144    float *r0, *r1, *r2, *r3;  in util_invert_mat4x4()  local
154    r0 = wtmp[0], r1 = wtmp[1], r2 = wtmp[2], r3 = wtmp[3];  in util_invert_mat4x4()
162    r2[0] = MAT(m, 2, 0), r2[1] = MAT(m, 2, 1), r2[2] = MAT(m, 2, 2), r2[3] = MAT(m, 2, 3),  in util_invert_mat4x4()
163    r2[6] = 1.0, r2[4] = r2[5] = r2[7] = 0.0,  in util_invert_mat4x4()
169    if (fabsf(r3[0]) > fabsf(r2[0]))  in util_invert_mat4x4()
170       SWAP_ROWS(r3, r2);  in util_invert_mat4x4()
171    if (fabsf(r2[0]) > fabsf(r1[0]))  in util_invert_mat4x4()
172       SWAP_ROWS(r2, r1);  in util_invert_mat4x4()
180    m2 = r2[0] / r0[0];  in util_invert_mat4x4()
184    r2[1] -= m2 * s;  in util_invert_mat4x4()
188    r2[2] -= m2 * s;  in util_invert_mat4x4()
192    r2[3] -= m2 * s;  in util_invert_mat4x4()
197       r2[4] -= m2 * s;  in util_invert_mat4x4()
203       r2[5] -= m2 * s;  in util_invert_mat4x4()
209       r2[6] -= m2 * s;  in util_invert_mat4x4()
215       r2[7] -= m2 * s;  in util_invert_mat4x4()
220    if (fabsf(r3[1]) > fabsf(r2[1]))  in util_invert_mat4x4()
221       SWAP_ROWS(r3, r2);  in util_invert_mat4x4()
222    if (fabsf(r2[1]) > fabsf(r1[1]))  in util_invert_mat4x4()
223       SWAP_ROWS(r2, r1);  in util_invert_mat4x4()
228    m2 = r2[1] / r1[1];  in util_invert_mat4x4()
230    r2[2] -= m2 * r1[2];  in util_invert_mat4x4()
232    r2[3] -= m2 * r1[3];  in util_invert_mat4x4()
236       r2[4] -= m2 * s;  in util_invert_mat4x4()
241       r2[5] -= m2 * s;  in util_invert_mat4x4()
246       r2[6] -= m2 * s;  in util_invert_mat4x4()
251       r2[7] -= m2 * s;  in util_invert_mat4x4()
256    if (fabsf(r3[2]) > fabsf(r2[2]))  in util_invert_mat4x4()
257       SWAP_ROWS(r3, r2);  in util_invert_mat4x4()
258    if (0.0F == r2[2])  in util_invert_mat4x4()
262    m3 = r3[2] / r2[2];  in util_invert_mat4x4()
263    r3[3] -= m3 * r2[3], r3[4] -= m3 * r2[4], r3[5] -= m3 * r2[5], r3[6] -= m3 * r2[6],  in util_invert_mat4x4()
264       r3[7] -= m3 * r2[7];  in util_invert_mat4x4()
276    m2 = r2[3]; /* now back substitute row 2 */  in util_invert_mat4x4()
277    s = 1.0F / r2[2];  in util_invert_mat4x4()
278    r2[4] = s * (r2[4] - r3[4] * m2), r2[5] = s * (r2[5] - r3[5] * m2),  in util_invert_mat4x4()
279    r2[6] = s * (r2[6] - r3[6] * m2), r2[7] = s * (r2[7] - r3[7] * m2);  in util_invert_mat4x4()
287    r1[4] = s * (r1[4] - r2[4] * m1), r1[5] = s * (r1[5] - r2[5] * m1),  in util_invert_mat4x4()
288    r1[6] = s * (r1[6] - r2[6] * m1), r1[7] = s * (r1[7] - r2[7] * m1);  in util_invert_mat4x4()
290    r0[4] -= r2[4] * m0, r0[5] -= r2[5] * m0, r0[6] -= r2[6] * m0, r0[7] -= r2[7] * m0;  in util_invert_mat4x4()
301    MAT(out, 1, 3) = r1[7], MAT(out, 2, 0) = r2[4];  in util_invert_mat4x4()
302    MAT(out, 2, 1) = r2[5], MAT(out, 2, 2) = r2[6];  in util_invert_mat4x4()
303    MAT(out, 2, 3) = r2[7], MAT(out, 3, 0) = r3[4];  in util_invert_mat4x4()