Normal vector compression

쉐이더가 아닌 곳에서 이 방법을 쓰게 되었다. -_-ㅋ
(손실 압축)

http://www.gpwiki.org/index.php/MathGem:Color_Operations


>>
Original
   5, 4, -3

[-1:1] <- Normalieze
   0.707107, 0.565685, -0.424264

[0:1] <- Prepare to encode  { x` = (x+1)/2 }
   0.853553, 0.782843, 0.287868

Compressed Vec3       { x` = x * 255 }
   217, 199, 73

Compressed 4 BYTE
   ffd9c749

... Now restore value ...

DWORD -> 4 BYTE
   217, 199, 73

[0:1] <- Prepare to decode
   0.85098, 0.780392, 0.286275

[-1:1] <- Normalize  { x = (x`*2)-1 }
   0.701961, 0.560784, -0.427451