Letters

By David E. Smith, Editor & Publisher, MacTutor

Any sympathetic souls

John Love, III

I’m having absolutely NO luck with MACDTS, or anyone else for that matter, trying to solve my following 2 separate & distinct problems. I KNOW this is an AWFUL lot, but I’m going crazy ?!*!?

; 1) Using _CopyBits to create a color PICT2 file:
entireScreenpointer; My globals
screenMap pointer; ...
pictBoundsrect   ; ...
picHdl  handle   ; ...

 clr.w  -(sp)
 bsr  TestForColor
 pop.w  d0
 beq.s  .bitMap
 ; ----------
.pixMap GetCWMgrPort !entireScreen
 move.l entireScreen,a0
 lea  portPixMap(a0),a1
 move.l a1,screenMap
 move.l portPixMap(a0),a1
 move.l (a1),a1  ; Handle -- Pointer.
 bra.s  .setBounds
 ;
.bitMap GetWMgrPort!entireScreen
 move.l entireScreen,a0
 lea  portBits(a0),a1
 move.l a1,.screenMap

 ; ~~~~~~~~~~

.setBoundsmove.l bounds+topLeft(a1),pictBounds+topLeft
 move.l bounds+botRight(a1),pictBounds+botRight
 ; ----------
.setPortSetPort  entireScreen
 ClipRect !pictBounds
 ; etc
 
.macDraw2 OpenPicture!pictBounds,=picHdl

 CopyBits screenMap,screenMap,!pictBounds,!pictBounds,#srcCopy,#0

 ClosePicture
 ; etc
 
; above code works in black-and-white mode, but NOT in color.
;
; I’ve tried : move.lentireScreen,a0
;move.l portPixMap(a0),screenMap
; Also :move.l entireScreen,a0
;move.l portPixMap(a0),a1
;move.l (a1),screenMap
;
; ... but neither permutation works --> an empty picHdl (10 bytes, obviously
; ... corresponding to just the picSize & picFrame fields).
; ... it doesn’t bomb, but the file comes up blank, that is, just
; ... the 512-byte header + those 10 bytes and nothing else.
; ... I think it’s kinda interesting that ONLY upon
;
;move.l portPixMap(a0),screenMap
;
; ... do I get a PICT2 file, albeit an empty one.
; ... In the other two cases, I get just a PICT file.
;
;SIGH !!
; ------------------------------

; 2) Switching color on & off on the fly, that is, changing the MODE:

; following was deduced from the “Cards and Drivers ...” book.
; This book is supposed to be official stuff from Apple, yet
; MacDTS fails to respond in other than purely qualitative prose.
;
; All my code does is turn video to a constant gray all over
; as if I had turned the video OFF.  All further execution ceases !!
; No bomb, but I must re-boot.
 
; My calling stuff:

origModeinteger  ; My globals
paramBlkRec byte ioFQElSize ; ...
VDPgInfobyteVDPageInfo  ; ...

 clr.w  -(sp)
 bsr  TestForColor
 pop.w  d0
 beq.s  .notColor
 
 ; ----------
 ; Save the current mode for reseting when done
 ; and then set to black-and-white:

.itsColor clr.w  -(sp)    ; result = Error code.
 push.l MainDevice
 pea  paramBlkRec; VARed ...
 pea  VDPgInfo
 bsr  GetMode
 lea  VDPgInfo,a1
 move.w csMode(a1),origMode ; ... for reseting later.
 pop.w  d0
 bsr  testError  ; Returns if d0 <> 0.
 ; ----------
 clr.w  -(sp)
 push.l MainDevice
 push.w #oneBitMode; ... for black-and-white.
 bsr  SetDeviceMode
 pop.w  d0
 bsr  testError
 
.notColor
 ; etc
 
.onExitingclr.w  -(sp)
 bsr  TestForColor
 pop.w  d0
 beq.s  .byeBye
 
 ; ----------
 ; Reset the mode to its original value:
 
.resetColor clr.w-(sp)
 push.l MainDevice
 push.w .origMode
 bsr  SetDeviceMode
 pop.w  d0
 bsr  .testError
 
.byeBye
 ; etc

; All my subroutine children:
; ======================================
; FUNCTION  TestForColor : BOOLEAN;
; Test for the presence of a Mac with Color QuickDraw AND a Color
; Monitor that the user has set to Color via the Control Panel
; or by using the “Switch-A-Roo” FKEY:

TestForColorfunc boolean
 noParms
 
 locals
.theWorld byte sysEnv1Size; Mac II stuff.
 endLocals
 
 enter
 
 movem.ld1-d7/a0-a5,-(sp) ; Save all your pennies !!
 ; ==========
 
 clr.w  .result  ; Assume NO color = B&W.
 
