# glMultMatrix.3G man page

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

## C Specification

void glMultMatrixd( const GLdouble *m )

void glMultMatrixf( const GLfloat *m )

## Parameters

m

Points to 16 consecutive values that are used as the elements of  a $4\text{ }×\text{ }4$ 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, $v\text{ }=\text{ }\left(v\left[0\right],v\left[1\right],v\left[2\right],v\left[3\right]\right)$. Then the current transformation is $C\text{ }×\text{ }v$, or

$\left(\begin{array}{cccc}\hfill c\left[0\right]\hfill & \hfill c\left[4\right]\hfill & \hfill c\left[8\right]\hfill & \hfill c\left[12\right]\text{ }\hfill \\ \hfill c\left[1\right]\hfill & \hfill c\left[5\right]\hfill & \hfill c\left[9\right]\hfill & \hfill c\left[13\right]\text{ }\hfill \\ \hfill c\left[2\right]\hfill & \hfill c\left[6\right]\hfill & \hfill c\left[10\right]\hfill & \hfill c\left[14\right]\text{ }\hfill \\ \hfill c\left[3\right]\hfill & \hfill c\left[7\right]\hfill & \hfill c\left[11\right]\hfill & \hfill c\left[15\right]\text{ }\hfill \end{array}\right)\text{ }\text{ }×\text{ }\text{ }\left(\begin{array}{c}\hfill v\left[0\right]\text{ }\hfill \\ \hfill v\left[1\right]\text{ }\hfill \\ \hfill v\left[2\right]\text{ }\hfill \\ \hfill v\left[3\right]\text{ }\hfill \end{array}\right)$

Calling glMultMatrix with an argument of $\text{m}\text{ }=\text{ }m\left[0\right],m\left[1\right],...,m\left[15\right]$  replaces the current transformation with $\left(C\text{ }×\text{ }M\right)\text{ }×\text{ }v$, or

$\left(\begin{array}{cccc}\hfill c\left[0\right]\hfill & \hfill c\left[4\right]\hfill & \hfill c\left[8\right]\hfill & \hfill c\left[12\right]\text{ }\hfill \\ \hfill c\left[1\right]\hfill & \hfill c\left[5\right]\hfill & \hfill c\left[9\right]\hfill & \hfill c\left[13\right]\text{ }\hfill \\ \hfill c\left[2\right]\hfill & \hfill c\left[6\right]\hfill & \hfill c\left[10\right]\hfill & \hfill c\left[14\right]\text{ }\hfill \\ \hfill c\left[3\right]\hfill & \hfill c\left[7\right]\hfill & \hfill c\left[11\right]\hfill & \hfill c\left[15\right]\text{ }\hfill \end{array}\right)\text{ }\text{ }×\text{ }\text{ }\left(\begin{array}{cccc}\hfill m\left[0\right]\hfill & \hfill m\left[4\right]\hfill & \hfill m\left[8\right]\hfill & \hfill m\left[12\right]\text{ }\hfill \\ \hfill m\left[1\right]\hfill & \hfill m\left[5\right]\hfill & \hfill m\left[9\right]\hfill & \hfill m\left[13\right]\text{ }\hfill \\ \hfill m\left[2\right]\hfill & \hfill m\left[6\right]\hfill & \hfill m\left[10\right]\hfill & \hfill m\left[14\right]\text{ }\hfill \\ \hfill m\left[3\right]\hfill & \hfill m\left[7\right]\hfill & \hfill m\left[11\right]\hfill & \hfill m\left[15\right]\text{ }\hfill \end{array}\right)\text{ }\text{ }×\text{ }\text{ }\left(\begin{array}{c}\hfill v\left[0\right]\text{ }\hfill \\ \hfill v\left[1\right]\text{ }\hfill \\ \hfill v\left[2\right]\text{ }\hfill \\ \hfill v\left[3\right]\text{ }\hfill \end{array}\right)$

Where '$×$' denotes matrix multiplication, and $v$ is represented as a $4\text{ }×\text{ }1$ matrix.

## 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