Guide to Get Started with Canvas animation in Angular

In this article, you learned how to use the HTML5 Canvas and its 2D graphics context. I showed how to draw simple shapes, and finally, we were able to animate multiple objects on the canvas.

#angular #canvas 
 

Guide to Get Started with Canvas animation in Angular

How to test HTML canvas with Cypress

How to test an HTML canvas? Let's see an example of visual regression testing with Cypress.

#html #canvas #cypress 

How to test HTML canvas with Cypress
Dylan  Iqbal

Dylan Iqbal

1627933500

Build a Space Game: Draw Hero and Monsters to Canvas

The Canvas

The canvas is an HTML element that by default has no content; it's a blank slate. You need to add to it by drawing on it.

Read more about the Canvas API on MDN.

Here's how it's typically declared, as part of the page's body:

<canvas id="myCanvas" width="200" height="100"></canvas>

Above we are setting the id, width and height.

  • id: set this so you can obtain a reference when you need to interact with it.
  • width: this is the width of the element.
  • height: this is the height of the element.

Drawing simple geometry

The Canvas is using a cartesian coordinate system to draw things. Thus it uses an x-axis and y-axis to express where something is located. The location 0,0 is the top left position and the bottom right is what you said to be the WIDTH and HEIGHT of the canvas.

the canvas's grid

Image from MDN

To draw on the canvas element you will need to go through the following steps:

  1. Get a reference to the Canvas element.
  2. Get a reference on the Context element that sits on the canvas element.
  3. Perform a drawing operation using the context element.

Code for the above steps usually looks like so:

// draws a red rectangle
//1. get the canvas reference
canvas = document.getElementById("myCanvas");

//2. set the context to 2D to draw basic shapes
ctx = canvas.getContext("2d");

//3. fill it with the color red
ctx.fillStyle = 'red';

//4. and draw a rectangle with these parameters, setting location and size
ctx.fillRect(0,0, 200, 200) // x,y,width, height

The Canvas API mostly focuses on 2D shapes, but you can also draw 3D elements to a web site; for this, you might use the WebGL API.

You can draw all sorts of things with the Canvas API like:

  • Geometrical shapes, we've already showed how to draw a rectangle, but there is much more you can draw.
  • Text, you can draw a text with any font and color you wish.
  • Images, you can draw an image based off of an image asset like a .jpg or .png for example.

Try it! You know how to draw a rectangle, can you draw a circle to a page? Take a look at some interesting Canvas drawings on CodePen. Here's a particularly impressive example.

Load and draw an image asset

You load an image asset by creating an Image object and set its src property. Then you listen to the load event to know when it's ready to be used. The code looks like this:

Load asset

const img = new Image();
img.src = 'path/to/my/image.png';
img.onload = () => {
  // image loaded and ready to be used
}

Load asset pattern

It's recommended to wrap the above in a construct like so, so it's easier to use and you only try to manipulate it when it's fully loaded:

function loadAsset(path) {
  return new Promise((resolve) => {
    const img = new Image();
    img.src = path;
    img.onload = () => {
      // image loaded and ready to be used
      resolve(img);
    }
  })
}

// use like so

async function run() {
  const heroImg = await loadAsset('hero.png')
  const monsterImg = await loadAsset('monster.png')
}

To draw game assets to a screen, your code would look like this:

async function run() {
  const heroImg = await loadAsset('hero.png')
  const monsterImg = await loadAsset('monster.png')

  canvas = document.getElementById("myCanvas");
  ctx = canvas.getContext("2d");
  ctx.drawImage(heroImg, canvas.width/2,canvas.height/2);
  ctx.drawImage(monsterImg, 0,0);
}

Now it's time to start building your game

What to build

You will build a web page with a Canvas element. It should render a black screen 1024*768. We've provided you with two images:

Hero ship

Hero ship

5*5 monster

Monster ship

Recommended steps to start development

Locate the files that have been created for you in the your-work sub folder. It should contain the following:

-| assets
  -| enemyShip.png
  -| player.png
-| index.html
-| app.js
-| package.json

Open the copy of this folder in Visual Studio Code. You need to have a local development environment setup, preferably with Visual Studio Code with NPM and Node installed. If you don't have npm set up on your computer, here's how to do that.

Start your project by navigating to the your_work folder:

cd your-work
npm start

The above will start a HTTP Server on address http://localhost:5000. Open up a browser and input that address. It's a blank page right now, but that will change

Note: to see changes on your screen, refresh your browser.

Add code

Add the needed code to your-work/app.js to solve the below

Draw a canvas with black background

tip: add two lines under the appropriate TODO in /app.js, setting the ctx element to be black and the top/left coordinates to be at 0,0 and the height and width to equal that of the canvas.

