pointerpointer.com's use of voronoi, canvas, and javascript
Why Hacker News recommends it
HN links it as the author's own breakdown of Pointer Pointer's inner workings.
What it is
Paul Irish explains how pointerpointer.com works. It uses a hidden canvas of colored Voronoi regions to look up which photo matches the cursor position.
Recommended by 1 HN commenters across 1 different months, 2012 to 2025.
What Hacker News said
Recommends Conlectus · 2020-12 · on “Pointer Pointer (2012)”
Here's a picture of all the different regions: [LINK] For those curious if how it works, Paul Irish did a breakdown of it quite a while ago: [this video] TL:DW - Vornoi Diagrams[1] and manual tagging, no machine learning needed. [1] [LINK]
Cites paulirish · 2012-06 · on “PointerPointer: points to your cursor”
I made a quick video explaining how the webapp works: [this video] Essentially, using the gridPositions.json to populate a Voronoi Grid (toggle display of the <canvas> in your browser). Then your cursor position is used against the grid to find which shape encloses it which maps back to the source JPEG which is then displayed.
Cites petercooper · 2025-10 · on “Pointer Pointer (2012)”
Paul Irish explained the basics of how it works here: [this video] I wonder if you could create something similar nowadays using generative AI but with the finger in a very specific location without pregenerating thousands of images.