Shadertoy: The flag of Romania - 001.

Today I make the flag of Romania.
About this flag you can read at Wikipedia.
The goal of this simple tutorial is to learn the link between iResolution and the fill areas.
First, you need to normalized pixel coordinates from 0 to 1.
The gl_FragColor is a vec4 type of float values in the range 0 to 1.
We can use this property by fill the areas of the screen.
The example can be changed to use the RGBA.
The source code is this:

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    // Normalized pixel coordinates (from 0 to 1)
    vec2 uv = fragCoord/iResolution.xy;
    // Output to screen
    // fill the screen with red
    fragColor = vec4(1,0,0,0);
    // fill the 2/3 of size with yellow color
    if(uv.x<(1.0/1.5))
    fragColor = vec4(1,1,0,0);
    // fill the last 1/3 with the blue color 
    if(uv.x<1 .0="" code="" fragcolor="vec4(0,0,1,0);">

This is the result of this shader:

The neon effect with javascript P5 JavaScript library.

The P5.js is a JavaScript library for creative coding.
You can use by adding this link on your HTML area using the script tag:

https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.9.0/p5.min.js

You can use it like any JavaScript library.
You have two functions: setup and a draw for setup and drawing.

function setup() {
  createCanvas(window.innerWidth, window.innerHeight);
}

function draw() {
  ellipse(50, 50, 80, 80);
}

Then you can fill these functions with any javascript code.
You can see a neon effect with two bezier functions.
The example uses the mouse movement to change the bezier lines.
You can see many examples created by me at codepen website.

Steam on Linux distro Fedora 31 .

You can easily install the Steam tool on Fedora 31.

[root@desk my_bash_scripts]# dnf install steam -y
Last metadata expiration check: 0:20:14 ago on Sun 10 Nov 2019 07:29:46 PM EET.
Dependencies resolved.
...
  pcre-8.43-2.fc31.1.i686                                                       
  pixman-0.38.4-1.fc31.i686                                                     
  pulseaudio-libs-13.0-1.fc31.i686                                              
  rest-0.8.1-6.fc31.i686                                                        
  systemd-libs-243-4.gitef67743.fc31.i686                                       
  xz-libs-5.2.4-6.fc31.i686                                                     

Complete!

Then you can run it with this command:

[mythcat@desk ~]$ steam 
Running Steam on fedora 31 64-bit
STEAM_RUNTIME is enabled automatically
Pins potentially out-of-date, rebuilding...
...
  Initializing engine controller
  Post-initializing framework
-------------------------------------------------------------------------------
  Connected to server (registration)
  Disconnecting from server
  Disconnected from server
  Connected to server (game)
  Preparing engine controller for exit
  Disconnecting from server
-------------------------------------------------------------------------------
Game removed: AppID 488440 "", ProcID 152924 
Uploaded AppInterfaceStats to Steam
Exiting app 488440
No cached sticky mapping in ActivateActionSet.

I tested with the game Angeldust, but you can run any game.
From these funny games like Hibiscus Red, Gatlin' Demo to the last Counter-Strike.
These two screenshots show you how work's this tool game:

Shadertoy: Simple sky with shadertoy tool.

Today I create a simple sky with the online tool shadertoy.
I used Fedora 30 distro Linux and my old video card:

VGA compatible controller: NVIDIA Corporation GT218 [GeForce 210] (rev a2)

This is the output: