;*************************************** ;*** Collsion Checking Routines *** ;*** Copyright (c) J.Gregory 1996-97 *** ;*** v2.0 15/03/97 *** ;*************************************** ; Params - Pointer to ColWork struct ; Returns - Array of upto 20 collision LONG pairs as follows :- ; No Collision Type=0 ; Boundary Collsion BCol Type=1,Ref=NULL ; ColArea Collision ACol Type=2,Ref=ColArea pointer ; Fixed WObject Collision FCol Type=3,Ref=WObject pointer ; Transient WObject Coll TCOL Type=4,Ref=WObject pointer ; NOTE - Type of 0 Terminates array. Max colls is 20 so 41st LONG is ; always a terminator. ; Collision Priorities in case more than 20 collisions is as follows:- ; BCol,ACol,TCol then FCol (Fixed WObjects are least important) ; Trashes ColWork->R1Start during run ; d0 is set to type of 1st Collison, otherwise 0 ; a0 = ColWork base pointer ; a1 = ColWork->CW_Ret array base pointer ; a2 = Remaining returns LONG pairs counter (init=10) ; a5 = WObject to ignore 1 ; a6 = WObject to ignore 2 ; d0 = Focus Wx ; d1 = Focus Wy ; d2 = Focus Height ; d3 = Focus Radius ;------------------------------ ; Collsion Check Main Line ;------------------------------ _ASM_ChkCol: movem.l d1-d7/a0-a6,-(sp) ; Stack Everything except d0 (ret) & SP move.l 60(sp),a0 ; Get ColWork base pointer (56+4) lea CW_Ret(a0),a1 ; Get returns array base pointer move.l #19,a2 ; Set remaining returns pairs counter ;^^ temp set to 19 from 20 for debug checking move.l CW_Wx(a0),d0 ; Get Focus Wx move.l CW_Wy(a0),d1 ; Get Focus Wy move.l CW_Height(a0),d2 ; Get Focus Height move.l CW_Radius(a0),d3 ; Get Focus Radius move.l CW_Ignore1(a0),a5 ; Get Ignore1 WObject pointer move.l CW_Ignore2(a0),a6 ; Get Ignore2 WObject pointer jsr ACC_BCol ; Check for boundary collisions jsr ACC_ACol ; Check for ColArea collisions jsr ACC_TCol ; Check for transient WObject collisions jsr ACC_FCol ; Check for fixed WObject collsions move.l #0,(a1)+ ; Write terminating NULL to returns array move.l CW_Ret(a0),d0 ; Return 1st Collision type in d0 ACC_Ret: movem.l (sp)+,d1-d7/a0-a6 ; Get registers back from stack rts ;----------------------------------- ; Check for boundary collisions ;----------------------------------- ACC_BCol: cmp.l CW_XMin(a0),d0 ; Check Focus Wx against Min/Max bounds blt ACCB_Hit cmp.l CW_XMax(a0),d0 bgt ACCB_Hit cmp.l CW_YMin(a0),d1 ; Check Focus Wy against Min/Max bounds blt ACCB_Hit cmp.l CW_YMax(a0),d1 bgt ACCB_Hit cmp.l CW_HMin(a0),d2 ; Check Focus Height against Min/Max bounds blt ACCB_Hit cmp.l CW_HMax(a0),d2 bgt ACCB_Hit ACCB_Ret: rts ACCB_Hit: move.l #1,(a1)+ ; Add boundary collision to returns array move.l #0,(a1)+ suba.l #1,a2 ; Decrement remaining returns counter rts ;---------------------------------- ; Check for ColArea collisions ;---------------------------------- ACC_ACol: cmpa.l #0,a2 ; Return if returns array full ble ACCA_Ret move.l CW_ColArea(a0),a3 ; Get ColArea array base pointer ACCA_Loop: move.l CA_Wx(a3),d4 ; Get ColArea Wx beq ACCA_Ret ; If Wx=0 then end of array bmi ACCA_Next ; If Wx<0 