Load textures

tip: add the player and enemy images using await loadTexture and passing in the image path. You won't see them on the screen yet!

Draw hero in the center of the screen in the bottom half

tip: use the drawImage API to draw heroImg to the screen, setting canvas.width / 2 - 45 and canvas.height - canvas.height / 4);

Draw 5*5 monsters

tip: Now you can uncomment the code to draw enemies on the screen. Next, go to the createEnemies function and build it out.

First, set up some constants:

const MONSTER_TOTAL = 5;
const MONSTER_WIDTH = MONSTER_TOTAL * 98;
const START_X = (canvas.width - MONSTER_WIDTH) / 2;
const STOP_X = START_X + MONSTER_WIDTH;

then, create a loop to draw the array of monsters onto the screen:

for (let x = START_X; x < STOP_X; x += 98) {
    for (let y = 0; y < 50 * 5; y += 50) {
      ctx.drawImage(enemyImg, x, y);
    }
  }

Result

The finished result should look like so:

Black screen with a hero and 5*5 monsters

Solution

Please try solving it yourself first but if you get stuck, have a look at a solution

Challenge

You've learned about drawing with the 2D-focused Canvas API; take a look at the WebGL API, and try to draw a 3D object.

Post-Lecture Quiz

Post-lecture quiz

Review & Self Study

Learn more about the Canvas API by reading about it.

Assignment

Play with the Canvas API

Originally published at https://github.com/microsoft/Web-Dev-For-Beginners/blob/main/6-space-game/2-drawing-to-canvas/README.md 

#gamedev #html #canvas

 

 

Build a Space Game: Draw Hero and Monsters to Canvas
Sherman  Zemlak

Sherman Zemlak

1627135920

PART II: Coding JavaScript Snake Game (Plain Vanilla JavaScript & HTML Canvas)

Learn how to build a the iconic Snake game using JavaScript in the browser! We will be using plain vanilla JS to code this fun game. This is the second part in a two part series of how to make a snake game in the browser using vanilla JavaScript.

We use an object orientated approach to build the snake game using javascript. Follow along as we create this iconic game.

PART 1: https://www.youtube.com/watch?v=21eSpMtJwrc

Code on GitHub: https://github.com/kriscfoster/Snake-Game

Don’t forget to Subscribe here: https://www.youtube.com/channel/UCWkzkhQ3syxBjjAYwqCbzYg?sub_confirmation=1

#javascript #html #canvas

PART II: Coding JavaScript Snake Game (Plain Vanilla JavaScript & HTML Canvas)
Helene  Ward

Helene Ward

1626835200

Building A Drawing App using Canvas & ReactJS - Manoj Singh Negi - Recraft Relic

Building a drawing app using Canvas & ReactJS

React

Canvas

Additional information

#reactjs #react #recraft relic #canvas

Building A Drawing App using Canvas & ReactJS - Manoj Singh Negi - Recraft Relic
Gail  Wilderman

Gail Wilderman

1626241244

Starting A Software Business From Scratch - 6 Practical Tips

Six practical tips to launch a software company from scratch - this video will become part of my complete software startup guide.

More information about the Business Model Canvas and the other books I refer to:

My gear:
📷 Sony A7C - https://amzn.to/3aShCtw
🎙 Rode Wireless GO - https://amzn.to/3pSLFVU
💡 GVM RGB LED light - https://amzn.to/3qRNJid
💡 GVM 100W light with lantern softbox - https://amzn.to/2NuU8lk

☕If you want to support this channel, you can buy me a coffee here: https://www.buymeacoffee.com/arjancodes.

If you enjoyed this content, give this video a like. If you want to watch more of my upcoming videos, consider subscribing to my channel!

DISCLAIMER - The links in this description might be affiliate links. If you purchase a product or service through one of those links, I may receive a small commission. There is no additional charge to you. Thanks for supporting my channel so I can continue to provide you with free content each week!

#scratch #software #canvas

Starting A Software Business From Scratch - 6 Practical Tips

Business Model Canvas: How to Create your Startup Outline

This demonstration of a business model was proposed by business theorist Alexander Osterwalder and professor at the University of Lausanne, Yves Pigneur. They analyzed the work of many business experts and consolidated their ideas into one framework. They called it the Business Model Canvas.

Here’s how it works.

