import type { NumberArray } from '../../types' ; param a param out param startIndex returns export function fp64ify ( a , out = [ ] , startIndex = 0 ) { const hiPart = Math . fround ( a ) ; const loPart = a - hiPart ; out [ startIndex ] = hiPart ; out [ startIndex + 1 ] = loPart ; return out ; } param a returns export function fp64LowPart ( a ) { return a - Math . fround ( a ) ; } param matrix returns export function fp64ifyMatrix4 ( matrix ) { const matrixFP64 = new Float32Array ( 32 ) ; for ( let i = 0 ; i < 4 ; ++ i ) { for ( let j = 0 ; j < 4 ; ++ j ) { const index = i * 4 + j ; fp64ify ( matrix [ j * 4 + i ] , matrixFP64 , index * 2 ) ; } } return matrixFP64 ; }