a1200   NEWS   APPS   DOCS   ABOUT
a1200
----
a1200
----
Autodocs
 Libraries:
 graphics.library
  AddAnimOb
  AddBob
  AddFont
  AddVSprite
  AllocBitMap
  AllocDBufInfo
  AllocRaster
  AllocSpriteDataA
  AndRectRegion
  AndRegionRegion
  Animate
  AreaCircle
  AreaDraw
  AreaEllipse
  AreaEnd
  AreaMove
  AskFont
  AskSoftStyle
  AttachPalExtra
  AttemptLockLayerRom
  BestModeIDA
  BitMapScale
  BltBitMap
  BltBitMapRastPort
  BltClear
  BltMaskBitMapRastPort
  BltPattern
  BltTemplate
  CBump
  CEND
  CINIT
  CMOVE
  CWAIT
  CalcIVG
  ChangeExtSpriteA
  ChangeSprite
  ChangeVPBitMap
  ClearEOL
  ClearRectRegion
  ClearRegion
  ClearScreen
  ClipBlit
  CloseFont
  CloseMonitor
  CoerceMode
  CopySBitMap
  DisownBlitter
  DisposeRegion
  DoCollision
  Draw
  DrawEllipse
  DrawGList
  EraseRect
  ExtendFont
  FindColor
  FindDisplayInfo
  Flood
  FontExtent
  FreeBitMap
  FreeColorMap
  FreeCopList
  FreeCprList
  FreeDBufInfo
  FreeGBuffers
  FreeRaster
  FreeSprite
  FreeSpriteData
  FreeVPortCopLists
  GetAPen
  GetBPen
  GetBitMapAttr
  GetColorMap
  GetDisplayInfoData
  GetDrMd
  GetExtSpriteA
  GetGBuffers
  GetOPen
  GetRGB32
  GetRGB4
  GetRPAttrA
  GetSprite
  GetVPModeID
  GfxAssociate
  GfxFree
  GfxLookUp
  GfxNew
  InitArea
  InitBitMap
  InitGMasks
  InitGels
  InitMasks
  InitRastPort
  InitTmpRas
  InitVPort
  InitView
  LoadRGB32
  LoadRGB4
  LoadView
  LockLayerRom
  MakeVPort
  ModeNotAvailable
  Move
  MoveSprite
  MrgCop
  NewRegion
  NextDisplayInfo
  ObtainBestPenA
  ObtainPen
  OpenFont
  OpenMonitor
  OrRectRegion
  OrRegionRegion
  OwnBlitter
  PolyDraw
  QBSBlit
  QBlit
  ReadPixel
  ReadPixelArray8
  ReadPixelLine8
  RectFill
  ReleasePen
  RemBob
  RemFont
  RemIBob
  RemVSprite
  ScalerDiv
  ScrollRaster
  ScrollRasterBF
  ScrollVPort
  SetABPenDrMd
  SetAPen
  SetBPen
  SetChipRev
  SetCollision
  SetDrMd
  SetFont
  SetMaxPen
  SetOPen
  SetOutlinePen
  SetRGB32
  SetRGB32CM
  SetRGB4
  SetRGB4CM
  SetRPAttrA
  SetRast
  SetSoftStyle
  SetWriteMask
  SortGList
  StripFont
  SyncSBitMap
  Text
  TextExtent
  TextFit
  TextLength
  UnlockLayerRom
  VBeamPos
  VideoControl
  WaitBOVP
  WaitBlit
  WaitTOF
  WriteChunkyPixels
  WritePixel
  WritePixelArray8
  WritePixelLine8
  XorRectRegion
  XorRegionRegion
Include
GuruMeditation
Docs » Autodocs » graphics.library » AllocDBufInfo

NAME

       AllocDBufInfo -- Allocate structure for multi-buffered animation (V39)

SYNOPSIS

       AllocDBufInfo(vp)
		      a0
	struct DBufInfo * AllocDBufInfo(struct ViewPort *)

FUNCTION

	Allocates a structure which is used by the ChangeVPBitMap()
	routine.

INPUTS

       vp  =  A pointer to a ViewPort structure.

BUGS

NOTES

	Returns 0 if there is no memory available or if the display mode
	of the viewport does not support double-buffering.
	The only fields of the DBufInfo structure which can be used by application
	programs are the dbi_SafeMessage, dbi_DispMessage, dbi_UserData1 and 
	dbi_UserData2 fields.
	dbi_SafeMessage and dbi_DispMessage are standard exec message structures
	which may be used for synchronizing your animation with the screen update.
	dbi_SafeMessage is a message which is replied to when it is safe to write to
	the old BitMap (the one which was installed when you called ChangeVPBitMap).
	dbi_DispMessage is replied to when it is safe to call ChangeVPBitMap again
	and be certain that the new frame has been seen at least once.
	The dbi_UserData1 and dbi_UserData2 fields, which are stored after each
	message, are for your application to stuff any data into that it may need
	to examine when looking at the reply coming into the ReplyPort for either
	of the embedded Message structures.
	DBufInfo structures MUST be allocated with this function. The size of
	the structure will grow in future releases. 
	The following fragment shows proper double buffering synchronization:
	int SafeToChange=TRUE, SafeToWrite=TRUE, CurBuffer=1;
	struct MsgPort *ports[2];    /* reply ports for DispMessage and SafeMessage 
*/
	struct BitMap *BmPtrs[2];
	struct DBufInfo *myDBI;
	... allocate bitmap pointers, DBufInfo, set up viewports, etc.
	myDBI->dbi_SafeMessage.mn_ReplyPort=ports[0];
	myDBI->dbi_DispMessage.mn_ReplyPort=ports[1];
	while (! done)
	{
	    if (! SafeToWrite)
		while(! GetMsg(ports[0])) Wait(1l<<(ports[0]->mp_SigBit));
	    SafeToWrite=TRUE;
	    ... render to bitmap # CurBuffer.
	    if (! SafeToChange)
		while(! GetMsg(ports[1])) Wait(1l<<(ports[1]->mp_SigBit));
	    SafeToChange=TRUE;
	    WaitBlit();         /* be sure rendering has finished */
	    ChangeVPBitMap(vp,BmPtrs[CurBuffer],myDBI);
	    SafeToChange=FALSE;
	    SafeToWrite=FALSE;
	    CurBuffer ^=1;	/* toggle current buffer */
	}
       if (! SafeToChange)	/* cleanup pending messages */
	    while(! GetMsg(ports[1])) Wait(1l<<(ports[1]->mp_SigBit));
       if (! SafeToWrite)	/* cleanup */
	    while(! GetMsg(ports[0])) Wait(1l<<(ports[0]->mp_SigBit));

SEE ALSO

FreeDBufInfo(), ChangeVPBitMap()

Comments

Name:
E-mail: Use this if you want a message if you get a response, will not be shown.
Comment:
Select correct short for:

Defjam

HZ
DJ
PHA
DC

Comments:
$VER: d0.se 1.14 Copyright © 2011-2024 Tobias Geijersson support at d0 dot se