What is DPI scaling technology

Traditional DPI scaling mechanism

The traditional DPI scaling mechanism is used by Windows XP, and developers are self-checking for potential problems with font scaling.

Pros: Clear Fonts

Cons: Typographical disorders (UI element text box overlay, table text overflow, interface beyond screen edge)

Modern dpi scaling mechanism: DPI Virtualization

The modern DPI scaling mechanism is used by Windows vista/win7/win8/win8.1. If the DPI scale does not exceed 125%, continue to use the traditional DPI scaling mechanism, and then turn this new mode on. It should be noted that the 125% scale in most cases does not cause serious interface confusion, and the font is clear after zooming.

Specifically, DPI scaling is disabled for programs that report support for DPI adaptation.

For programs that do not report support for DPI adaptation, the system uses the following mechanism:

If the scale is an integer multiple of 100%, the system uses a point to zoom in on the multipoint. When you select a scale of 200%/300%/..., the original interface in 1 points in turn corresponds to 4 points/9 points ....

If the scaling is not an integer multiple of 100%, the system first submits the virtual resolution to the application, then the system renders the software interface from the screen and then zooms to the user's chosen DPI level.

Take 1920*1080 resolution, scale 150% for example. The system first submits the current resolution of 1280x720 to the application, obtains the off-screen rendering interface, and then uses the conventional image interpolation algorithm to enlarge. To be reminded, interpolation will inevitably lead to a series of problems such as blurred interfaces, font aliasing, and so on.

Advantages: Normal Interface

Cons: Blurred interface

Win10 dpi scaling mechanism: Full DPI Virtualization

Win10 dpi scaling mechanism most parts are consistent with the modern DPI scaling mechanism, except that all DPI levels (including 125%) are DPI-virtualized, ensuring the interface is normal.

▲ the Win10 dpi mechanism on the left and the Win8.1 dpi mechanism on the right

Finally, a brief introduction to the Mac DPI scaling mechanism, the retina screen unified using the 200% DPI zoom level, the principle of implementation and Windows no difference. The only difference is that MAC OS x software, when displaying video and images, uses 100% DPI in the video image area to ensure the quality of video and image display.