Virtual Display provides a display to the system which is not necessarily linked to the real display hardware. Applications and middleware, e.g. system compositor, should be able to use this display as usual. The concrete implementation of this technology is in charge to decide how to proceed with the received content. Virtual Display can be considered as subcategory of Surface Sharing.
- Simple to use because it abstracts the details of display implementation for the middleware
- Doesn't provide a fine granular control over the display content but it is still good enough for a lot of use-cases
- Entire display content is handled instead of applications content
Virtual Display doesn't describe a certain sharing technology, it is more a concept which can be used to realize distribute HMI use-cases. Important characteristic of the Virtual Display concept is that the entire display content is handled instead of handling content from dedicated applications. The system which provides the content should have the display which looks like the normal one display but is not necessarily liked to the physical display, so the middleware and applications can use this as normal display and provide content to it as usual. Such display can be called Virtual Display. So the The implementation of Virtual Display on the producer site should be generic enough to look like the normal display and should take care of the transferring the content which is provided from the applications to another HMI unit or system and this . This basically means a final graphical surface need to be transferred, therefore we it can be consider this as subcategory of Surface Sharing. On the receiver site the content can be handled with more flexibility. It could be directly used as content for physical display, mapped to a physical layer or used as part of a composition combined with another local available content. This flexibility makes the definition and the separation between different technologies a bit blurry. Important characteristic of the Virtual Display concept is the we are handling the entire display content instead of handling content from dedicated applications
Example: virtual display in Weston
Open source wayland compositor- Weston provides an example of Virtual Display implementation. ...