Dart Matrix

void preTranslate(Matrix4 leftMatrix, double x, double y) {
  if(x == 0 && y == 0) {
    return;
  }

  for (int i = 0; i < 4; ++i) {
    var value = leftMatrix.entry(0, i) * x + leftMatrix.entry(1, i) * y;
    value += leftMatrix.entry(2, i) + leftMatrix.entry(3, i);
    leftMatrix.setEntry( 3, i, value);
  }
}

void preScale(Matrix4 leftMatrix, double x, double y) {
  if(x == 1 && y == 1) {
    return;
  }

  for (int i = 0; i < 4; i++) {
     leftMatrix.setEntry( 0, i, leftMatrix.entry(0, i) * x);
     leftMatrix.setEntry( 1, i, leftMatrix.entry(1, i) * y);
  }

}