;EASE$$$ READ ONLY COPY of file “RECTS.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'
;-----------------------------------------------------------
;
;
;	  ****	 *****	 ***   *****   ***
;	  *   *  *		*	*	 *	  *   *
;	  *   *  *		*		 *	  *
;	  ****	 ***	*		 *	   ***
;	  * *	 *		*		 *		  *
;	  *  *	 *		*	*	 *	  *   *
;	  *   *  *****	 ***	 *	   ***
;
;
;
;  Procedures for operating on rectangles.
;


StdRect PROC  EXPORT
		IMPORT CheckPic,PutPicVerb,PutPicRect
		IMPORT PutRect,FrRect,PushVerb,DrawRect
;---------------------------------------------------------------
;
;  PROCEDURE StdRect(verb: GrafVerb; r: Rect);
;
;  A6 OFFSETS OF PARAMS AFTER LINK:
;
PARAMSIZE		EQU 	6
VERB			EQU 	PARAMSIZE+8-2			;GRAFVERB
RECT			EQU 	VERB-4				;LONG, ADDR OF RECT

		LINK	A6,#0					;NO LOCALS
		MOVEM.L D7/A3-A4,-(SP)				;SAVE REGS
		MOVE.B	VERB(A6),D7 			;GET VERB
		JSR 	CHECKPIC				;SET UP A4,A3 AND CHECK PICSAVE
		BLE.S	NOTPIC					;BRANCH IF NOT PICSAVE

		MOVE.B	D7,-(SP)				;PUSH VERB
		JSR 	PutPicVerb				;PUT ADDIONAL PARAMS TO THEPIC
		MOVEQ	#$30,D0 				;GET RECTNOUN IN HI NIBBLE
		ADD 	D7,D0					;PUT VERB IN LO NIBBLE
		MOVE.B	D0,-(SP)				;PUSH OPCODE
		MOVE.L	RECT(A6),-(SP)				;PUSH ADDR OF RECT
		JSR 	PutPicRect				;PUT OPCODE AND RECTANGLE

NOTPIC	MOVE.L	RECT(A6),-(SP)				;PUSH RECT FOR FrRect or DrawRect
		TST.B	D7					;IS VERB FRAME ?
		BNE.S	NOTFR					;NO, CONTINUE
		TST.L	RGNSAVE(A3) 			;YES, IS RGNSAVE TRUE ?
		BEQ.S	NOTRGN					;NO, CONTINUE

		MOVE.L	RECT(A6),-(SP)				;YES, PUSH ADDR OF RECT
		MOVE.L	RGNBUF(A4),-(SP)			;PUSH RGNBUF
		PEA 	RGNINDEX(A4)				;PUSH VAR RGNINDEX
		PEA 	RGNMAX(A4)				;PUSH VAR RGNMAX
		JSR 	PutRect 				;ADD A RECT TO THERGN

NOTRGN	JSR 	FrRect					;FrRect(rect)
		BRA.S	GOHOME

NOTFR	JSR 	PushVerb				;PUSH MODE AND PATTERN
		JSR 	DRAWRECT				;DrawRect(rect,mode,pat);

GOHOME	MOVEM.L (SP)+,D7/A3-A4				;RESTORE REGS
		UNLINK	PARAMSIZE,'STDRECT '



PushVerb PROC  EXPORT
;----------------------------------------------------------
;
;  PUSH A MODE AND A PATTERN, BASED ON VERB
;  ENTER WITH VERB IN D7, GRAFGLOBALS IN A4, THEPORT IN A3.
;
;  CLOBBERS A0.
;
;	 frame:  pnMode,  pnPat
;	 paint:  pnMode,  pnPat
;	 erase:  patCopy, bkPat
;	 invert: patXor,  black
;	 fill:	 patCopy, fillPat
;
		MOVE.L	(SP)+,A0				;POP RETURN ADDR
		MOVE	#8,-(SP)				;PUSH MODE = PATCOPY (IE. DEFAULT)
		CMP.B	#1,D7					;CASE ON VERB
		BLE.S	PAINT1
		CMP.B	#3,D7
		BLT.S	ERASE1
		BEQ.S	INVERT1

