IROX-FIXEDMATH

Fixed Precision Math Primitives

Wikipedia's article on Fixed-point arithmetic

All of the fractional components are scaled by the max value of the fractional size.

Works acceptably well:

• FixedU32 - Q16.16 - u16/u16
• FixedI32 - Q15.16 - i16/u16
  • Each fractional value represents 1/u16::MAX ~= 1.5259e-5 or 0.000_015_259, or about 15.3 micro, and can accurately represent SI-prefixes: milli/1e-3 with no loss of accuracy.
• FixedU64 - Q32.32 - u32/u32
• FixedI64 - Q31.32 - i32/u32
  • Each fractional value represents 1/u32::MAX ~= 2.328306e-10 or 0.000_000_000_238_306, or about 238.3 pico, and can accurately represent SI-prefixes milli/1e-3, micro/1e-6, and nano/1e-9 with no loss of accuracy.

Beta quality/Some known issues:

• FixedU128 - Q64.64 - u64/u64 [1]
• FixedI128 - Q63.64 - i64/u64 [1]
  • Each fractional value represents 1/u64::MAX] ~= 5.4210e-20 or 0.000_000_000_000_000_000_054_210, or about 54.2 zepto, and can accurately represent SI-prefixes milli/1e-3, micro/1e-6, nano/1e-9, pico/1e-12, femto/1e-15, and atto/1e-18 with no loss of accuracy.

[1]: Multiplication doesn't roll over properly, so FloatExt aren't supported.

No-STD support:

• Fully No-STD, No-Alloc

Cargo Features:

• None