+ // note: orientation does not matter, as transpose(invert(transpose(m))) == invert(m), proof:
+ // transpose(invert(transpose(m))) * m
+ // = transpose(invert(transpose(m))) * transpose(transpose(m))
+ // = transpose(transpose(m) * invert(transpose(m)))
+ // = transpose(identity)
+ // = identity
+
+ // this seems to help gcc's common subexpression elimination, and also makes the code look nicer
+ float m00 = in1->m[0][0], m01 = in1->m[0][1], m02 = in1->m[0][2], m03 = in1->m[0][3],
+ m10 = in1->m[1][0], m11 = in1->m[1][1], m12 = in1->m[1][2], m13 = in1->m[1][3],
+ m20 = in1->m[2][0], m21 = in1->m[2][1], m22 = in1->m[2][2], m23 = in1->m[2][3],
+ m30 = in1->m[3][0], m31 = in1->m[3][1], m32 = in1->m[3][2], m33 = in1->m[3][3];
+
+ // calculate the adjoint
+ out->m[0][0] = (m11*(m22*m33 - m23*m32) - m21*(m12*m33 - m13*m32) + m31*(m12*m23 - m13*m22));
+ out->m[0][1] = -(m01*(m22*m33 - m23*m32) - m21*(m02*m33 - m03*m32) + m31*(m02*m23 - m03*m22));
+ out->m[0][2] = (m01*(m12*m33 - m13*m32) - m11*(m02*m33 - m03*m32) + m31*(m02*m13 - m03*m12));
+ out->m[0][3] = -(m01*(m12*m23 - m13*m22) - m11*(m02*m23 - m03*m22) + m21*(m02*m13 - m03*m12));
+ out->m[1][0] = -(m10*(m22*m33 - m23*m32) - m20*(m12*m33 - m13*m32) + m30*(m12*m23 - m13*m22));
+ out->m[1][1] = (m00*(m22*m33 - m23*m32) - m20*(m02*m33 - m03*m32) + m30*(m02*m23 - m03*m22));
+ out->m[1][2] = -(m00*(m12*m33 - m13*m32) - m10*(m02*m33 - m03*m32) + m30*(m02*m13 - m03*m12));
+ out->m[1][3] = (m00*(m12*m23 - m13*m22) - m10*(m02*m23 - m03*m22) + m20*(m02*m13 - m03*m12));
+ out->m[2][0] = (m10*(m21*m33 - m23*m31) - m20*(m11*m33 - m13*m31) + m30*(m11*m23 - m13*m21));
+ out->m[2][1] = -(m00*(m21*m33 - m23*m31) - m20*(m01*m33 - m03*m31) + m30*(m01*m23 - m03*m21));
+ out->m[2][2] = (m00*(m11*m33 - m13*m31) - m10*(m01*m33 - m03*m31) + m30*(m01*m13 - m03*m11));
+ out->m[2][3] = -(m00*(m11*m23 - m13*m21) - m10*(m01*m23 - m03*m21) + m20*(m01*m13 - m03*m11));
+ out->m[3][0] = -(m10*(m21*m32 - m22*m31) - m20*(m11*m32 - m12*m31) + m30*(m11*m22 - m12*m21));
+ out->m[3][1] = (m00*(m21*m32 - m22*m31) - m20*(m01*m32 - m02*m31) + m30*(m01*m22 - m02*m21));
+ out->m[3][2] = -(m00*(m11*m32 - m12*m31) - m10*(m01*m32 - m02*m31) + m30*(m01*m12 - m02*m11));
