vorg / geom-builder Goto Github PK

all your options have dual type which seems confusing - why not just pass 0?

It is possible to build mesh with more than 64k vertices that creates clamped indices due to Uint16Array array for cell. Either we should switch to Uint32Array or upgrade to it once positionsIndex is above 60k

Currently we come with assumptions about supported attributes e.g. that positions are always enabled

const builder = createGeomBuilder({ colors: 4, cells: 3 })

builder.addPosition([0, 0, 0])
builder.addColor([0, 0, 0, 1])
builder.count //1
builder.positions //Float32Array [0, 0, 0]

a more generic API could be as follows:

const builder = createGeomBuilder({ positions: 3, colors: 4, cells: { stride: 3, type: Uint32Array }})

builder.add('positions', [0.0, 0.0, 0.0])
builder.add('colors', [0.0, 0.0, 0.0, 1.0])
builder.add('cells', [0, 1, 2])

buidler.positions //Float32Array [0, 0, 0]

The builder.add('positions', []) fees weird, it should be builder.add('position', []) but then how do we guess the name? By adding s automatically?

Also

builder.positions

//vs 

builder.get('position')

Also if we change API so much this should be new module e.g. auto-expanding-buffer. What makes it geometry specific is assumption that all attributes grow at the same rate which is actually not always true (e.g. instancing). Would the api be then builder.count('position') and or builder.count('cells')?

auto-buffer

auto-buffer auto expanding buffer. Is there something similar on npm already?

That also leads to builder.resetAll() and more granular builder.reset('position')... which leads to fact that maybe we need builder per buffer?

const autoBuffer = require('auto-buffer') //free npm name!
const positions = autoBuffer() //no predefined stride/size, probably starts with length 32
positions.add([0, 0, 0])
positions.count //undefined
positions.length //3, actual used length since last reset, not allocated buffer size
let count = positions.length / 3 //diy
positions.reset()

Geom builder allows to do addPosition([x, y, z]) and addPosition(x, y, z) to avoid vector allocation. To enable this I use arguments parameter. Turns out it allocates a lot of junk in Firefox causing GC hiccups and has impact on CPU in Safari and Chrome as well.

//1 old
GeomBuilder.prototype.addPosition = function (pos) {
  var values = arguments[0].length ? pos : arguments

//2 new, best
GeomBuilder.prototype.addPosition = function (pos) {
  var values = pos

// 3 better than 1, but still slower than 2
GeomBuilder.prototype.addPosition = function (...pos) {
  var values = pos[0].length ? pos[0] : pos