Display Driver

The display driver is responsible for interacting with the display hardware and the graphics device interface (GDI) module of Microsoft Windows. A display driver should support inking to provide the user with visible feedback as the pen moves. Technically, the Pen API does not require inking support from the display driver. However, the system is far more practical and convenient when the user can see the ink trail left by the pen.

Two types of display drivers are supported: Display Control Interface (DCI) drivers (called DCI Providers) and non-DCI drivers, such as older VGA or 8514 drivers. For DCI Providers, no extra work is required to support the pen interface.

To support inking in a non-DCI driver, the display driver must be able to:

  • Export the GetLPDevice function to provide Windows with a value identifying the pen hardware.

  • Export the InkReady function, which Windows calls to notify the driver that the pen is in motion and Windows is ready to display ink. InkReady must be able to handle calls during system interrupts.

  • Provide a pointer in the shape of a pen.

Windows pics/PENAPI00090001.gif not the display driver pics/PENAPI00090001.gif displays the ink. When Windows receives notice through its InkReady function, the driver calls back into Windows to draw the ink.

For more details on display drivers, refer to the device driver kit (DDK) for Windows 95.

Software for developers
Delphi Components
.Net Components
Software for Android Developers
More information resources
MegaDetailed.Net
Unix Manual Pages
Delphi Examples