npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

glsl-float-to-rgba

v1.0.0

Published

WebGL shader function to encode a 32-bit float to the RGBA color channels of a texel

Downloads

90

Readme

glsl-float-to-rgba

Installation

npm install --save glsl-float-to-rgba

Signature

vec4 floatToRgba(float texelFloat, bool littleEndian);

Usage

This package exports a GLSL function, floatToRgba, that encodes a 32-bit floating point values to the RGBA channels of a WebGL texture. This is a workaround for the lack of support in baseline WebGL 1.0 for floating-point textures. WebGL 2.0 allows floating-point textures, and WebGL 1.0 allows them when the extension OES_texture_float is available, but OES_texture_float only guarantees reading from floating-point textures, not writing to. This package seeks to fill that gap.

floatToRgba is designed to be used as a GLSLify module. To encode a texel in your shader code, pass the float to the function floatToRgba. Note that because the function has to encode the float to its constituent bits, it needs to know whether the machine on which it's running uses big-endian or little-endian representation.

// fragment shader

#pragma glslify: floatToRgba = require('glsl-float-to-rgba')

// does the machine use little-endian representation?
uniform bool littleEndian;

void main() {
  float floatValue = ...

  gl_FragColor = floatToRgba(floatValue, littleEndian);
}
var pixels = new Uint8Array(CANVAS.width * CANVAS.height * 4);
gl.readPixels(0, 0, CANVAS.width, CANVAS.height, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
pixels = new Float32Array(pixels.buffer);

Here's a simple way to compute endianness in JavaScript. Pass the result as a uniform variable to your shader.

const littleEndian = (function machineIsLittleEndian() {
  const uint8Array = new Uint8Array([0xAA, 0xBB]);
  const uint16array = new Uint16Array(uint8Array.buffer);
  return uint16array[0] === 0xBBAA;
})();

Attribution

Based on routine described here.