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supermario/base/SuperMarioProj.1994-02-09/QuickDraw/Classic/DrawArc.m.a

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Bring in sources, and document
2019-06-29 15:17:50 +00:00
;
; File: DrawArc.m.a
;
; Contains: xxx put contents here (or delete the whole line) xxx
;
; Written by: xxx put name of writer here (or delete the whole line) xxx
;
; Copyright: © 1988-1990 by Apple Computer, Inc., all rights reserved.
;
; Change History (most recent first):
;
; <3> 10/10/90 JL Change FixRatio to MFixRatio to avoid conflict with Traps.a
; <2> 7/20/90 gbm Move stackframe definition inside procs, to avoid global symbol
; collisions
; <1.1> 11/11/88 CCH Fixed Header.
; <1.0> 11/9/88 CCH Adding to EASE.
; <1.2> 10/12/88 CCH Changed “m.GrafType.a” to “GrafType.m.a”.
; <1.1> 5/18/88 MSH Changed inclides to use m.GRAPHTYPES to work under EASE.
; <1.0> 2/11/88 BBM Adding file for the first time into EASE…
;
; To Do:
;
;EASE$$$ READ ONLY COPY of file “DRAWARC.m.a”
; 1.1 CCH 11/11/1988 Fixed Header.
; 1.0 CCH 11/ 9/1988 Adding to EASE.
; OLD REVISIONS BELOW
; 1.2 CCH 10/12/1988 Changed “m.GrafType.a” to “GrafType.m.a”.
; 1.1 MSH 5/18/88 Changed inclides to use m.GRAPHTYPES to work under EASE.
; 1.0 BBM 2/11/88 Adding file for the first time into EASE…
; END EASE MODIFICATION HISTORY
BLANKS ON
STRING ASIS
INCLUDE 'GRAFTYPES.m.a'
;-----------------------------------------------------------
;
; --> DRAWARC.TEXT
;
; Routine to draw solid or hollow Ovals, RoundRects or Arcs.
;
DrawArc PROC EXPORT
IMPORT InitOval,BumpOval,SlopeFromAngle
IMPORT RSect,ShieldCursor,ShowCursor,TrimRect
IMPORT InitRgn,SeekRgn,PatExpand,ColorMap
IMPORT XorSlab,DrawSlab,SlabMode,FastSlabMode,MaskTab
;----------------------------------------------------------------
;
; PROCEDURE DrawArc(dstRect: Rect;
; hollow: BOOLEAN;
; ovalWidth,ovalHeight,mode: INTEGER;
; pat: Pattern;
; startAngle,arcAngle: INTEGER);
;
;------------------------------------------------------
;
; OFFSETS IN AN OVAL STATE RECORD:
;
OVALTOP EQU 0 ;INTEGER
OVALBOT EQU OVALTOP+2 ;INTEGER
OVALY EQU OVALBOT+2 ;INTEGER
RSQYSQ EQU OVALY+2 ;LONGINT
SQUARE EQU RSQYSQ+4 ;64 BIT LONGFIX
ODDNUM EQU SQUARE+8 ;64 BIT LONGFIX
ODDBUMP EQU ODDNUM+8 ;64 BIT LONGFIX
LEFTEDGE EQU ODDBUMP+8 ;32 BIT FIXED POINT
RIGHTEDGE EQU LEFTEDGE+4 ;32 BIT FIXED POINT
ONEHALF EQU RIGHTEDGE+4 ;32 BIT FIXED POINT
OVALSIZE EQU ONEHALF+4 ;SIZE OF AN OVALREC
;------------------------------------------------
;
; A6 OFFSETS OF PARAMETERS AFTER LINK:
;
PARAMSIZE EQU 20 ;TOTAL SIZE OF PARAMETERS
DSTRECT EQU PARAMSIZE+8-4 ;ADDR OF RECT
HOLLOW EQU DSTRECT-2 ;BOOLEAN
OVALWIDTH EQU HOLLOW-2 ;INTEGER
OVALHEIGHT EQU OVALWIDTH-2 ;INTEGER
MODE EQU OVALHEIGHT-2 ;INTEGER
PAT EQU MODE-4 ;LONG, ADDR OF PATTERN
STARTANGLE EQU PAT-2 ;INTEGER
ARCANGLE EQU STARTANGLE-2 ;INTEGER
;-------------------------------------------------
;
; A6 OFFSETS OF LOCAL VARIABLES AFTER LINK:
;
EXPAT EQU -64 ;16 LONGS
MINRECT EQU EXPAT-8 ;RECT
STATEA EQU MINRECT-RGNREC ;RGN STATE RECORD
STATEB EQU STATEA-RGNREC ;RGN STATE RECORD
STATEC EQU STATEB-RGNREC ;RGN STATE RECORD
SAVESTK EQU STATEC-4 ;LONG
RECTFLAG EQU SAVESTK-2 ;WORD
MASKBUF EQU RECTFLAG-4 ;LONG
BUFLEFT EQU MASKBUF-2 ;WORD
BUFSIZE EQU BUFLEFT-2 ;WORD
MODECASE EQU BUFSIZE-4 ;LONG
DSTLEFT EQU MODECASE-4 ;LONG
SAVEA5 EQU DSTLEFT-4 ;LONG
PORT EQU SAVEA5-4 ;LONG
FASTFLAG EQU PORT-2 ;BYTE
TEMPRECT EQU FASTFLAG-8 ;RECT
INNEROVAL EQU TEMPRECT-OVALSIZE ;OVAL RECORD
OUTEROVAL EQU INNEROVAL-OVALSIZE ;OVAL RECORD
SKIPTOP EQU OUTEROVAL-2 ;WORD
SKIPBOT EQU SKIPTOP-2 ;WORD
ARCFLAG EQU SKIPBOT-1 ;BYTE FLAG
SKIPFLAG EQU ARCFLAG-1 ;BYTE FLAG
STOPANGLE EQU SKIPFLAG-2 ;INTEGER
MIDVERT EQU STOPANGLE-2 ;INTEGER
MIDHORIZ EQU MIDVERT-2 ;INTEGER
WIDTH EQU MIDHORIZ-2 ;INTEGER
HEIGHT EQU WIDTH-2 ;INTEGER
SLOPE1 EQU HEIGHT-4 ;LONG, FIXED POINT
SLOPE2 EQU SLOPE1-4 ;LONG, FIXED POINT
LINE1 EQU SLOPE2-4 ;LONG, FIXED POINT
LINE2 EQU LINE1-4 ;LONG, FIXED POINT
FLAG1 EQU LINE2-2 ;WORD
FLAG2 EQU FLAG1-2 ;WORD
OUTERLEFT EQU FLAG2-2 ;WORD
OUTERRIGHT EQU OUTERLEFT-2 ;WORD
INNERLEFT EQU OUTERRIGHT-2 ;WORD
INNERRIGHT EQU INNERLEFT-2 ;WORD
PATINDEX EQU INNERRIGHT-2 ;WORD
VARSIZE EQU PATINDEX ;SIZE OF LOCAL VARIABLES
LINK A6,#VARSIZE ;ALLOCATE LOCAL VARS
MOVEM.L D0-D7/A1-A5,-(SP) ;SAVE REGS
MOVE.L SP,SAVESTK(A6) ;REMEMBER STACK FOR LATER
MOVE.L A5,SAVEA5(A6) ;REMEMBER GLOBAL PTR
MOVE.L GRAFGLOBALS(A5),A0 ;POINT TO QUICKDRAW GLOBALS
MOVE.L THEPORT(A0),A3 ;GET CURRENT GRAFPORT
TST PNVIS(A3) ;IS PNVIS NEG ?
