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))