FILL1	PEA 	FILLPAT(A3) 			;PUSH PAT := FILLPAT
		BRA.S	DONE

ERASE1	PEA 	BKPAT(A3)				;PUSH PAT = BKPAT
		BRA.S	DONE

INVERT1 ADD.W	#2,(SP) 				;ADJUST, PUSH MODE = PATXOR
		PEA 	BLACK(A4)				;PUSH PAT = BLACK
		BRA.S	DONE

PAINT1	MOVE	PNMODE(A3),(SP) 			;REPLACE, PUSH MODE = PNMODE
		PEA 	PNPAT(A3)				;PUSH PAT = PNPAT

DONE	JMP 	(A0)					;RETURN TO CALLER



FillRect PROC  EXPORT	
		EXPORT CallRect,FrameRect,PaintRect,EraseRect,InvertRect
;----------------------------------------------------------
;
;  PROCEDURE FillRect(r: Rect; pat: Pattern);
;
		MOVE.L	(SP)+,A0				;POP RETURN ADDR
		MOVE.L	(SP)+,A1				;POP ADDR OF PATTERN
		MOVE.L	A0,-(SP)				;PUT RETURN ADDR BACK
		MOVE.L	GRAFGLOBALS(A5),A0			;POINT TO LISAGRAF GLOBALS
		MOVE.L	THEPORT(A0),A0				;GET CURRENT GRAFPORT
		LEA 	FILLPAT(A0),A0				;POINT TO FILLPAT
		MOVE.L	(A1)+,(A0)+ 			;COPY PAT INTO FILLPAT
		MOVE.L	(A1)+,(A0)+ 			;ALL EIGHT BYTES
		MOVEQ	#FILL,D0				;VERB = FILL
		BRA.S	CallRect				;SHARE COMMON CODE



;----------------------------------------------------------
;
;  PROCEDURE FrameRect(r: Rect);
;
FrameRect
		MOVEQ	#FRAME,D0				;VERB = FRAME
		BRA.S	CallRect				;SHARE COMMON CODE


;----------------------------------------------------------
;
;  PROCEDURE PaintRect(r: Rect);
;
PaintRect
		MOVEQ	#PAINT,D0				;VERB = PAINT
		BRA.S	CallRect				;SHARE COMMON CODE


;----------------------------------------------------------
;
;  PROCEDURE EraseRect(r: Rect);
;
EraseRect
		MOVEQ	#ERASE,D0				;VERB = ERASE
		BRA.S	CallRect				;SHARE COMMON CODE


;----------------------------------------------------------
;
;  PROCEDURE InvertRect(r: Rect);
;
InvertRect
		MOVEQ	#INVERT,D0				;VERB = INVERT
		BRA.S	CallRect				;SHARE COMMON CODE


;---------------------------------------------------------------
;
;  PROCEDURE CallRect(r: Rect);
;
;  code shared by FrameRect, PaintRect, EraseRect, InvertRect, and FillRect.
;  enter with verb in D0.
;
CallRect
		MOVE.L	(SP)+,A0				;POP RETURN ADDR
		MOVE.L	(SP)+,A1				;POP ADDR OF RECT
		MOVE.B	D0,-(SP)				;PUSH VERB
		MOVE.L	A1,-(SP)				;PUSH ADDR OF RECT
		MOVE.L	A0,-(SP)				;RESTORE RETURN ADDR
		MOVE.L	GRAFGLOBALS(A5),A0			;POINT TO LISAGRAF GLOBALS
		MOVE.L	THEPORT(A0),A0				;GET CURRENT GRAFPORT
		MOVE.L	GRAFPROCS(A0),D0			;IS GRAFPROCS NIL ?
		MOVE.L	JStdRect,A0 			;get piece of trap table
		BEQ.S	USESTD					;YES, USE STD PROC
		MOVE.L	D0,A0
		MOVE.L	RECTPROC(A0),A0 			;NO, GET PROC PTR
USESTD	JMP 	(A0)					;GO TO IT


DrawRect PROC  EXPORT	
		IMPORT RgnBlt
;----------------------------------------------------------
;
;  PROCEDURE DrawRect(r: Rect; mode: INTEGER; pat: Pattern);
;
;  Rectangle is given in local coordinates.
;
;  A6 OFFSETS OF PARAMS AND LOCALS AFTER LINK:
;
PARAMSIZE		EQU 	10				;TOTAL BYTES OF PARAMS
DSTRECT 		EQU 	PARAMSIZE+8-4			;LONG, ADDR OF RECT
MODE			EQU 	DSTRECT-2			;WORD
PAT 		EQU 	MODE-4				;LONG, ADDR OF PAT

