Posts about Konva.js, the JavaScript library adding an object model and other super powers to the HTML5 canvas lib.
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.