BLT GOHOME ;YES, QUIT
MOVE.L A3,PORT(A6) ;SAVE CURRENT GRAFPORT
;-------------------------------------------------------
;
; QUIT IF MODE NOT IN 8..15
;
MOVEQ #-8,D0 ;MASK TO KILL BOTTOM 3 BITS
AND MODE(A6),D0 ;GET ALL BUT 3 BITS OF MODE
CMP #8,D0 ;IS PEN MODE 8..15 ?
BNE GOHOME ;NO, QUIT
;----------------------------------------------------------------
;
; ADJUST MODE AND PATTERN IF COLOR FILTERING.
;
TST COLRBIT(A3) ;IS COLORBIT NEG ?
BMI.S NOCOLOR ;YES, DON'T MAP
MOVE MODE(A6),-(SP) ;PUSH INPUT MODE
MOVE.L PAT(A6),-(SP) ;PUSH ADDR OF INPUT PATTERN
JSR COLORMAP ;ALTER BY THECOLOR, THEFILTER
MOVE.L (SP)+,PAT(A6) ;GET (ALTERED) PATTERN
MOVE (SP)+,MODE(A6) ;GET (ALTERED) MODE
NOCOLOR MOVE.L A3,A5 ;PUT GRAFPORT IN A5
;---------------------------------------------------------
;
; GET CLIPRGN AND VISRGN HANDLES AND DE-REFERENCE THEM
;
MOVE.L CLIPRGN(A5),A2 ;GET CLIPRGN HANDLE
MOVE.L (A2),A2 ;GET CLIPRGN POINTER
MOVE.L VISRGN(A5),A3 ;GET VISRGN HANDLE
MOVE.L (A3),A3 ;GET VISRGN POINTER
;-----------------------------------------------------------------------
;
; CALC MINRECT, THE INTERSECTION OF DSTRECT, BITMAP BOUNDS,
; CLIPRGN BBOX, AND VISRGN BBOX. QUIT IF NO INTERSECTION.
;
MOVE.L DSTRECT(A6),-(SP) ;PUSH DSTRECT
PEA PORTBITS+BOUNDS(A5) ;PUSH BITMAP BOUNDS
PEA RGNBBOX(A2) ;PUSH CLIPRGN BBOX
PEA RGNBBOX(A3) ;PUSH VISRGN BBOX
MOVE #4,-(SP) ;PUSH NRECTS=4
PEA MINRECT(A6) ;PUSH DST ADDR
JSR RSECT ;CALC INTERSECTION
BEQ GOHOME ;QUIT IF NO INTERSECT
;
; CHECK FOR BOTH VISRGN AND CLIPRGN RECTANGULAR
;
CLR.B FASTFLAG(A6) ;FASTFLAG := FALSE
CMP #10,RGNSIZE(A2) ;IS CLIPRGN RECTANGULAR ?
BNE.S FLAGOK ;NO, CONTINUE
CMP #10,RGNSIZE(A3) ;IS VISRGN RECTANGULAR ?
BEQ.S CKPAT ;YES, CONTINUE
;
; If only visRgn is non-rectangular, then check if
; its intersection with minrect would be rectangular.
; IF TrimRect(visRgn,minRect) then treat as rectangular.
;
MOVE.L visRgn(A5),-(SP) ;push rgnHandle
PEA minRect(A6) ;push addr of minRect
JSR TrimRect ;call trimRect
BLT GOHOME ;quit if intersection empty
BGT.S FLAGOK ;continue if non-rectangular
;
; CHECK FOR BLACK OR WHITE PATTERN
;
CKPAT MOVE.L PAT(A6),A0 ;POINT TO PATTERN
MOVE.L (A0)+,D0 ;GET 1ST HALF OF PATTERN
CMP.L (A0)+,D0 ;IS IT SAME AS 2ND HALF ?
BNE.S FLAGOK ;NO, CONTINUE
NOT.L D0 ;IS PATTERN BLACK ?
BEQ.S YESFLAG ;YES, WE MADE IT
NOT.L D0 ;IS PATTERN WHITE ?
BNE.S FLAGOK ;NO, CONTINUE
EOR #4,MODE(A6) ;YES, ALTER MODE AS IF BLACK
YESFLAG ST FASTFLAG(A6) ;REMEMBER RECT CLIPPED AND BLACK
;
; fast case: map mode into black,xor,white, or do-nothing
;
MOVEQ #7,D0 ;GET 3 BIT MASK
AND MODE(A6),D0 ;GET 3 BITS OF MODE
MOVE.B MODEMAP(D0),D0 ;MAP TO BLACK,XOR,WHITE,NOP
BMI GOHOME ;QUIT IF DO-NOTHING MODE
MOVE D0,MODE(A6) ;UPDATE MODE
BRA.S FLAGOK ;AND CONTINUE
MODEMAP DC.B 0,0,1,2,2,255,255,255
FLAGOK
CLR.B SKIPFLAG(A6) ;INIT TO NOT SKIPPING
;--------------------------------------------------
;
; ADJUST IF ARCANGLE NEGATIVE, QUIT IF ARC = 0
; NOTE WHETHER FULL CIRCLE OR ARC
;
MOVE ARCANGLE(A6),D0 ;GET ARC ANGLE
BEQ GOHOME ;QUIT IF ARC ANGLE = 0
BPL.S POSANG ;IS ANGLE NEG ?
ADD D0,STARTANGLE(A6) ;YES, ADJUST START ANGLE
NEG D0 ;AND MAKE ARC ANGLE POSITIVE
MOVE D0,ARCANGLE(A6) ;UPDATE INPUT PARAM
POSANG CMP #360,D0 ;IS ARC ANGLE < 360 ?
SLT ARCFLAG(A6) ;REMEMBER FOR LATER
BGE NOTARC ;NO, SKIP SETUP
;---------------------------------------------------------------
;
; IF ARCANGLE < 360 THEN SET UP ARC STUFF
;
; TREAT STARTANGLE MOD 360
;
MOVE STARTANGLE(A6),D0 ;GET STARTANGLE
EXT.L D0 ;SIGN EXTEND FOR DIVIDE
DIVS #360,D0 ;TREAT STARTANGLE MOD 360
SWAP D0 ;GET THE REMAINDER
TST D0 ;WAS IT NEGATIVE ?
BPL.S STARTOK ;NO, CONTINUE
ADD #360,D0 ;YES, PUT IN RANGE 0..359
STARTOK MOVE D0,STARTANGLE(A6) ;REPLACE INPUT PARAM
ADD ARCANGLE(A6),D0 ;CALC STOPANGLE
CMP #360,D0 ;IS IT >= 360 ?
