FBX_ASCII.sublime-syntax

%YAML 1.2
---
# Sublime Text syntax highlighting for Autodesk FBX ASCII format.
# File extension: .fbx (ASCII format)
# By: vector_cmdr (https://github.com/vectorcmdr)

name: FBX ASCII
file_extensions:
  - fbx
scope: source.fbx.ascii

variables:
  # Whitespace and basic tokens
  ws: '[ \t]+'
  identifier: '[A-Za-z_][A-Za-z0-9_]*'
  # FBX node/property names often include ':' (e.g., "Model::Cube")
  # and may include other punctuation in practice, but ':' is very common.
  identifier_colon: '[A-Za-z_][A-Za-z0-9_]*(?:::[^ \t\r\n{",]+)?'

  # Numbers: 1, -1, 1.0, -1.0, 1e-3, -1.2E+6
  number: '[-+]?(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][-+]?\d+)?'

contexts:
  main:
    - include: comments
    - include: header_keywords
    - include: object_block
    - include: property_line
    - include: literals
    - include: punctuation

  # FBX comment style is typically ';' to end of line in ASCII exports
  comments:
    - match: ';.*$'
      scope: comment.line.semicolon.fbx

  # Common header-ish tokens seen near top of file (not exhaustive)
  header_keywords:
    - match: '\b(Kaydara\s+FBX\s+Binary|Kaydara\s+FBX)\b'
      scope: keyword.other.header.fbx
    - match: '\bFBXHeaderExtension\b'
      scope: entity.name.section.fbx
    - match: '\bFBXVersion\b'
      scope: keyword.other.version.fbx

  # Top-level and nested object blocks:  NodeName: <props> {
  # Examples:
  #   Objects:  {
  #   Model: 1234, "Model::Cube", "Mesh" {
  object_block:
    - match: '^(?:(?<=\A)|(?<=\n))\s*(?:{{identifier}}|{{identifier_colon}})(?=\s*:)'
      scope: entity.name.section.fbx
    - match: ':'
      scope: punctuation.separator.key-value.fbx
      push:
        - meta_scope: meta.fbx.node
        - include: comments
        - include: literals
        - include: punctuation
        - include: typed_property_hints
        - include: commas
        - match: '\{'
          scope: punctuation.section.block.begin.fbx
          pop: true
        - match: '$'
          pop: true

  # Property-like lines inside blocks frequently look like:
  #   P: "Lcl Translation", "Lcl Translation", "", "A",0,0,0
  #   C: "OO",123,456
  property_line:
    - match: '^\s*(P|C|A|T|U|S|D|R|K)\b(?=\s*:)'
      scope: keyword.other.record.fbx
    - match: ':'
      scope: punctuation.separator.key-value.fbx

  typed_property_hints:
    # FBX uses type-ish string tags in many places (examples: "Model", "Mesh", "Geometry", "Deformer")
    # and also property system hints like "A", "KString", "Number", etc.
    - match: '(?<=,)\s*"([A-Za-z][A-Za-z0-9_]*)"\s*(?=,|\s*\{|$)'
      scope: constant.other.typehint.fbx

  literals:
    - include: strings
    - include: numbers
    - include: booleans
    - include: nulls

  strings:
    # Double-quoted strings are common, including escaped quotes.
    - match: '"'
      scope: punctuation.definition.string.begin.fbx
      push:
        - meta_scope: string.quoted.double.fbx
        - match: '\\.'
          scope: constant.character.escape.fbx
        - match: '"'
          scope: punctuation.definition.string.end.fbx
          pop: true

  numbers:
    - match: '\b{{number}}\b'
      scope: constant.numeric.fbx

  booleans:
    # FBX ASCII often encodes booleans as 0/1, but some exporters may use TRUE/FALSE.
    - match: '\b(TRUE|FALSE|True|False)\b'
      scope: constant.language.boolean.fbx

  nulls:
    - match: '\bNULL\b'
      scope: constant.language.null.fbx

  commas:
    - match: ','
      scope: punctuation.separator.sequence.fbx

  punctuation:
    - match: '\{'
      scope: punctuation.section.block.begin.fbx
    - match: '\}'
      scope: punctuation.section.block.end.fbx
    - match: '\['
      scope: punctuation.section.brackets.begin.fbx
    - match: '\]'
      scope: punctuation.section.brackets.end.fbx
    - match: '\('
      scope: punctuation.section.parens.begin.fbx
    - match: '\)'
      scope: punctuation.section.parens.end.fbx
    - match: '\.'
      scope: punctuation.accessor.dot.fbx
...