Legacy Document

Important: The information in this document is obsolete and should not be used for new development.

Inside Macintosh: Imaging With QuickDraw /

Chapter 6 - Offscreen Graphics Worlds / Offscreen Graphics Worlds Reference

GWorldFlags
Several routines in this chapter expect or return values defined by the GWorldFlags data type, which is defined as follows:
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}
);
Field Description

pixPurge
If you specify this flag for the flags parameter of the NewGWorld function, NewGWorld (described on page 6-16) makes the base address for the offscreen pixel image purgeable.
noNewDevice
If you specify this flag for the flags parameter of the NewGWorld function, NewGWorld does not create a new offscreen GDevice record; instead, NewGWorld uses either the GDevice record you specify or the GDevice record for a video card on the user's system.
useTempMem
If you specify this in the flags parameter of the NewGWorld function, NewGWorld creates the base address for an offscreen pixel image in temporary memory. You generally should not use this flag. You should use temporary memory only for fleeting purposes and only with the AllowPurgePixels procedure (described on page 6-34) so that other applications can launch.
keepLocal
If you specify this in the flags parameter of the NewGWorld function, NewGWorld creates a pixel image in Macintosh main memory where it cannot be cached to a graphics accelerator card.
gWorldFlag4
Reserved.
gWorldFlag5
Reserved.
pixelsPurgeable

If you specify this in the state parameter of the SetPixelsState procedure (described on page 6-37), SetPixelsState makes the base address for an offscreen pixel map purgeable. If you use the SetPixelsState procedure without passing it this flag, then SetPixelsState makes the base address for an offscreen pixel map unpurgeable. If the GetPixelsState function (described on page 6-36) returns this flag, then the base address for an offscreen pixel is purgeable.
pixelsLocked
If you specify this flag for the state parameter of the SetPixelsState procedure, SetPixelsState locks the base address for an offscreen pixel image. If you use the SetPixelsState procedure without passing it this flag, then SetPixelsState unlocks the offscreen pixel image. If the GetPixelsState function returns this flag, then the base address for an offscreen pixel is locked.
gWorldFlag8
Reserved.
gWorldFlag9
Reserved.
gWorldFlag10
Reserved.
gWorldFlag11
Reserved.
gWorldFlag12
Reserved.
gWorldFlag13
Reserved.
gWorldFlag14
Reserved.
gWorldFlag15
Reserved.
mapPix
If the UpdateGWorld function (described on page 6-23) returns this flag, then it remapped the colors in the offscreen pixel map to a new color table.
newDepth
If the UpdateGWorld function returns this flag, then it translated the offscreen pixel map to a different pixel depth.
alignPix
If the UpdateGWorld function returns this flag, then it realigned the offscreen pixel image to an onscreen window.
newRowBytes
If the UpdateGWorld function returns this flag, then it changed the rowBytes field of the PixMap record for the offscreen graphics world.
reallocPix
If the UpdateGWorld function returns this flag, then it reallocated the base address for the offscreen pixel image. Your application should then reconstruct the pixel image or draw directly in a window instead of preparing the image in an offscreen graphics world.
gWorldFlag21
Reserved.
gWorldFlag22
Reserved.
gWorldFlag23
Reserved.
gWorldFlag24
Reserved.
gWorldFlag25
Reserved.
gWorldFlag26
Reserved.
gWorldFlag27
Reserved.
clipPix
If the UpdateGWorld function returns this flag, then it clipped the pixel image.
stretchPix
If the UpdateGWorld function returns this flag, then it stretched or shrank the offscreen image.
ditherPix
If the UpdateGWorld function returns this flag, then it dithered the offscreen image.
gwFlagErr
If the UpdateGWorld function returns this flag, then it was unsuccessful and the offscreen graphics world was left unchanged.