BLT.S STOPOK ;NO, CONTINUE
SUB #360,D0 ;YES, PUT IN RANGE 0..359
STOPOK MOVE D0,STOPANGLE(A6) ;SAVE STOPANGLE FOR LATER
MOVE.L DSTRECT(A6),A0 ;POINT TO DSTRECT
MOVE TOP(A0),D0
ADD BOTTOM(A0),D0
ASR #1,D0
MOVE D0,MIDVERT(A6) ;MID VERT := (DSTBOT+DSTTOP)/2
MOVE LEFT(A0),D0
ADD RIGHT(A0),D0
ASR #1,D0
MOVE D0,MIDHORIZ(A6) ;MID HORIZ := (DSTLEFT+DSTRIGHT)/2
MOVE RIGHT(A0),D0
SUB LEFT(A0),D0
MOVE D0,WIDTH(A6) ;WIDTH := DSTRIGHT - DSTLEFT
MOVE BOTTOM(A0),D0
SUB TOP(A0),D0
MOVE D0,HEIGHT(A6) ;HEIGHT := DSTBOTTOM -DSTTOP
CLR.L -(SP) ;MAKE ROOM FOR FCN RESULT
MOVE WIDTH(A6),-(SP)
MOVE HEIGHT(A6),-(SP)
_MFixRatio ;CALC ASPECT RATIO
MOVE.L (SP)+,D7 ;SAVE RESULT IN D7
;--------------------------------------------
;
; CALC SLOPE1 FROM STARTANGLE
;
CLR.L -(SP) ;MAKE ROOM FOR FCN RESULT
MOVE STARTANGLE(A6),-(SP) ;PUSH STARTANG
JSR SlopeFromAngle ;CALC SLOPE1
MOVE.L (SP)+,D0 ;POP SLOPE1
CLR.L -(SP) ;ROOM FOR FCN RESULT
MOVE.L D0,-(SP) ;PUSH SLOPE1
MOVE.L D7,-(SP) ;PUSH ASPECT RATIO
_MFixMul ;scale slope1
MOVE.L (SP)+,SLOPE1(A6) ;SAVE RESULT FOR LATER
;--------------------------------------------
;
; CALC SLOPE2 FROM STOPANGLE
;
CLR.L -(SP) ;MAKE ROOM FOR FCN RESULT
MOVE STOPANGLE(A6),-(SP) ;PUSH STOPANGLE
JSR SlopeFromAngle ;CALC SLOPE2
MOVE.L (SP)+,D0 ;POP SLOPE2
CLR.L -(SP) ;ROOM FOR FCN RESULT
MOVE.L D0,-(SP) ;PUSH SLOPE
MOVE.L D7,-(SP) ;PUSH ASPECT RATIO
_MFixMul ;SCALE SLOPE2
MOVE.L (SP)+,SLOPE2(A6) ;SAVE RESULT FOR LATER
;---------------------------------------------------------
;
; CALC HORIZ COORDS OF LINE1 AND LINE2 AT TOP OF DSTRECT
;
MOVE MIDHORIZ(A6),D6
SWAP D6
CLR.W D6 ;CALC MIDHORIZ*64K
MOVE HEIGHT(A6),D7
LSR #1,D7 ;CALC HEIGHT DIV 2
MOVE SLOPE1+2(A6),D0 ;GET LO WORD OF SLOPE
MULU D7,D0 ;CALC LO PARTIAL PRODUCT
MOVE.L D0,LINE1(A6) ;ACCUMULATE IT
MOVE.W SLOPE1(A6),D0 ;GET HI WORD OF SLOPE
MULS D7,D0 ;CALC HI PARTIAL PRODUCT
ADD.W D0,LINE1(A6) ;ADD TO HI WORD OF ACCUMULATOR
MOVE.L D6,D0 ;COPY MIDHORIZ*64K
SUB.L LINE1(A6),D0 ;CALC MIDH*64K-SLOPE*(HT DIV 2)
MOVE.L D0,LINE1(A6) ;STORE AS LINE1 HORIZ AT TOP
MOVE SLOPE2+2(A6),D0 ;GET LO WORD OF SLOPE
MULU D7,D0 ;CALC LO PARTIAL PRODUCT
MOVE.L D0,LINE2(A6) ;ACCUMULATE IT
MOVE.W SLOPE2(A6),D0 ;GET HI WORD OF SLOPE
MULS D7,D0 ;CALC HI PARTIAL PRODUCT
ADD.W D0,LINE2(A6) ;ADD TO HI WORD OF ACCUMULATOR
SUB.L LINE2(A6),D6 ;CALC MIDH*64K-SLOPE*(HT DIV 2)
MOVE.L D6,LINE2(A6) ;STORE AS LINE2 HORIZ AT TOP
;----------------------------------------------------------
;
; SET UP FLAG1 AND FLAG2 TO TELL WHICH HALF EACH LINE IS ACTIVE IN:
; CODE IS: NEG = ACTIVE IN TOP, POS = ACTIVE IN BOTTOM, 0 = HORIZONTAL
;
MOVE STARTANGLE(A6),D0
CMP #180,D0 ;IS STARTANGLE < 180 ?
BGE.S @1 ;NO, CONTINUE
SUB #90,D0 ;YES, FLAG1:=STARTANGLE-90
BRA.S @2 ;CONTINUE
@1 SUB #270,D0
NEG D0 ;FLAG1 := 270-STARTANGLE
@2 MOVE D0,FLAG1(A6) ;SAVE FOR LATER
MOVE STOPANGLE(A6),D0
CMP #180,D0 ;IS STOPANGLE < 180 ?
BGE.S @3 ;NO, CONTINUE
SUB #90,D0 ;YES, FLAG2:=STOPANGLE-90
BRA.S @4 ;CONTINUE
@3 SUB #270,D0
NEG D0 ;FLAG2 := 270-STOPANGLE
@4 MOVE D0,FLAG2(A6) ;SAVE FOR LATER
;
; SET UP SKIPFLAG TO SKIP OVER UNUSED ARC PORTIONS
;
MOVE ARCANGLE(A6),D0
CMP #180,D0 ;IS ARC ANGLE > 180 ?
BGT.S OBTUSE ;SKIP IF ANGLE > 180
BLT.S ACUTE ;DEAL WITH ACUTE ANGLE
CMP #90,STARTANGLE(A6) ;OTHERWISE ANGLE=180
SEQ SKIPFLAG(A6) ;SO SKIP IF START=90
BRA.S OBTUSE
ACUTE MOVE FLAG1(A6),D0
OR FLAG2(A6),D0
SPL SKIPFLAG(A6) ;SKIP:=FLAG1 AND FLAG2 BOTH >= 0
OBTUSE
NOTARC
;---------------------------------------------------------------
;
; INIT OUTER OVAL STATE RECORD
;
MOVE.L DSTRECT(A6),A0 ;POINT TO DSTRECT
LEA OUTEROVAL(A6),A1 ;POINT TO OUTER OVAL RECORD
MOVE OVALHEIGHT(A6),D1 ;GET OVALHEIGHT
MOVE OVALWIDTH(A6),D2 ;GET OVALWIDTH
JSR INITOVAL ;INITIALIZE OUTER OVAL RECORD
MOVE OVALHEIGHT(A6),D0 ;GET OVALHEIGHT
ASR #1,D0 ;CALC OVAL HEIGHT DIV 2
ADD OUTEROVAL+OVALTOP(A6),D0 ;ADD OUTEROVAL TOP
MOVE D0,SKIPTOP(A6) ;SAVE SKIPTOP
MOVE.L DSTRECT(A6),A0 ;POINT TO DSTRECT
ADD BOTTOM(A0),D0 ;ADD BOTTOM
SUB TOP(A0),D0 ;SUBTRACT TOP
SUB OVALHEIGHT(A6),D0 ;SUBTRACT OVALHEIGHT
MOVE D0,SKIPBOT(A6) ;SAVE SKIPBOT
;---------------------------------------------------
;
; IF THIS IS A HOLLOW OVAL, THEN CALC DSTRECT INSET BY PENSIZE,
; AND INIT INNEROVAL. (IF INNEROVAL EMPTY, SWITCH TO SOLID).
