66 lines
2 KiB
Text
66 lines
2 KiB
Text
local ACCELERATION = 100
|
|
local DECELERATION = 200
|
|
local MAX_SPEED = 400
|
|
local WHEEL_BASE = 80
|
|
|
|
local UP = vmath.vector3(0, 1, 0)
|
|
|
|
function init(self)
|
|
msg.post(".", "acquire_input_focus")
|
|
|
|
self.left_speed = 0
|
|
self.right_speed = 0
|
|
self.left_fwd = false
|
|
self.left_rev = false
|
|
self.right_fwd = false
|
|
self.right_rev = false
|
|
end
|
|
|
|
local function update_speed(speed, drive, dt)
|
|
if drive ~= 0 then
|
|
local target = drive * MAX_SPEED
|
|
local step = ACCELERATION * dt
|
|
if speed < target then
|
|
return math.min(speed + step, target)
|
|
else
|
|
return math.max(speed - step, target)
|
|
end
|
|
else
|
|
local step = DECELERATION * dt
|
|
if speed > 0 then
|
|
return math.max(speed - step, 0)
|
|
else
|
|
return math.min(speed + step, 0)
|
|
end
|
|
end
|
|
end
|
|
|
|
function update(self, dt)
|
|
local left_drive = (self.left_fwd and 1 or 0) - (self.left_rev and 1 or 0)
|
|
local right_drive = (self.right_fwd and 1 or 0) - (self.right_rev and 1 or 0)
|
|
|
|
self.left_speed = update_speed(self.left_speed, left_drive, dt)
|
|
self.right_speed = update_speed(self.right_speed, right_drive, dt)
|
|
|
|
-- differential drive: speed difference creates rotation, average creates forward motion
|
|
local linear_speed = (self.left_speed + self.right_speed) / 2
|
|
local angular_vel = (self.right_speed - self.left_speed) / WHEEL_BASE
|
|
|
|
local rot = go.get_rotation()
|
|
rot = rot * vmath.quat_rotation_z(angular_vel * dt)
|
|
go.set_rotation(rot)
|
|
|
|
local p = go.get_position()
|
|
p = p + vmath.rotate(rot, UP * linear_speed * dt)
|
|
go.set_position(p)
|
|
|
|
end
|
|
|
|
function on_input(self, action_id, action)
|
|
local held = action.pressed or not action.released
|
|
if action_id == hash("a_key") then self.left_fwd = held
|
|
elseif action_id == hash("q_key") then self.left_rev = held
|
|
elseif action_id == hash("d_key") then self.right_fwd = held
|
|
elseif action_id == hash("e_key") then self.right_rev = held
|
|
end
|
|
end
|