+ out->m[3][3] = (m00*(m11*m22 - m12*m21) - m10*(m01*m22 - m02*m21) + m20*(m01*m12 - m02*m11));
+
+ // calculate the determinant (as inverse == 1/det * adjoint, adjoint * m == identity * det, so this calculates the det)
+ det = m00*out->m[0][0] + m10*out->m[0][1] + m20*out->m[0][2] + m30*out->m[0][3];
+ if (det == 0.0f)
+ return 0;
+
+ // multiplications are faster than divisions, usually
+ det = 1.0f / det;
+
+ // manually unrolled loop to multiply all matrix elements by 1/det
+ out->m[0][0] *= det; out->m[0][1] *= det; out->m[0][2] *= det; out->m[0][3] *= det;
+ out->m[1][0] *= det; out->m[1][1] *= det; out->m[1][2] *= det; out->m[1][3] *= det;
+ out->m[2][0] *= det; out->m[2][1] *= det; out->m[2][2] *= det; out->m[2][3] *= det;
+ out->m[3][0] *= det; out->m[3][1] *= det; out->m[3][2] *= det; out->m[3][3] *= det;
+
+ return 1;
+}
+#elif 1
+// Adapted from code contributed to Mesa by David Moore (Mesa 7.6 under SGI Free License B - which is MIT/X11-type)
+int Matrix4x4_Invert_Full (matrix4x4_t *out, const matrix4x4_t *in1)
+{
+ matrix4x4_t temp;
+ double det;
+ int i, j;
+
+#ifdef MATRIX4x4_OPENGLORIENTATION
+ temp.m[0][0] = in1->m[1][1]*in1->m[2][2]*in1->m[3][3] - in1->m[1][1]*in1->m[2][3]*in1->m[3][2] - in1->m[2][1]*in1->m[1][2]*in1->m[3][3] + in1->m[2][1]*in1->m[1][3]*in1->m[3][2] + in1->m[3][1]*in1->m[1][2]*in1->m[2][3] - in1->m[3][1]*in1->m[1][3]*in1->m[2][2];
+ temp.m[1][0] = -in1->m[1][0]*in1->m[2][2]*in1->m[3][3] + in1->m[1][0]*in1->m[2][3]*in1->m[3][2] + in1->m[2][0]*in1->m[1][2]*in1->m[3][3] - in1->m[2][0]*in1->m[1][3]*in1->m[3][2] - in1->m[3][0]*in1->m[1][2]*in1->m[2][3] + in1->m[3][0]*in1->m[1][3]*in1->m[2][2];
+ temp.m[2][0] = in1->m[1][0]*in1->m[2][1]*in1->m[3][3] - in1->m[1][0]*in1->m[2][3]*in1->m[3][1] - in1->m[2][0]*in1->m[1][1]*in1->m[3][3] + in1->m[2][0]*in1->m[1][3]*in1->m[3][1] + in1->m[3][0]*in1->m[1][1]*in1->m[2][3] - in1->m[3][0]*in1->m[1][3]*in1->m[2][1];
+ temp.m[3][0] = -in1->m[1][0]*in1->m[2][1]*in1->m[3][2] + in1->m[1][0]*in1->m[2][2]*in1->m[3][1] + in1->m[2][0]*in1->m[1][1]*in1->m[3][2] - in1->m[2][0]*in1->m[1][2]*in1->m[3][1] - in1->m[3][0]*in1->m[1][1]*in1->m[2][2] + in1->m[3][0]*in1->m[1][2]*in1->m[2][1];
