# modeling/src/geometries/geom3/toCompactBinary.js

``````const poly3 = require('../poly3')

/**
* Return the given geometry in compact binary representation.
* @param {geom3} geometry - the geometry
* @return {TypedArray} compact binary representation
* @alias module:modeling/geometries/geom3.toCompactBinary
*/
const toCompactBinary = (geometry) => {
const polygons = geometry.polygons
const transforms = geometry.transforms

const numberOfPolygons = polygons.length
const numberOfVertices = polygons.reduce((count, polygon) => count + polygon.vertices.length, 0)
let color = [-1, -1, -1, -1]
if (geometry.color) color = geometry.color

// FIXME why Float32Array?
const compacted = new Float32Array(1 + 16 + 4 + 1 + numberOfPolygons + (numberOfVertices * 3))
// type + transforms + color + numberOfPolygons + numberOfVerticesPerPolygon[] + vertices data[]

compacted[0] = 1 // type code: 0 => geom2, 1 => geom3 , 2 => path2

compacted[1] = transforms[0]
compacted[2] = transforms[1]
compacted[3] = transforms[2]
compacted[4] = transforms[3]
compacted[5] = transforms[4]
compacted[6] = transforms[5]
compacted[7] = transforms[6]
compacted[8] = transforms[7]
compacted[9] = transforms[8]
compacted[10] = transforms[9]
compacted[11] = transforms[10]
compacted[12] = transforms[11]
compacted[13] = transforms[12]
compacted[14] = transforms[13]
compacted[15] = transforms[14]
compacted[16] = transforms[15]

compacted[17] = color[0]
compacted[18] = color[1]
compacted[19] = color[2]
compacted[20] = color[3]

compacted[21] = numberOfVertices

let ci = 22
let vi = ci + numberOfPolygons
polygons.forEach((polygon) => {
const points = poly3.toPoints(polygon)
// record the number of vertices per polygon
compacted[ci] = points.length
ci++
// convert the vertices
for (let i = 0; i < points.length; i++) {
const point = points[i]
compacted[vi + 0] = point[0]
compacted[vi + 1] = point[1]
compacted[vi + 2] = point[2]
vi += 3
}
})
// TODO: how about custom properties or fields ?
return compacted
}

module.exports = toCompactBinary
``````