OpenPort

void OpenPort(whichPort );

GrafPtr whichPort ; pointer to a GrafPort structure

OpenPort initializes fields for a new GrafPort, allocates memory for its

visRgn and clipRgn, and activates the GrafPort.

whichPort is a GrafPtr (pointer to a 108-byte GrafPort structure). This

structure may reside as a static or auto variable in a procedure or

you you may allocate the storage via NewPtr.

Notes: You normally won't need to use this, since the Window Manager calls this

function when you create a window via NewWindow or GetNewWindow.

If used, the typical sequence is:

myPortPtr = (GrafPtr) NewPtr( sizeof(GrafPort) );

OpenPort( myPortPtr );

Use ClosePort to dispose of the memory allocated. As above, the Window

Manager does this for you when you close a window.

Don't use a handle to store a GrafPort. A GrafPort must not move between

the time you open it and the time you close it. QuickDraw keeps a list of

pointers to open ports. If a port moves, QuickDraw won't be able to find it.

The fields of whichPort GrafPort are initialized as follows:

Field Data Type Initial Setting

device short 0 (the screen)

portBits BitMap screenBits (global variable)

portRect Rect screenBits.bounds (global variable)

visRgn RgnHandle handle to a rectangular region covering

(-32767,-32767) to (32767, 32767)

clipRgn RgnHandle handle to a rectangular region (as above)

fillPat Pattern black

pnLoc Point (0,0)

pnSize Point (1,1)

pnMode short patCopy (8)

pnPat Pattern black (global variable)

pnVis short 0 ( visible)

txFont short 0 (system font; i.e., chicago)

txFace Style plain (0)

txMode short srcOr (2)

txSize short 0 (system font size; i.e., 12)

spExtra Fixed 0

fgColor long blackColor (33)

bkColor long whiteColor (30)

colrBit short 0

patStretch short 0

picSave Handle NIL (0)

rgnSave Handle NIL (0)

polySave Handle NIL (0)

grafProcs QDProcsPtr NIL (0)