 move.w #1,d0    ; Version #1.
 lea  .theWorld,a0
 _SysEnvirons
 tst.w  d0
 bne.s  .notColor
 ; ----------
.noErrortst.b  hasColorQD(a0) ; A0 --> theWorld.
 beq.s  .notColor
 ; ----------
 GetGDevice =a1  ; Handle -->
 move.l (a1),a1  ;   Pointer.
 move.l gdPMap(a1),a0; Ditto ...
 move.l (a0),a0
 cmpi.w #1,pmPixelSize(a0)
 beq.s  .notColor

.color  st.result
 ; ----------
.notColor

 ; ==========
.end  movem.l  (sp)+,d1-d7/a0-a5 ; Withdraw life savings !!
 
 exit

; ======================================
; FUNCTION  WhereIsTheDevice (whatDevice: GDHandle) : dceHandle;
; Slot #, Slot ID, etc ??
WhereIsTheDevice funchandle
.whatDevice handle
 endParms
 
 noLocals
 
.devRefNumrequ d1
 enter
 
 movem.ld1-d7/a0-a5,-(sp) ; Save your goodies !!
 ; ==========
 clr.l  .result  ; Assume nowhere !!
 
 move.l .whatDevice,a0
 move.l (a0),a0  ; Handle --> Pointer.
 move.w gdRefNum(a0),.devRefNum
 ; tst.w.devRefNum
 beq.s  .end; Nowhere !!
 ; ----------
 not.w  .devRefNum ; = Unit #
 lsl.w  #2,.devRefNum; 4 bytes per entry.
 move.l UTableBase,a1; --> DCE Table.
 move.l (a1,.devRefNum),.result  ; = dceHandle.
 
 ; ==========
.end  movem.l  (sp)+,d1-d7/a0-a5 ; Dig up your treasure !!
 exit

; ======================================
; FUNCTION  GetMode (whatDevice: GDHandle; VAR paramBlk: paramBlkRec;
;     VAR VDPgInfo: VDPgInfoRec) : INTEGER;
; csMode, csPage, etc ??

GetMode funcinteger; Error code.
.whatDevice handle
.paramBlk var
.VDPgInfo var
 endParms
 
 noLocals
.paramBlkPtrrequ a0
.dceHandlerequ a1
.dcePtr requa1
 
 enter
 
 movem.ld1-d7/a0-a5,-(sp) ; Save your goodies !!
 ; ==========
 move.w #-1,.result; Assume a problem.
 
 move.l .paramBlk,.paramBlkPtr; A Pointer.
 move.l #ioFQElSize-1,d0
.clearBlk1clr.b  (.paramBlkPtr)+
 dbra d0,.clearblk1
 ; ----------
 move.l .VDPgInfo,a2 ; Another Pointer.
 move.l #VDPageInfo-1,d2
.clearBlk2clr.b  (a2)+
 dbra d2,.clearBlk2
 
 clr.l  -(sp)    ; FUNCTIONal result.
 push.l .whatDevice
 bsr  WhereIsTheDevice
 pop.l  .dceHandle
 cmpi.l #0,.dceHandle
 beq.s  .end; Oh-Oh !!
 move.l (.dceHandle),.dcePtr
 ; ----------
 move.l .paramBlk,.paramBlkPtr; Reset.
 ; clr.lioCompletion(.paramBlkPtr)
 move.w dCtlRefNum(.dcePtr),ioRefNum(.paramBlkPtr)
 ; move.b #fsCurPerm,ioPermssn(.paramBlkPtr)   ; = 0
 ; clr.lioMix(.paramBlkPtr)
 ; clr.wioFlags(.paramBlkPtr)
 move.b dCtlSlot(.dcePtr),ioSlot(.paramBlkPtr)
 move.b dCtlSlotID(.dcePtr),ioID(.paramBlkPtr)
 
 move.w #cscGetMode,csCode(.paramBlkPtr)
 move.l .VDPgInfo,csParam(.paramBlkPtr)      ; VARed.
 _Status,immed
 move.w d0,.result
 ; ==========
.end  movem.l  (sp)+,d1-d7/a0-a5 ; Dig up your treasure !!
 
 exit

; ======================================
; FUNCTION  SetMode (whatDevice: GDHandle; paramBlk: paramBlkPtr;
;     VDPgInfo: VDPgInfoPtr) : INTEGER;
;
; csMode, csPage, etc !!

SetMode funcinteger; Error code.
.whatDevice handle
.paramBlk pointer
.VDPgInfo pointer
 endParms
 
 noLocals
 
.paramBlkPtrrequ a0
.dceHandlerequ a1
.dcePtr requa1
 
 enter
 
 movem.ld1-d7/a0-a5,-(sp)
 ; ==========
 
 clr.l  -(sp)    ; FUNCTIONal result.
 push.l .whatDevice
 bsr  WhereIsTheDevice
 pop.l  .dceHandle
 cmpi.l #0,.dceHandle
 bne.s  .setNewMode; Everything’s cool !!
.itsNowhere move.w #-1,d0
 bra.s  .ohOh
 ; ----------
.setNewMode move.l (.dceHandle),.dcePtr
 move.l .paramBlk,.paramBlkPtr
 move.w #cscSetMode,csCode(.paramBlkPtr)
 move.l .VDPgInfo,csParam(.paramBlkPtr)
 _Control,immed

