Summary of Offscreen Graphics Worlds
Pascal Summary
Constants
CONST
cDepthErr = -157; {invalid pixel depth}
pixPurgeBit = 0; {set to to make base address for }
{ offscreen pixel image purgeable}
noNewDeviceBit = 1; {set to not create a new GDevice }
{ record for offscreen world}
useTempMemBit = 2; {set to create base address for offscreen }
{ pixel image in temporary memory}
keepLocalBit = 3; {set to keep offscreen pixel image in }
{ main memory}
pixelsPurgeableBit = 6; {set to make base address for pixel image }
{ purgeable}
pixelsLockedBit = 7; {set to lock base address for offscreen }
{ pixel image}
mapPixBit = 16; {set by UpdateGWorld if it remapped }
{ colors to a new color table}
newDepthBit = 17; {set by UpdateGWorld if it translated }
{ pixel map to a different pixel depth}
alignPixBit = 18; {set by UpdateGWorld if it realigned }
{ pixel image to onscreen window}
newRowBytesBit = 19; {set by UpdateGWorld if it changed }
{ rowBytes field of PixMap record}
reallocPixBit = 20; {set by UpdateGWorld if it reallocated }
{ base address for offscreen pixel image}
clipPixBit = 28; {set to clip pixel image}
stretchPixBit = 29; {set to stretch or shrink pixel image}
ditherPixBit = 30; {set to dither pixel image}
gwFlagErrBit = 31; {set by UpdateGWorld if it failed}
Data Types
TYPE GWorldPtr = CGrafPtr;
TYPE GWorldFlags =
SET OF (
pixPurge, {specify to NewGWorld to make base address for }
{ offscreen pixel image purgeable}
noNewDevice, {specify to NewGWorld to not create a new GDevice }
{ record for offscreen world}
useTempMem, {specify to NewGWorld to create base address for }
{ offscreen pixel image in temporary memory}
keepLocal, {specify to NewGWorld to keep offscreen pixel image }
{ in main memory}
gWorldFlag4, {reserved}
gWorldFlag5, {reserved}
pixelsPurgeable, {returned by GetPixelsState to indicate that base }
{ address for offscreen pixel image is purgeable; }
{ specify to SetPixelsState to make base address }
{ for pixel image purgeable}
pixelsLocked, {returned by GetPixelsState to indicate that base }
{ address for offscreen pixel image is locked; }
{ specify to SetPixelsState to lock base address }
{ for offscreen pixel image}
gWorldFlag8, {reserved}
gWorldFlag9, {reserved}
gWorldFlag10, {reserved}
gWorldFlag11, {reserved}
gWorldFlag12, {reserved}
gWorldFlag13, {reserved}
gWorldFlag14, {reserved}
gWorldFlag15, {reserved}
mapPix, {returned by UpdateGWorld if it remapped colors to }
{ a new color table}
newDepth, {returned by UpdateGWorld if it translated pixel }
{ map to a different pixel depth}
alignPix, {returned by UpdateGWorld if it realigned pixel }
{ image to onscreen window}
newRowBytes, {returned by UpdateGWorld if it changed rowBytes }
{ field of PixMap record}
reallocPix, {returned by UpdateGWorld if it reallocated }
{ base address for offscreen pixel image}
gWorldFlag21, {reserved}
gWorldFlag22, {reserved}
gWorldFlag23, {reserved}
gWorldFlag24, {reserved}
gWorldFlag25, {reserved}
gWorldFlag26, {reserved}
gWorldFlag27, {reserved}
clipPix, {specify to UpdateGWorld to update and clip pixel }