		LINK	A6,#0					;NO LOCAL VARS
		MOVE.L	GRAFGLOBALS(A5),A0			;POINT TO LISAGRAF GLOBALS
		MOVE.L	THEPORT(A0),A1				;GET CURRENT GRAFPORT
		TST 	PNVIS(A1)				;IS PNVIS >= 0 ?
		BLT.S	GOHOME					;NO, QUIT
		PEA 	PORTBITS(A1)				;PUSH SRCBITS = DSTBITS
		MOVE.L	(SP),-(SP)				;PUSH DSTBITS
		MOVE.L	DSTRECT(A6),-(SP)			;PUSH SRCRECT = DSTRECT
		MOVE.L	(SP),-(SP)				;PUSH DSTRECT
		MOVE	MODE(A6),-(SP)				;PUSH MODE
		MOVE.L	PAT(A6),-(SP)				;PUSH ADDR OF PATTERN
		MOVE.L	CLIPRGN(A1),-(SP)			;PUSH CLIPRGN
		MOVE.L	VISRGN(A1),-(SP)			;PUSH VISRGN
		MOVE.L	WIDEOPEN(A0),-(SP)			;PUSH WIDE OPEN
		JSR 	RGNBLT					;CALL RGNBLT
GOHOME	UNLINK	PARAMSIZE,'DRAWRECT'



FrRect	PROC  EXPORT
		IMPORT RgnBlt
;----------------------------------------------------------
;
;  PROCEDURE FrRect(r: Rect);
;  Draws an outline inside a rect.
;
;  A6 OFFSETS OF PARAMETERS AND LOCALS AFTER LINK:
;
DSTRECT 		EQU 	8				;LONG, ADDR OF RECT
H1			EQU 	-2				;WORD
H2			EQU 	H1-2				;WORD
H3			EQU 	H2-2				;WORD
H4			EQU 	H3-4				;WORD
V1			EQU 	H4-2				;WORD
V2			EQU 	V1-2				;WORD
V3			EQU 	V2-2				;WORD
V4			EQU 	V3-4				;WORD
TEMPRECT		EQU 	V4-8				;RECT
VARSIZE 		EQU 	TEMPRECT			;TOTAL SIZE OF LOCALS


		LINK	A6,#VARSIZE 			;SET UP STACK FRAME
		MOVE.L	GRAFGLOBALS(A5),A0			;POINT TO LISAGRAF GLOBALS
		MOVE.L	THEPORT(A0),A0				;GET CURRENT GRAFPORT
		TST 	PNVIS(A0)				;IS PNVIS NEGATIVE ?
		BLT 	GOHOME					;YES, DON'T DRAW AT ALL
		MOVE.L	DSTRECT(A6),A1				;POINT TO INPUT RECT
		MOVE.L	(A1)+,TEMPRECT+TOPLEFT(A6)		;COPY INPUT RECT
		MOVE.L	(A1)+,TEMPRECT+BOTRIGHT(A6)
;
;  Now set up h1,h2,h3,h4 and v1,v2,v3,v4
;
		LEA 	TEMPRECT(A6),A1 			;POINT TO COPIED RECT
		MOVE	PNSIZE+H(A0),D2 			;GET PEN WIDTH
		MOVE	LEFT(A1),D0
		MOVE	D0,H1(A6)				;H1:=LEFT
		ADD 	D2,D0
		MOVE	D0,H2(A6)				;H2:=LEFT+PENWIDTH
		MOVE	RIGHT(A1),D1
		MOVE	D1,H4(A6)				;H4:=RIGHT
		SUB 	D2,D1
		MOVE	D1,H3(A6)				;H3:=RIGHT-PENWIDTH
		CMP 	D1,D0					;IS H2 >= H3 ?
		BGE.S	@1					;YES, FILL IT IN SOLID

		MOVE	PNSIZE+V(A0),D2 			;GET PEN HEIGHT
		MOVE	TOP(A1),D0
		MOVE	D0,V1(A6)				;V1:=TOP
		ADD 	D2,D0
		MOVE	D0,V2(A6)				;V2:=TOP+PENHEIGHT
		MOVE	BOTTOM(A1),D1
		MOVE	D1,V4(A6)				;V4:=BOTTOM
		SUB 	D2,D1
		MOVE	D1,V3(A6)				;V3:=BOTTOM-PENHEIGHT
		CMP 	D1,D0					;IS V2 >= V3 ?
		BGE.S	@1					;YES, FILL IT IN SOLID

