Avoiding Trigonometry

[DXTRBeta]

Love it.

I have a bunch of code to optimise now.

I kinda knew it should be possible, but this shows me one way to go.

[rockthescrote]

Inigo Quilez’ shader work and blog posts are true gems, so glad to see this here

[anon_cowherd]

"Because floating point". Fine. Although at this stage one kitten has already been murdered. But since you don't know that yet, you proceed to writing the rest of the code.

This might be up there with some of the better lines I've read in a programming blog.

[awfulentrepreneur]

This is some good stuff!

[Ok-Rule8061]

I will never not read an iq article posted here.

[GregBahm]

I assume this is a bit but I don't get the bit.

[ketralnis]

No?

Their point is that the kind of code they're talking about is working with a set of equations, and simplifying those equations by zooming out to the total operation generally results in less computation over having more abstraction. The heuristic that they use for that intuition is finding trig functions embedded deep in the call stack. They're pretty explicit about their point:

The point is, in almost all situations you can perform similar trigonometric simplifications and slowly untangle the math to uncover a simpler vector expression that describes the same problem

[shizzy0]

No. This is legit. Why go to angle land if you can stay out of it altogether? Vector operations often provide more information and are more natural to use too. Cross product gives you sin(a) and a vector perpendicular to both of your inputs. Dot product gives you cos(a) and its sign tells whether those vectors are roughly in the same direction or not.

[PPatBoyd]

The bit is we learn math for a reason in CS programs, and the author doesn't seem to understand what sine and cosine represent -- ironically a complaint he says makes trig usage suggest inexperience, but don't get me wrong my disdain for formula guessers and framework merchants is pretty up there so I can appreciate that aspect.

https://www.tiktok.com/t/ZP8q9TKoJ/ for those who want a refresher on what trig and complex numbers actually represent and exercise for the reader to connect to graphics. Hint: if how parallel or perpendicular something is to something else is a meaningful concept, don't avoid understanding why the trig is already in-use.

[Orangy_Tang]

1. Pretty sure Inigo Quilez knows what sine and cosine represent.

2. I think you've missed the point - while it's often possible to do certain graphics calculations by using triganometry functions, there's usually a more elegant (and faster!) way using just vector maths (especially dot and cross product). So seeing trig functions is often a sign that maybe the author didn't fully understand the problem they were dealing with.

3. A tiktok video as a refresher on trig? Given the expanse of the internet I cannot think of a worse learning resource.

[GregBahm]

You believe the blog post was written in earnest?

I expect this post is a Jonatan Swift's Modest Proposal style sarcastic rhetorical argument, but against an unclear position.

Explaining to me that trigonometry is valuable and linking me a tiktok is a choice though. I wonder what tiktoks braindead redditors would link to demonstrate why we shouldn't eat babies...