quack-twn/data/scripts/game.lua

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 function Vector2(x, y)
    if y == nil then
        return {x = x, y = x}
    end
    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
            capture = false
        end
    end
    
    local dir = Vector3(draw_camera_from_principal_axes{position = position, yaw = head_rotation}.direction)
    dir.y = 0
    dir = dir:normalized()

    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

    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}
end