pack.go

package main

import (
	"github.com/denysvitali/gc_log"
	"math"
)

type vec struct {
	x float64
	y float64
	z float64
	w float64
}

func clamp(v float64, minv float64, maxv float64) float64 {
	return math.Min(math.Max(v, minv), maxv)
}

func main() {
	v1 := vec{
		0, -1, 0, 0,
	}

	x := int32(math.Round(clamp(v1.x, -1.0, 1.0) * 511.0))
	y := int32(math.Round(clamp(v1.y, -1.0, 1.0) * 511.0))
	z := int32(math.Round(clamp(v1.z, -1.0, 1.0) * 511.0))
	w := int32(math.Round(clamp(v1.w, -1.0, 1.0) * 1.0))

	var packed uint32 = 0

	packed += uint32(x) & 0x3FF << 20
	packed += uint32(y) & 0x3FF << 10
	packed += uint32(z) & 0x3FF << 2
	packed += uint32(w) & 0x02 << 0

	log.Info("%v %v", []int32{x,y,z,w}, packed)

	if packed != 525312 {
		panic(packed)
	}
}