NAME
glMultMatrixd, glMultMatrixf
- multiply the current matrix with the specified matrix
C SPECIFICATION
void ggllMMuullttMMaattrriixxdd(
const GLdouble _*_m )
void ggllMMuullttMMaattrriixxff(
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
ggllMMuullttMMaattrriixx 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 ggllMMaattrriixxMMooddee). 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 ggllMMuullttMMaattrriixx 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 matrices in column-major order.
The order of the multiplication is important. For example, if the current
transformation is a rotation, and ggllMMuullttMMaattrriixx 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
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllMMuullttMMaattrriixx
is executed between the execution of ggllBBeeggiinn
and the corresponding execution of ggllEEnndd.
ASSOCIATED GETS
ggllGGeett with argument GGLL__MMAATTRRIIXX__MMOODDEE
ggllGGeett with argument GGLL__CCOOLLOORR__MMAATTRRIIXX
ggllGGeett with argument GGLL__MMOODDEELLVVIIEEWW__MMAATTRRIIXX
ggllGGeett with argument GGLL__PPRROOJJEECCTTIIOONN__MMAATTRRIIXX
ggllGGeett with argument GGLL__TTEEXXTTUURREE__MMAATTRRIIXX
SEE ALSO
ggllLLooaaddIIddeennttiittyy((33GG)),
ggllLLooaaddMMaattrriixx((33GG)),
ggllMMaattrriixxMMooddee((33GG)),
ggllPPuusshhMMaattrriixx((33GG))