Converts into Adjugate matrix and scales by scale
Source
void scaleAdjoint(double scale) { // Adapted from code by Richard Carling. double a1 = _m4storage[0]; double b1 = _m4storage[4]; double c1 = _m4storage[8]; double d1 = _m4storage[12]; double a2 = _m4storage[1]; double b2 = _m4storage[5]; double c2 = _m4storage[9]; double d2 = _m4storage[13]; double a3 = _m4storage[2]; double b3 = _m4storage[6]; double c3 = _m4storage[10]; double d3 = _m4storage[14]; double a4 = _m4storage[3]; double b4 = _m4storage[7]; double c4 = _m4storage[11]; double d4 = _m4storage[15]; _m4storage[0] = (b2 * (c3 * d4 - c4 * d3) - c2 * (b3 * d4 - b4 * d3) + d2 * (b3 * c4 - b4 * c3)) * scale; _m4storage[1] = -(a2 * (c3 * d4 - c4 * d3) - c2 * (a3 * d4 - a4 * d3) + d2 * (a3 * c4 - a4 * c3)) * scale; _m4storage[2] = (a2 * (b3 * d4 - b4 * d3) - b2 * (a3 * d4 - a4 * d3) + d2 * (a3 * b4 - a4 * b3)) * scale; _m4storage[3] = -(a2 * (b3 * c4 - b4 * c3) - b2 * (a3 * c4 - a4 * c3) + c2 * (a3 * b4 - a4 * b3)) * scale; _m4storage[4] = -(b1 * (c3 * d4 - c4 * d3) - c1 * (b3 * d4 - b4 * d3) + d1 * (b3 * c4 - b4 * c3)) * scale; _m4storage[5] = (a1 * (c3 * d4 - c4 * d3) - c1 * (a3 * d4 - a4 * d3) + d1 * (a3 * c4 - a4 * c3)) * scale; _m4storage[6] = -(a1 * (b3 * d4 - b4 * d3) - b1 * (a3 * d4 - a4 * d3) + d1 * (a3 * b4 - a4 * b3)) * scale; _m4storage[7] = (a1 * (b3 * c4 - b4 * c3) - b1 * (a3 * c4 - a4 * c3) + c1 * (a3 * b4 - a4 * b3)) * scale; _m4storage[8] = (b1 * (c2 * d4 - c4 * d2) - c1 * (b2 * d4 - b4 * d2) + d1 * (b2 * c4 - b4 * c2)) * scale; _m4storage[9] = -(a1 * (c2 * d4 - c4 * d2) - c1 * (a2 * d4 - a4 * d2) + d1 * (a2 * c4 - a4 * c2)) * scale; _m4storage[10] = (a1 * (b2 * d4 - b4 * d2) - b1 * (a2 * d4 - a4 * d2) + d1 * (a2 * b4 - a4 * b2)) * scale; _m4storage[11] = -(a1 * (b2 * c4 - b4 * c2) - b1 * (a2 * c4 - a4 * c2) + c1 * (a2 * b4 - a4 * b2)) * scale; _m4storage[12] = -(b1 * (c2 * d3 - c3 * d2) - c1 * (b2 * d3 - b3 * d2) + d1 * (b2 * c3 - b3 * c2)) * scale; _m4storage[13] = (a1 * (c2 * d3 - c3 * d2) - c1 * (a2 * d3 - a3 * d2) + d1 * (a2 * c3 - a3 * c2)) * scale; _m4storage[14] = -(a1 * (b2 * d3 - b3 * d2) - b1 * (a2 * d3 - a3 * d2) + d1 * (a2 * b3 - a3 * b2)) * scale; _m4storage[15] = (a1 * (b2 * c3 - b3 * c2) - b1 * (a2 * c3 - a3 * c2) + c1 * (a2 * b3 - a3 * b2)) * scale; }