NAME

readRGB − returns values of specific pixels

SPECIFICATION

C
long readRGB(n, red, green, blue)
short n;
RGBvalue red[], green[], blue[];

FORTRAN
integer*4 function readRG(n, red, green, blue)
integer*4 n
character*(*) red, green, blue

Pascal
function readRGB(n: longint; var red, green, blue:
RGBvalue): longint;

DESCRIPTION

readRGB attempts to read up to n pixel values from the bitplanes.  It reads them into the red, green, and blue arrays starting from the current character position along a single scan line (constant y) in the direction of increasing x.  readRGB returns the number of pixels actually read, which is the number specified in n if the starting point is at least that number away from the edge of the current viewport.  The values of pixels read outside the current viewport are undefined. 

readRGB updates the current character position to one pixel to the right of the last one read; it does not define it if new position is outside the viewport. 

readRGB is available only in RGB mode. 

SEE ALSO

readpixels, writeRGB IRIS Graphics Programming, Section 3.9, Writing and Reading Pixels

NOTE

This routine is available only in immediate mode. 

Version 2.5  —  April 22, 1987