;
;  PEN IS NOT SO BIG AS TO FILL IN SOLID.  BREAK RECT INTO 4 EDGES.
;
		MOVE	H1(A6),TEMPRECT+LEFT(A6)
		MOVE	H3(A6),TEMPRECT+RIGHT(A6)
		MOVE	V1(A6),TEMPRECT+TOP(A6)
		MOVE	V2(A6),TEMPRECT+BOTTOM(A6)
		BSR.S	DORECT					;PAINT TOP EDGE

		MOVE	H3(A6),TEMPRECT+LEFT(A6)
		MOVE	H4(A6),TEMPRECT+RIGHT(A6)
		MOVE	V3(A6),TEMPRECT+BOTTOM(A6)
		BSR.S	DORECT					;PAINT RIGHT EDGE

		MOVE	H2(A6),TEMPRECT+LEFT(A6)
		MOVE	V3(A6),TEMPRECT+TOP(A6)
		MOVE	V4(A6),TEMPRECT+BOTTOM(A6)
		BSR.S	DORECT					;PAINT BOTTOM EDGE

		MOVE	H1(A6),TEMPRECT+LEFT(A6)
		MOVE	H2(A6),TEMPRECT+RIGHT(A6)
		MOVE	V2(A6),TEMPRECT+TOP(A6)
@1		BRA.S	FILLED					;PAINT LEFT EDGE


;--------------------------------------------------------
;
;  LOCAL ROUTINE TO PAINT TEMPRECT, GIVEN IN LOCAL COORDS
;
DORECT	MOVE.L	GRAFGLOBALS(A5),A0			;POINT TO LISAGRAF GLOBALS
		MOVE.L	THEPORT(A0),A1				;POINT TO CURRENT GRAFPORT
		PEA 	PORTBITS(A1)				;PUSH SRCBITS = DSTBITS
		MOVE.L	(SP),-(SP)				;PUSH DSTBITS
		PEA 	TEMPRECT(A6)				;PUSH SRCRECT = DSTRECT
		MOVE.L	(SP),-(SP)				;PUSH DSTRECT, LOCAL COORDS
		MOVE	PNMODE(A1),-(SP)			;PUSH PEN MODE
		PEA 	PNPAT(A1)				;PUSH ADDR OF PEN PATTERN
		MOVE.L	CLIPRGN(A1),-(SP)			;PUSH CLIPRGN
		MOVE.L	VISRGN(A1),-(SP)			;PUSH VISRGN
		MOVE.L	WIDEOPEN(A0),-(SP)			;PUSH WIDE OPEN
		JSR 	RGNBLT					;CALL RGNBLT
		RTS

FILLED	BSR 	DORECT					;FILL TEMPRECT SOLID
GOHOME	UNLINK	4,'FRRECT  '



SetRect PROC  EXPORT
;----------------------------------------------------------
;
;  PROCEDURE SetRect(VAR r: Rect; left,top,right,bottom: INTEGER);
;  { assign 4 integers into a rectangle }
;
		MOVE.L	(SP)+,A0				;POP RETURN ADDR
		MOVE.L	(SP)+,D1				;POP BOTRIGHT POINT
		MOVE.L	(SP)+,D0				;POP TOPLEFT POINT
		MOVE.L	(SP)+,A1				;POP ADDR OF RECT
		MOVE.L	D0,(A1)+				;INSTALL TOPLEFT
		MOVE.L	D1,(A1)+				;INSTALL BOTRIGHT
		JMP 	(A0)					;RETURN



EqualRect FUNC	EXPORT	
;----------------------------------------------------------
;
;  FUNCTION  EqualRect(rect1,rect2: Rect): BOOLEAN;
;
;  CLOBBERS D0,A0,A1.
;
		MOVE.L	(SP)+,D0				;POP RETURN ADDR
		MOVE.L	(SP)+,A1				;POP ADDR OF RECT2
		MOVE.L	(SP)+,A0				;POP ADDR OF RECT1
		CMPM.L	(A0)+,(A1)+ 			;IS TOPLEFT SAME ?
		BNE.S	FALSE					;NO, RETURN FALSE
		CMPM.L	(A0)+,(A1)+ 			;YES, IS BOTRIGHT SAME TOO ?
		BNE.S	FALSE					;NO, RETURN FALSE
		MOVE.B	#1,(SP) 				;YES, RETURN TRUE
		BRA.S	DONE					;AND QUIT
FALSE	CLR.B	(SP)					;RETURN FALSE
DONE	MOVE.L	D0,-(SP)				;PUSH RETURN ADDR
		RTS 					;AND RETURN