+ temp.m[0][1] = -in1->m[0][1]*in1->m[2][2]*in1->m[3][3] + in1->m[0][1]*in1->m[2][3]*in1->m[3][2] + in1->m[2][1]*in1->m[0][2]*in1->m[3][3] - in1->m[2][1]*in1->m[0][3]*in1->m[3][2] - in1->m[3][1]*in1->m[0][2]*in1->m[2][3] + in1->m[3][1]*in1->m[0][3]*in1->m[2][2];
+ temp.m[1][1] = in1->m[0][0]*in1->m[2][2]*in1->m[3][3] - in1->m[0][0]*in1->m[2][3]*in1->m[3][2] - in1->m[2][0]*in1->m[0][2]*in1->m[3][3] + in1->m[2][0]*in1->m[0][3]*in1->m[3][2] + in1->m[3][0]*in1->m[0][2]*in1->m[2][3] - in1->m[3][0]*in1->m[0][3]*in1->m[2][2];
+ temp.m[2][1] = -in1->m[0][0]*in1->m[2][1]*in1->m[3][3] + in1->m[0][0]*in1->m[2][3]*in1->m[3][1] + in1->m[2][0]*in1->m[0][1]*in1->m[3][3] - in1->m[2][0]*in1->m[0][3]*in1->m[3][1] - in1->m[3][0]*in1->m[0][1]*in1->m[2][3] + in1->m[3][0]*in1->m[0][3]*in1->m[2][1];
+ temp.m[3][1] = in1->m[0][0]*in1->m[2][1]*in1->m[3][2] - in1->m[0][0]*in1->m[2][2]*in1->m[3][1] - in1->m[2][0]*in1->m[0][1]*in1->m[3][2] + in1->m[2][0]*in1->m[0][2]*in1->m[3][1] + in1->m[3][0]*in1->m[0][1]*in1->m[2][2] - in1->m[3][0]*in1->m[0][2]*in1->m[2][1];
+ temp.m[0][2] = in1->m[0][1]*in1->m[1][2]*in1->m[3][3] - in1->m[0][1]*in1->m[1][3]*in1->m[3][2] - in1->m[1][1]*in1->m[0][2]*in1->m[3][3] + in1->m[1][1]*in1->m[0][3]*in1->m[3][2] + in1->m[3][1]*in1->m[0][2]*in1->m[1][3] - in1->m[3][1]*in1->m[0][3]*in1->m[1][2];
+ temp.m[1][2] = -in1->m[0][0]*in1->m[1][2]*in1->m[3][3] + in1->m[0][0]*in1->m[1][3]*in1->m[3][2] + in1->m[1][0]*in1->m[0][2]*in1->m[3][3] - in1->m[1][0]*in1->m[0][3]*in1->m[3][2] - in1->m[3][0]*in1->m[0][2]*in1->m[1][3] + in1->m[3][0]*in1->m[0][3]*in1->m[1][2];
+ temp.m[2][2] = in1->m[0][0]*in1->m[1][1]*in1->m[3][3] - in1->m[0][0]*in1->m[1][3]*in1->m[3][1] - in1->m[1][0]*in1->m[0][1]*in1->m[3][3] + in1->m[1][0]*in1->m[0][3]*in1->m[3][1] + in1->m[3][0]*in1->m[0][1]*in1->m[1][3] - in1->m[3][0]*in1->m[0][3]*in1->m[1][1];
+ temp.m[3][2] = -in1->m[0][0]*in1->m[1][1]*in1->m[3][2] + in1->m[0][0]*in1->m[1][2]*in1->m[3][1] + in1->m[1][0]*in1->m[0][1]*in1->m[3][2] - in1->m[1][0]*in1->m[0][2]*in1->m[3][1] - in1->m[3][0]*in1->m[0][1]*in1->m[1][2] + in1->m[3][0]*in1->m[0][2]*in1->m[1][1];
