enable reverse driving

This commit is contained in:
Travis Shears 2026-05-14 09:44:09 +01:00
parent 9032f44830
commit 00a999caf4
Signed by: travisshears
GPG key ID: CB9BF1910F3F7469

View file

@ -1,7 +1,7 @@
go.property("acceleration", 100)
go.property("deceleration", 200)
go.property("max_speed", 400)
go.property("wheel_base", 40) -- pixels between left and right wheels
local ACCELERATION = 100
local DECELERATION = 200
local MAX_SPEED = 400
local WHEEL_BASE = 80
local UP = vmath.vector3(0, 1, 0)
@ -10,27 +10,41 @@ function init(self)
self.left_speed = 0
self.right_speed = 0
self.left_input = false
self.right_input = false
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)
-- each wheel accelerates when its key is held, decelerates otherwise
if self.left_input then
self.left_speed = math.min(self.left_speed + self.acceleration * dt, self.max_speed)
else
self.left_speed = math.max(self.left_speed - self.deceleration * dt, 0)
end
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)
if self.right_input then
self.right_speed = math.min(self.right_speed + self.acceleration * dt, self.max_speed)
else
self.right_speed = math.max(self.right_speed - self.deceleration * dt, 0)
end
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) / self.wheel_base
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)
@ -40,15 +54,13 @@ function update(self, dt)
p = p + vmath.rotate(rot, UP * linear_speed * dt)
go.set_position(p)
-- reset each frame (on_input re-sets if key is still held)
self.left_input = false
self.right_input = false
end
function on_input(self, action_id, action)
if action_id == hash("a_key") then
self.left_input = true
elseif action_id == hash("d_key") then
self.right_input = true
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