mat3_multiply.dart

/// Print the calculation which multiplies two 3x3 matrices.
///
/// The matrices store their elements in a flat array in column order.
void main() {
  StringBuffer buffer = new StringBuffer();
  String l = "m1";
  String r = "m2";
  for (int col in new Iterable.generate(3)) {
    for (int row in new Iterable.generate(3)) {
      buffer.writeAll([
        "$l[${0 + row}]*$r[${col * 3 + 0}]",
        "$l[${3 + row}]*$r[${col * 3 + 1}]",
        "$l[${6 + row}]*$r[${col * 3 + 2}]",
      ], " + ");
      buffer.write(",\n");
    }
  }
  print(buffer.toString());
}

/*
m1[0]*m2[0] + m1[3]*m2[1] + m1[6]*m2[2],
m1[1]*m2[0] + m1[4]*m2[1] + m1[7]*m2[2],
m1[2]*m2[0] + m1[5]*m2[1] + m1[8]*m2[2],
m1[0]*m2[3] + m1[3]*m2[4] + m1[6]*m2[5],
m1[1]*m2[3] + m1[4]*m2[4] + m1[7]*m2[5],
m1[2]*m2[3] + m1[5]*m2[4] + m1[8]*m2[5],
m1[0]*m2[6] + m1[3]*m2[7] + m1[6]*m2[8],
m1[1]*m2[6] + m1[4]*m2[7] + m1[7]*m2[8],
m1[2]*m2[6] + m1[5]*m2[7] + m1[8]*m2[8],
*/