+ temp.m[0][3] = -in1->m[0][1]*in1->m[1][2]*in1->m[2][3] + in1->m[0][1]*in1->m[1][3]*in1->m[2][2] + in1->m[1][1]*in1->m[0][2]*in1->m[2][3] - in1->m[1][1]*in1->m[0][3]*in1->m[2][2] - in1->m[2][1]*in1->m[0][2]*in1->m[1][3] + in1->m[2][1]*in1->m[0][3]*in1->m[1][2];
+ temp.m[1][3] = in1->m[0][0]*in1->m[1][2]*in1->m[2][3] - in1->m[0][0]*in1->m[1][3]*in1->m[2][2] - in1->m[1][0]*in1->m[0][2]*in1->m[2][3] + in1->m[1][0]*in1->m[0][3]*in1->m[2][2] + in1->m[2][0]*in1->m[0][2]*in1->m[1][3] - in1->m[2][0]*in1->m[0][3]*in1->m[1][2];
+ temp.m[2][3] = -in1->m[0][0]*in1->m[1][1]*in1->m[2][3] + in1->m[0][0]*in1->m[1][3]*in1->m[2][1] + in1->m[1][0]*in1->m[0][1]*in1->m[2][3] - in1->m[1][0]*in1->m[0][3]*in1->m[2][1] - in1->m[2][0]*in1->m[0][1]*in1->m[1][3] + in1->m[2][0]*in1->m[0][3]*in1->m[1][1];
+ temp.m[3][3] = in1->m[0][0]*in1->m[1][1]*in1->m[2][2] - in1->m[0][0]*in1->m[1][2]*in1->m[2][1] - in1->m[1][0]*in1->m[0][1]*in1->m[2][2] + in1->m[1][0]*in1->m[0][2]*in1->m[2][1] + in1->m[2][0]*in1->m[0][1]*in1->m[1][2] - in1->m[2][0]*in1->m[0][2]*in1->m[1][1];
+#else
+ temp.m[0][0] = in1->m[1][1]*in1->m[2][2]*in1->m[3][3] - in1->m[1][1]*in1->m[3][2]*in1->m[2][3] - in1->m[1][2]*in1->m[2][1]*in1->m[3][3] + in1->m[1][2]*in1->m[3][1]*in1->m[2][3] + in1->m[1][3]*in1->m[2][1]*in1->m[3][2] - in1->m[1][3]*in1->m[3][1]*in1->m[2][2];
+ temp.m[0][1] = -in1->m[0][1]*in1->m[2][2]*in1->m[3][3] + in1->m[0][1]*in1->m[3][2]*in1->m[2][3] + in1->m[0][2]*in1->m[2][1]*in1->m[3][3] - in1->m[0][2]*in1->m[3][1]*in1->m[2][3] - in1->m[0][3]*in1->m[2][1]*in1->m[3][2] + in1->m[0][3]*in1->m[3][1]*in1->m[2][2];
+ temp.m[0][2] = in1->m[0][1]*in1->m[1][2]*in1->m[3][3] - in1->m[0][1]*in1->m[3][2]*in1->m[1][3] - in1->m[0][2]*in1->m[1][1]*in1->m[3][3] + in1->m[0][2]*in1->m[3][1]*in1->m[1][3] + in1->m[0][3]*in1->m[1][1]*in1->m[3][2] - in1->m[0][3]*in1->m[3][1]*in1->m[1][2];
+ temp.m[0][3] = -in1->m[0][1]*in1->m[1][2]*in1->m[2][3] + in1->m[0][1]*in1->m[2][2]*in1->m[1][3] + in1->m[0][2]*in1->m[1][1]*in1->m[2][3] - in1->m[0][2]*in1->m[2][1]*in1->m[1][3] - in1->m[0][3]*in1->m[1][1]*in1->m[2][2] + in1->m[0][3]*in1->m[2][1]*in1->m[1][2];
+ temp.m[1][0] = -in1->m[1][0]*in1->m[2][2]*in1->m[3][3] + in1->m[1][0]*in1->m[3][2]*in1->m[2][3] + in1->m[1][2]*in1->m[2][0]*in1->m[3][3] - in1->m[1][2]*in1->m[3][0]*in1->m[2][3] - in1->m[1][3]*in1->m[2][0]*in1->m[3][2] + in1->m[1][3]*in1->m[3][0]*in1->m[2][2];
