glMultMatrixd(3)

NAME

       glMultMatrixd,  glMultMatrixf  -  multiply  the current matrix with the
       specified matrix

C SPECIFICATION

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

       delim $$

PARAMETERS

       m  Points to 16 consecutive values that are used as the elements  of  a
          $4 ~times~ 4$ 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 $C ~times~ v$, or

                                      down 130
       {{ left (  matrix {
          ccol { c[0] above c[1] above c[2] above c[3] }
          ccol { c[4] above c[5] above c[6] above c[7] }
          ccol { c[8] above c[9] above c[10] above c[11] }
          ccol { c[12]~ above c[13]~ above c[14]~ above c[15]~ } } right  )  }
       ~~ times ~~ {left ( matrix { ccol { v[0]~ above v[1]~ above v[2]~ above
       v[3]~ } } right )} }

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

                                      down 130
       {{ left (  matrix {
          ccol { c[0] above c[1] above c[2] above c[3] }
          ccol { c[4] above c[5] above c[6] above c[7] }
          ccol { c[8] above c[9] above c[10] above c[11] }
          ccol { c[12]~ above c[13]~ above c[14]~ above c[15]~ } } right  )  }
       ~~ times ~~ { left (  matrix {
          ccol { m[0] above m[1] above m[2] above m[3] }
          ccol { m[4] above m[5] above m[6] above m[7] }
          ccol { m[8] above m[9] above m[10] above m[11] }
          ccol  {  m[12]~ above m[13]~ above m[14]~ above m[15]~ } } right ) }
       ~~ times ~~ {left ( matrix { ccol { v[0]~ above v[1]~ above v[2]~ above
       v[3]~ } } right )} }

       Where  '$times$'  denotes matrix multiplication, and $v$ is represented
       as a $4 ~times~ 1$ 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
       single precision.

       In many computer languages $4 ~times~ 4$ arrays are represented in row-
       major  order. The transformations just described represent these matri-
       ces in column-major order.  The order of the multiplication  is  impor-
       tant.  For  example,  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 results of that translation.

ERRORS

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

ASSOCIATED GETS

       glGet with argument GL_MATRIX_MODE
       glGet with argument GL_COLOR_MATRIX
       glGet with argument GL_MODELVIEW_MATRIX
       glGet with argument GL_PROJECTION_MATRIX
       glGet with argument GL_TEXTURE_MATRIX

SEE ALSO

       glLoadIdentity(3G),         glLoadMatrix(3G),         glMatrixMode(3G),
       glPushMatrix(3G)

                                                              GLMULTMATRIX(3G)