{ image}
stretchPix, {specify to UpdateGWorld to update and stretch or }
{ shrink pixel image}
ditherPix, {specify to UpdateGWorld to dither pixel image}
gwFlagErr, {returned by UpdateGWorld if it failed}
);
Routines
Creating, Altering, and Disposing of Offscreen Graphics Worlds
FUNCTION NewGWorld (VAR offscreenGWorld: GWorldPtr;
pixelDepth: Integer; boundsRect: Rect;
cTable: CTabHandle; aGDevice: GDHandle;
flags: GWorldFlags): QDErr;
FUNCTION NewScreenBuffer (globalRect: Rect;
purgeable: Boolean; VAR gdh: GDHandle;
VAR offscreenPixMap: PixMapHandle): QDErr;
FUNCTION NewTempScreenBuffer
(globalRect: Rect;
purgeable: Boolean;
VAR gdh: GDHandle;
VAR offscreenPixMap: PixMapHandle): QDErr;
FUNCTION UpdateGWorld (VAR offscreenGWorld: GWorldPtr;
pixelDepth: Integer; boundsRect: Rect;
cTable: CTabHandle; aGDevice: GDHandle;
flags: GWorldFlags): GWorldFlags;
PROCEDURE DisposeGWorld (offscreenGWorld: GWorldPtr);
PROCEDURE DisposeScreenBuffer
(offscreenPixMap: PixMapHandle);
Saving and Restoring Graphics Ports and Offscreen Graphics Worlds
PROCEDURE GetGWorld (VAR port: CGrafPtr; VAR gdh: GDHandle);
PROCEDURE SetGWorld (port: CGrafPtr; gdh: GDHandle);
FUNCTION GetGWorldDevice (offscreenGWorld: GWorldPtr): GDHandle;
Managing an Offscreen Graphics World's Pixel Image
FUNCTION GetGWorldPixMap (offscreenGWorld: GWorldPtr): PixMapHandle;
FUNCTION LockPixels (pm: PixMapHandle): Boolean;
PROCEDURE UnlockPixels (pm: PixMapHandle);
PROCEDURE AllowPurgePixels (pm: PixMapHandle);
PROCEDURE NoPurgePixels (pm: PixMapHandle);
FUNCTION GetPixelsState (pm: PixMapHandle): GWorldFlags;
PROCEDURE SetPixelsState (pm: PixMapHandle; state: GWorldFlags);
FUNCTION GetPixBaseAddr (pm: PixMapHandle): Ptr;
FUNCTION PixMap32Bit (pmHandle: PixMapHandle): Boolean;
C Summary
Constants
enum { /* bit assignments for GWorldFlags data type */
pixPurgeBit = 0, /* set to to make base address for
offscreen pixel image purgeable */
noNewDeviceBit = 1, /* set to not create a new GDevice
record for offscreen world */
useTempMemBit = 2, /* set to create base address for offscreen
pixel image in temporary memory */
keepLocalBit = 3, /* set to keep offscreen pixel image in
main memory */
pixelsPurgeableBit = 6, /* set to make base address for pixel image
purgeable */
pixelsLockedBit = 7, /* set to lock base address for offscreen
pixel image */
mapPixBit = 16, /* set by UpdateGWorld if it remapped
colors to a new color table */
newDepthBit = 17, /* set by UpdateGWorld if it translated
pixel map to a different pixel depth */
alignPixBit = 18, /* set by UpdateGWorld if it realigned
pixel image to onscreen window */
newRowBytesBit = 19, /* set by UpdateGWorld if it changed
rowBytes field of PixMap record */
reallocPixBit = 20, /* set by UpdateGWorld if it reallocated
base address for offscreen pixel image */
clipPixBit = 28, /* set to update and clip pixel image */
stretchPixBit = 29, /* set to update and stretch or shrink pixel
image */
ditherPixBit = 30, /* set to dither pixel image */