;
MOVE #32767,INNEROVAL+OVALTOP(A6) ;INIT INNEROVAL NOT USED
TST.B HOLLOW(A6) ;IS HOLLOWFLAG TRUE ?
BEQ.S SOLID ;NO, SKIP INNER OVAL
MOVE.L DSTRECT(A6),A0 ;POINT TO DSTRECT
MOVEM.W (A0),D0-D3 ;GET DSTRECT INTO REGS
MOVE.L PNSIZE(A5),D4 ;GET THEPORT^.PNSIZE
ADD D4,D1 ;LEFT := DSTLEFT + PENWIDTH
SUB D4,D3 ;RIGHT := DSTRIGHT - PENWIDTH
CMP D3,D1 ;IS LEFT >= TOP ?
BGE.S SOLID ;YES, EMPTY RECT
SWAP D4 ;GET PNSIZE.V
ADD D4,D0 ;TOP := DSTTOP + PENHEIGHT
SUB D4,D2 ;BOTTOM := DSTBOTTOM - PENHEIGHT
CMP D2,D0 ;IS TOP >= BOTTOM ?
BGE.S SOLID ;YES, EMPTY RECT
MOVEM.W D0-D3,TEMPRECT(A6) ;STORE RESULTS INTO TEMPRECT
LEA TEMPRECT(A6),A0 ;POINT TO DSTRECT INSET BY PENSIZE
LEA INNEROVAL(A6),A1 ;POINT TO INNER OVAL RECORD
MOVE OVALHEIGHT(A6),D1
SUB D4,D1 ;INNER HEIGHT:=OUTER-2*PENHEIGHT
SUB D4,D1
MOVE OVALWIDTH(A6),D2
SWAP D4 ;GET PEN WIDTH
SUB D4,D2 ;INNER WIDTH:=OUTER-2*PENWIDTH
SUB D4,D2
JSR INITOVAL ;INITIALIZE INNER OVAL RECORD
SOLID
;----------------------------------------------------------------
;
; HIDE CURSOR IF CURSOR INTERSECTS MINRECT.
;
PEA MINRECT(A6) ;PUSH SHIELDRECT PARAMETER
MOVE.L PORTBITS+BOUNDS+TOPLEFT(A5),-(SP) ;PUSH DELTA TO CONVERT TO GLOBAL
MOVE.L SAVEA5(A6),A5 ;GET GLOBAL PTR
JSR SHIELDCURSOR ;HIDE CURSOR IF IT INTERSECTS
MOVE.L PORT(A6),A5 ;RESTORE GRAFPORT IN A5
;------------------------------------
;
; CALC BUFLEFT
;
MOVE MINRECT+LEFT(A6),D2 ;GET MINRECT LEFT
SUB PORTBITS+BOUNDS+LEFT(A5),D2 ;CONVERT TO GLOBAL COORDS
AND #$FFF0,D2 ;TRUNC TO MULT OF 16
ADD PORTBITS+BOUNDS+LEFT(A5),D2 ;CONVERT BACK TO GLOBAL
MOVE D2,BUFLEFT(A6) ;SAVE AS BUFLEFT
;
; IF FASTFLAG, THEN SKIP REGION SETUP
;
TST.B FASTFLAG(A6) ;RECT CLIPPED AND BLACK ?
BNE SKIPSETUP ;YES, DON'T WASTE TIME WITH SETUP
;
; CALC BUFSIZE
;
MOVE MINRECT+RIGHT(A6),D0 ;GET MINRECT RIGHT
SUB D2,D0 ;CALC MAXH-BUFLEFT
LSR #5,D0 ;DIV BY 32 FOR LONGS
MOVE D0,BUFSIZE(A6) ;BUFSIZE = # LONGS - 1
;-------------------------------------------------------------------------
;
; ALLOCATE AND CLEAR A SCANLINE BUFFER FOR THE COMPOSITE MASK
;
CLRMASK CLR.L -(SP) ;ALLOCATE AND CLEAR ONE LONG
DBRA D0,CLRMASK ;LOOP TILL DONE
MOVE.L SP,MASKBUF(A6) ;REMEMBER WHERE MASKBUF IS
;-------------------------------------------------------------------------
;
; INIT STATE RECORDS AND ALLOCATE BUFFERS FOR EACH NON-RECTANGULAR REGION
;
CLR D5 ;INIT BOTH ARE RECT
MOVE #-32767,STATEA+THISV(A6) ;INIT REGION STATEA
MOVE #32767,STATEA+NEXTV(A6) ;TO HARMLESS IN CASE RECT
CMP #10,RGNSIZE(A2) ;IS CLIPRGN RECTANGULAR ?
BEQ.S ARECT ;YES, CONTINUE
ADD #2,D5 ;NO, SET ITS FLAG
MOVE.L A2,A0 ;POINT TO CLIPRGN
LEA STATEA(A6),A1 ;POINT TO STATE RECORD A
BSR.S INITONE ;INIT STATE, ALLOC BUFFER
ARECT
MOVE #-32767,STATEB+THISV(A6) ;INIT REGION STATEB
MOVE #32767,STATEB+NEXTV(A6) ;TO HARMLESS IN CASE RECT
CMP #10,RGNSIZE(A3) ;IS VISRGN RECTANGULAR ?
BEQ.S BRECT ;YES, CONTINUE
ADD #4,D5 ;NO, SET ITS FLAG
MOVE.L A3,A0 ;POINT TO VISRGN
LEA STATEB(A6),A1 ;POINT TO STATE RECORD B
PEA BRECT ;PUSH FAKE RETURN ADDR
INITONE MOVE MINRECT+LEFT(A6),D0 ;GET MINH
MOVE MINRECT+RIGHT(A6),D1 ;GET MAXH
MOVE BUFLEFT(A6),D2 ;GET BUFLEFT
JMP INITRGN ;INIT STATE, ALLOC BUFFER
BRECT
;--------------------------------------------------------------------
;
; IF BOTH REGIONS ARE RECTANGULAR, THEN DRAW MINRECT INTO MASK BUFFER
;
MOVE.W D5,RECTFLAG(A6) ;ARE ALL RGNS RECT ?
BNE.S NOTRECT ;NO, CONTNUE
MOVE.L MASKBUF(A6),A0 ;YES, POINT TO MASK BUFFER
MOVE MINRECT+LEFT(A6),D3 ;SET UP LEFT
SUB BUFLEFT(A6),D3 ;MAKE IT BUFFER RELATIVE
MOVE MINRECT+RIGHT(A6),D4 ;SET UP RIGHT
SUB BUFLEFT(A6),D4 ;MAKE IT BUFFER RELATIVE
JSR XorSlab ;AND XOR BETWEEN THEM
NOTRECT
SKIPSETUP
;------------------------------------
;
; CALC STARTING DSTLEFT
;
MOVE MINRECT+TOP(A6),D1 ;GET MINRECT TOP
SUB PORTBITS+BOUNDS+TOP(A5),D1 ;CONVERT TO GLOBAL COORDS
MULU PORTBITS+ROWBYTES(A5),D1 ;MULT BY DST ROWBYTES
ADD.L PORTBITS+BASEADDR(A5),D1 ;ADD START OF BITMAP
SUB PORTBITS+BOUNDS+LEFT(A5),D2 ;CONVERT BUFLEFT TO GLOBAL
LSR #3,D2 ;CALC BUFLEFT DIV 8
EXT.L D2 ;CLR HI WORD
ADD.L D2,D1 ;ADD HORIZ BYTE OFFSET
MOVE.L D1,DSTLEFT(A6) ;SAVE AS DSTLEFT
;----------------------------------------------------
;
; MAKE ALL HORIZONTAL COORDINATES RELATIVE TO BUFFER
;
MOVE BUFLEFT(A6),D1
SUB D1,MINRECT+LEFT(A6)
SUB D1,MINRECT+RIGHT(A6)
SUB.W D1,OUTEROVAL+LEFTEDGE(A6) ;ADJUST OUTEROVAL LEFTEDGE.INT
SUB.W D1,OUTEROVAL+RIGHTEDGE(A6) ;ADJUST OUTEROVAL RIGHTEDGE.INT
SUB.W D1,INNEROVAL+LEFTEDGE(A6) ;ADJUST INNEROVAL LEFTEDGE.INT
SUB.W D1,INNEROVAL+RIGHTEDGE(A6) ;ADJUST INNEROVAL RIGHTEDGE.INT
SUB.W D1,LINE1(A6) ;ADJUST LINE1
SUB.W D1,LINE2(A6) ;ADJUST LINE2
;---------------------------------------------------
;
; SET UP CASE JUMP BASED ON MODE AND FASTFLAG
;
MOVE MODE(A6),D2 ;GET (ALTERED) PEN MODE
TST.B FastFlag(A6) ;Rect clipoped and black ?
