# pcbdata struct

This document describes pcbdata json structure that plugin
extracts from PCB file and injects into generated bom page.

Notes on conventions:
* Coordinate system has origin in top left corner i.e. Y grows downwards
* All angles are in degrees measured clockwise from positive X axis vector
* Units are arbitrary but some browsers will not handle too large numbers
  well so sticking to mm/mils is preferred.

```js
pcbdata = {
   // Describes bounding box of all edge cut drawings.
   // Used for determining default zoom and pan values to fit
   // whole board on canvas.
  "edges_bbox": {
    "minx": 1,
    "miny": 2,
    "maxx": 100,
    "maxy": 200,
  },
  // Describes all edge cut drawings including ones in footprints.
  // See drawing structure description below.
  "edges": [drawing1, drawing2, ...],
  "drawings": {
    // Contains all drawings + reference + value texts on silkscreen
    // layer grouped by front and back.
    "silkscreen": {
      "F": [drawing1, drawing2, ...],
      "B": [drawing1, drawing2, ...],
    },
    // Same as above but for fabrication layer.
    "fabrication": {
      "F": [drawing1, drawing2, ...],
      "B": [drawing1, drawing2, ...],
    },
  },
  // Describes footprints.
  // See footprint structure description below.
  // index of entry corresponds to component's numeric ID
  "footprints": [
    footprint1,
    footprint2,
    ...
  ],
  // Optional track data. Vias are 0 length tracks.
  "tracks": {
    "F": [
      {
        // In case of line segment or via (via is 0 length segment)
        "start": [x, y],
        "end": [x, y],
        // In case of arc
        "center": [x, y],
        "startangle":
        "radius": radius,
        "startangle": angle1,
        "endangle": angle2,
        // Common fields
        "width": w,
        // Optional net name
        "net": netname,
        // Optional drill diameter (un-tented vias only)
        "drillsize": x
      },
      ...
    ],
    "B": [...]
  },
  // Optional zone data (should be present if tracks are present).
  "zones": {
    "F": [
      {
        // SVG path of the polygon given as 'd' attribute of svg spec.
        // If "svgpath" is present "polygons" is ignored.
        "svgpath": svgpath,
        // optional fillrule flag, defaults to nonzero
        "fillrule": "nonzero" | "evenodd",
        "polygons": [
          // Set of polylines same as in polygon drawing.
          [[point1x, point1y], [point2x, point2y], ...],
        ],
        // Optional net name.
        "net": netname,
      },
      ...
    ],
    "B": [...]
  },
  // Optional net name list.
  "nets": [net1, net2, ...],
  // PCB metadata from the title block.
  "metadata": {
    "title": "title",
    "revision": "rev",
    "company": "Horns and Hoofs",
    "date": "2019-04-18",
  },
  // Contains full bom table as well as filtered by front/back.
  // See bom row description below.
  "bom": {
    "both": [bomrow1, bomrow2, ...],
    "F":  [bomrow1, bomrow2, ...],
    "B":  [bomrow1, bomrow2, ...],
    // numeric IDs of DNP components that are not in BOM
    "skipped": [id1, id2, ...]
    // Fields map is keyed on component ID with values being field data.
    // It's order corresponds to order of fields data in config struct.
    "fields" {
      id1: [field1, field2, ...],
      id2: [field1, field2, ...],
      ...
    }
  },
  // Contains parsed stroke data from newstroke font for
  // characters used on the pcb.
  "font_data": {
    "a": {
      "w": character_width,
      // Contains array of polylines that form the character shape.
      "l": [
        [[point1x, point1y], [point2x, point2y],...],
        ...
      ]
    },
    "%": {
      ...
    },
    ...
  },
}
```

# drawing struct

All drawings are either graphical items (arcs, lines, circles, curves)
or text.

Rendering method and properties are determined based on `type`
attribute.


## graphical items

### segment

```js
{
  "type": "segment",
  "start": [x, y],
  "end": [x, y],
  "width": width,
}
```

### rect

```js
{
  "type": "rect",
  "start": [x, y], // coordinates of opposing corners
  "end": [x, y],
  "width": width,
}
```

### circle

```js
{
  "type": "circle",
  "start": [x, y],
  "radius": radius,
  // Optional boolean, defaults to 0
  "filled": 0,
  // Line width (only has effect for non-filled shapes)
  "width": width,
}
```

### arc

```js
{
  "type": "arc",
  "width": width,
  // SVG path of the arc given as 'd' attribute of svg spec.
  // If this parameter is specified everything below it is ignored.
  "svgpath": svgpath,
  "start": [x, y], // arc center
  "radius": radius,
  "startangle": angle1,
  "endangle": angle2,
}
```

### curve

```js
{
  "type": "curve", // Bezier curve
  "start": [x, y],
  "end": [x, y],
  "cpa": [x, y], // control point A
  "cpb": [x, y], // control point B
  "width": width,
}
```

