+
+static inline float cgm_msubdet(float *m, int row, int col)
+{
+ cgm_msubmatrix(m, row, col);
+ return cgm_mdet(m);
+}
+
+static inline float cgm_mcofactor(float *m, int row, int col)
+{
+ float min = cgm_msubdet(m, row, col);
+ return (row + col) & 1 ? -min : min;
+}
+
+static inline float cgm_mdet(float *m)
+{
+ return m[0] * cgm_msubdet(m, 0, 0) - m[1] * cgm_msubdet(m, 0, 1) +
+ m[2] * cgm_msubdet(m, 0, 2) - m[3] * cgm_msubdet(m, 0, 3);
+}
+
+static inline void cgm_mtranspose(float *m)
+{
+ int i, j;
+ for(i=0; i<4; i++) {
+ for(j=0; j<i; j++) {
+ int a = i * 4 + j;
+ int b = j * 4 + i;
+ float tmp = m[a];
+ m[a] = m[b];
+ m[b] = tmp;
+ }
+ }
+}
+
+static inline void cgm_mcofmatrix(float *m)
+{
+ float tmp[16];
+ int i, j;
+
+ cgm_mcopy(tmp, m);
+
+ for(i=0; i<4; i++) {
+ for(j=0; j<4; j++) {
+ m[i * 4 + j] = cgm_mcofactor(tmp, i, j);
+ }
+ }
+}
+
+static inline int cgm_minverse(float *m)
+{
+ int i, j;
+ float tmp[16];
+ float inv_det;
+ float det = cgm_mdet(m);
+ if(det == 0.0f) return -1;
+ inv_det = 1.0f / det;
+
+ cgm_mcopy(tmp, m);
+
+ for(i=0; i<4; i++) {
+ for(j=0; j<4; j++) {
+ m[i * 4 + j] = cgm_mcofactor(tmp, j, i) * inv_det; /* transposed */
+ }
+ }
+}