BEQ.S @1 ;no, use slow drawslab loop
JSR FastSlabMode ;yes, get fast modeCase in A4
MOVE.L A4,MODECASE(A6) ;SAVE FOR LATER
CLR PATINDEX(A6) ;MAKE UNUSED PATINDEX EVEN
BRA GOFORIT ;SKIP PATTERN STUFF
@1 JSR SlabMode ;get slow modeCase in A4
MOVE.L A4,MODECASE(A6) ;SAVE FOR LATER
;------------------------------------------------------------------
;
; EXPAND 8 BYTE PATTERN TO 16 LONGS AND INIT PATTERN SELECTOR
;
CLR.L D7 ;SAY NOT INVERTED
MOVE MODE(A6),D2 ;GET MODE
BCLR #2,D2 ;TEST AND CLR INVERT BIT
BEQ.S NOTINV ;SKIP IF NOT INVERTED
NOT.L D7 ;INVERTED; D7 GETS ALL 1'S
NOTINV MOVE PORTBITS+BOUNDS+LEFT(A5),D2 ;GET GLOBAL-LOCAL OFFSET
MOVE.L PAT(A6),A0 ;POINT TO BYTE WIDE PATTERN
LEA EXPAT(A6),A1 ;POINT TO EXPANDED PATTERN
MOVE.L SAVEA5(A6),A5 ;GET GLOBAL PTR
JSR PATEXPAND ;EXPAND 8 BYTE PATTERN TO 16 LONGS
MOVE.L PORT(A6),A5 ;RESTORE GRAFPORT IN A5
MOVEQ #$F,D0 ;TREAT COORD MOD 16
AND MINRECT+TOP(A6),D0 ;GET TOP VERT LOCAL COORD
LSL #2,D0 ;QUAD FOR 4 BYTE PATTERNS
MOVE D0,PATINDEX(A6) ;SET UP PATTERN INDEX
;------------------------------------------------------------
;
; BUMP OVAL STATE RECORDS UNLESS VERT IS BETWEEN SKIPTOP AND SKIPBOT
;
GOFORIT MOVE OUTEROVAL+OVALTOP(A6),D7 ;START VERT:= OUTER OVAL TOP
NEXTROW CMP SKIPTOP(A6),D7 ;IS VERT < SKIPTOP ?
BLT.S YESBUMP ;YES, OK TO BUMP OVALS
CMP SKIPBOT(A6),D7 ;IS VERT >= SKIPBOT ?
BLT.S NOBUMP ;NO, SKIP BUMPING
YESBUMP MOVE D7,-(SP) ;STASH CURRENT VERT
MOVE D7,D0 ;COPY CURRENT VERTICAL
LEA OUTEROVAL(A6),A3 ;POINT TO OUTER OVAL STATE RECORD
JSR BUMPOVAL ;BUMP IT TO NEXT SCANLINE
MOVE (SP),D0 ;COPY CURRENT VERT
LEA INNEROVAL(A6),A3 ;POINT TO INNER OVAL STATE RECORD
JSR BUMPOVAL ;BUMP IT TO NEXT SCANLINE
MOVE (SP)+,D7 ;RECOVER SAVED CURRENT VERT
;--------------------------------------------------
;
; ADJUST ARC STUFF AS WE CROSS THE MIDDLE VERTICALLY
;
NOBUMP CMP MIDVERT(A6),D7 ;IS CURRENT VERT = MIDVERT ?
BNE.S NOTMID ;NO, CONTINUE
TST.B ARCFLAG(A6) ;ARE WE DOING AN ARC ?
BEQ.S NOTMID ;NO, SKIP
NEG FLAG1(A6) ;YES, INVERT FLAGS AS WE CROSS
NEG FLAG2(A6)
;
; RE-CALCULATE SKIPFLAG, AND QUIT IF IT BECOMES TRUE
;
CLR.B SKIPFLAG(A6)
MOVE ARCANGLE(A6),D0
CMP #180,D0 ;IS ARC ANGLE > 180 ?
BGT.S OBTUSE1 ;SKIP IF ANGLE > 180
BLT.S ACUTE1 ;DEAL WITH ACUTE ANGLE
CMP #270,STARTANGLE(A6) ;IS STARTANGLE = 270 ?
BNE.S OBTUSE1 ;NO, CONTINUE
BRA DONE ;YES, WE'RE ALL DONE
ACUTE1 MOVE FLAG1(A6),D0
OR FLAG2(A6),D0
BPL DONE ;QUIT IF BOTH FLAG1 AND FLAG2>=0
OBTUSE1
;
; NOW SWAP THE ROLES OF LINE1 AND LINE2 AS THEY CROSS THE MIDDLE
;
MOVE FLAG1(A6),D0 ;SWAP FLAG1 AND FLAG2
MOVE FLAG2(A6),FLAG1(A6)
MOVE D0,FLAG2(A6)
MOVE.L LINE1(A6),D0 ;SWAP LINE1 AND LINE2
MOVE.L LINE2(A6),LINE1(A6)
MOVE.L D0,LINE2(A6)
MOVE.L SLOPE1(A6),D0 ;SWAP SLOPE1 AND SLOPE2
MOVE.L SLOPE2(A6),SLOPE1(A6)
MOVE.L D0,SLOPE2(A6)
NOTMID CMP MINRECT+TOP(A6),D7 ;IS CURRENT VERT < MINV ?
BLT NODRAW ;YES, DON'T DRAW
TST.B SKIPFLAG(A6) ;ARE WE SKIPPING ?
BNE NEXTPAT ;YES, SKIP
;------------------------------------------------
;
; SEEK MASK TO THE CURRENT VERTICAL, AND
; BRANCH BASED ON SOLID OR HOLLOW OVAL OR ARC.
;
TST.B FASTFLAG(A6) ;RECT CLIPPED AND BLACK ?
BNE.S NOMASK ;YES, DON'T BOTHER WITH MASK
BSR SEEKMASK ;MAKE MASKBUF CURRENT
NOMASK TST.B ARCFLAG(A6) ;ARE WE DOING AN ARC ?
BNE.S DOARC ;YES, GO TO IT
CMP INNEROVAL+OVALTOP(A6),D7 ;IS VERT >= INNEROVAL OVALTOP ?
