Force Javascript array to Float32

Question

I'm working with WebGL, so I need Float32Arrays all the time. Is there a way to force an array to be a Float32Array? I tried this:

var cubeVertices = new Float32Array(3 * 4 * 6);
cubeVertices = [
   /* Vertices */
];

But this appears to change the type to a Float64Array, since I can't use it with WebGL, but it works when I do a new Float32Array(cubeVertices). I don't really want to use the new Float32Array command all the time, since it allocates memory that is of no use, because I don't need several copies of my data.

So is there a way of creating a Float32Array without having two arrays, where one is never used again?

user_3001856 · Answer

There are only 3 ways to create the actual Float32Array:

new Float32Array(length)
TypedArray.from(source[, mapFn[, thisArg]]) source
TypedArray.of(element0[, element1[, ...[, elementN]]]) source

user_11043913 · Answer

I think this will be correct for you.

var num=[6676.88,8878.99.....];
var floatVal=num.map(function(value){
     return Math.fround(value);
});
console.log(floatVal);

user_7687038 · Answer

You can do

Float32Array.from(yourArray);

The from method converts Array-like objects to Float32Array and is available for other Array types on javascript, like Array, Float32Array or Int16Array.

You can read more about this on the "Indexed Collections" of the following URL: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects

user_11914177 · Answer

So I kind of created my own solution out of these answers, so that there aren't two arrays wasting memory. I use the Float32Array.from function and create a local array there that should be deleted after that line, so my code looks like this:

var cubeVertices = Float32Array.from(
  [
     0.5, -0.5, -0.5,
    -0.5, -0.5, -0.5,
     0.5,  0.5, -0.5,
    -0.5,  0.5, -0.5
  ]
);

Thanks to Akxe, using Float32Array.of would be even better, but it is not very widely supported.

Force Javascript array to Float32

4 Answers