Math Utilities

Math and conversion utilities shared across the livery editor modules.

Overview

ui_liveryEditor_utils provides common math helpers used throughout the livery editor - angle conversions, rounding, coordinate extraction, range cycling, and action map resolution.

Extension path: lua/ge/extensions/ui/liveryEditor/utils.lua

Exports (M)

Internals

Angle Conversion

local convertRadiansToDegrees = function(radians)
  return radians * (180 / math.pi)
end

local convertDegreesToRadians = function(degrees)
  local radians = degrees * (math.pi / 180)
  return tonumber(string.format("%.14f", radians))
end

The radians-to-degrees conversion preserves full precision. Degrees-to-radians truncates to 14 decimal places to avoid floating-point drift.

Rounding

local roundAndTruncateDecimal = function(number, decimals)
  decimals = decimals or 1
  local scale = 10 ^ decimals
  return math.ceil(number * scale - 0.5) / scale
end

Uses ceiling-minus-half for symmetric rounding (round-half-up behaviour).

Cycle Range

local cycleRange = function(value, min, max)
  value = value % max
  if value < min then
    value = value + max
  end
  return value
end

Used for wrapping rotation degrees: cycleRange(370, 0, 360) → 10.

Coordinate Extraction

getXYCoordinates reads from a decalPos vector using camera-defined axis indices, allowing the same code to work regardless of camera orientation.

How It Works

1. Transform modules call convertRadiansToDegrees / convertDegreesToRadians for UI display
2. roundAndTruncateDecimal keeps displayed values clean (e.g., 0.001 precision for position)
3. cycleRange ensures rotation values stay within 0–360
4. getActionMapNameByTool resolves tool names to action map identifiers for input binding

Example Usage

local utils = extensions.ui_liveryEditor_utils

-- Convert rotation for display
local degrees = utils.convertRadiansToDegrees(1.5708)  -- ~90.0

-- Round for UI
local rounded = utils.roundAndTruncateDecimal(0.12345, 2)  -- 0.12

-- Wrap rotation
local wrapped = utils.cycleRange(-10, 0, 360)  -- 350

Additional Exports

The following exports are available but not yet documented in detail:

• M.convertDegreesToRadians
• M.convertRadiansToDegrees
• M.cycleRange
• M.getActionMapNameByTool
• M.getBaseDegreesValue
• M.getXYCoordinates
• M.roundAndTruncateDecimal

See Also

• Livery Editor - Camera - Related reference
• Livery Editor - Controls - Related reference
• Livery Editor - Edit Mode - Related reference
• UI System Guide - Guide