BLT SOVAL ;NO, TREAT AS SOLID OVAL
CMP INNEROVAL+OVALBOT(A6),D7 ;IS VERT < INNEROVAL OVALTOP ?
BGE SOVAL ;NO, TREAT AS SOLID OVAL
BRA HOVAL ;YES, PROCESS HOLLOW OVAL
;----------------------------------------------
;
; SOLID OR HOLLOW ARC: CALC OUTERLEFT AND OUTERRIGHT
;
DOARC MOVE.W OUTEROVAL+LEFTEDGE(A6),D1 ;GET HI WORD OF OUTEROVAL LEFT
TST FLAG1(A6) ;IS LINE1 ACTIVE ?
BPL.S @1 ;NO, CONTINUE
CMP.W LINE1(A6),D1 ;YES, CHECK LINE1 HORIZ COORD
BGE.S @1
MOVE.W LINE1(A6),D1 ;CALC MAX(OVALLEFT,LINE1)
@1 MOVE D1,OUTERLEFT(A6) ;SAVE OUTER LEFT
MOVE.W OUTEROVAL+RIGHTEDGE(A6),D2 ;GET HI WORD OF OUTEROVAL RIGHT
TST FLAG2(A6) ;IS LINE2 ACTIVE ?
BPL.S @2 ;NO, CONTINUE
CMP.W LINE2(A6),D2 ;YES, CHECK LINE2 HORIZ COORD
BLE.S @2
MOVE.W LINE2(A6),D2 ;CALC MIN(OVALRIGHT,LINE2)
@2 MOVE D2,OUTERRIGHT(A6) ;SAVE OUTER RIGHT
CMP INNEROVAL+OVALTOP(A6),D7 ;IS VERT >= INNEROVAL OVALTOP ?
BLT SARC ;NO, PROCESS SOLID ARC
CMP INNEROVAL+OVALBOT(A6),D7 ;IS VERT < INNEROVAL OVALTOP ?
BGE SARC ;NO, PROCESS SOLID ARC
;--------------------------------------------------
;
; HOLLOW ARC: CALC INNERLEFT AND INNERRIGHT
;
HARC MOVE.W INNEROVAL+LEFTEDGE(A6),D0 ;GET HI WORD OF INNEROVAL LEFT
TST FLAG2(A6) ;IS LINE2 ACTIVE ?
BPL.S @1 ;NO, CONTINUE
CMP.W LINE2(A6),D0 ;YES, CHECK LINE2 HORIZ COORD
BLE.S @1
MOVE.W LINE2(A6),D0 ;CALC MIN(OVALLEFT,LINE2)
@1 MOVE D0,INNERLEFT(A6) ;SAVE INNER LEFT
MOVE.W INNEROVAL+RIGHTEDGE(A6),D0 ;GET HI WORD OF INNEROVAL RIGHT
TST FLAG1(A6) ;IS LINE1 ACTIVE ?
BPL.S @2 ;NO, CONTINUE
CMP.W LINE1(A6),D0 ;YES, CHECK LINE1 HORIZ COORD
BGE.S @2
MOVE.W LINE1(A6),D0 ;CALC MAX(OVALRIGHT,LINE1)
@2 MOVE D0,INNERRIGHT(A6) ;SAVE INNER RIGHT
;--------------------------------------------------
;
; IF OUTERLEFT < OUTERRIGHT THEN PAINT TWO SLABS
;
CMP D2,D1 ;IS OUTERLEFT < OUTERRIGHT ?
BGE.S @3 ;NO, CONTINUE
MOVE INNERLEFT(A6),D2
BSR.S ONESLAB
MOVE INNERRIGHT(A6),D1
MOVE OUTERRIGHT(A6),D2
BRA DOSLAB
@3
;
; ELSE IF BOTH LINES ACTIVE AND ANGLE > 180 THEN PAINT TWO OR THREE SLABS
;
MOVE FLAG1(A6),D0
AND FLAG2(A6),D0 ;ARE BOTH LINES ACTIVE ?
BPL NEXTPAT ;NO, CONTINUE
CMP #180,ARCANGLE(A6) ;IS THE ANGLE > 180 ?
BLE NEXTPAT ;NO, CONTINUE
CMP INNERLEFT(A6),D2 ;IS INNERLEFT=OUTERRIGHT?
BNE.S @4 ;NO, CONTINUE
MOVE.W INNEROVAL+LEFTEDGE(A6),D2 ;YES DRAW A THIRD SLAB
BRA.S @5
@4 MOVE OUTERLEFT(A6),D0
CMP INNERRIGHT(A6),D0 ;IS INNERRIGHT=OUTERLEFT ?
BNE.S NOT3 ;NO, CONTINUE
MOVE.W INNEROVAL+RIGHTEDGE(A6),D1 ;YES, DRAW A THIRD SLAB
MOVE OUTERRIGHT(A6),D2
@5 BSR.S ONESLAB
NOT3
MOVE OUTEROVAL+LEFTEDGE(A6),D1
MOVE INNERLEFT(A6),D2
BSR.S ONESLAB
MOVE INNERRIGHT(A6),D1
MOVE.W OUTEROVAL+RIGHTEDGE(A6),D2
BRA.S DOSLAB
;---------------------------------------------------------
;
; LOCAL PROCEDURE TO SET UP AND DRAW ONE SLAB
;
ONESLAB MOVEQ #$3F,D6 ;GET WRAP-AROUND MASK
AND PATINDEX(A6),D6 ;GET PATINDEX MOD 64
MOVE.L EXPAT(A6,D6),D6 ;GET THIS ROW'S PATTERN
LEA MaskTab,A0 ;POINT TO MASK TABLE
MOVE.L DSTLEFT(A6),A1 ;INIT DSTPTR TO LEFT
MOVE.L MASKBUF(A6),A2 ;INIT MASKPTR TO LEFT
LEA MINRECT(A6),A3 ;POINT TO MINRECT
MOVE.L MODECASE(A6),A4 ;GET MODE CASE JUMP
JMP DrawSlab
;----------------------------------------------------
;
; SOLID ARC: IF OUTERLEFT < OUTERRIGHT THEN PAINT ONE SLAB
;
SARC CMP D2,D1 ;IS OUTERLEFT < OUTERRIGHT ?
BLT.S DOSLAB ;YES, DO ONE SLAB BETWEEN THEM
;
; ELSE IF BOTH LINES ACTIVE AND ANGLE > 180 THEN PAINT TWO SLABS
;
MOVE FLAG1(A6),D0
AND FLAG2(A6),D0 ;ARE BOTH LINES ACTIVE ?
BPL.S NEXTPAT ;NO, CONTINUE
CMP #180,ARCANGLE(A6) ;IS THE ANGLE > 180 ?
