Codapi an interactive code playground service.

Interactive code examples for all types of technical writing.

Embed executable code snippets directly into your product documentation, online course or blog post.

Supports 30 playgrounds out of the box, plus custom sandboxes if you need them.

You can run in-browser playgrounds without a server, use the Codapi cloud, or host a sandbox server yourself.

Read more on the official website.

CodePen : Home RoughJS and Wired elements example .

Inkscape : Create an extension for inkscape.

You can create your own extensions in inkscape with all features you need to improve the working area.

One extension can have minimum two file: the basic Python source code and another file with the graphic user interface ...

The source code of Python file can be link with the G.U.I. source code type file INX.

The source code for python can be customized and this is the main reason is no need to add it here.

Let's see the source code for the INX file:

<?xml version="1.0" encoding="UTF-8"?>
<inkscape-extension xmlns="http://www.inkscape.org/namespace/inkscape/extension">
    <name>Default extension example</name>
    <id>default.extensions.example</id>
    <param name="tab" type="notebook">
        <page name="Options" gui-text="Options">
            <param name="value_int" type="int" min="0" max="9" gui-text="INT type value from 0 up to 9 : ">10</param>
            <param name="value_bool" type="bool" gui-text="BOOL value set to false : ">false</param>
            <param name="value_space" type="float" gui-text="FLOAT value set to 0.1 custom range min 0.0 up max=99.0 : " min="0.0" max="99.0">0.1</param>
                <param name="option_group selection" type="optiongroup" appearance="combo" gui-text="Options :">
                <option value="1">1</option>
                <option value="2">2</option>
                <option value="3">3</option>
            </param>
		<param name="grouppick" type="bool" gui-text="selection pick ..." gui-description="This is gui-description">false</param>
            <param name="pickmode" type="optiongroup" appearance="combo" gui-text="pick values group:">
                <option value="first">first</option>
                <option value="second">second</option>
            </param> 
	</page>
        <page name="Help" gui-text="Help for default extension example">
            <label xml:space="preserve">This is example of default extension example
	You can use this INX file and PY files type named 'default_extension_example'</label>
        </page>
    </param>
    <effect>
        <object-type>all</object-type>
        <effects-menu>
            <submenu name="catafest"/>
        </effects-menu>
    </effect>
    <script>
        <command location="inx" interpreter="python">default_extension_example.py</command>
    </script>
</inkscape-extension>

Bellow you can see some screenshots with these result

Blender 3D : Sorcar - Procedural modeling in Blender using Node Editor.

You can follow the blenderartists.org - forum.

The project addon can be found on the GitHUb repo.

News : Shader Editor source code.

If you follow my blogger, you've seen some shaders I made for my background phone.

These shaders are created with this Android app called Shader Editor.

You can find the source code of this application on this GitHub project.

CodePen: CodePen Home WebGL Flower Pattern (Voronoi diagram GLSL)

You can find good web development with a great graphics on Ksenia Kondrashova codepen account.

See this example named: CodePen Home WebGL Flower Pattern (Voronoi diagram GLSL):

GitHub webgpu samples.

These examples can be found at GitHub samples.

CodePen: Simple example with css-doodle web component.

This is a simple example with css-doodle javascript web component for drawing patterns with CSS.

See the Pen Untitled by Cătălin George Feștilă (@catafest) on CodePen.

BVH and three.js meshes implementation.

This article is about the BVH implementation to speed up raycasting and enable spatial queries against three.js meshes.

The full source code can be found on this GitHub project.

You can see a good example on this demo page with this Tyrannosaurus rex

CodePen: Google visualization with GeoChart.

In this exameple I used visualization with GeoChart.

See the Pen Untitled by Cătălin George Feștilă (@catafest) on CodePen.

CodePen: The pantone color of the year 2022.

The pantone color of the year 2022 is this.

See the Pen the Pantone Color of year 2022 by Cătălin George Feștilă (@catafest) on CodePen.

CodePen: ... challenges every time.

This website comes with challenges all the time, see this week example:

THIS WEEK’S CHALLENGE,Book Text ...Your challenge: Give this book excerpt some tasteful text styles.

Here's what I managed to do for this week:

CodePen: How can share sketchfab 3D models.

The Viewer API lets you build web apps on top of Sketchfab’s 3D viewer. With the API, you can control the viewer in JavaScript. It provides functions for starting, stopping the viewer, moving the camera, taking screenshots and more.

See the official webpage.

News : Unity comes with LookDev Studio.

... most people love this game engine, today a new feature comes to show us how good is this game engine. you can see also another character named FIA.

