Re: A82: another ?

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Re: A82: another ?


If I knew what _ILINE did maybe I could help you more. But I do know a
routine that draws a horizontal black line. This is from Fast Tunnel by
AVD:

; ** BlackLine       from Plain Jump by Andreas Ess ** Modified for
TUNNEL
;                                                  and optimized
(thrashed)
; Returns: Horizontal Line from (B,E)-(C,E)
BlackLine:
  PUSH HL
  PUSH DE
  LD  HL, GRAPH_MEM             ; ** we are always doing top line
  LD  D, 0 \ LD   E, B
  SRL E \ SRL  E \ SRL  E       ; Divide x by 8
  ADD HL, DE                    ; HL now contains video-offset (B, C)

  LD  A, C                      ; Calc # of times to repeat line loop
  SUB B
  INC A \ LD  C, A
  LD  A, B                      ; Load real x1-pos into A
  AND %00000111                 ;  and make mask
  LD  B, A                      ; Find number to shift
  LD  D, %10000000              ; Video-Mask setup
  LD  A, (HL)                   ; Get Data ready
  JR  Z, BLoop                  ; Ready for Line Plotting?
ShiftBLoop:
  SRL D
  DJNZ ShiftBLoop
BLoop:                          ; Ready-go!
  OR  D                         ; Set bit to black

  DEC C
  JR  Z, EndBlack               ; Decrement Counter - see if done and end

  RRC D                         ; Shift mask right
  JR  NC, BLoop                 ; Did the mask disappear?
  LD  (HL), A \ INC  HL \ LD   A, (HL)

  JR  BLoop
EndBlack:
  LD  (HL), A
  POP DE
  POP HL
  RET


On Sat, 14 Mar 1998 17:45:59 -0500 Craig <cjslush@mindspring.com> writes:
>
>Anyone happen to have a routine that does the equivalent to the call 
>_ILINE
>in the 83??
>
>--
>Craig
>http://cjslush.home.mindspring.com
>***
>

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