+ temp.m[1][1] = in1->m[0][0]*in1->m[2][2]*in1->m[3][3] - in1->m[0][0]*in1->m[3][2]*in1->m[2][3] - in1->m[0][2]*in1->m[2][0]*in1->m[3][3] + in1->m[0][2]*in1->m[3][0]*in1->m[2][3] + in1->m[0][3]*in1->m[2][0]*in1->m[3][2] - in1->m[0][3]*in1->m[3][0]*in1->m[2][2];
+ temp.m[1][2] = -in1->m[0][0]*in1->m[1][2]*in1->m[3][3] + in1->m[0][0]*in1->m[3][2]*in1->m[1][3] + in1->m[0][2]*in1->m[1][0]*in1->m[3][3] - in1->m[0][2]*in1->m[3][0]*in1->m[1][3] - in1->m[0][3]*in1->m[1][0]*in1->m[3][2] + in1->m[0][3]*in1->m[3][0]*in1->m[1][2];
+ temp.m[1][3] = in1->m[0][0]*in1->m[1][2]*in1->m[2][3] - in1->m[0][0]*in1->m[2][2]*in1->m[1][3] - in1->m[0][2]*in1->m[1][0]*in1->m[2][3] + in1->m[0][2]*in1->m[2][0]*in1->m[1][3] + in1->m[0][3]*in1->m[1][0]*in1->m[2][2] - in1->m[0][3]*in1->m[2][0]*in1->m[1][2];
+ temp.m[2][0] = in1->m[1][0]*in1->m[2][1]*in1->m[3][3] - in1->m[1][0]*in1->m[3][1]*in1->m[2][3] - in1->m[1][1]*in1->m[2][0]*in1->m[3][3] + in1->m[1][1]*in1->m[3][0]*in1->m[2][3] + in1->m[1][3]*in1->m[2][0]*in1->m[3][1] - in1->m[1][3]*in1->m[3][0]*in1->m[2][1];
+ temp.m[2][1] = -in1->m[0][0]*in1->m[2][1]*in1->m[3][3] + in1->m[0][0]*in1->m[3][1]*in1->m[2][3] + in1->m[0][1]*in1->m[2][0]*in1->m[3][3] - in1->m[0][1]*in1->m[3][0]*in1->m[2][3] - in1->m[0][3]*in1->m[2][0]*in1->m[3][1] + in1->m[0][3]*in1->m[3][0]*in1->m[2][1];
+ temp.m[2][2] = in1->m[0][0]*in1->m[1][1]*in1->m[3][3] - in1->m[0][0]*in1->m[3][1]*in1->m[1][3] - in1->m[0][1]*in1->m[1][0]*in1->m[3][3] + in1->m[0][1]*in1->m[3][0]*in1->m[1][3] + in1->m[0][3]*in1->m[1][0]*in1->m[3][1] - in1->m[0][3]*in1->m[3][0]*in1->m[1][1];
+ temp.m[2][3] = -in1->m[0][0]*in1->m[1][1]*in1->m[2][3] + in1->m[0][0]*in1->m[2][1]*in1->m[1][3] + in1->m[0][1]*in1->m[1][0]*in1->m[2][3] - in1->m[0][1]*in1->m[2][0]*in1->m[1][3] - in1->m[0][3]*in1->m[1][0]*in1->m[2][1] + in1->m[0][3]*in1->m[2][0]*in1->m[1][1];
+ temp.m[3][0] = -in1->m[1][0]*in1->m[2][1]*in1->m[3][2] + in1->m[1][0]*in1->m[3][1]*in1->m[2][2] + in1->m[1][1]*in1->m[2][0]*in1->m[3][2] - in1->m[1][1]*in1->m[3][0]*in1->m[2][2] - in1->m[1][2]*in1->m[2][0]*in1->m[3][1] + in1->m[1][2]*in1->m[3][0]*in1->m[2][1];
