TRANSFORM_POINTS(3G)

NAME

transform_points − transform points to device coordinate points using the current transformation matrix.

SYNOPSIS

C SYNTAX

void transform_points(fildes,wc_pts,dc_pts,
numpts,homogeneous)
int fildes,numpts,homogeneous;
float wc_pts[],dc_pts[];

FORTRAN77 SYNTAX

        subroutine transform_points(fildes,wc_pts,
dc_pts,num_pts,homogeneous)
        integer*4 fildes,numpts,homogeneous
        real wc_pts(numpts*3),dc_pts(numpts*3)

PASCAL SYNTAX

procedure transform_points(fildes:integer;
var wc_pts,dc_pts:array[lo..hi:integer]of real;
numpts,homogeneous:integer);

HP-UX COMPATIBILITY

Level: HP-UX/STANDARD

Origin: HP

DESCRIPTION

INPUT PARAMETERS

fildes
is an integer file descriptor returned by gopen when an I/O path to a graphic device is opened.
wc_pts
array of points to be transformed (in world coordinates)

OUTPUT PARAMETERS

dc_pts
array of transformed points in device coordinates.

DISCUSSION

This procedure uses the current transformation matrix and transformation mode (2-dimension or 3-dimension) to calculate the device coordinate point values. If the homogeneous (perspective) coordinate is zero, the data is three dimensional with 3 coordinates per point. If the homogeneous (perspective) coordinate is non zero then there are 4 coordinates per point with the fourth being the homogeneous coordinate. No perspective divide is performed. This function makes use of the floating point hardware in the device if present and can be used for generalized (n x 4) * (4 x 4) transformations.

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