Important: The information in this document is obsolete and should not be used for new development.
Managing an Offscreen Graphics World's Pixel Image
Use theGetGWorldPixMap
function to obtain a handle to thePixMap
record for an offscreen graphics world. You can then pass this handle, which is of data typePixMapHandle
, in parameters to several routines that allow you to manage an offscreen graphics world's pixel image.To prevent the base address for an offscreen pixel image from being moved (while you draw into or copy from its pixel map, for example), pass its handle to the
LockPixels
function. When you are finished drawing into or copying from an offscreen pixel map, pass its handle to theUnlockPixels
procedure.You can use the
AllowPurgePixels
procedure to make the base address for an offscreen pixel image purgeable. To prevent the Memory Manager from purging the base address for an offscreen pixel map, use theNoPurgePixels
procedure.To save the current information about the memory allocated for an offscreen pixel image, you can use the
GetPixelsState
function. To restore this state, you can use theSetPixelsState
procedure.You can use the
GetPixBaseAddr
function to obtain a pointer to the beginning of a pixel image in memory. You can use thePixMap32Bit
function to determine whether a pixel map requires 32-bit addressing mode for access to its pixel image.
Subtopics
- GetGWorldPixMap
- LockPixels
- UnlockPixels
- AllowPurgePixels
- NoPurgePixels
- GetPixelsState
- SetPixelsState
- GetPixBaseAddr
- PixMap32Bit