EmptyRect FUNC	EXPORT	
;----------------------------------------------------------
;
;  FUNCTION  EmptyRect(r: Rect): BOOLEAN;
;
;  CLOBBERS D0,D1,A0,A1.
;
		MOVE.L	(SP)+,A1				;POP RETURN ADDR
		MOVE.L	(SP)+,A0				;POP ADDR OF RECT
		MOVE	(A0)+,D0				;GET TOP
		MOVE	(A0)+,D1				;GET LEFT
		CMP 	(A0)+,D0				;IS TOP >= BOTTOM ?
		BGE.S	EMPTY					;YES, RETURN TRUE
		CMP 	(A0)+,D1				;IS LEFT >= RIGHT ?
		BGE.S	EMPTY					;YES, RETURN TRUE
		CLR.B	(SP)					;NOT EMPTY, RETURN FALSE
		BRA.S	DONE					;AND QUIT
EMPTY	MOVE.B	#1,(SP) 				;RETURN TRUE
DONE	JMP 	(A1)					;RETURN



OffsetRect PROC  EXPORT 	
;----------------------------------------------------------
;
;  PROCEDURE OffsetRect(VAR r: Rect; dh,dv: INTEGER);
;
		MOVE.L	(SP)+,A0				;POP RETURN ADDR
		MOVE	(SP)+,D1				;POP DV
		MOVE	(SP)+,D0				;POP DH
		MOVE.L	(SP)+,A1				;POP ADDR OF RECT
		ADD 	D1,(A1)+				;TOP:=TOP+DV
		ADD 	D0,(A1)+				;LEFT:=LEFT+DH
		ADD 	D1,(A1)+				;BOTTOM:=BOTTOM+DV
		ADD 	D0,(A1)+				;RIGHT:=RIGHT+DH
		JMP 	(A0)					;RETURN


InsetRect PROC	EXPORT	
;----------------------------------------------------------
;
;  PROCEDURE InsetRect(VAR r: Rect; dh,dv: INTEGER);
;  { inset a rectangle on all 4 sides }
;
		MOVE.L	(SP)+,A0				;POP RETURN ADDR
		MOVE	(SP)+,D1				;POP DV
		MOVE	(SP)+,D0				;POP DH
		MOVE.L	(SP)+,A1				;POP ADDR OF RECT
		ADD 	D1,(A1)+				;ADD DV TO TOP
		ADD 	D0,(A1)+				;ADD DH TO LEFT
		SUB 	D1,(A1)+				;SUBTRACT DV FROM BOTTOM
		SUB 	D0,(A1)+				;SUBTRACT DH FROM RIGHT
DONE	JMP 	(A0)					;RETURN



SectRect FUNC  EXPORT	
		EXPORT RSect
;---------------------------------------------------------
;
;  FUNCTION SectRect(srcA,srcB: Rect; VAR dstC: Rect): BOOLEAN;
;
;  Returns TRUE and intersection in dst,
;  else FALSE and dst = 0,0,0,0.
;  Dst may also be used as one of the inputs
;
;
;  A6 OFFSETS OF PARAMETERS AFTER LINK:
;
PARAMSIZE		EQU 	12				;SIZE OF PARAMETERS
RESULT			EQU 	PARAMSIZE+8 		;BOOLEAN RESULT
SRCA			EQU 	RESULT-4			;LONG, ADDR OF RECTANGLE
SRCB			EQU 	SRCA-4				;LONG, ADDR OF RECTANGLE
DST 		EQU 	SRCB-4				;LONG, ADDR OF RECTANGLE


