current_position = go.get_position()
	if vmath.length_sqr(self.direction) > 1 then
		self.direction = vmath.normalize(self.direction)
	end
	go.set_position(current_position + self.direction * self.speed * dt)
	self.direction = vmath.vector3(0, 0, 0)
end

local function flip(self)
	sprite.set_hflip("#sprite", self.direction.x > 0)
end

local function start_animation(self, new_animation)
	if self.current_animation ~= new_animation then
		sprite.play_flipbook("#sprite", new_animation)
		self.current_animation = new_animation
	end
end


local function animate(self)
	if self.direction.x == 0 and self.direction.y == 0 then
		start_animation(self, "player_idle")
	else
		start_animation(self, "player_walk")
	end
end

function update(self, dt)
	walk(self, dt)
	animate(self)
	flip(self)
end 

function on_input(self, action_id, action)
	if action_id == ACTION_RIGHT then
		self.direction.x = 1
	elseif action_id == ACTION_LEFT then
		self.direction.x = -1
	elseif action_id == ACTION_UP then
		self.direction.y = 1
	elseif action_id == ACTION_DOWN then
		self.direction.y = -1
	end
end

function final(self)
	msg.post("#", "release_input_focus")
end

But my character is not animated. The flip(self) function also does not work.
Then I tried to move animate(self) and flip(self) inside the on_input() function.

function update(self, dt)
	walk(self, dt)
end 

function on_input(self, action_id, action)
	if action_id == ACTION_RIGHT then
		self.direction.x = 1
	elseif action_id == ACTION_LEFT then
		self.direction.x = -1
	elseif action_id == ACTION_UP then
		self.direction.y = 1
	elseif action_id == ACTION_DOWN then
		self.direction.y = -1
	end
	
	animate(self)
	flip(self)
end

Then the flip(self) function works well, but the “player_walk” animation is played constantly.
Obviously, I don’t understand some simple things about the on_input() and update() functions, and I want to understand how it works.

Defold version 1.9.3
OS: Windows 10

#2

You call walk(self, dt) first. And if you look at the end of your walk() function you set direction to 0:

self.direction = vmath.vector3(0, 0, 0)
``

Both animate() and flip() use self.direction to determine which animation to play and if the sprite should flip. Change the order of function calls and call walk() last!
1 Like
#3

Thank you! Everything works now.