Libraries

The Mir project is a collection of C++ libraries for writing Wayland compositors. This document describes what those libraries are and how they depend on one another.

Public libraries

The following libraries are intended for published for public consumption:

  • miral

  • mircommon

  • mircore

  • miroil

  • mirplatform

  • mirserver

  • mirwayland

When you build the project, these libraries are found in <build_directory>/lib.

Additionally, Mir publishes libraries that add support for different platforms. These can be found in <build_directory>/lib/server-modules. These libraries are loaded at runtime by Mir and provide access to the underlying graphics and input hardware of that platform. The libraries that Mir provides are:

  • graphics-atomic-kms

  • graphics-gbm-kms

  • graphics-eglstream-kms

  • graphics-wayland

  • graphics-dummy

  • server-x11

  • server-virtual

  • renderer-egl-generic

  • input-evdev

  • input-stub

Dependency graph

In the following diagram, each arrow denotes that the library at the start of the arrow depends on the library at the end of the arrow.

Diagram: A flow chart depicting how the libraries of Mir relate to one another.

        classDiagram
    mircommon --> mircore
    mirwayland --> mircore
    miral --> mircore
    miroil --> mircore
    mirserver --> mircore
    InputPlatform --> mircore
    DisplayPlatform --> mircore
    RenderingPlatform --> mircore

    mirwayland --> mircommon
    mirserver --> mircommon
    miral --> mircommon
    miroil --> mircommon
    mirplatform --> mircommon

    mirserver --> mirwayland

    mirserver --> mirplatform
    InputPlatform --> mirplatform
    DisplayPlatform --> mirplatform
    RenderingPlatform --> mirplatform

    mirserver --> InputPlatform: dynamically loads
    mirserver --> DisplayPlatform: dynamically loads
    mirserver --> RenderingPlatform: dynamically loads

    miral --> mirserver
    miroil --> mirserver

    namespace platform {
        class InputPlatform
        class DisplayPlatform
        class RenderingPlatform
    }

    

There are a few things of note in this diagram:

  • miral and mircore are intended to be the primary user-facing libraries

  • miroil is a special compatibility layer for the Lomiri project is not intended for general consumption

  • mirserver depends on the most libraries as it is the brains of the operation

  • mircommon provide common functionalities for every other library in the system

  • The input and graphics platforms (represented as input_X and graphics_X in the diagram) are dynamically loaded by mirserver when the engine starts up.