The common mechanism associated with physically and logically separate display spaces in a computer display?

Question: The common mechanism associated with physically and logically separate display spaces in a computer display?

One of the topics that often comes up in the field of computer graphics is the concept of display spaces. A display space is a region of the screen where graphical elements can be rendered and manipulated. Display spaces can be either physically or logically separate from each other, depending on how they are implemented and used.

Physically separate display spaces are those that occupy different parts of the hardware screen, such as multiple monitors or windows. These display spaces have distinct coordinates and boundaries, and they can be controlled independently by the user or the application. For example, a user can drag a window from one monitor to another, or resize it to fit the available space.

Logically separate display spaces are those that share the same hardware screen, but are rendered using different transformations or projections. These display spaces have overlapping coordinates and boundaries, and they can be combined or blended together by the application. For example, a game can use a perspective projection for the main scene, and an orthographic projection for the heads-up display (HUD).

The common mechanism associated with both types of display spaces is the use of viewports. A viewport is a rectangular area that defines how a display space is mapped to the hardware screen. A viewport specifies the origin, size, and clipping region of a display space, as well as the transformation matrix that converts its coordinates to screen coordinates. By using different viewports, an application can create and manage multiple display spaces on the same screen.