Konva - HTML5 canvas manual route drawing solution
This is from a StackOverflow answer I made in response to a request for a way to show a route on a map with bends. In essence this is manipulation of the points array for a Konva Line object.
Konva
Posts about Konva.js, the JavaScript library adding an object model and other super powers to the HTML5 canvas lib.
Dev - HTML5 Canvas & the DOM explained, and why use a lib?
I've seen a few questions on The 'Net around how the HTML5 canvas fits into the DOM and whether canvas content can be styled via CSS - here's my explanation. I also mention a few libraries and why you would want to use them...
Members only
Konva - Star rating control
Members only
Konva - Point & shape collision detection
Thinking about shape-point collision detection in a case where there are many shapes on the stage, and how to improve performance. Here's my explanation of those functions and an possibly better approach.
Members only
Konva - making a shape fill the view
Someone asked on the Konva discord channel how to have a shape - in this case a group - be positioned and zoomed so that the shape fills the canvas view and is centered vertically and horizontally. Here's my answer...
Members only
Thinking about an approach to do-undo-redo
Coding a project that needs an undo-redo feature? Me too - here's my thinking from the end of the development on the subject based on my learnings coding a rich text editor.
Members only
Konva - Animation for HTML5 canvas
I wanted to learn about animation on the canvas so I'm making a smooth spiral animation of the first 199 words of David Bowie's 'Space Oddity' using the excellent Konva canvas library and its animation feature.
Members only
Konva - A workaround for inaccurate Path measuring via SVG
Long story short, Konvas path measuring for Path.getLength() and Path.getPointAtLength() methods are broken. The math involved is very complex and its not surprising that there are bugs. But also there's a simple and higher performance workaround so on balance its not so bad Lets take a look....
Members only