+ temp.m[3][1] = in1->m[0][0]*in1->m[2][1]*in1->m[3][2] - in1->m[0][0]*in1->m[3][1]*in1->m[2][2] - in1->m[0][1]*in1->m[2][0]*in1->m[3][2] + in1->m[0][1]*in1->m[3][0]*in1->m[2][2] + in1->m[0][2]*in1->m[2][0]*in1->m[3][1] - in1->m[0][2]*in1->m[3][0]*in1->m[2][1];
+ temp.m[3][2] = -in1->m[0][0]*in1->m[1][1]*in1->m[3][2] + in1->m[0][0]*in1->m[3][1]*in1->m[1][2] + in1->m[0][1]*in1->m[1][0]*in1->m[3][2] - in1->m[0][1]*in1->m[3][0]*in1->m[1][2] - in1->m[0][2]*in1->m[1][0]*in1->m[3][1] + in1->m[0][2]*in1->m[3][0]*in1->m[1][1];
+ temp.m[3][3] = in1->m[0][0]*in1->m[1][1]*in1->m[2][2] - in1->m[0][0]*in1->m[2][1]*in1->m[1][2] - in1->m[0][1]*in1->m[1][0]*in1->m[2][2] + in1->m[0][1]*in1->m[2][0]*in1->m[1][2] + in1->m[0][2]*in1->m[1][0]*in1->m[2][1] - in1->m[0][2]*in1->m[2][0]*in1->m[1][1];
+#endif
+
+ det = in1->m[0][0]*temp.m[0][0] + in1->m[1][0]*temp.m[0][1] + in1->m[2][0]*temp.m[0][2] + in1->m[3][0]*temp.m[0][3];
+ if (det == 0.0f)
+ return 0;
+
+ det = 1.0f / det;
+
+ for (i = 0;i < 4;i++)
+ for (j = 0;j < 4;j++)
+ out->m[i][j] = temp.m[i][j] * det;
+
+ return 1;
+}
+#else
+int Matrix4x4_Invert_Full (matrix4x4_t *out, const matrix4x4_t *in1)
+{
+ double *temp;
+ double *r[4];
+ double rtemp[4][8];
+ double m[4];
+ double s;
+
+ r[0] = rtemp[0];
+ r[1] = rtemp[1];
+ r[2] = rtemp[2];
+ r[3] = rtemp[3];
+
+#ifdef MATRIX4x4_OPENGLORIENTATION
+ r[0][0] = in1->m[0][0]; r[0][1] = in1->m[1][0]; r[0][2] = in1->m[2][0]; r[0][3] = in1->m[3][0];
+ r[0][4] = 1.0; r[0][5] = r[0][6] = r[0][7] = 0.0;
+
+ r[1][0] = in1->m[0][1]; r[1][1] = in1->m[1][1]; r[1][2] = in1->m[2][1]; r[1][3] = in1->m[3][1];
+ r[1][5] = 1.0; r[1][4] = r[1][6] = r[1][7] = 0.0;
+
+ r[2][0] = in1->m[0][2]; r[2][1] = in1->m[1][2]; r[2][2] = in1->m[2][2]; r[2][3] = in1->m[3][2];
+ r[2][6] = 1.0; r[2][4] = r[2][5] = r[2][7] = 0.0;
+
+ r[3][0] = in1->m[0][3]; r[3][1] = in1->m[1][3]; r[3][2] = in1->m[2][3]; r[3][3] = in1->m[3][3];
+ r[3][7] = 1.0; r[3][4] = r[3][5] = r[3][6] = 0.0;
+#else
+ r[0][0] = in1->m[0][0]; r[0][1] = in1->m[0][1]; r[0][2] = in1->m[0][2]; r[0][3] = in1->m[0][3];
+ r[0][4] = 1.0; r[0][5] = r[0][6] = r[0][7] = 0.0;
+
