.INCLUDE GRAFTYPES.TEXT ;----------------------------------------------------------- ; ; --> DRAWARC.TEXT ; ; Routine to draw solid or hollow Ovals, RoundRects or Arcs. ; ;------------------------------------------------------ ; ; 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 .PROC DrawArc,8 .REF InitOval,BumpOval,SlopeFromAngle .REF RSect,ShieldCursor,ShowCursor,TrimRect .REF InitRgn,SeekRgn,PatExpand,ColorMap .REF XorSlab,DrawSlab,SlabMode,FastSlabMode,MaskTab ;---------------------------------------------------------------- ; ; PROCEDURE DrawArc(dstRect: Rect; ; hollow: BOOLEAN; ; ovalWidth,ovalHeight,mode: INTEGER; ; pat: Pattern; ; startAngle,arcAngle: INTEGER); ; ;------------------------------------------------ ; ; 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 = 0 ? BEQ.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 .BYTE 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) _FixRatio ;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 _FixMul ;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 _FixMul ;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 .WORD IGNORE-RECTJMP ;DO NOTHING IF BOTH RECT .WORD A-RECTJMP .WORD B-RECTJMP .WORD 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 .PROC INITOVAL,4 ;------------------------------------------------------------ ; ; 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 ; ;----------------------------------------------------------- ; ; 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 _FixRatio ;CALC FIXED POINT HEIGHT/WIDTH MOVE.L (SP),-(SP) ;DUPLICATE RESULT PEA ODDNUM(A1) ;PUSH ADDR FOR RESULT _LongMul ;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 .PROC BUMPOVAL,2 ;------------------------------------------------------------ ; ; 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 ; ; ;------------------------------------------------------- ; ; 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