.ohOh move.wd0,.result    
 ; ==========
.end  movem.l  (sp)+,d1-d7/a0-a5
 
 
 exit

; ======================================
; FUNCTION  SetDeviceMode (whatDevice: GDHandle; mode: INTEGER) : INTEGER;
;
; Set the specified Device to a particular color mode:

SetDeviceMode  funcinteger; Error code.
.whatDevice handle
.mode integer
 endParms
 
 locals
.paramBlkRecbyte ioFQElSize
.VDPgInfo byte VDPageInfo
 endLocals
 
.paramBlkPtrrequ a0
.dceHandlerequ a1
.dcePtr requa1
 enter
 
 movem.ld1-d7/a0-a5,-(sp)
 ; ==========
 
.getOldStuffclr.w-(sp)    ; result = Error code.
 push.l .whatDevice
 pea  .paramBlkRec ; VARed ...
 pea  .VDPgInfo
 bsr  GetMode
 pop.w  d0
 bne.s  .ohOh

.whereInThe?clr.l-(sp)    ; FUNCTIONal result.
 push.l .whatDevice
 bsr  WhereIsTheDevice
 pop.l  .dceHandle
 cmpi.l #0,.dceHandle
 bne.s  .setGray ; Everything’s cool !!
.itsNowhere move.w #-1,d0
 bra.s  .ohOh
 ; ----------
.setGraymove.l (.dceHandle),.dcePtr; Recommended middle step.
 lea  .paramBlkRec,.paramBlkPtr
 move.w #cscGrayPage,csCode(.paramBlkPtr)
 lea  .VDPgInfo,a2
 move.l a2,csParam(.paramBlkPtr)
 _Control,immed
 tst.w  d0
 ; bne.s.ohOh    ; This call is optional.

.setNewMode clr.w-(sp)    ; Error code.
 push.l .whatDevice
 pea  .paramBlkRec
 lea  .VDPgInfo,a1
 move.w .mode,csMode(a1)  ; Change the mode.
 pea  .VDPgInfo
 bsr  SetMode
 pop.w  d0
 
.ohOh move.wd0,.result    
 ; ==========
.end  movem.l  (sp)+,d1-d7/a0-a5
 
 exit

Onstad’s Answer

Flashpoint

Paul Onstad’s question in the August 1989 issue of MacTutor on page 4: you must do a CreateResFile() after the Create to add the resource map data to the resource fork. [Note: you must Create FIRST, CreateResFile SECOND.]

Segmented XCMD Problem Solved

Peter B. Nagel

With several gentle nudges from various helpful persons on CompuServe, I was able quite successfully to implement a solution in HyperTMON to the segmented XCMD problem that three individuals described in the Mousehole Report column in your August issue.

MPW’s -ss linker option will allow the creation of XCMD segments well in excess of the normal 32k limit on the intra-code segment addresses. Through a judicious resorting of my linked modules, I was able to create XCMDs approaching 38k. To enlarge an XCMD beyond that limit, however, I found that it was necessary, and certainly possible, to segment XCMDs through the use of separate code resources.

To do this, create and link a separate code resource whose entry point jumps to a case statement that branches to the appropriate procedures and functions in the resource. Then define a parameter block with sufficient fields to hold all the possible parameters that could be passed to all the procedures and functions in that code resource. From within the XCMD, then, you can include the following code (minus appropriate error checking) to retrieve the separate code resource, initialize the parameter block, and jump to you external code:

Procedure JumpToNewCode(paramBlkHndl: paramHndl; procAddress: Ptr);
InLine  $205F, { MOVE.L (A7)+, A0; address of procedure}
 $4E90, { JSR (A0); jump to procedure}

Procedure CallNewCode(selector: integer; param1: integer; param2: longint; 
param3: Ptr; Var param4: Handle; Var param5: Boolean);
Var
 paramBlkHndl : paramHndl;
 codeAddr : Handle;
Begin {Procedure CallNewCode}
 codeAddr := GetResource(‘CODE’, 1234);
 MoveHHi(codeAddr);
 HLock(codeAddr);
 paramBlkHndl := NewHandle(sizeof(paramHndl));
 with paramBlkHndl^^ do
 begin
 {fill in parameters}
 end;
 JumpToNewCode(paramBlkHndl, StripAddress(codeAddr^));
 HUnlock(codeAddr);
 HPurge(codeAddr);
 with paramBlkHndl^^ do
 begin
 {return Var values}
 end;
 DisposHandle(paramBlkHndl);
end; {Procedure CallNewCode}

At one time, it appeared that, when memory became really tight, HyperCard may have been unceremoniously disposing of my code resources, and so I ended up calling BlockMove to place them in nonrelocatable blocks, since I needed them around at all times. I am still not sure that it wasn’t my own fault, but I would be interested in knowing if any of your readers have had a similar problem.