AcquireCacheView() gets pixels from the in-memory or disk pixel cache as defined by the geometry parameters. A pointer to the pixels is returned if the pixels are transferred, otherwise a NULL is returned.
The format of the AcquireCacheView method is:
const PixelPacket *AcquireCacheView(const ViewInfo *view_info,
const long x,const long y,const unsigned long columns,
const unsigned long rows,ExceptionInfo *exception)
A description of each parameter follows:
view_info
The address of a structure of type ViewInfo.
x,y,columns,rows
These values define the perimeter of a region ofpixels.
exception
Return any errors or warnings in this structure.
CloseCacheView() closes the specified view returned by a previous call to OpenCacheView().
The format of the CloseCacheView method is:
void CloseCacheView(ViewInfo *view_info)
A description of each parameter follows:
view_info
The address of a structure of type ViewInfo.
GetCacheView() gets pixels from the in-memory or disk pixel cache as defined by the geometry parameters. A pointer to the pixels is returned if the pixels are transferred, otherwise a NULL is returned.
The format of the GetCacheView method is:
PixelPacket *GetCacheView(ViewInfo *view_info,const long x,const long y,
const unsigned long columns,const unsigned long rows)
A description of each parameter follows:
pixels
Method GetCacheView returns a null pointer if an erroroccurs, otherwise a pointer to the view_info pixels.
view_info
The address of a structure of type ViewInfo.
x,y,columns,rows
These values define the perimeter of a region ofpixels.
GetCacheViewIndexes() returns the indexes associated with the specified view.
The format of the GetCacheViewIndexes method is:
IndexPacket *GetCacheViewIndexes(const ViewInfo *view_info)
A description of each parameter follows:
view_info
The address of a structure of type ViewInfo.
GetCacheViewPixels() returns the pixels associated with the specified view.
The format of the GetCacheViewPixels method is:
PixelPacket *GetCacheViewPixels(const ViewInfo *view_info)
A description of each parameter follows:
view_info
The address of a structure of type ViewInfo.
OpenCacheView() opens a view into the pixel cache.
The format of the OpenCacheView method is:
ViewInfo *OpenCacheView(Image *image)
A description of each parameter follows:
image
The image.
SetCacheView() gets pixels from the in-memory or disk pixel cache as defined by the geometry parameters. A pointer to the pixels is returned if the pixels are transferred, otherwise a NULL is returned.
The format of the SetCacheView method is:
PixelPacket *SetCacheView(ViewInfo *view_info,const long x,const long y,
const unsigned long columns,const unsigned long rows)
A description of each parameter follows:
view_info
The address of a structure of type ViewInfo.
x,y,columns,rows
These values define the perimeter of a region ofpixels.
SyncCacheView() saves the view_info pixels to the in-memory or disk cache. The method returns MagickTrue if the pixel region is synced, otherwise MagickFalse.
The format of the SyncCacheView method is:
MagickBooleanType SyncCacheView(ViewInfo *view_info)
A description of each parameter follows:
view_info
The address of a structure of type ViewInfo.