Posts about Konva.js, the JavaScript library adding an object model and other super powers to the HTML5 canvas lib.
I needed some niche automated testing for my keyboard and mouse handler for a canvas-focussed rich text editor control I'm working on. I have to mock a series of user actions and run multiple tests. I had to go DIY - here's what I made...
I’ve seen experienced devs crash and burn on the differences between working with the HTML5 canvas element and the HTML DOM. Here’s some short-cut learnings to help you refactor your brain the canvas way and keep you moving...
Users expect graphics apps to have a background - this gives them a sense of the shapes relationships and scale. This ingenious solution was proposed by @Kristofer[Borgware] and uses fillPatternImage to make an infinite background.
As the ClearScript faqtorial says ‘ClearScript is a library that allows you to add scripting to your .NET applications’. So – if you need to provide a scripting facility in your C# app then ClearScript might be an option. What can it do?
You can get the pixels color values from any part of your canvas. What you get is an array that doesn't have any obvious correlation to the width and height of the area you requested. What gives and how can you iterate through what you got?
It's easy to find out that to flip an image we can set the scaleX or Y to -1. But there's a problem here because images are based on the rect and have their origin at (0, 0). To make a proper in-place flip we have a little more work to do. Lets take a look...
A common use-case has rulers along the edges of the view to help users position shapes accurately. But how can we set the size of these rulers with unknown stage size? Here is a solution for optimised infinite rulers.