		LINK	A6,#0					;NO LOCAL VARS
		MOVE.L	SRCA(A6),-(SP)				;PUSH SRCA POINTER
		MOVE.L	SRCB(A6),-(SP)				;PUSH SRCB POINTER
		MOVE	#2,-(SP)				;PUSH NRECTS=2
		MOVE.L	DST(A6),-(SP)				;PUSH DST POINTER
		BSR.S	RSECT					;CALC INTERSECTION
		SNE 	RESULT(A6)				;STORE BOOLEAN RESULT
		NEG.B	RESULT(A6)				;CONVERT $FF TO $01
NOTEMPTY UNLINK  PARAMSIZE,'SECTRECT'


;---------------------------------------------------
;
;  ASSEMBLY CALLABLE ROUTINE TO COMPUTE THE INTERSECTION OF
;  ANY NUMBER OF RECTANGLES.
;
;  INPUTS: PUSH ADDRESSES OF EACH INPUT RECTANGLE (LONGS)
;	   PUSH # OF RECTANGLES (WORD)
;	   PUSH ADDRESS OF OUTPUT RECTANGLE (LONG)
;
;  RETURNS DST=(0,0,0,0) AND Z-FLAG SET IF NO INTERSECTION
;
;  CLOBBERS: D0,A0
;
RSECT	LINK A6,#0
		MOVEM.L D1-D4/A1,-(SP)				;SAVE REGS
		LEA 	12(A6),A1				;POINT TO NRECTS
		MOVE	(A1)+,D0				;GET NRECTS COUNT
		BLE.S	EMPTY					;EMPTY IF NRECTS <= 0
		MOVE.L	(A1)+,A0				;POINT TO FIRST RECT
		MOVEM.W (A0)+,D1/D2/D3/D4			;GET TOP, LEFT, BOT, RIGHT
		SUB 	#1,D0					;DECREMENT RECT COUNT
		BRA.S	RTOK					;CHECK THIS RECT AND LOOP

NEXTRECT MOVE.L (A1)+,A0				;POINT TO NEXT RECT
		CMP    (A0)+,D1 				;IS TOP < NEXT TOP ?
		BGE.S	TOPOK					;NO, CONTINUE
		MOVE	-2(A0),D1				;YES, TOP:=NEXT TOP
TOPOK	CMP 	(A0)+,D2				;IS LEFT < NEXT LEFT ?
		BGE.S	LEFTOK					;NO, CONTINUE
		MOVE	-2(A0),D2				;YES, LEFT:=NEXT LEFT
LEFTOK	CMP 	(A0)+,D3				;IS BOTTOM > NEXT BOT ?
		BLE.S	BOTOK					;NO, CONTINUE
		MOVE	-2(A0),D3				;YES, BOTTOM:=NEXT BOT
BOTOK	CMP 	(A0)+,D4				;IS RIGHT > NEXT RIGHT ?
		BLE.S	RTOK					;NO, CONTINUE
		MOVE	-2(A0),D4				;YES, RIGHT:=NEXT RIGHT
RTOK	CMP 	D1,D3					;IS BOTTOM <= TOP ?
		BLE.S	EMPTY					;YES, EMPTY
		CMP 	D2,D4					;IS RIGHT <= LEFT ?
		BLE.S	EMPTY					;YES, EMPTY
		DBRA	D0,NEXTRECT 			;LOOP FOR ALL RECTANGLES
		BRA.S	DONE

EMPTY	CLR 	D1					;ALL EMPTY RECTS ARE (0,0,0,0)
		CLR 	D2
		CLR 	D3
		CLR 	D4
DONE	MOVE.L	8(A6),A0				;GET DST ADDR
		MOVE	D1,(A0)+				;STORE DST TOP
		MOVE	D2,(A0)+				;DST LEFT
		MOVE	D3,(A0)+				;DST BOT
		MOVE	D4,(A0)+				;DST RIGHT
		MOVE	12(A6),D0				;GET NRECTS COUNT AGAIN
		LSL 	#2,D0					;TIMES 4 BYTES PER RECTANGLE
		ADD 	#6,D0					;PLUS 6 BYTES FOR NRECTS AND DSTPTR
		CMP 	D1,D3					;SET Z-FLAG IF EMPTY RECT
		MOVEM.L (SP)+,D1-D4/A1				;RESTORE REGS
		UNLK	A6					;RELEASE STATIC FRAME PTR
		MOVE.L	(SP)+,A0				;POP RETURN ADDR
		ADD 	D0,SP					;STRIP VARIABLE NUMBER OF PARAMS
		JMP 	(A0)					;RETURN WITH Z-FLAG IF EMPTY