then deleted entry so skip sub.l d3,d4 ; Sub Focus Radius from Wx (Lower X) cmp.l d4,d0 ; Is Focus Wx < Lower X blt ACCA_Next ; If yes skip to next ColArea move.l CA_Wx2(a3),d4 ; Get ColArea Wx2 add.l d3,d4 ; Add Focus Radius to Wx2 (Upper X) cmp.l d4,d0 ; Is Focus Wx > Upper X bgt ACCA_Next ; If yes skip to next ColArea move.l CA_Wy(a3),d4 ; Get ColArea Wy sub.l d3,d4 ; Sub Focus Radius from Wy (Lower Y) cmp.l d4,d1 ; Is Focus Wy < Lower Y blt ACCA_Next ; If yes skip to next ColArea move.l CA_Wy2(a3),d4 ; Get ColArea Wy2 add.l d3,d4 ; Add Focus Radius to Wy2 (Upper Y) cmp.l d4,d1 ; Is Focus Wy > Upper Y bgt ACCA_Next ; If yes skip to next ColArea move.l CA_Floor(a3),d4 ; Get ColArea floor height sub.l d3,d4 ; Sub Focus radius from Floor cmp.l d4,d2 ; Is Focus Height < Floor blt ACCA_Next ; If yes skip to next ColArea move.l CA_Ceil(a3),d4 ; Get ColArea ceiling height add.l d3,d4 ; Add Focus radius to ceiling height cmp.l d4,d2 ; Is Focus Height > Ceiling bgt ACCA_Next ; If yes skip to next ColArea ACCA_Hit: move.l #2,(a1)+ ; Write Collision type code move.l a3,(a1)+ ; Write Collision Ref (*ColArea) suba.l #1,a2 ; Decrement remaing returns space counter cmpa.l #0,a2 ; Is remaining space 0 ?? beq ACCA_Ret ; If yes then end scan ACCA_Next: adda.l #CA_SizeOf,a3 ; Move to next entry in array bra ACCA_Loop ; Go back to top of loop ACCA_Ret: rts ;--------------------------------------- ; Scan for Fixed WObject collisions ;--------------------------------------- ACC_FCol: cmpa.l #0,a2 ; Is returns array full ? ble ACCF_Ret ; If yes then return move.l CW_R1Start(a0),d4 ; Get Row Start move.l CW_R1End(a0),d5 ; Get Row End jsr ACCF_ScanRow ; Scan First SP Row move.l CW_R2Start(a0),d4 ; Get Row Start move.l CW_R2End(a0),d5 ; Get Row End jsr ACCF_ScanRow ; Scan Second SP Row ACCF_Ret: rts ;--- Check SP Row --- ; Stores a7 (sp) temporarily in CW_R1Start so can be used ACCF_ScanRow: cmpa.l #0,a2 ; Exit if no returns data space remains beq ACCF_Ret move.l CW_SpcPart(a0),a3 ; Get SP Pointers table base address move.l a0,-(sp) ; Stack work struct base pointer ACCFSR_Loop: cmp.l d5,d4 ; Is current pos > row End ?? bgt ACCFSR_Ret ; If yes then nothing to check so return move.l (a3,d4*4),a4 ; Get WObject pointer cmpa.l #0,a4 ; Is WObject pointer=NULL ?? beq ACCFSR_Next ; If yes then skip to next cmpa.l a5,a4 ; Is WObject=Ignore1 ?? beq ACCFSR_Next ; If yes then skip to next cmpa.l a6,a4 ; Is WObject=Ignore2 ?? beq ACCFSR_Next ; If yes then skip to next move.l WO_Radius(a4),a0 ; Get WObject Radius & Skip if =0 cmpa.l #0,a0 ; Is radius<=0 ?? ble ACCFSR_Next ; If yes skip to next WObject adda.l d3,a0 ; Add Focus Radius to WObject Radius move.l WO_Wx(a4),d6 ; Get WOb Wx move.l d6,d7 ; Get temp copy of Wx sub.l a0,d7 ; Sub Radius's from Wx (=Lower X bound) cmp.l d7,d0 ; Is Focus Wx < Lower X bound blt ACCFSR_Next ; If yes then skip to next add.l a0,d6 ; Add radius's to Wx (=Upper X bound) cmp.l d6,d0 ; Is Focus Wx > Upper X bound bgt ACCFSR_Next ; If yes then skip to next move.l WO_Wy(a4),d6 ; Get