fromMat4.js
function fromMat4(out, a) {
  out[0] = a[0]
  out[1] = a[1]
  out[2] = a[2]
  out[3] = a[4]
  out[4] = a[5]
  out[5] = a[6]
  out[6] = a[8]
  out[7] = a[9]
  out[8] = a[10]
  return out
}
function fromMat4(out, a) {
  out[0] = a[0]
  out[1] = a[1]
  out[2] = a[2]
  out[3] = a[4]
  out[4] = a[5]
  out[5] = a[6]
  out[6] = a[8]
  out[7] = a[9]
  out[8] = a[10]
  return out
}
function fromMat4 ( out , a ) { out [ 0 ] = a [ 0 ] out [ 1 ] = a [ 1 ] out [ 2 ] = a [ 2 ] out [ 3 ] = a [ 4 ] out [ 4 ] = a [ 5 ] out [ 5 ] = a [ 6 ] out [ 6 ] = a [ 8 ] out [ 7 ] = a [ 9 ] out [ 8 ] = a [ 10 ] return out }
Copies the upper-left 3x3 values into the given mat3.

@alias mat3.fromMat4
@param {mat3} out the receiving 3x3 matrix
@param {mat4} a   the source 4x4 matrix
@returns {mat3} out
Copies the upper - left 3x3 values into the given mat3 .