UnionRect PROC	EXPORT	
		EXPORT Pt2Rect
;----------------------------------------------------------
;
;  PROCEDURE UnionRect(* src1,src2: Rect; VAR dst: Rect *);
;
;  { compute smallest rectangle containing both input rectangles   }
;  { works correctly even if one of the sources is the destination }
;
		MOVE.L	12(SP),A0			;GET ADDR OF SRC1
		MOVE.L	8(SP),A1			;GET ADDR OF SRC2

		MOVE	(A0)+,D0			;TOP:=TOP1
		CMP 	(A1)+,D0			;IS TOP2 < TOP ?
		BLE.S	TOPOK				;NO, CONTINUE
		MOVE	-2(A1),D0			;YES, TOP:=TOP2
TOPOK	SWAP	D0				;PUT TOP IN HI WORD
		MOVE	(A0)+,D0			;LEFT:=LEFT1
		CMP 	(A1)+,D0			;IS LEFT2 < LEFT ?
		BLE.S	LEFTOK				;NO, CONTINUE
		MOVE	-2(A1),D0			;YES, LEFT:=LEFT2
LEFTOK	MOVE	(A0)+,D1			;BOTTOM:=BOTTOM1
		CMP 	(A1)+,D1			;IS BOTTOM2 > BOTTOM ?
		BGE.S	BOTOK				;NO, CONTINUE
		MOVE	-2(A1),D1			;YES, BOTTOM:=BOTTOM2
BOTOK	SWAP	D1				;PUT BOTTOM IN HI WORD
		MOVE	(A0)+,D1			;RIGHT:=RIGHT1
		CMP 	(A1)+,D1			;IS RIGHT2 > RIGHT1 ?
		BGE.S	RIGHTOK 			;NO, CONTINUE
		MOVE	-2(A1),D1			;YES, RIGHT:=RIGHT2
RIGHTOK MOVE.L	4(SP),A0			;POINT TO DST RECT
		MOVE.L	D0,(A0)+			;INSTALL TOPLEFT
		MOVE.L	D1,(A0)+			;INSTALL BOTRIGHT
		BRA.S	SHARE				;STRIP 3 PARAMETERS AND RETURN


;----------------------------------------------------------
;
;  PROCEDURE Pt2Rect(* pt1,pt2: Point; VAR dst: Rect *);
;
;  { make a rectangle from two points }
;
Pt2Rect MOVE.L	4(SP),A0			;POINT TO DST RECT
		MOVE	14(SP),D0			;GET H1
		MOVE	10(SP),D1			;GET H2
		CMP 	D0,D1				;IS H2 < H1 ?
		BGE.S	HOK 			;NO, CONTINUE
		EXG 	D0,D1				;YES, SWAP THEM
HOK 	MOVE	D0,LEFT(A0) 		;INSTALL DST LEFT  = MIN(H1,H2)
		MOVE	D1,RIGHT(A0)			;INSTALL DST RIGHT = MAX(H1,H2)
		MOVE	12(SP),D0			;GET V1
		MOVE	8(SP),D1			;GET V2
		CMP 	D0,D1				;IS V2 < V1 ?
		BGE.S	VOK 			;NO, CONTINUE
		EXG 	D0,D1				;YES, SWAP THEM
VOK 	MOVE	D0,TOP(A0)			;INSTALL DST TOP	= MIN(V1,V2)
		MOVE	D1,BOTTOM(A0)			;INSTALL DST BOTTOM = MAX(V1,V2)
SHARE	MOVE.L	(SP)+,A0			;POP RETURN ADDR
		ADD 	#12,SP				;STRIP 3 PARAMETERS
		JMP 	(A0)				;AND RETURN



PtInRect FUNC  EXPORT	
;------------------------------------------------------------
;
;  FUNCTION PtInRect(pt: Point; r: Rect): BOOLEAN;
;
;  Returns TRUE if point is within the rectangle.
;
;  A6 OFFSETS OF PARAMETERS AFTER LINK:
;
PARAMSIZE		EQU 	8				;SIZE OF PARAMETERS
RESULT			EQU 	PARAMSIZE+8 		;A6 OFFSETS AFTER LINK
PT			EQU 	RESULT-4			;POINT, VALUE
R			EQU 	PT-4				;LONG, ADDR OF RECTANGLE

