@teachinglab/omd/src/json-schemas.md

omd

# OMD JSON Schemas

## tapeDiagram
```json
{
  "omdType": "tapeDiagram",
  "values": [number|string, ...], //any numbers should be inputted as NUMBERS, e.g 4 not '4'
  "colors": [string, ...],
  "labelSet": [
    {
      "omdType": "omdTapeLabel",
      "startIndex": number, //inclusive
      "endIndex": number, //exclusive
      "label": string,
      "showBelow": boolean
    }
  ],
  "unitWidth": number,
  "showValues": boolean
}
```

- values: segment magnitudes or expressions (strings allowed).
- colors: per-segment fills (optional; falls back to lightGray).
- labelSet: range labels either by indices (startIndex/endIndex) or by absolute values (startValue/endValue).
- unitWidth: pixel width per numeric unit.

## balanceHanger
```json
{
  "omdType": "balanceHanger",
  "leftValues": [number|string, ...],
  "rightValues": [number|string, ...],
  "tilt": "left" | "right" | "none",
  "fontFamily": string,
  "fontSize": number
}
```

- leftValues/rightValues: stacks rendered on each side.
- tilt: beam visual tilt.

## coordinatePlane
```json
{
  "omdType": "coordinatePlane",
  "xMin": number,
  "xMax": number,
  "yMin": number,
  "yMax": number,
  "xLabel": string,
  "yLabel": string,
  "axisLabelOffsetPx": number,
  "size": "small" | "medium" | "large",
  "tickInterval": number,
  "tickLabelOffsetPx": number,
  "forceAllTickLabels": boolean,
  "graphEquations": [
    {
      "equation": string,            // supports 'y = ...' or expression in x
      "domain": { "min": number, "max": number },
      "color": string,
      "strokeWidth": number,
      "label": string,
      "labelAtX": number,
      "labelPosition": "above" | "below" | "left" | "right"
    }
  ],
  "lineSegments": [
    { "point1": [number, number], "point2": [number, number], "color": string, "strokeWidth": number }
  ],
  "dotValues": [ [number, number, string?], ... ],
  "shapeSet": [
    { "omdType": "rightTriangle" | "isoscelesTriangle" | "rectangle" | "ellipse" | "circle" | "regularPolygon", /* shape-specific fields */ }
  ]
}
```

- graphEquations: each equation plotted within its domain.
- lineSegments: raw segment overlays.
- dotValues: points as [x, y, optionalColor].
- shapeSet: geometric overlays rendered in plane units.

## table
```json
{
  "omdType": "table",
  "title": string,
  "headers": [string, ...],
  "data": [ [any, ...], ... ],      // array-of-arrays; columns align with headers
  "equation": string,                // optional; generates rows from y=f(x) takes precendence over any data provided
  "xMin": number,
  "xMax": number,
  "stepSize": number,
  "fontFamily": string,
  "headerFontFamily": string,
  "fontSize": number,
  "headerFontSize": number,
  "cellHeight": number,
  "headerHeight": number,
  "minCellWidth": number,
  "maxCellWidth": number,
  "padding": number
}
```

- If equation is provided, rows are generated in range [xMin, xMax] with stepSize.
- When autoSizeCells is true, widths are inferred from content.