Artists – no matter their expertise – need a place to quickly import, iterate on, and refine their art.

You can find a source code with this project on the GitHub website.

CodePen: RGB colors.

Example with the javascript programming language presented in my codepen account solves the following issues:

• create HTML tag div for each for iteration;
• create an id for each div tag;
• build an RGB color with red, green, and blue using a random function;
• read that id and used to set the color background of each div;
• print the RGB value for each color and set background color;

Let's see the example:

See the Pen by Cătălin George Feștilă (@catafest) on CodePen.

CodePen: Lottie for Web, Android, iOS, React Native, and Windows - 001.

Lottie is a mobile library for Web, and iOS that parses Adobe After Effects animations exported as JSON with Bodymovin and renders them natively on mobile!, see GitHub project.

You can find Lottie files on this website. 

This is a simple example with lottie-player.js:

See the Pen lottie-player html 001 by Cătălin George Feștilă (@catafest) on CodePen.

CodePen: A simple progressbar with CSS.

A simple test with CSS about how to create two simple progress bars. The code source of this example - https://codepen.io/catafest/pen/rNjmdwa show us about the cascading source code in CSS and how this works pe properties in CSS. This difference of the source code in CSS change the speed of the animation:

 animation: animate 6s ease-in-out infinite;
...
 animation: animate 1s ease-in-out infinite;

Some changes to the CSS source code are not allowed because they have no effect on the end result or must be used in order to complete the base code and have the end result. Another good example is flex:

display: flex;

On the parent element also changes how width and height work. CSS codes defines have no effect on a flex container. ... I can tell you that it is not very easy to change a project based on CSS, so the steps of designing and building a website are very important.

See the Pen CSS excample 001 by Cătălin George Feștilă (@catafest) on CodePen.

OpenProcessing - simple tree_001.

This is modified example from this in order to build another good tree using openprocessing website interface.

You can see this example on my account.

Let's see the source code:

/*--based on https://openprocessing.org/sketch/396851--*/

var nbranchs = 73;
function setup() {
  createCanvas(640, 400);
  background(0, 0, 128);
  
  noFill();
  stroke(128);
  noLoop();
}

function draw() {
  tree(100, 200, 150, 350);
}
function mousePressed() {
  background(0, 0, 128);
  redraw();
}

function branch(x, y, dx, dy) {
  var sign = random(dx+1.0)/(abs(dx)+5.0);
  
  for (var i = 0; i <= x; i += 3) {
    var idx = i/x;
    
    var xi = bezierPoint(x, x + dx/2,   x + dx, x + dx, idx);
    var yi = bezierPoint(y, y, y + dy, y + dy, idx);

    line(xi, yi, xi + sign*random(8), yi + random(18));  
	
  }
}

function tree(left, right, top, bottom) {
  for (var idx = 0; idx < nbranchs; idx += 1) {
    
    // choose a random y position
    var y = random(bottom, top);
		
    
    // choose a random x position inside of a triangle
    var dx = map(y, bottom, top, 0.0, (right-left)/2.0);
    var x = random(left + dx, right - dx);
		
    var x1 = random(left + dx, right - dx);
    
		// choose the size of the branch according to the position on the tree
    var w = map (x, left, right, random(-25) -25, random(25)+25) + 1;
    var h = map (y, bottom, top, 5 +random(20), 5);
    
		var w1 = map (x, left, right, random(-35), random(35)) + 3;
    var h1 = map (y, bottom, top, random(10), random(10));
    // randonize the size
    var dw = random(-10, 5);
    var dh = random (-5, 5);
  	
		var dw1 = random(-5, 1);
    var dh1 = random (-1, 1);
    // create the new branch
		branch(x1, y, w1 + dw1, h1 + dh1);
		stroke(random(0),random(128),random(15));
		branch(x1, y, w1 + dw1, h1 + dh1);
		stroke(random(25),random(255),random(50));
    branch(x, y, w + dw, h + dh);
    
  }
}

Shadertoy: Modulo N and shader effects.

You can see easily how the math function modulo n affects the shaders.

These three colors are the result of the function modulo n.

You can see two vectors with two modulo ivec areas with these values: 6 and 3.

You can make changes and you see similar results.

A good math teacher can explain why this is happening.

Let me give you a hint: encryption and decryption theories.

The wrld for custom maps.

A good map can have many features.
If you don't want to build one using advanced programming language then you can use this website.
You can use this with an online map with Unity, JavaScript, iOS and Android.
You can also build your indoor map and visualize any building in 3D.
All of these features let you optimize building management, resources, and planning.
The map can have many features like time of day, weather and seasons and heat map.
The next example is an outdoor map of my location.