+ r[1][0] = in1->m[1][0]; r[1][1] = in1->m[1][1]; r[1][2] = in1->m[1][2]; r[1][3] = in1->m[1][3];
+ r[1][5] = 1.0; r[1][4] = r[1][6] = r[1][7] = 0.0;
+
+ r[2][0] = in1->m[2][0]; r[2][1] = in1->m[2][1]; r[2][2] = in1->m[2][2]; r[2][3] = in1->m[2][3];
+ r[2][6] = 1.0; r[2][4] = r[2][5] = r[2][7] = 0.0;
+
+ r[3][0] = in1->m[3][0]; r[3][1] = in1->m[3][1]; r[3][2] = in1->m[3][2]; r[3][3] = in1->m[3][3];
+ r[3][7] = 1.0; r[3][4] = r[3][5] = r[3][6] = 0.0;
+#endif
+
+ if (fabs (r[3][0]) > fabs (r[2][0])) { temp = r[3]; r[3] = r[2]; r[2] = temp; }
+ if (fabs (r[2][0]) > fabs (r[1][0])) { temp = r[2]; r[2] = r[1]; r[1] = temp; }
+ if (fabs (r[1][0]) > fabs (r[0][0])) { temp = r[1]; r[1] = r[0]; r[0] = temp; }
+
+ if (r[0][0])
+ {
+ m[1] = r[1][0] / r[0][0];
+ m[2] = r[2][0] / r[0][0];
+ m[3] = r[3][0] / r[0][0];
+
+ s = r[0][1]; r[1][1] -= m[1] * s; r[2][1] -= m[2] * s; r[3][1] -= m[3] * s;
+ s = r[0][2]; r[1][2] -= m[1] * s; r[2][2] -= m[2] * s; r[3][2] -= m[3] * s;
+ s = r[0][3]; r[1][3] -= m[1] * s; r[2][3] -= m[2] * s; r[3][3] -= m[3] * s;
+
+ s = r[0][4]; if (s) { r[1][4] -= m[1] * s; r[2][4] -= m[2] * s; r[3][4] -= m[3] * s; }
+ s = r[0][5]; if (s) { r[1][5] -= m[1] * s; r[2][5] -= m[2] * s; r[3][5] -= m[3] * s; }
+ s = r[0][6]; if (s) { r[1][6] -= m[1] * s; r[2][6] -= m[2] * s; r[3][6] -= m[3] * s; }
+ s = r[0][7]; if (s) { r[1][7] -= m[1] * s; r[2][7] -= m[2] * s; r[3][7] -= m[3] * s; }
+
+ if (fabs (r[3][1]) > fabs (r[2][1])) { temp = r[3]; r[3] = r[2]; r[2] = temp; }
+ if (fabs (r[2][1]) > fabs (r[1][1])) { temp = r[2]; r[2] = r[1]; r[1] = temp; }
+
+ if (r[1][1])
+ {
+ m[2] = r[2][1] / r[1][1];
+ m[3] = r[3][1] / r[1][1];
+ r[2][2] -= m[2] * r[1][2];
+ r[3][2] -= m[3] * r[1][2];
+ r[2][3] -= m[2] * r[1][3];
+ r[3][3] -= m[3] * r[1][3];
+
+ s = r[1][4]; if (s) { r[2][4] -= m[2] * s; r[3][4] -= m[3] * s; }
+ s = r[1][5]; if (s) { r[2][5] -= m[2] * s; r[3][5] -= m[3] * s; }
+ s = r[1][6]; if (s) { r[2][6] -= m[2] * s; r[3][6] -= m[3] * s; }
+ s = r[1][7]; if (s) { r[2][7] -= m[2] * s; r[3][7] -= m[3] * s; }
+
+ if (fabs (r[3][2]) > fabs (r[2][2])) { temp = r[3]; r[3] = r[2]; r[2] = temp; }
+
+ if (r[2][2])
+ {
+ m[3] = r[3][2] / r[2][2];
+ r[3][3] -= m[3] * r[2][3];