BLE.S NEXTPAT ;NO, CONTINUE
MOVE OUTEROVAL+LEFTEDGE(A6),D1
BSR ONESLAB
MOVE OUTERLEFT(A6),D1
MOVE.W OUTEROVAL+RIGHTEDGE(A6),D2
BRA.S DOSLAB
;--------------------------------------------------
;
; HOLLOW OVAL: DRAW TWO SLABS BETWEEN OUTER AND INNER OVALS
;
HOVAL MOVE.W OUTEROVAL+LEFTEDGE(A6),D1 ;GET OUTEROVAL LEFTEDGE.INT
MOVE.W INNEROVAL+LEFTEDGE(A6),D2 ;GET INNEROVAL LEFTEDGE.INT
BSR ONESLAB ;DRAW HORIZ SLAB BETWEEN THEM
MOVE.W INNEROVAL+RIGHTEDGE(A6),D1 ;GET OUTEROVAL RIGHTEDGE.INT
MOVE.W OUTEROVAL+RIGHTEDGE(A6),D2 ;GET INNEROVAL RIGHTEDGE.INT
BSR ONESLAB ;DRAW HORIZ SLAB BETWEEN THEM
BRA.S NEXTPAT
;----------------------------------------------------
;
; SOLID OVAL: DRAW ONE SLAB BETWEEN LEFT AND RIGHT EDGES OF OUTER OVAL
;
SOVAL MOVE.W OUTEROVAL+LEFTEDGE(A6),D1 ;GET OUTEROVAL LEFTEDGE.INT
MOVE.W OUTEROVAL+RIGHTEDGE(A6),D2 ;GET OUTEROVAL RIGHTEDGE.INT
DOSLAB BSR ONESLAB ;DRAW HORIZ SLAB BETWEEN THEM
;-------------------------------------------------------------------
;
; BUMP DESTINATION VERTICALLY AND LOOP FOR ALL SCAN LINES
;
NEXTPAT ADD #4,PATINDEX(A6) ;BUMP PATTERN INDEX
MOVE PORTBITS+ROWBYTES(A5),D0 ;GET DST ROWBYTES
EXT.L D0 ;MAKE IT LONG
ADD.L D0,DSTLEFT(A6) ;BUMP DST TO NEXT ROW
NODRAW MOVE.L SLOPE1(A6),D0 ;BUMP LINE1 AND LINE2
ADD.L D0,LINE1(A6)
MOVE.L SLOPE2(A6),D0
ADD.L D0,LINE2(A6)
ADD #1,D7 ;BUMP CURRENT VERT
CMP MINRECT+BOTTOM(A6),D7 ;HAVE WE REACHED THE BOTTOM YET ?
BLT NEXTROW ;NO, LOOP FOR MORE
DONE MOVE.L SAVEA5(A6),A5 ;GET GLOBAL PTR
JSR SHOWCURSOR ;RESTORE CURSOR
GOHOME MOVE.L SAVESTK(A6),SP ;STRIP BUFFER
MOVEM.L (SP)+,D0-D7/A1-A5 ;RESTORE REGISTERS
UNLINK PARAMSIZE,'DRAWARC '
;-----------------------------------------------------------------------------
;
; LOCAL ROUTINE TO UPDATE THE MASK BUFFER
; BASED ON WHICH REGIONS ARE RECTANGULAR
;
SEEKMASK MOVE D7,D0 ;GET CURRENT VERT COORD
MOVE RECTFLAG(A6),D1 ;GET RECTFLAG = 0,2,4
MOVE RECTJMP(D1),D1 ;GET OFFSET FROM TABLE
JMP RECTJMP(D1) ;TAKE CASE JUMP
RECTJMP DC.W IGNORE-RECTJMP ;DO NOTHING IF BOTH RECT
DC.W A-RECTJMP
DC.W B-RECTJMP
DC.W AB-RECTJMP
;
; ONLY REGION A IS NON RECTANGULAR. UPDATE IT AND USE IT AS THE MASK
;
A LEA STATEA(A6),A1
JSRSEEK JSR SEEKRGN
MOVE.L SCANBUF(A1),MASKBUF(A6)
IGNORE RTS
;
; ONLY REGION B IS NON RECTANGULAR. UPDATE IT AND USE IT AS THE MASK
;
B LEA STATEB(A6),A1
BRA.S JSRSEEK
;
; REGIONS A AND B ARE NON-RECTANGULAR. UPDATE EACH,
; THEN FORM INTERSECTION IN THE MASK BUFFER.
;
AB LEA STATEA(A6),A1
JSR SEEKRGN
LEA STATEB(A6),A1
JSR SEEKRGN
MOVE.L STATEA+SCANBUF(A6),A0
MOVE.L STATEB+SCANBUF(A6),A1
MOVE.L MASKBUF(A6),A2
MOVE BUFSIZE(A6),D1
ABLOOP MOVE.L (A0)+,D0
AND.L (A1)+,D0
MOVE.L D0,(A2)+
DBRA D1,ABLOOP
RTS
INITOVAL PROC EXPORT
;------------------------------------------------------------
;
; PROCEDURE InitOval(dstRect: Rect; VAR oval: OvalRec;
; ovalWidth,ovalHeight: INTEGER);
;
; initialize an oval state record to fit the given rectangle.
;
; INPUTS: A0: dstRect
; A1: ovalRec
; D1: ovalHeight
; D2: ovalWidth
;
; CLOBBERS D0,D1,D2
;
;------------------------------------------------------
;
; OFFSETS IN AN OVAL STATE RECORD:
;
OVALTOP EQU 0 ;INTEGER
OVALBOT EQU OVALTOP+2 ;INTEGER
OVALY EQU OVALBOT+2 ;INTEGER
RSQYSQ EQU OVALY+2 ;LONGINT
SQUARE EQU RSQYSQ+4 ;64 BIT LONGFIX
ODDNUM EQU SQUARE+8 ;64 BIT LONGFIX
ODDBUMP EQU ODDNUM+8 ;64 BIT LONGFIX
LEFTEDGE EQU ODDBUMP+8 ;32 BIT FIXED POINT
RIGHTEDGE EQU LEFTEDGE+4 ;32 BIT FIXED POINT
ONEHALF EQU RIGHTEDGE+4 ;32 BIT FIXED POINT
OVALSIZE EQU ONEHALF+4 ;SIZE OF AN OVALREC
;-----------------------------------------------------------
;
; INIT OVAL TOP AND BOTTOM TO DSTRECT TOP AND BOTTOM
;
MOVE TOP(A0),OVALTOP(A1) ;INIT OVAL TOP
MOVE BOTTOM(A0),OVALBOT(A1) ;INIT OVAL BOTTOM
; CHECK OVALWIDTH AND OVALHEIGHT, PIN AT 0
TST D2 ;IS OVALWIDTH NEGATIVE ?
BPL.S OK1 ;NO, CONTINUE
CLR D2 ;YES, PIN IT TO 0
OK1 TST D1 ;IS OVALHEIGHT NEGATIVE ?
BPL.S OK2 ;NO, CONTINUE
CLR D1 ;YES, PIN IT TO 0
OK2
; CHECK OVALWIDTH AND OVALHEIGHT, TRIM IF BIGGER THAN DSTRECT
MOVE RIGHT(A0),D0
SUB LEFT(A0),D0 ;CALC DSTRECT WIDTH
CMP D0,D2 ;IS OVALWIDTH > DSTWIDTH ?
BLE.S OK3 ;NO,CONTINUE
MOVE D0,D2 ;YES, OVALWIDTH:= DSTWIDTH
OK3 MOVE BOTTOM(A0),D0
SUB TOP(A0),D0 ;CALC DSTRECT HEIGHT
CMP D0,D1 ;IS OVALHEIGHT > DSTHEIGHT ?