gwFlagErrBit = 31 /* set by UpdateGWorld if it failed */
};
enum { /* constants for GWorldFlags data type */
pixPurge = 1 << pixPurgeBit,
noNewDevice = 1 << noNewDeviceBit,
useTempMem = 1 << useTempMemBit,
keepLocal = 1 << keepLocalBit,
pixelsPurgeable = 1 << pixelsPurgeableBit,
pixelsLocked = 1 << pixelsLockedBit,
mapPix = 1 << mapPixBit,
newDepth = 1 << newDepthBit,
alignPix = 1 << alignPixBit,
newRowBytes = 1 << newRowBytesBit,
reallocPix = 1 << reallocPixBit,
clipPix = 1 << clipPixBit,
stretchPix = 1 << stretchPixBit,
ditherPix = 1 << ditherPixBit,
gwFlagErr = 1 << gwFlagErrBit
};
enum {
cDepthErr = -157 /* invalid pixel depth */
};
Data Types
typedef CGrafPtr GWorldPtr;
typedef unsigned long GWorldFlags;
Functions
Creating, Altering, and Disposing of Offscreen Graphics Worlds
pascal QDErr NewGWorld (GWorldPtr *offscreenGWorld, short PixelDepth,
const Rect *boundsRect, CTabHandle cTable,
GDHandle aGDevice, GWorldFlags flags);
pascal QDErr NewScreenBuffer
(const Rect *globalRect, Boolean purgeable, GDHandle *gdh, PixMapHandle *offscreenPixMap);
pascal QDErr NewTempScreenBuffer
(const Rect *globalRect, Boolean purgeable, GDHandle *gdh, PixMapHandle *offscreenPixMap);
pascal GWorldFlags UpdateGWorld
(GWorldPtr *offscreenGWorld, short pixelDepth, const Rect *boundsRect, CTabHandle cTable, GDHandle aGDevice, GWorldFlags flags);
pascal void DisposeGWorld (GWorldPtr offscreenGWorld);
pascal void DisposeScreenBuffer
(PixMapHandle offscreenPixMap);
Saving and Restoring Graphics Ports and Offscreen Graphics Worlds
pascal void GetGWorld (CGrafPtr *port, GDHandle *gdh);
pascal void SetGWorld (CGrafPtr port, GDHandle gdh);
pascal GDHandle GetGWorldDevice
(GWorldPtr offscreenGWorld);
Managing an Offscreen Graphics World's Pixel Image
pascal PixMapHandle GetGWorldPixMap
(GWorldPtr offscreenGWorld);
pascal Boolean LockPixels (PixMapHandle pm);
pascal void UnlockPixels (PixMapHandle pm);
pascal void AllowPurgePixels
(PixMapHandle pm);
pascal void NoPurgePixels (PixMapHandle pm);
pascal GWorldFlags GetPixelsState
(PixMapHandle pm);
pascal void SetPixelsState (PixMapHandle pm, GWorldFlags state);
pascal Ptr GetPixBaseAddr (PixMapHandle pm);
pascal Boolean PixMap32Bit (PixMapHandle pmHandle);
Assembly-Language Summary
Trap Macros Requiring Routine Selectors
_QDExtensions
| Selector | Routine |
| $00160000 | NewGWorld |
| $00040001 | LockPixels |
| $00040002 | UnlockPixels |
| $00160003 | UpdateGWorld |
| $00040004 | DisposeGWorld |
| $00080005 | GetGWorld |
| $00080006 | SetGWorld |
| $0004000B | AllowPurgePixels |
| $0004000C | NoPurgePixels |
| $0004000D | GetPixelsState |
| $0008000E | SetPixelsState |
| $0004000F | GetPixBaseAddr |
| $000E0010 | NewScreenBuffer |
| $00040011 | DisposeScreenBuffer |
| $00040012 | GetGWorldDevice |
| $000E0015 | NewTempScreenBuffer |
| $00040016 | PixMap32Bit |
| $00040017 | GetGWorldPixMap |
Result Codes
| noErr | 0 | No error |
| paramErr | -50 | Illegal parameter |
| cNoMemErr | -152 | Failed to allocate memory for structures |
| cDepthErr | -157 | Invalid pixel depth |
