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NEWLAYER(9.2)                                                    NEWLAYER(9.2)

NAME
       newlayer,  dellayer,  lbitblt,  lpoint, lrectf, lsegment, ltexture, up‐
       front - layer control and graphics

SYNOPSIS
       #include <jerq.h>

       Layer *newlayer(r); Rectangle r;

       void dellayer(l) Layer *l;

       void lbitblt(sl, r, dl, p, f) Layer *sl, *dl;  Rectangle  r;  Point  p;
       Code f;

       void lpoint(l, p, f) Layer *l; Point p; Code f;

       void lrectf(l, r, f) Layer *l; Rectangle r; Code f;

       void segment(l, p, q, f) Layer *l; Point p, q; Code f;

       void ltexture(l, r, t, f) Layer *l; Rectangle r; Texture *t; Code f;

DESCRIPTION
       Newlayer creates a layer in Rectangle r in the physical display bitmap,
       and returns its address, or 0 on failure.  Newproc(9.2) explains how to
       attach a process to a layer.

       Dellayer  de-allocates  a  layer;  the  associated process must also be
       freed (see newproc(9.2)).

       The routines lbitblt, lpoint, lsegment and ltexture are  equivalent  to
       their bitblt(9.3) counterparts except that they never inhibit the mouse
       cursor,  so they are mainly useful only for implementation of efficient
       composite graphics operations such as circle-drawing.  Because  of  the
       duality  of  Bitmaps and Layers, arguments of either type may be passed
       freely to any of the graphics primitives.

SEE ALSO
       bitblt(9.3), newproc(9.2)
       Graphics in Overlapping Bitmap Layers, Rob Pike, ACM Trans.  on  Graph‐
       ics, April 1983.

                                                                 NEWLAYER(9.2)