+ r[3][4] -= m[3] * r[2][4];
+ r[3][5] -= m[3] * r[2][5];
+ r[3][6] -= m[3] * r[2][6];
+ r[3][7] -= m[3] * r[2][7];
+
+ if (r[3][3])
+ {
+ s = 1.0 / r[3][3];
+ r[3][4] *= s;
+ r[3][5] *= s;
+ r[3][6] *= s;
+ r[3][7] *= s;
+
+ m[2] = r[2][3];
+ s = 1.0 / r[2][2];
+ r[2][4] = s * (r[2][4] - r[3][4] * m[2]);
+ r[2][5] = s * (r[2][5] - r[3][5] * m[2]);
+ r[2][6] = s * (r[2][6] - r[3][6] * m[2]);
+ r[2][7] = s * (r[2][7] - r[3][7] * m[2]);
+
+ m[1] = r[1][3];
+ r[1][4] -= r[3][4] * m[1], r[1][5] -= r[3][5] * m[1];
+ r[1][6] -= r[3][6] * m[1], r[1][7] -= r[3][7] * m[1];
+
+ m[0] = r[0][3];
+ r[0][4] -= r[3][4] * m[0], r[0][5] -= r[3][5] * m[0];
+ r[0][6] -= r[3][6] * m[0], r[0][7] -= r[3][7] * m[0];
+
+ m[1] = r[1][2];
+ s = 1.0 / r[1][1];
+ r[1][4] = s * (r[1][4] - r[2][4] * m[1]), r[1][5] = s * (r[1][5] - r[2][5] * m[1]);
+ r[1][6] = s * (r[1][6] - r[2][6] * m[1]), r[1][7] = s * (r[1][7] - r[2][7] * m[1]);
+
+ m[0] = r[0][2];
+ r[0][4] -= r[2][4] * m[0], r[0][5] -= r[2][5] * m[0];
+ r[0][6] -= r[2][6] * m[0], r[0][7] -= r[2][7] * m[0];
+
+ m[0] = r[0][1];
+ s = 1.0 / r[0][0];
+ r[0][4] = s * (r[0][4] - r[1][4] * m[0]), r[0][5] = s * (r[0][5] - r[1][5] * m[0]);
+ r[0][6] = s * (r[0][6] - r[1][6] * m[0]), r[0][7] = s * (r[0][7] - r[1][7] * m[0]);
+
+#ifdef MATRIX4x4_OPENGLORIENTATION
+ out->m[0][0] = r[0][4];
+ out->m[0][1] = r[1][4];
+ out->m[0][2] = r[2][4];
+ out->m[0][3] = r[3][4];
+ out->m[1][0] = r[0][5];
+ out->m[1][1] = r[1][5];
+ out->m[1][2] = r[2][5];
+ out->m[1][3] = r[3][5];
+ out->m[2][0] = r[0][6];
+ out->m[2][1] = r[1][6];
+ out->m[2][2] = r[2][6];
+ out->m[2][3] = r[3][6];
+ out->m[3][0] = r[0][7];
+ out->m[3][1] = r[1][7];
+ out->m[3][2] = r[2][7];
+ out->m[3][3] = r[3][7];
+#else
+ out->m[0][0] = r[0][4];
+ out->m[0][1] = r[0][5];
+ out->m[0][2] = r[0][6];
+ out->m[0][3] = r[0][7];
+ out->m[1][0] = r[1][4];
+ out->m[1][1] = r[1][5];
+ out->m[1][2] = r[1][6];
+ out->m[1][3] = r[1][7];
+ out->m[2][0] = r[2][4];
+ out->m[2][1] = r[2][5];
+ out->m[2][2] = r[2][6];
+ out->m[2][3] = r[2][7];
+ out->m[3][0] = r[3][4];
+ out->m[3][1] = r[3][5];
+ out->m[3][2] = r[3][6];
+ out->m[3][3] = r[3][7];
+#endif
+
+ return 1;
+ }
+ }
+ }
+ }
+
+ return 0;