		LINK	A6,#0					;NO LOCAL VARS
		MOVE.L	R(A6),A0				;GET RECT PTR
		MOVE	PT+H(A6),D0 			;GET HORIZ COORD
		MOVE	PT+V(A6),D1 			;GET VERT COORD
		CLR.B	RESULT(A6)				;INIT BOOLEAN TO FALSE
		CMP 	(A0)+,D1				;IS PT.V < TOP ?
		BLT.S	FALSE					;YES, QUIT
		CMP 	(A0)+,D0				;IS PT.H < LEFT ?
		BLT.S	FALSE					;YES, QUIT
		CMP 	(A0)+,D1				;IS PT.V >= BOTTOM ?
		BGE.S	FALSE					;YES, QUIT
		CMP 	(A0)+,D0				;IS PT.H >= RIGHT ?
		BGE.S	FALSE					;YES, QUIT
		ADDQ.B	#1,RESULT(A6)				;RETURN BOOLEAN TRUE
FALSE	UNLINK	PARAMSIZE,'PTINRECT'



PutRect PROC  EXPORT
		IMPORT SETHSIZE
;----------------------------------------------------------------
;
;  PROCEDURE PutRect(r: Rect; bufHandle: Handle; VAR index,size: INTEGER);
;
;  Puts the four inversion points of a rectangle
;
;  Clobbers D0,A0,A1
;
;  A6 OFFSETS OF PARAMETERS AFTER LINK:
;
PARAMSIZE		EQU 	16				;TOTAL SIZE OF PARAMETERS
RECT			EQU 	PARAMSIZE+8-4			;LONG, ADDR OF RECT
BUFHANDLE		EQU 	RECT-4				;LONG, HANDLE
INDEX			EQU 	BUFHANDLE-4 		;LONG, ADDR OF INTEGER
SIZE			EQU 	INDEX-4 			;LONG, ADDR OF INTEGER


		LINK	A6,#0					;NO LOCAL VARIABLES

;------------------------------------------------------------
;
; IS THERE ROOM FOR FOUR NEW POINTS IN THE POINT BUFFER ?
;
		MOVE.L	INDEX(A6),A0				;POINT TO INDEX
		MOVE.L	SIZE(A6),A1 			;POINT TO SIZE
		MOVEQ	#16,D0
		ADD 	(A0),D0 				;GET CURRENT INDEX + 16
		CMP 	(A1),D0 				;IS NEW INDEX > SIZE ?
		BLE.S	SIZEOK					;NO, CONTINUE


;-------------------------------------------------------------
;
;  NO, GROW THE POINT BUFFER ENOUGH FOR 256 MORE POINTS
;
		ADD 	#1024,(A1)				;ADD 1024 TO SIZE
		MOVEM.L D3/A2,-(SP) 			;SAVE REGS
		MOVE.L	BUFHANDLE(A6),-(SP) 		;PUSH HANDLE PARAM
		MOVE	(A1),-(SP)				;PUSH NEW SIZE
		JSR 	SETHSIZE 				;MAKE THE BUFFER BIGGER
		MOVEM.L (SP)+,D3/A2 			;RESTORE REGS
		MOVE.L	INDEX(A6),A0				;POINT TO INDEX AGAIN


;------------------------------------------------------------
;
;  NOW INSTALL THE 4 NEW INVERSION POINTS
;
SIZEOK	MOVE.L	BUFHANDLE(A6),A1			;GET BUFHANDLE
		MOVE.L	(A1),A1 				;DE-REFERENCE HANDLE
		ADD 	(A0),A1 				;ADD INDEX FOR POINTER
		ADD 	#16,(A0)				;BUMP INDEX
		MOVE.L	RECT(A6),A0 			;POINT TO RECTANGLE
		MOVE.L	TOPLEFT(A0),(A1)+			;PUT TOPLEFT POINT
		MOVE	TOP(A0),(A1)+				;PUT TOP-RIGHT POINT
		MOVE	RIGHT(A0),(A1)+
		MOVE	BOTTOM(A0),(A1)+			;PUT BOTTOM-LEFT POINT
		MOVE	LEFT(A0),(A1)+
		MOVE.L	BOTRIGHT(A0),(A1)+			;PUT BOTRIGHT POINT
		UNLINK	PARAMSIZE,'PUTRECT '



		END