BLE.S OK4 ;NO,CONTINUE
MOVE D0,D1 ;YES, OVALHEIGHT:= DSTHEIGHT
OK4
; SET UP OVAL LEFT EDGE AND OVAL RIGHT EDGE, FIXED POINT NUMBERS
MOVE.W RIGHT(A0),RIGHTEDGE(A1) ;RIGHTEDGE.INT := DSTRECT.RIGHT
CLR.W RIGHTEDGE+2(A1) ;RIGHTEDGE.FRACT := 0
MOVE.W LEFT(A0),LEFTEDGE(A1) ;LEFTEDGE.INT := DSTRECT.LEFT
CLR.W LEFTEDGE+2(A1) ;LEFTEDGE.FRACT := 0
MOVE D2,D0 ;GET OVAL WIDTH
SWAP D0 ;PUT IN HI WORD
CLR D0 ;CLEAR LO WORD FOR FIXED POINT
LSR.L #1,D0 ;CALC OVAL WIDTH DIV 2
ADD.L D0,LEFTEDGE(A1) ;ADD OVALWD/2 TO LEFTEDGE
SUB.L D0,RIGHTEDGE(A1) ;SUBTRACT OVALWD/2 FROM LEFTEDGE
MOVE.L #$00008000,D0 ;GET FIXED POINT 1/2
MOVE.L D0,ONEHALF(A1) ;SAVE IN OVAL STATE RECORD
ADD.L D0,RIGHTEDGE(A1) ;BIAS RIGHT EDGE +1/2
; INIT OVALY TO -OVALHEIGHT + 1 (SCALED BY 2, BIASED 1/2 SCANLINE)
MOVEQ #1,D0
SUB D1,D0
MOVE D0,OVALY(A1) ;OVALY:=1-HEIGHT
; INIT RSQYSQ TO 2*OVALHEIGHT-1
MOVE D1,D0 ;GET HEIGHT
EXT.L D0 ;CLEAR OUT HI WORD
ADD.L D0,D0 ;CALC 2*HEIGHT
SUB.L #1,D0 ;CALC 2*HEIGHT - 1
MOVE.L D0,RSQYSQ(A1) ;RSQYSQ:=2*HEIGHT-1
; INIT SQUARE TO 0.0
CLR.L SQUARE(A1) ;SQUARE:=0
CLR.L SQUARE+4(A1) ;FRACT PART := 0 TOO
; ODDNUM:= 1 TIMES ASPECT RATIO SQUARED
CLR.L -(SP) ;GET READY FOR FUNCTION RESULT
MOVE D1,-(SP) ;PUSH NUMERATOR=HEIGHT
MOVE D2,-(SP) ;PUSH DENOMINATOR=WIDTH
_MFixRatio ;CALC FIXED POINT HEIGHT/WIDTH
MOVE.L (SP),-(SP) ;DUPLICATE RESULT
PEA ODDNUM(A1) ;PUSH ADDR FOR RESULT
_MLongMul ;CALC 64BIT (HEIGHT/WIDTH) SQUARED
; ODDBUMP:= 2 TIMES ASPECT RATIO SQUARED
MOVE.L ODDNUM+4(A1),D0 ;GET LO LONG OF RESULT
ADD.L D0,D0 ;DOUBLE IT
MOVE.L D0,ODDBUMP+4(A1) ;STORE INTO LO LONG OF ODDBUMP
MOVE.L ODDNUM(A1),D0
ADDX.L D0,D0 ;DOUBLE HI LONG WITH CARRY
MOVE.L D0,ODDBUMP(A1)
RTS
BUMPOVAL PROC EXPORT
;------------------------------------------------------------
;
; LOCAL PROCEDURE BumpOval(VAR oval: OvalRec; vert: INTEGER);
;
; bump an oval state record to the next scanline down.
;
; INPUTS: A3 POINTS TO OVAL STATE RECORD
; D0 CONTAINS CURRENT VERT
;
; CLOBBERS D0-D7,A0-A3
;
;
;------------------------------------------------------
;
; OFFSETS IN AN OVAL STATE RECORD:
;
OVALTOP EQU 0 ;INTEGER
OVALBOT EQU OVALTOP+2 ;INTEGER
OVALY EQU OVALBOT+2 ;INTEGER
RSQYSQ EQU OVALY+2 ;LONGINT
SQUARE EQU RSQYSQ+4 ;64 BIT LONGFIX
ODDNUM EQU SQUARE+8 ;64 BIT LONGFIX
ODDBUMP EQU ODDNUM+8 ;64 BIT LONGFIX
LEFTEDGE EQU ODDBUMP+8 ;32 BIT FIXED POINT
RIGHTEDGE EQU LEFTEDGE+4 ;32 BIT FIXED POINT
ONEHALF EQU RIGHTEDGE+4 ;32 BIT FIXED POINT
OVALSIZE EQU ONEHALF+4 ;SIZE OF AN OVALREC
;-------------------------------------------------------
;
; ONLY BUMP IF VERT IS BETWEEN OVALTOP AND OVALBOT
;
CMP (A3)+,D0 ;IS VERT < OVAL TOP ?
BLT.S GOHOME ;YES, IGNORE
CMP (A3)+,D0 ;IS VERT >= OVAL BOTTOM ?
BGE.S GOHOME ;YES, IGNORE
MOVE (A3),D0 ;GET OVALY
ADD #2,(A3)+ ;ADD 2 TO OVALY FOR NEXT TIME
MOVEM.L (A3),D1-D7/A0-A2 ;GET REST OF THE OVAL RECORD
BRA.S WHILE1 ;GO TO LOOP START
;------------------------------------------
;
; register usage:
;
; D0: vert
; D1: RSQYSQ
; D2,D3: SQUARE
; D4,D5: ODDNUM
; D6,D7: ODDBUMP
; A0: LEFTEDGE
; A1: RIGHTEDGE
; A2: #$00008000
; A3: modified oval ptr
;
;-----------------------------------------------
;
; WHILE SQUARE < RSQYSQ DO MAKE OVAL BIGGER
;
MORE1 ADD.L A2,A1 ;RIGHTEDGE := RIGHTEDGE + 1/2
SUB.L A2,A0 ;LEFTEDGE := LEFTEDGE - 1/2
ADD.L D5,D3 ;SQUARE := SQUARE + ODDNUM
ADDX.L D4,D2 ;ALL 64 BITS OF IT
ADD.L D7,D5 ;ODDNUM := ODDNUM + ODDBUMP
ADDX.L D6,D4 ;ALL 64 BITS OF IT
WHILE1 CMP.L D1,D2 ;IS SQUARE < RSQYSQ ?
BLT MORE1 ;YES, LOOP
BRA.S WHILE2 ;NO, GO TO NEXT LOOP START
;-----------------------------------------------
;
; WHILE SQUARE > RSQYSQ DO MAKE OVAL SMALLER
;
MORE2 SUB.L A2,A1 ;RIGHTEDGE := RIGHTEDGE - 1/2
ADD.L A2,A0 ;LEFTEDGE := LEFTEDGE + 1/2
SUB.L D7,D5 ;ODDNUM := ODDNUM - ODDBUMP
SUBX.L D6,D4 ;ALL 64 BITS OF IT
SUB.L D5,D3 ;SQUARE := SQUARE + ODDNUM
SUBX.L D4,D2 ;ALL 64 BITS OF IT
WHILE2 CMP.L D1,D2 ;IS SQUARE > RSQYSQ ?
BGT MORE2 ;YES, LOOP
ADD #1,D0 ;CALC OVALY+1
EXT.L D0 ;SIGN EXTEND TO A LONG
ASL.L #2,D0 ;CALC 4*(OVALY+1)
SUB.L D0,D1 ;RSQYSQ := RSQYSQ-4*(OVALY+1)
MOVEM.L D1-D7/A0-A2,(A3) ;UPDATE OVAL RECORD
GOHOME RTS
END
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