TITLE	"VIDF - Vlib 4.1"
	NAME	('VIDF')
;=================================================================
;  Copyright (C) 1989 by Harold F. Bower.  Permission granted to
; Alpha Systems Corp. to distribute with The Libraries, Version 4
;-----------------------------------------------------------------
; Author  : Harold F. Bower
; Date    : 3 Mar 89
; Version : 1.0
; Module  : VIDF
; Abstract:  This module contains the corner drawing routines
;	ULEFT, URIGHT, LLEFT and LRIGHT which print the respective
;	graphics corner routines.
; Revision:
;	1.1  19 Jan 90  Joe Wright
;	Changed to treat the internal graphics table.
;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
;  Module Entry Points

	PUBLIC		ULEFT, URIGHT, LLEFT, LRIGHT

;  External References

	EXT		@GULC, @GURC, @GLLC, @GLRC, @GSET0

	.Z80
	CSEG
;===============================================================
; ULEFT - Draw upper left graphics corner character
;  Entry: - None
;  Exit :  A = 0 and Zero Flag Set (Z) if Error
;	   A = FFH and Zero flag Reset (NZ) if Operation OK
;  Uses : AF
; Special Requirements: None
;===============================================================

ULEFT:	PUSH	HL		; Save regs
	LD	HL,@GULC	; Point to character
	JR	DRC0		; ..continue below

;===============================================================
; URIGHT - Draw upper right graphics corner character
;  Entry: - None
;  Exit :  A = 0 and Zero Flag Set (Z) if Error
;	   A = FFH and Zero flag Reset (NZ) if Operation OK
;  Uses : AF
; Special Requirements: None
;===============================================================

URIGHT:	PUSH	HL		; Save regs
	LD	HL,@GURC	; Point to character
	JR	DRC0

;===============================================================
; LLEFT - Draw lower left graphics corner character
;  Entry: - None
;  Exit :  A = 0 and Zero Flag Set (Z) if Error
;	   A = FFH and Zero flag Reset (NZ) if Operation OK
;  Uses : AF
; Special Requirements: None
;===============================================================

LLEFT:	PUSH	HL		; Save regs
	LD	HL,@GLLC	; Point to character
	JR	DRC0		; ..continue below

;===============================================================
; LRIGHT - Draw lower right graphics corner character
;  Entry: - None
;  Exit :  A = 0 and Zero Flag Set (Z) if Error
;	   A = FFH and Zero flag Reset (NZ) if Operation OK
;  Uses : AF
; Special Requirements: None
;===============================================================

LRIGHT:	PUSH	HL		; Save regs
	LD	HL,@GLRC	; Get string from Environment
DRC0:	JP	@GSET0		; Finish up in other module

	END