About SE-307: Is the implicit Double to CGFloat conversion a performance hit on 64 bit platforms?

[mayoff (Rob Mayoff)]

I would like to propose the SexagesimalFloatingPoint protocol and, in Swift 5⅚, change CGFloat to conform to it…

[tera]

@ksluder

some form of rational coordinates

I'd love to see fractional coordinates used in future APIs. Comparing coordinates for equality and uniform precision across the whole range of values is more important for graphics API than ability to represent values like 1e±300. Modern CPUs should be fast enough to handle it.

[ksluder (Kyle Sluder)]

@tera

Modern CPUs should be fast enough to handle it.

I suspect not. Especially when rasterizing Bézier paths. Such a system would probably require lowering to IEEE floats at some point.

[tera]

You mean it won't be possible to calculate square or cubic roots of those fractional numbers directly, or it would be too slow, or it would involve a back and forth translation between those and floats? hmm. Someone must have tried that already? Anyone knows a modern precedent?