In the Electrical Potential lesson, you have a super cool Scalar Field simulation. I noticed you were doing some tricks to get it to render quickly, like rendering at a lower resolution while animating. I do a lot of HTML canvas work, so I figured I'd take a crack at implementing something like it, to see if I could improve the render performance.
• (Small Improvement) When updating the particle positions (your physicsAll function), you can skip a bunch of loop iterations and redundant distance math by using j > i rather than i != j, and updating both particles together: https://github.com/ivanreese/electrons/blob/8b21d1cf8c80e16c...
• (Big Improvement) Rather than using fillRect to draw each square of the scalarField, manipulate the canvas pixel data directly. Use context.getImageData() to get a ByteArray, then loop through it and update the color in each pixel. Much faster than using fills when you want to color every pixel in the canvas independently: https://github.com/ivanreese/electrons/blob/8b21d1cf8c80e16c...
• (Aesthetic Improvement) I also render at a lower resolution, and I use the CSS blur filter to smooth out the result: canvas { filter: blur(4px) }
I hope some of these suggestions are helpful. None of them require switching to a new rendering technology (like WebGL), and it should be pretty easy to slot them in to your existing code. Feel free to drop me a line if you'd like help implementing anything.
Last but not least, thanks for creating this fantastic educational resource! I work for a learning media company that produces some electrical content, and I shared your work with my teammates as an example of what we could aspire to. It was a real hit.
I just want to say comments like these make me very happy. It really captures a kind of 'hacker spirit' that I try to be part of (and not just when it comes to programming). Thanks!
thanks! This is great! I'm going to work on implementing these changes. The context.getImageData() might enable me to improve some other simulations as well.
Here's what I came up with: http://electrons.surge.sh
• (Small Improvement) When updating the particle positions (your physicsAll function), you can skip a bunch of loop iterations and redundant distance math by using j > i rather than i != j, and updating both particles together: https://github.com/ivanreese/electrons/blob/8b21d1cf8c80e16c...
• (Big Improvement) Rather than using fillRect to draw each square of the scalarField, manipulate the canvas pixel data directly. Use context.getImageData() to get a ByteArray, then loop through it and update the color in each pixel. Much faster than using fills when you want to color every pixel in the canvas independently: https://github.com/ivanreese/electrons/blob/8b21d1cf8c80e16c...
• (Aesthetic Improvement) I also render at a lower resolution, and I use the CSS blur filter to smooth out the result: canvas { filter: blur(4px) }
I hope some of these suggestions are helpful. None of them require switching to a new rendering technology (like WebGL), and it should be pretty easy to slot them in to your existing code. Feel free to drop me a line if you'd like help implementing anything.
Last but not least, thanks for creating this fantastic educational resource! I work for a learning media company that produces some electrical content, and I shared your work with my teammates as an example of what we could aspire to. It was a real hit.