0:00 Y-Combinator and startup culture
0:50 Explaining a Business Model Canvas
3:08 Customer Segments
3:56 Value Propositions
4:38 Channels
5:19 Customer Relationships
6:25 Revenue Streams
7:01 Key Resources
7:39 Key Activities
8:06 Key Partnerships
8:48 Cost Structure
9:48 The finished canvas

Learn more about AltexSoft: https://www.altexsoft.com
Follow us on LinkedIn: https://www.linkedin.com/company/altexsoft/mycompany/
Follow us on Facebook: https://www.facebook.com/altexsoft/
Follow us on Twitter: https://twitter.com/AltexSoft
Follow us on Instagram: https://www.instagram.com/altexsoftcom/

Sources:

[ 1 ] https://techcrunch.com/2019/10/02/these-are-the-top-y-combinator-companies-of-all-time-based-on-valuation/?guccounter=1&guce_referrer=aHR0cHM6Ly93d3cuZ29vZ2xlLmNvbS8&guce_referrer_sig=AQAAAEL4g-JnddXodEhQ-x_g1AurfzoZwcxMitvCBQ-64_L4fV2dzl3eVkT9qC9klL3QXRnMV2Ki9S4lbwMhwURynxmLZFu2PkofM3ylZsUyqr_w8uWxJfFfwOrYEaCZL4MsVcbJizcMXrzRsaBDAoiIG-oYsOStnFY0LuTLv4wVJ_hO
[ 2 ] https://www.ycombinator.com/faq/
[ 3 ] https://www.wsj.com/articles/SB973617475136917228
[ 4 ] https://www.fool.com/investing/2019/07/08/why-did-apple-just-pay-samsung-nearly-700-million.aspx

Music by Blue Dot Sessions (www.sessions.blue) :

Anders by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Master by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Winter Theme by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Anders by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Planting Flags by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

A Path Unwinding by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Slow Toe by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Bouncing by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

The Provisions by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Pat Dog by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

BurrowBurrow by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Darn That Weasel by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Spank Lit by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Theme by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Rabbit Hole by Blue Dot Sessions is licensed under a Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/).

Video footages by Videvo

#canvas

Business Model Canvas: How to Create your Startup Outline
Kabanda  Nat

Kabanda Nat

1624269978

Techniques for Animating on the Canvas in React

A lot of building with React is about maintaining the state of the view. The first time I animated something on a canvas in React I held the state and the code to draw it in the same component. After browsing examples online, I came across this rotating square on CodePen. What I really liked about this example was the way the state was separated from the drawing with the use of two components. The state of the drawing was then passed from the animating component to the drawing component through props.

I recreated the original to show the separation.

#web dev #react #animating #canvas #techniques

Techniques for Animating on the Canvas in React

How to get started coding in JavaScript & Canvas

In today’s video, We will show you how to get started coding in JavaScript & Canvas . Create a jumping red square using just JavaScript & Canvas!

Code: https://github.com/morganpage/red-jumper

Subscribe:https://www.youtube.com/c/MorganPageTech/featured

#javascript #canvas

How to get started coding in JavaScript & Canvas
Code  JS

Code JS

1623623460

2D Animations with Canvas and JavaScript

Learn how to draw onto a canvas element with JavaScript and animate the drawings.

Code example here: https://github.com/shama/letswritecod…

Subscribe: https://www.youtube.com/c/kylerobinsonyoung/featured

#javascript #canvas

2D Animations with Canvas and JavaScript
Sarai  Thompson

Sarai Thompson

1623124380

How to Draw and Animate Objects using HTML5 Canvas and JavaScript

I love playing games. And I love coding too. So, one day, I got thinking, why not use those coding skills to make a game? But it sounds hard. How would one even get started?

With baby steps.

In this article, you’ll learn to draw and animate objects using HTML5 Canvas and JavaScript before we optimize for performance.

“Animation is not the art of drawings that move but the art of movements that are drawn.” — Norman McLaren

Here’s what we’ll cover today:

#html5 #canvas #javascript #game-development

How to Draw and Animate Objects using HTML5 Canvas and JavaScript

Automated Heatmap Verification E2E using Selenium and Canvas

What is a heatmap?

Heatmaps are a powerful way to understand what users do on your website pages — where they click, how far they scroll, what they look at or ignore.

heat map shows a color-coded overlay of mouse (and tap) movement on a single website page. The ‘popularity’ of page elements is displayed using a color scale from red (the most popular parts of the page) to blue (the least-used parts of a page).

How to Verify Heatmap Plotting Service via Automation?

How to check if clicks are being plotted correctly? How to check if there is no data loss while plotting the clicks? How can we verify that our Heatmap service is working as expected?

The answer to the above questions is HTML Canvas. As in general heatmaps are rendered on HTML canvas, we can leverage that to verify Heatmap plotting via Selenium or any other Automation tool. The best part of using Canvas is that it can be integrated easily with your existing Automation scripts.

How can we use Canvas for Heatmap Automation?

There are two phases in order to verify the Heatmap Plotting via Automation.

Phase 1

The first phase is to perform clicks on the page on which we want to test Heatmap Plotting and store the click coordinates i.e. the point where we have performed the clicks. This can be easily done using Selenium or any other automation tool.

