void GLAPIENTRY glMultMatrixd( const GLdouble *m )
       void GLAPIENTRY glMultMatrixf( const GLfloat *m )

PARAMETERS
       m  Points to 16 consecutive values that are used as the  elements  of  a
          4×4 column-major matrix.

DESCRIPTION
       glMultMatrix  multiplies the current matrix with the one specified using
       m, and replaces the current matrix with the product.

       The current matrix  is  determined  by  the  current  matrix  mode  (see
       glMatrixMode).  It is either the projection matrix, modelview matrix, or
       the texture matrix.

EXAMPLES
       If the current matrix is C, and the coordinates to be  transformed  are,
       v=(v[0],v[1],v[2],v[3]).  Then the current transformation is C×v, or

                             c[0] c[4] c[8]  c[12]   v[0]
                            ⎝c[1] c[5] c[9]  c[13]⎠×⎝v[1]⎠
                             c[2] c[6] c[10] c[14]   v[2]
                             c[3] c[7] c[11] c[15]   v[3]

       Calling  glMultMatrix with an argument of m=m[0],m[1],...,m[15] replaces
       the current transformation with (C×M)×v, or

                 c[0] c[4] c[8]  c[12]   m[0] m[4] m[8]  m[12]   v[0]
                ⎝c[1] c[5] c[9]  c[13]⎠×⎝m[1] m[5] m[9]  m[13]⎠×⎝v[1]⎠
                 c[2] c[6] c[10] c[14]   m[2] m[6] m[10] m[14]   v[2]
                 c[3] c[7] c[11] c[15]   m[3] m[7] m[11] m[15]   v[3]

       Where '×' denotes matrix multiplication, and v is represented as  a  4×1
       matrix.

NOTES
       While  the elements of the matrix may be specified with single or double
       precision, the GL may store or operate on these values in less than sin‐
       gle precision.

       In  many  computer languages 4×4 arrays are represented in row-major or‐
       der. The transformations just described represent these matrices in col‐
       umn-major  order.  The order of the multiplication is important. For ex‐
       ample, if the current transformation is a rotation, and glMultMatrix  is
       called  with  a  translation matrix, the translation is done directly on
       the coordinates to be transformed, while the rotation is done on the re‐
       sults of that translation.

ERRORS
       GL_INVALID_OPERATION  is  generated  if glMultMatrix is executed between
       the execution of glBegin and the corresponding execution of glEnd.