193 lines
7.7 KiB
Plaintext
Executable File
193 lines
7.7 KiB
Plaintext
Executable File
.INCLUDE GRAFTYPES.TEXT
|
|
;------------------------------------------------------------------
|
|
;
|
|
; --> SEEKRGN.TEXT
|
|
;
|
|
; Routines to play back a region into a scanline buffer.
|
|
;
|
|
;
|
|
|
|
|
|
.PROC INITRGN,0
|
|
;------------------------------------------------------
|
|
;
|
|
; INPUTS: A0: RGNPTR
|
|
; A1: STATE RECORD
|
|
; D0: MINH
|
|
; D1: MAXH
|
|
; D2: BUFLEFT
|
|
;
|
|
; OUTPUTS: ALL FIELDS OF STATE RECORD,
|
|
; SCANBUF ALLOCATED ON STACK
|
|
;
|
|
; CLOBBERS: D0,D1,A0
|
|
;
|
|
MOVE D0,MINH(A1) ;INSTALL MINH
|
|
MOVE D1,MAXH(A1) ;INSTALL MAXH
|
|
MOVE D2,LEFTH(A1) ;INSTALL LEFTH
|
|
MOVE.L A0,RGNPTR(A1) ;INSTALL RGNPTR
|
|
MOVE #-32767,THISV(A1) ;THISV := -32767
|
|
MOVE RGNBBOX+TOP(A0),NEXTV(A1) ;NEXTV := RGN BBOX TOP
|
|
LEA RGNDATA(A0),A0 ;POINT TO FIRST DATA
|
|
MOVE.L A0,DATAPTR(A1) ;INIT DATAPTR
|
|
MOVE.L (SP)+,A0 ;POP RETURN ADDR
|
|
SUB D2,D1 ;CALC BUFFER WIDTH IN DOTS
|
|
LSR #5,D1 ;DIV BY 32 FOR #LONGS-1
|
|
MOVE D1,SCANSIZE(A1) ;SAVE SCANSIZE FOR LATER
|
|
|
|
CLRLOOP CLR.L -(SP) ;ALLOCATE AND CLEAR BUFFER
|
|
DBRA D1,CLRLOOP
|
|
MOVE.L SP,SCANBUF(A1) ;REMEMBER BUFFER START
|
|
JMP (A0) ;RETURN
|
|
|
|
|
|
|
|
.PROC SEEKRGN,0
|
|
.REF MaskTab
|
|
;------------------------------------------------------------------
|
|
;
|
|
; SeekRgn(rgnState,vert);
|
|
;
|
|
; ROUTINE TO PLAY BACK A REGION FORWARD OR BACKWARD UNTIL ITS SCAN
|
|
; BUFFER CONTAINS THE BITMAP FOR THE GIVEN VERTICAL COORDINATE.
|
|
;
|
|
; INPUTS: A1 POINTS TO A REGION STATE RECORD
|
|
; DO CONTAINS THE DESIRED VERTICAL COORD
|
|
;
|
|
; OUTPUTS: UPDATES THISV, NEXTV, DATAPTR, AND SCANBUF^ OF STATE RECORD
|
|
; D1-->1 IF CHANGE, 0 IF NO CHANGE. (Z-FLAG SET IF NO CHANGE)
|
|
;
|
|
; CLOBBERS: A0,D1.
|
|
;
|
|
|
|
;----------------------------------------------------
|
|
;
|
|
; RETURN QUICKLY IF SCANBUF IS ALREADY CURRENT.
|
|
;
|
|
CMP NEXTV(A1),D0 ;IS DESIRED VERT >= NEXTV ?
|
|
BGE.S DOWN ;YES, BUMP DOWNWARD
|
|
CMP THISV(A1),D0 ;IS DESIRED VERT < CURRENT VERT ?
|
|
BLT.S UP ;YES, BUMP UPWARD
|
|
CLR D1 ;ELSE REPORT NO CHANGES
|
|
RTS ;AND RETURN
|
|
|
|
|
|
;-----------------------------------------------------
|
|
;
|
|
; TO MOVE UPWARDS, JUST RESET TO START AND MOVE DOWN.
|
|
;
|
|
UP MOVE.L SCANBUF(A1),A0 ;POINT TO SCANBUF
|
|
MOVE SCANSIZE(A1),D1 ;GET BUFFER SIZE
|
|
CLRLP CLR.L (A0)+ ;CLEAR A LONG
|
|
DBRA D1,CLRLP ;LOOP ENTIRE SCANBUF
|
|
MOVE.L RGNPTR(A1),A0 ;GET RGNPTR
|
|
MOVE RGNBBOX+TOP(A0),NEXTV(A1) ;NEXTV := TOP VERT
|
|
MOVE #-32767,THISV(A1) ;RESET THISV TO -32767
|
|
LEA RGNDATA(A0),A0 ;POINT TO START OF REGION DATA
|
|
MOVE.L A0,DATAPTR(A1) ;RESET DATAPTR
|
|
CMP NEXTV(A1),D0 ;IS DESIRED VERT >= NEXTV ?
|
|
BLT DONE ;NO, QUIT
|
|
|
|
|
|
;------------------------------------------------------
|
|
;
|
|
; WHILE DESIRED VERT >= NEXTV DO BUMP DOWN.
