Added a comment to our use of the term 'adjoint' in BLI_math.

In modern usage this means the conjugate transpose, but we stick to
the classical usage (i.e. adjugate matrix), like Eigen does.

1 files changed, 4 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_math_matrix.h b/source/blender/blenlib/BLI_math_matrix.h
index 5900e391d3e..6fb983a622e 100644
--- a/source/blender/blenlib/BLI_math_matrix.h
+++ b/source/blender/blenlib/BLI_math_matrix.h
@@ -173,6 +173,10 @@ bool is_orthonormal_m4(float mat[4][4]);
 bool is_uniform_scaled_m3(float mat[3][3]);
 bool is_uniform_scaled_m4(float m[4][4]);
 
+/* Note: 'adjoint' here means the adjugate (adjunct, "classical adjoint") matrix!
+ * Nowadays 'adjoint' usually refers to the conjugate transpose,
+ * which for real-valued matrices is simply the transpose.
+ */
 void adjoint_m2_m2(float R[2][2], float A[2][2]);
 void adjoint_m3_m3(float R[3][3], float A[3][3]);
 void adjoint_m4_m4(float R[4][4], float A[4][4]);