Problem while performing StretchBlt on HP 1010, HP 1018, HP 1020 andHP 3050
Our application uses Windows GDI library to perform rendering and
display of data/output onto
the devices such as Screen and Printer.
While I am trying to print the data onto a series of printers (HP
1010, HP 1018, HP 1020 and HP
3050) I am facing a typical problem.
1. Appropriate DC for the intended device is created [Printer DC
created for a selected printer in this case]
2. The data is displayed onto the identified position onto the DC
The details of data (fields) to be displayed and their position onto
the DC is calculated before the printing begins.
If sufficient space is available for displaying/printing a field
(data), then it is displayed directly onto the DC (using TextOut.
However at situations, the space available for printing (displaying) a
piece of data may not be enough. In such scenario, I display such
information onto a temperory (display) DC and then perform
StretchBlt(....) onto the printer DC.
StretchBlt is capable of performing both Stretch / shrink from source
DC to the destination DC.
[MSDN: The StretchBlt function copies a bitmap from a source rectangle
into a destination rectangle, stretching or compressing the bitmap to
fit the dimensions of the destination rectangle, if necessary. The
system stretches or compresses (shrinks) the bitmap according to the
stretching mode currently set in the destination device context].
In this case:
- Data is first displayed / outputted onto tempDC
- Then StretchBlt is performed from tempDC to PrinterDC
The rectangular area on the destination DC is more than source
rectangular area then data is stretched
If the rectangular area on the destination DC is less than source
rectangular area then data is shrinked
StretchBlt(...) allows us to specify the raster operation to use while
performing this task as its last parameter.
Here I am using SRCAND. When I use SRCAND raster operation the data is
displayed in actual font size instead of shrinking. This results on
loss of data (as sufficient width/height) is not available to
The same operation works on several other DeskJet/LaserJet (including
HP) printers. But it fails on the above mentioned set of printers.
If I try to use other raster operation such as SRCCOPY, it is able to
shrink the data and display properly. I can't use other operations. I
have to use SRCAND (as I would like to retain any data that is already
displayed within the rectangular area).
I also observed that, if the destination rectangular area is more than
source rectangular area: then it is able to stretch and display the
data without any loss (even with SRCAND raster operation)
Please let me know, if any of you have already encountered such
problem and any solution
Thanks & Regards,
Tally Solutions Pvt Ltd.