split player into its own class file, use udata for state

data/scripts/classes/player.lua

@@ -0,0 +1,41 @@
+local Vector3 = require "vector3"
+local util = require "util"
+
+-- this is a static class, so no instancing shenanigans needed
+
+local Player = {
+  position = Vector3(),
+  velocity = Vector3(),
+
+  speed = 0.07,
+  mouse_sensitivity = 0.01,
+
+  yaw = 0,
+  yaw_speed = 0.05,
+}
+
+function Player:tick(ctx)
+  input_action{name = "left", control = "A"}
+  input_action{name = "right", control = "D"}
+  input_action{name = "forward", control = "W"}
+  input_action{name = "back", control = "S"}
+
+  local camera_forward = Vector3(draw_camera_from_principal_axes(self).direction)
+  camera_forward.y = 0
+  camera_forward = camera_forward:normalized()
+  local camera_right = camera_forward:cross(Vector3.UP)
+
+  local forward_input = util.b2n(input_action_pressed{name = "forward"}) - util.b2n(input_action_pressed{name = "back"})
+  local strafe_input = util.b2n(input_action_pressed{name = "right"}) - util.b2n(input_action_pressed{name = "left"})
+
+  local direction = ((camera_forward * forward_input) + (camera_right * strafe_input)):normalized()
+  self.velocity = direction * self.speed
+
+  if ctx.mouse_capture then
+    self.yaw = self.yaw + self.mouse_sensitivity * ctx.mouse_movement.x
+  end
+
+  self.position = self.position + self.velocity
+end
+
+return Player

data/scripts/game.lua

@@ -1,17 +1,7 @@
 local FONT = "fonts/Lunchtype21_Regular.ttf"
 
 local Vector3 = require "vector3"
-local capture = false
-
-local head_rotation = 0
-local rotate_speed = 0.05
-
-local mouse_sensitivity = 0.01
-
-local spd = 0.07
-
-local position = Vector3()
-local velocity = Vector3()
+local player = require "classes.player"
 
 local function Vector2(x, y)
     if y == nil then
@@ -20,63 +10,23 @@ local function Vector2(x, y)
     return {x = x, y = y}
 end
 
-local function wrap(value, min, max)
-    local range = max - min
-    if value == 0 then
-        return min
-    end
-    
-    local result = value - (range * math.floor((value - min) / range))
-    if result == max then
-        return min
-    end
-    
-    return result
-end
-
-local function b2n(value)
-    return value and 1 or 0
-end
-
 function game_tick()
     -- ctx.initialization_needed is true first frame and every time dynamic reload is performed
     if ctx.initialization_needed then
         -- ctx.udata persists on reload
-        ctx.udata = {}
-    end
-    ctx.mouse_capture = capture
-    input_action{name="toggle_mouse", control="ESCAPE"}
-
-    input_action{name = "left", control = "A"}
-    input_action{name = "right", control = "D"}
-    input_action{name = "forward", control = "W"}
-    input_action{name = "back", control = "S"}
-
-    if input_action_just_pressed{name = "toggle_mouse"} then
-        if not capture then
-            capture = true
-        else
+        ctx.udata = {
             capture = false
+        }
     end
+    ctx.mouse_capture = ctx.udata.capture
+    input_action{name="toggle_mouse", control="ESCAPE"}
+    if input_action_just_pressed{name = "toggle_mouse"} then
+        ctx.udata.capture = not ctx.udata.capture
     end
 
-    local dir = Vector3(draw_camera_from_principal_axes{position = position, yaw = head_rotation}.direction)
-    dir.y = 0
-    dir = dir:normalized()
+    player:tick(ctx)
 
-    if not capture then
-        local rot_d = b2n(input_action_pressed{name = "right"}) - b2n(input_action_pressed{name = "left"})
-        head_rotation = head_rotation + rot_d * rotate_speed
-    else
-        head_rotation = head_rotation + mouse_sensitivity * ctx.mouse_movement.x
-    end
+    draw_billboard{position = Vector3(0, 0, 3), size = Vector2(1, 1), texture = "images/duck.png"}
 
-    local mov_d = b2n(input_action_pressed{name = "forward"}) - b2n(input_action_pressed{name = "back"})
-    velocity = dir * spd * mov_d
-
-    position = position + velocity
-
-    draw_billboard{position = Vector3(5, 0, 0), size = Vector2(1, 1), texture = "images/duck.png"}
-
-    draw_text{position = Vector2(0), string = "vel: " .. tostring(velocity), font = FONT}
+    draw_text{position = Vector2(0), string = "vel: " .. tostring(player.velocity), font = FONT}
 end

data/scripts/trig.lua

@@ -1,3 +0,0 @@
-local M = {}
-
-return M

data/scripts/util.lua

@@ -0,0 +1,20 @@
+local util = {}
+
+function util.printt(t)
+  if type(t) == 'table' then
+      local s = '{ '
+      for k,v in pairs(t) do
+        if type(k) ~= 'number' then k = '"'..k..'"' end
+        s = s .. '['..k..'] = ' .. util.print(v) .. ','
+      end
+      return s .. '} '
+  else
+      return tostring(t)
+  end
+end
+
+function util.b2n(value)
+  return value and 1 or 0
+end
+
+return util

data/scripts/vector3.lua

@@ -135,7 +135,43 @@ end
 
 function Vector3:normalized()
   local length = math.sqrt(self:length_squared())
+  if length == 0 then
+    return Vector3()
+  end
   return Vector3(self.x / length, self.y / length, self.z / length)
 end
+
+function Vector3:dot(with)
+  if not is_weak_vector3(with) then
+    error("Vector3: with must be a Vector3-like table. Returning 0")
+    return 0
+  end
+
+  local v2 = Vector3(with)
+  return self.x * v2.x + self.y * v2.y + self.z * v2.z
+end
+
+function Vector3:cross(with)
+  if not is_weak_vector3(with) then
+    error("Vector3: with must be a Vector3-like table. Returning Vector3()")
+    return Vector3()
+  end
+  local v2 = Vector3(with)
+  return Vector3 {
+    self.y * v2.z - self.z * v2.y,
+    self.z * v2.x - self.x * v2.z,
+    self.x * v2.y - self.y * v2.x,
+  }
+end
+
+---- CONSTANTS
+
+Vector3.UP = Vector3(0, 1, 0)
+Vector3.DOWN = -Vector3.UP
+Vector3.FORWARD = Vector3(0, 0, -1)
+Vector3.BACK = -Vector3.FORWARD
+Vector3.RIGHT = Vector3(1, 0, 0)
+Vector3.LEFT = -Vector3.RIGHT
+
 -------------------
 return Vector3