{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://libraries.ludic-canvas.victorqueiroz.dev/font-atlas.schema.json",
  "title": "Ludic Canvas font atlas configuration",
  "type": "object",
  "additionalProperties": false,
  "required": ["output", "fonts"],
  "properties": {
    "$schema": { "type": "string" },
    "output": {
      "type": "string",
      "minLength": 1,
      "description": "Output directory, relative to this configuration file."
    },
    "charset": {
      "type": "string",
      "minLength": 1,
      "default": "[0x20, 0x7E]",
      "description": "Default msdf-atlas-gen Unicode charset expression."
    },
    "fonts": {
      "type": "array",
      "minItems": 1,
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": ["name", "source"],
        "properties": {
          "name": {
            "type": "string",
            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_-]{0,63}$",
            "description": "Unique face name and output filename stem; names are case-insensitive for collision checks."
          },
          "source": {
            "type": "string",
            "minLength": 1,
            "description": "Single-face TTF, OTF, WOFF or WOFF2 file, relative to this configuration file."
          },
          "size": {
            "type": "number",
            "minimum": 8,
            "maximum": 128,
            "default": 48,
            "description": "Atlas pixels per em. Text fontSize is chosen separately at runtime."
          },
          "distanceRange": {
            "type": "number",
            "minimum": 1,
            "maximum": 32,
            "default": 6,
            "description": "Distance range in atlas pixels."
          },
          "charset": {
            "type": "string",
            "minLength": 1,
            "description": "Override the configuration's charset expression for this font."
          },
          "characters": {
            "type": "string",
            "description": "Additional literal Unicode characters. Space and question mark are always included."
          },
          "variations": {
            "type": "object",
            "propertyNames": { "pattern": "^[A-Za-z0-9 ]{4}$" },
            "additionalProperties": { "type": "number" },
            "description": "Variable-font axis values, for example { wght: 600 }. Unknown axes fail generation."
          }
        }
      }
    }
  }
}