NAME

DvSetBackgroundRaster − Set the raster object for a view background

SYNOPSIS

C:

void DvSetBackgroundRaster(view, raster, callback)
DtObject view;
DtObject raster;
DtObject callback;

FORTRAN:

CALL DVSBR(VIEW, RASTER, CBACK)
INTEGER∗4 VIEW
INTEGER∗4 RASTER
INTEGER∗4 CBACK

DESCRIPTION

DvSetBackgroundRaster sets the raster object raster to be used as a background image of the view view.  If raster is DcNullPtr <DCNULL> then the background color (set by DvSetBackgroundColor <DVSBC>) will be used.  The callback object callback will be called if the dimensions of the raster are not the same as the dimensions of the view in device coordinates.  The callback object returns a raster object to be used for the dimensions of the view as mapped on the device.  See DvSetBackgroundJust for a description of how mismatches in view and raster dimensions are handled. 

The callback function is called with the standard callback parameter data plus the 3 additional parameters, the raster object, the width of the view in device coordinates, and the height of the view in device coordinates.  The callback function should return a raster object.  The function in C should look like this:

DtObject my_callback(data, raster, width, height)
DtPtr data;/∗ if data is a pointer to data ∗/
Dt32Bits data;/∗ if data is a value ∗/
DtObject raster;
DtInt width;
DtInt height;

FORTRAN:

INTEGER∗4 MYCBK(DATA, RASTER, WIDTH, HEIGHT)
INTEGER∗4 DATA
INTEGER∗4 RASTER
INTEGER∗4 WIDTH
INTEGER∗4 HEIGHT

Within the callback function the data of the raster can be obtained via a call to DsInqRaster <DSQR>. 

ERRORS

DvSetBackgroundRaster will fail if the view handle is invalid. 

[WARNING - invalid view handle]

SEE ALSO

DsInqRaster(3D), DvInqBackgroundJust(3D), DvInqBackgroundRaster(3D), DvSetBackgroundJust(3D)

September 02, 1992