Performing Clicks on the Page and Storing the Coordinate Data

Over here, we are clicking on the element, getting its location from the top of the DOM, get the element size, and based on that we can find the center coordinates of the element w.r.t. the DOM. We push the coordinates extracted to the clickDataArray and after we have clicked on all elements, we can push the clickDataArray into a CSV or a JSON file.

If you want to click randomly on a page and not on a specific web element, that can also be done by getting the DOM height and width, and use that to generate a random X, Y coordinate and similarly to the code above we can push the coordinates into an array and then push them into a CSV or a JSON.

Phase 2

The second phase is to leverage canvas functions and the coordinate data stored in Phase 1 in order to verify if heatmaps are plotted correctly.

Over here, we first of all check if heatmap canvas is empty, and if the canvas is empty, we should not check further as Canvas being empty means that Heatmap plotting hasn’t worked.

#heatmap #automation #selenium #canvas

Automated Heatmap Verification E2E using Selenium and Canvas

Faizal Ghazali

1622778419

Javascript Drawing App Using the HTML5 Canvas Element

In this video, you’ll create a Javascript drawing app using HTML5, the canvas element, and JavaScript. Mark will review the code line by line and demonstrate the HTML canvas drawing app. You’ll learn to use JavaScript to draw on the Canvas element as well as clearing the canvas and saving the canvas drawings.

Download the code at https://social.frameworktv.com/finger…

Subscribe: https://www.youtube.com/c/FrameworkTechMedia/featured

#javascript #html5 #canvas

Javascript Drawing App Using the HTML5 Canvas Element

The Future Web: Will Canvas Rendering Replace the DOM?

markup we’re seeing, and review the CSS that styles it. But all these aspects of web development may be nothing more than a brief and transient anomaly in the history of software design.

So what happens now?

The canvas rendering approach will spread

There’s a saying: Where Google goes, others follow.

Roughly 15 years ago, Google was a trailblazer with asynchronous JavaScript calls (then called AJAX). They pioneered techniques for Gmail and Google Maps that later became a foundational part of web development. Now, Google’s shift to drawing UI on a canvas will legitimatize the approach for a new generation of web developers.

Currently, using canvas rendering forces you to clear a fairly high bar. Along the way to building Google Docs, Google has reimplemented huge swaths of functionality that most programmers take for granted, such as features for precise layout, text selection, spell checking, and optimized repainting. Today, there are only a few companies in the world that would undertake a similar task just to eke out a potential performance improvement.

The biggest challenge is accessibility. In order to comply with accessibility regulations (necessary to be a government vendor, like Google, and also important just to be a good web citizen), your application needs to meet specific requirements. The canvas-based version of Google Docs still needs to give first-class support for screen readers, screen magnifiers, high-contrast settings, and low-dexterity features. One way they do that is by implementing an invisible DOM that shadows the real canvas-rendered content, but exists only to inform assistive tools. And of course these two models need to be kept perfectly in sync.

#html5 #google #programming #canvas #dom

The Future Web: Will Canvas Rendering Replace the DOM?
Tyrique  Littel

Tyrique Littel

1620718500

Using SVG vs. Canvas: A Short Guide

Canvas and SVG allow web developers to draw images onto the screen, but they have very different APIs and approaches to doing so.

So, you need to add some charts to your app or site? By now you’ve figured out that there are many different ways to accomplish this, most of which utilize one of two primary technologies: SVG and the Canvas API.

In order to decide which will best fit your needs, we need to look at SVG’s and Canvas’s relative strengths and weaknesses and how those play into the different chart-drawing solutions available.

Canvas and SVG are both technologies that allow web developers to draw images onto the screen, but they have very different APIs and approaches to doing so.

What is SVG?

SVG stands for “scalable vector graphics” and represents a body of standards for declaratively defining the properties of an image (things like the shapes themselves, fill color, stroke color, and the like).

<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg">
  <circle cx="50" cy="50" r="45" fill="#FFA69E" />
</svg>

Simple SVG Circle Result

SVG images are created either inline with HTML code by adding an <svg> tag, or can be defined in separate files (with the .svg extension) and referenced in the HTML.

What is Canvas?

Canvas is a lower-level browser standard API that allows developers to imperatively “draw” directly onto the image by issuing a series of commands:

const canvas = document.querySelector('canvas');
const ctx = canvas.getContext('2d');
ctx.fillStyle = '#FFA69E';
ctx.arc(50, 50, 45, 0, 2 * Math.PI);
ctx.fill();

Simple Canvas Circle Result

Canvas images are created by adding a <canvas> element to the HTML and then manipulating that element via the JavaScript DOM API as shown above.

#svg #canvas #web-development #javascript

Using SVG vs. Canvas: A Short Guide