DEVPOINTER(2)
NAME
devpointer − I/O interface for the pointer device
SYNOPSIS
include "draw.m"; # for Draw->Pointer include "devpointer.m"; ptr:= load Devpointer Devpointer->PATH;
init: fn(file: string, posn: chan of ref Draw->Pointer): int; bytes2ptr: fn(buf: array of byte) : ref Draw->Pointer; ptr2bytes: fn(ptr: ref Draw->Pointer): array of byte;
DESCRIPTION
Devpointer reads messages from pointer devices with the same data format as /dev/pointer, converting them to Pointer adts.
Init spawns a process to read continually the pointer device specified by file and send a Pointer adts over the channel specified by posn. If file is nil, the default device is /dev/pointer.
Bytes2ptr converts the array of bytes buf to a Pointer and returns a reference to it. Buf should consist of exactly Devpointer->Size bytes and be in the format returned by /dev/pointer.
Ptr2bytes provides the inverse transformation of bytes2ptr: it packs the data into an array of bytes of appropriate format, which it returns.
FILES
/dev/pointer