### polygon

```js
{
  "type": "polygon",
  // Optional, defaults to 1
  "filled": 1,
  // Line width (only has effect for non-filled shapes)
  "width": width
  // SVG path of the polygon given as 'd' attribute of svg spec.
  // If this parameter is specified everything below it is ignored.
  "svgpath": svgpath,
  "pos": [x, y],
  "angle": angle,
  "polygons": [
    // Polygons are described as set of outlines.
    [
      [point1x, point1y], [point2x, point2y], ...
    ],
    ...
  ]
}
```

## text

```js
{
  "pos": [x, y],
  "text": text,
  // SVG path of the text given as 'd' attribute of svg spec.
  // If this parameter is specified then height, width, angle,
  // text attributes and justification is ignored. Rendering engine
  // will not attempt to read character data from newstroke font and
  // will draw the path as is. "thickness" will be used as stroke width.
  "svgpath": svgpath,
  // If polygons are specified then remaining attributes are ignored
  "polygons": [
    // Polygons are described as set of outlines.
    [
      [point1x, point1y], [point2x, point2y], ...
    ],
    ...
  ],
  "height": height,
  "width": width,
  // -1: justify left/top
  // 0: justify center
  // 1: justify right/bot
  "justify": [horizontal, vertical],
  // Either the thickness or the fillrule must be used
  "thickness": thickness,
  // fillrule is only supported for svgpath
  "fillrule": "nonzero" | "evenodd",
  "attr": [
    // may include none, one or both
    "italic", "mirrored"
  ],
  "angle": angle,
  // Present only if text is reference designator
  "ref": 1,
  // Present only if text is component value
  "val": 1,
}
```

# footprint struct

Footprints are a collection of pads, drawings and some metadata.

```js
{
  "ref": reference,
  "center": [x, y],
  "bbox": {
    // Position of the rotation center of the bounding box.
    "pos": [x, y],
    // Rotation angle in degrees.
    "angle": angle,
    // Left top corner position relative to center (after rotation)
    "relpos": [x, y],
    "size": [x, y],
  },
  "pads": [
    {
      "layers": [
        // Contains one or both
        "F", "B",
      ],
      "pos": [x, y],
      "size": [x, y],
      "angle": angle,
      // Only present if pad is considered first pin.
      // Pins are considered first if it's name is one of
      // 1, A, A1, P1, PAD1
      // OR footprint has no pads named as one of above and
      // current pad's name is lexicographically smallest.
      "pin1": 1,
      // Shape is one of "rect", "oval", "circle", "roundrect", "chamfrect", custom".
      "shape": shape,
      // Only present if shape is "custom".
      // SVG path of the polygon given as 'd' attribute of svg spec.
      // If "svgpath" is present "polygons", "pos", "angle" are ignored.
      "svgpath": svgpath,
      "polygons": [
        // Set of polylines same as in polygon drawing.
        [[point1x, point1y], [point2x, point2y], ...],
        ...
      ],
      // Only present if shape is "roundrect" or "chamfrect".
      "radius": radius,
      // Only present if shape is "chamfrect".
      // chamfpos is a bitmask, left = 1, right = 2, bottom left = 4, bottom right = 8
      "chamfpos": chamfpos,
      "chamfratio": ratio,
      // Pad type is "th" for standard and NPTH pads
      // "smd" otherwise.
      "type": type,
      // Present only if type is "th".
      // One of "circle", "oblong" or "rect".
      "drillshape": drillshape,
      // Present only if type is "th". In case of circle shape x is diameter, y is ignored.
      "drillsize": [x, y],
      // Optional attribute.
      "offset": [x, y],
      // Optional net name
      "net": netname,
    },
    ...
  ],
  "drawings": [
    // Contains only copper F_Cu, B_Cu drawings of the footprint.
    {
      // One of "F", "B".
      "layer": layer,
      // See drawing struct description above.
      "drawing": drawing,
    },
    ...
  ],
  // One of "F", "B".
  "layer": layer,
}
```

# bom row struct

Bom row is a list of reference sets

Reference set is array of tuples of (ref, id) where id is just
a unique numeric identifier for each footprint that helps avoid
collisions when references are duplicated.

```js
[
  [reference_name, footprint_id],
  ...
]
```

# config struct

```js
config = {
  "dark_mode": bool,
  "show_pads": bool,
  "show_fabrication": bool,
  "show_silkscreen": bool,
  "highlight_pin1": "none" | "all" | "selected",
  "redraw_on_drag": bool,
  "board_rotation": int,
  "checkboxes": "checkbox1,checkbox2,...",
  "bom_view": "bom-only" | "left-right" | "top-bottom",
  "layer_view": "F" | "FB" | "B",
  "extra_fields": ["field1_name", "field2_name", ...],
}
```