WOb Wy move.l d6,d7 ; Get temp copy of Wy sub.l a0,d7 ; Sub Radius's from Wy (=Lower Y bound) cmp.l d7,d1 ; Is Focus Wy < Lower Y bound blt ACCFSR_Next ; If yes then skip to next add.l a0,d6 ; Add radius's to Wy (=Upper Y bound) cmp.l d6,d1 ; Is Focus Wy > Upper Y bound bgt ACCFSR_Next ; If yes then skip to next move.l WO_Height(a4),d6 ; Get WOb Height move.l d6,d7 ; Get temp copy of Height sub.l a0,d7 ; Sub Radius's from Height (=Floor) cmp.l d7,d2 ; Is Foucs Height < Floor blt ACCFSR_Next ; If yes then skip to next add.l a0,d6 ; Add Radius's to Height (=Ceiling) cmp.l d6,d2 ; IS Focus Height > Ceiling bgt ACCFSR_Next ; If yes then skip to next ACCFSR_Hit: move.l #3,(a1)+ ; Write FCol return type move.l a4,(a1)+ ; Write Out WObject pointer suba.l #1,a2 ; Decrement returns data space counter cmpa.l #0,a2 ; Is returns data space full ?? beq ACCFSR_Ret ACCFSR_Next: addq.l #1,d4 ; Increment current pos bra ACCFSR_Loop ; go around again ACCFSR_Ret: move.l (sp)+,a0 ; Restore work struct base pointer rts ;------------------------------------------- ; Scan for Transient WObject collisions ;------------------------------------------- ACC_TCol: cmpa.l #0,a2 ; Is returns array full ? ble ACCT_Ret ; If yes then return move.l CW_WObject(a0),a3 ; Get Pointer to 1st WObject to check ACCT_Loop: cmpa.l #0,a3 ; Is WObject pointer=NULL beq ACCT_Ret ; If yes then no more to check cmpa.l a5,a3 ; Is WObject=Ignore1 beq ACCT_Next ; If yes then skip to next cmpa.l a6,a3 ; Is WObject=Ignore2 beq ACCT_Next ; If yes then skip to next move.l WO_Radius(a3),d4 ; Get WObjects Radius ble ACCT_Next ; If Radius<=0 not collisionable so skip add.l d3,d4 ; Add Focus Radius to WObject Radius move.l WO_Wx(a3),d5 ; Get WObject Wx move.l d5,d6 ; Get temp copy of Wx sub.l d4,d6 ; Sub Radius's from Wx (=Lower X bound) cmp.l d6,d0 ; Is Focus Wx < Lower X bound blt ACCT_Next ; If yes then skip to next add.l d4,d5 ; Add Radius's to Wx (=Upper X bound) cmp.l d5,d0 ; Is Focus Wx > Upper X bound bgt ACCT_Next ; If yes then skip to next move.l WO_Wy(a3),d5 ; Get WObject Wy move.l d5,d6 ; Get temp copy of Wy sub.l d4,d6 ; Sub Radius's from Wy (=Lower Y bound) cmp.l d6,d1 ; Is Focus Wy < Lower Y bound blt ACCT_Next ; If yes then skip to next add.l d4,d5 ; Add Radius's to Wy (=Upper Y bound) cmp.l d5,d1 ; Is Focus Wy > Upper Y bound bgt ACCT_Next ; If yes then skip to next move.l WO_Height(a3),d5 ; Get WObject Height move.l d5,d6 ; Get temp copy of Height sub.l d4,d6 ; Sub Radius's form Height (=Floor) cmp.l d6,d2 ; Is Focus Height < Floor blt ACCT_Next ; If yes then skip to next add.l d4,d5 ; Add Radius's to Height (=Ceiling) cmp.l d5,d2 ; Is Focus Height > Ceiling bgt ACCT_Next ; If yes then skip to next ACCT_Hit: move.l #4,(a1)+ ; Write out TCol type move.l a3,(a1)+ ; Write out WObject pointer suba.l #1,a2 ; Decrement remaining returns space cmpa.l #0,a2 ; Is there any space remianing ?? ble ACCT_Ret ; If not then exit ACCT_Next: move.l WO_Prev(a3),a3 ; Move back down link list bra ACCT_Loop ; Go around again ACCT_Ret: rts