# display/

This directory is the implementation of the Display Compositor.

The Display Compositor combines frames submitted to the viz service through
frame sinks, and combines them into a single gpu or software resource to be
presented to the user.

This directory is agnostic w.r.t. platform-specific presentation details, which
are abstracted behind OutputSurface and SoftwareOutputDevice. Through these
APIs, it supports either compositing gpu resources (textures) into a single
texture/framebuffer, or software resources (bitmaps) into a single bitmap. Note
that the platform specific implementations details should live outside of
display/ (for example, they can live in display_embedder/ instead).

To understand surface and surface aggregation better, please refer to
[Surface and Surface Aggregation slides](https://docs.google.com/presentation/d/14FlKgkh0-4VvM5vLeCV8OTA7YoBasWlwKIJyNnUJltM/edit?usp=sharing).