COMPOSE MATRIX(3P) — SUNPHIGS LIBRARY

NAME

COMPOSE MATRIX − generate the composition of two homogeneous 2D matrices

SYNOPSIS

C Syntax

void
pcomposematrix ( a, b, error_ind, result )
Pmatrixa;matrix a
Pmatrixb;matrix b
Pint∗error_ind;OUT error indicator
Pmatrixresult;OUT result matrix

FORTRAN Syntax

SUBROUTINE pcom ( XFRMTA, XFRMTB, ERRIND, XFRMTO )
REALXFRMTA(3, 3)transformation matrix A
REALXFRMTB(3, 3)transformation matrix B
INTEGERERRINDOUT error indicator
REALXFRMTO(3, 3)OUT composed transformation matrix

Required PHIGS Operating States

(PHOP, ∗, ∗, ∗)

DESCRIPTION

Purpose

Use COMPOSE MATRIX to produce a 2D (3 x 3) homogeneous matrix that is the composition (matrix multiplication product) of two specified 3 x 3 matrices.

The returned matrix may be passed to the SET LOCAL TRANSFORMATION and SET GLOBAL TRANSFORMATION functions, or to any PHIGS function accepting a parameter of type Pmatrix.

C Input Parameters

a, bThe 2D (3 x 3) matrices used to calculate the composition matrix. Matrices are specified as a Pmatrix array defined in phigs.h as follows:

typedef Pfloat Pmatrix[3][3]

C Output Parameters

error_ind
A pointer to the location to store the error number of any error detected by this function.

resultThe resulting composition matrix.

FORTRAN Input Parameters

XFRMTA, XFRMTB
The 2D (3 x 3) matrices used to calculate the composition matrix.

FORTRAN Output Parameters

ERRIND
The error number of any error detected by this function.

XFRMTO
The resulting composition matrix.

Execution

COMPOSE MATRIX returns a 3 x 3 matrix that is the result of multiplying the two specified matrices a and b:

result = a x b

ERRORS

002Ignoring function, function requires state (PHOP, ∗, ∗, ∗)

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