|
|
;
|
|
DOWN MOVEM.L D0-D6/A2-A3,-(SP) ;SAVE REGS
|
|
MOVE D0,D2 ;SAVE VERT
|
|
MOVE.L DATAPTR(A1),A2 ;POINT TO VERT COORD
|
|
DOWN1 MOVE (A2)+,THISV(A1) ;UPDATE CURRENT VERT
|
|
|
|
|
|
;-------------------------------------------------
|
|
;
|
|
; GET LEFT AND RIGHT HORIZ COORDS
|
|
; AND TRIM AGAINST MINH AND MAXH
|
|
;
|
|
NEXTHOR MOVE (A2)+,D3 ;GET LEFT COORD
|
|
CMP #32767,D3 ;IS IT A TERMINATOR ?
|
|
BEQ.S DONE1 ;YES, QUIT
|
|
MOVE (A2)+,D4 ;GET RIGHT COORD
|
|
CMP MINH(A1),D4 ;IS RIGHT <= MINH ?
|
|
BLE NEXTHOR ;YES, IGNORE ON LEFT
|
|
CMP MAXH(A1),D3 ;IS LEFT >= MAXH ?
|
|
BGE NEXTHOR ;YES, IGNORE ON RIGHT
|
|
CMP MINH(A1),D3 ;IS LEFT < MINH ?
|
|
BGE.S LOK ;NO, CONTINUE
|
|
MOVE MINH(A1),D3 ;YES, TRIM LEFT
|
|
LOK CMP MAXH(A1),D4 ;IS RIGHT > MAXH ?
|
|
BLE.S ROK ;NO, CONTINUE
|
|
MOVE MAXH(A1),D4 ;YES, TRIM RIGHT
|
|
|
|
ROK SUB LEFTH(A1),D3 ;MAKE COORDS REL TO BUFFER
|
|
SUB LEFTH(A1),D4
|
|
|
|
|
|
;------------------------------------------
|
|
;
|
|
; GET LEFTMASK AND RIGHTMASK
|
|
;
|
|
LEA MASKTAB,A0 ;POINT TO MASK TABLE
|
|
MOVEQ #$F,D0 ;GET MASK FOR LO 4 BITS
|
|
|
|
MOVE D3,D5 ;COPY LEFT COORD
|
|
AND D0,D5 ;CALC LEFT MOD 16
|
|
ADD D5,D5 ;DOUBLE FOR INDEX
|
|
MOVE 0(A0,D5),D5 ;GET MASK FROM TABLE
|
|
NOT D5 ;INVERT FOR LEFTMASK
|
|
|
|
MOVE D4,D6 ;COPY RIGHT COORD
|
|
AND D0,D6 ;CALC RIGHT MOD 16
|
|
ADD D6,D6 ;DOUBLE FOR INDEX
|
|
MOVE 0(A0,D6),D6 ;GET RIGHTMASK IN D6
|
|
|
|
|
|
;------------------------------------------
|
|
;
|
|
; CALC LEFTWORD, BUFPTR, WORDCOUNT
|
|
;
|
|
LSR #4,D3 ;CONVERT DOTS TO WORDS
|
|
MOVE.L SCANBUF(A1),A3 ;COPY BUFSTART
|
|
ADD D3,A3
|
|
ADD D3,A3 ;INIT BUFPTR TO LEFTWORD
|
|
LSR #4,D4 ;CALC RIGHT DIV 16
|
|
SUB D3,D4 ;WORDCOUNT:=RIGHTWORD-LEFTWORD
|
|
BGT.S NOTIN1 ;BR IF NOT ALL IN ONE
|
|
|
|
|
|
;------------------------------------------
|
|
;
|
|
; LEFT AND RIGHT ARE ALL IN ONE WORD
|
|
;
|
|
AND D5,D6 ;COMBINE LEFT AND RIGHT MASKS
|
|
EOR D6,(A3) ;XOR COMBINATION INTO BUFFER
|
|
BRA NEXTHOR ;GO FOR MORE DH'S THIS SCAN
|
|
|
|
|
|
;------------------------------------------
|
|
;
|
|
; NOT ALL IN ONE WORD. DO LEFT, MIDDLE IF ANY, THEN RIGHT
|
|
;
|
|
NOTIN1 EOR D5,(A3)+ ;XOR LEFTMASK INTO BUFFER
|
|
BRA.S TEST ;SEE IF ANY FULL WORDS
|
|
INVLONG NOT.L (A3)+ ;INVERT 2 WHOLE WORDS
|
|
TEST SUBQ #2,D4 ;ANY FULL WORDS LEFT ?
|
|
BGT INVLONG ;YES, AT LEAST 2
|
|
BLT.S ENDWORD ;NO, FINISH UP LAST WITH MASK
|
|
NOT (A3)+ ;YES, DO LAST FULL WORD
|
|
ENDWORD EOR D6,(A3) ;XOR RIGHTMASK INTO BUFFER
|
|
BRA NEXTHOR ;GO FOR MORE DH'S THIS SCAN
|
|
|
|
|
|
DONE1 MOVE.L A2,DATAPTR(A1) ;UPDATE DATAPTR
|
|
MOVE (A2),NEXTV(A1) ;UPDATE NEXT VERT
|
|
CMP NEXTV(A1),D2 ;IS DESIRED VERT >= NEXTV ?
|
|
BGE DOWN1 ;YES, BUMP DOWN SOME MORE
|
|
MOVEM.L (SP)+,D0-D6/A2-A3 ;RESTORE REGS
|
|
DONE MOVEQ #1,D1 ;REPORT SCANLINE CHANGED
|
|
RTS ;AND RETURN
|
|
|
|
|
|
|
|
.END
|