src/math-helpers.js
function scaleAndAddRow (m, srcRow, destRow, scale) {
  const me = m.elements;
  let i = destRow;
  let j = srcRow;
  let alpha = (scale === undefined ? 1.0 : scale);
  me[i] += me[j] * alpha;
  me[i + 3] += me[j + 3] * alpha;
  me[i + 6] += me[j + 6] * alpha;
}
function scaleAndAddRow (m, srcRow, destRow, scale) {
  const me = m.elements;
  let i = destRow;
  let j = srcRow;
  let alpha = (scale === undefined ? 1.0 : scale);
  me[i] += me[j] * alpha;
  me[i + 3] += me[j + 3] * alpha;
  me[i + 6] += me[j + 6] * alpha;
}
function scaleAndAddRow ( m , srcRow , destRow , scale ) { const me = m . elements ; let i = destRow ; let j = srcRow ; let alpha = ( scale === undefined ? 1.0 : scale ) ; me [ i ] += me [ j ] * alpha ; me [ i + 3 ] += me [ j + 3 ] * alpha ; me [ i + 6 ] += me [ j + 6 ] * alpha ; }
Scales and adds the source row to the destination row.
@memberof Helpers
@param {Matrix2|Matrix3|Matrix4} m The matrix.
@param {number} srcRow The original row index.
@param {number} destRow The destination row index for the sum to be in.
@param {number} scale The number to scale the source row by.
Scales and adds the source row to the destination row .