GLMULTMATRIX(3G) UNIX Programmer's Manual GLMULTMATRIX(3G)

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

voidglMultMatrixd( const GLdouble *m) voidglMultMatrixf( const GLfloat *m)

mPoints to 16 consecutive values that are used as the ele- ments of a 4 x 4 column-major matrix.

glMultMatrixmultiplies the current matrix with the one specified usingm, and replaces the current matrix with the product. The current matrix is determined by the current matrix mode (seeglMatrixMode). It is either the projection matrix, modelview matrix, or the texture matrix.

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 x v, or | | |c[0] |c[1] |c[2] c[4] |c[3] c[5] c[6] c[8] c[7] c[9] c[10] c[12] | c[11] c[13] | | c[14] | | c[15] | x |v[0] | | |v[1] | | |v[2] | |v[3] | | | CallingglMultMatrixwith an argument of m = m[0],m[1],...,m[15] replaces the current transformation with (C x M) x v, or | | |c[0] |c[1] |c[2] c[4] |c[3] c[5] c[6] c[8] c[7] c[9] c[10] c[12] | c[11] c[13] | | c[14] | | c[15] | x |m[0] | |m[1] | |m[2] m[4] |m[3] m[5] m[6] m[8] m[7] m[9] m[10] m[12] | m[11] m[13] | | m[14] | | m[15] | x |v[0] | | |v[1] | | |v[2] | |v[3] | | | Where 'x' denotes matrix multiplication, and v is represented as a 4 x 1 matrix.

While the elements of the matrix may be specified with sin- gle or double precision, the GL may store or operate on MirBSD #10-current Printed 2021-12-07 1 GLMULTMATRIX(3G) UNIX Programmer's Manual GLMULTMATRIX(3G) these values in less than single precision. In many computer languages 4 x 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, andglMultMatrixis 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.

GL_INVALID_OPERATIONis generated ifglMultMatrixis exe- cuted between the execution ofglBeginand the corresponding execution ofglEnd.

glGetwith argumentGL_MATRIX_MODEglGetwith argumentGL_COLOR_MATRIXglGetwith argumentGL_MODELVIEW_MATRIXglGetwith argumentGL_PROJECTION_MATRIXglGetwith argumentGL_TEXTURE_MATRIX

glLoadIdentity(3G),glLoadMatrix(3G),glMatrixMode(3G),glPushMatrix(3G)MirBSD #10-current Printed 2021-12-07 2