PAGE,132
     EXTRN DRAWLINE:FAR

;     DAN ROLLINS  (213) 246-5021
;
;     TESTLINE---sample driver for DRAWLINE
;---------------------------------------------------------------
STACK   SEGMENT  PARA STACK 'STACK '
        DB       64 DUP('STACK   ')
STACK   ENDS
;---------------------------------------------------------------
DATA    SEGMENT  PARA PUBLIC 'DATA'

PARMS   DW       7 DUP (?)

;equates make it easier to program access to arguments

X1      EQU      WORD PTR [SI]
Y1      EQU      WORD PTR [SI+2]
X2      EQU      WORD PTR [SI+4]
Y2      EQU      WORD PTR [SI+6]
COLOR   EQU      WORD PTR [SI+8]
LEN     EQU      WORD PTR [SI+10]
SKIP    EQU      WORD PTR [SI+12]
DATA    ENDS
;---------------------------------------------------------------
TESTSEG SEGMENT PARA PUBLIC 'CODE'
        ASSUME  CS:TESTSEG, DS:DATA

TESTLINE PROC FAR
        PUSH  DS          ;save program prefix segment for exit
        XOR   AX,AX
        PUSH  AX          ;word of 0000 for exit return address

        MOV   AH,0        ;set mode function
        MOV   AL,4        ;med-res graphics
        INT   10H         ;initialize graphics mode

        MOV   AX,DATA     
        MOV   DS,AX               ;set up data segment
        MOV   SI,OFFSET DS:PARMS  ;point si to line parameter block

        MOV   COLOR,3     ;white  
        MOV   X1,0        ;start is top left of screen 
        MOV   Y1,0 
        MOV   X2,319      ;end is bottom right 
        MOV   Y2,199 

        MOV   LEN,0       ;display entire line
        MOV   SKIP,0
        CALL  DRAWLINE
        RET               ;program exits to DOS (or DEBUG)
TESTLINE   ENDP
TESTSEG  ENDS
         END    TESTLINE
 JGE   DL1        ;IF X1 <= X2 THEN NO CHANGE