int-pack-vec

For those times where you want to pack an integer into a vec on the gpu, and then unpack it back in javascript. Useful when constrained to a uint8 framebuffer because your device does not properly handle writing to a float framebuffer even though it supports the texture float extension. As happened to me with iOS debugging a mixmap picking feature.

example

The intended use of the package is displayed within the example file.

api

In glsl you can pack int values into the frag color using glslify and the following line to import the module:

#pragma glslify: pack = require('int-pack-vec/pack.glsl');

Once you read your value from the frame buffer, you can use the decode function to get your original value back:

const { decodeVec3 } = require('int-pack-vec')
const vec4 = regl.read({
  framebuffer,
  x: 0,
  y: 0,
  width: 1,
  height: 1,
})
const decoded = decodeVec3(vec4.slice(0, 3))