Emanuele Feronato

go.property(“gravity”, vmath.vector3(0, -4500, 0)) go.property(“ground_speed”, 450) go.property(“jump_speed”, 900) — distance between the platforms local PLATFORM_SPACING = 250 function init(self) msg.post(“.”, “acquire_input_focus”) self.velocity = vmath.vector3(self.ground_speed, 0, 0) — the platforms each consist of a ground and ladder game object — they are defined in game.collection — the game object ids are sequentially named ground1, ladder1, …, ground6, ladder6 — the list will be kept ordered so that the first element will represent the platform — at the bottom of the screen while the last element represents the platform at — the top of the screen self.platforms = { 1, 2, 3, 4, 5, 6 } for i,id in ipairs(self.platforms) do go.set_position(vmath.vector3(400, PLATFORM_SPACING * i, 0), “ground” .. id) end end function update(self, dt) msg.post(“@render:/”, “clear_color”, { color = vmath.vector4(0xaa / 0xff, 0xeea / 0xff, 1.0, 1.0) }) — ignore any movement logic while the player is climbing a ladder if self.climbing then return end — add gravity to the hero velocity self.velocity = self.velocity + self.gravity * dt — move the player — if the player has moved outside the left or right edge of the — the screen the horizontal component of the velocity is reversed — also flip the hero sprite local pos = go.get_position() pos = pos + self.velocity * dt if pos.x > 800 then pos.x = 800 self.velocity.x = -self.velocity.x sprite.set_hflip(“#sprite”, true) elseif pos.x < 0 then pos.x = 0 self.velocity.x = -self.velocity.x sprite.set_hflip(“#sprite”, false) end go.set_position(pos) — reset volatile state self.can_jump = false end function on_message(self, message_id, message, sender) if message_id == hash(“contact_point_response”) then if message.group == hash(“ground”) and not self.climbing then — resolve the collision by moving the hero out of the collision object — also reset the vertical component of the velocity go.set_position(go.get_position() + message.normal * message.distance) self.velocity.y = 0 self.can_jump = true elseif message.group == hash(“ladder”) and not self.climbing then self.velocity.y = 0 self.climbing = true for i,id in ipairs(self.platforms) do — fade out the bottom most ground and ladder if i == 1 then go.animate(“ground” .. id .. “#sprite”, “tint.w”, go.PLAYBACK_ONCE_FORWARD, 0, go.EASING_OUTCUBIC, 0.3) go.animate(“ladder” .. id .. “#sprite”, “tint.w”, go.PLAYBACK_ONCE_FORWARD, 0, go.EASING_OUTCUBIC, 0.3) end — animate the platform downwards — if the platform was animated outside of the view it will — be moved to the top go.animate(“ground” .. id, “position.y”, go.PLAYBACK_ONCE_FORWARD, go.get_position(“ground” .. id).y – PLATFORM_SPACING, go.EASING_LINEAR, 0.3, 0, function() self.climbing = false — if this was the first (ie bottom-most platform) we need to — move it to the top of the platforms — we also move it to the end of the list of platforms to — keep the order intact — and finally we also reset the alpha value (we faded it) if i == 1 then go.set(“ground” .. id .. “#sprite”, “tint.w”, 1.0) go.set(“ladder” .. id .. “#sprite”, “tint.w”, 1.0) table.insert(self.platforms, table.remove(self.platforms, i)) local pos = go.get_position(“ground” .. id) pos.y = pos.y + #self.platforms * PLATFORM_SPACING go.set_position(pos, “ground” .. id) end end) end end end end function on_input(self, action_id, action) if action_id == hash(“touch”) or action_id == hash(“jump”) then if action.pressed and self.can_jump then self.velocity.y = self.jump_speed end end end