Windows DPI scaling/highdpi support

Adds hint "SDL_WINDOWS_DPI_SCALING" which can be set to "1" to
change the SDL coordinate system units to be DPI-scaled points, rather
than pixels everywhere.

This means windows will be appropriately sized, even when created on
high-DPI displays with scaling.

e.g. requesting a 640x480 window from SDL, on a display with 125%
scaling in Windows display settings, will create a window with an
800x600 client area (in pixels).

Setting this to "1" implicitly requests process DPI awareness
(setting SDL_WINDOWS_DPI_AWARENESS is unnecessary),
and forces SDL_WINDOW_ALLOW_HIGHDPI on all windows.
This commit is contained in:
Eric Wasylishen 2022-06-07 02:01:27 -06:00 committed by Sam Lantinga
parent df36f926fc
commit ab81a559f4
16 changed files with 624 additions and 34 deletions

View file

@ -1838,6 +1838,27 @@ extern "C" {
*/
#define SDL_HINT_WINDOWS_DPI_AWARENESS "SDL_WINDOWS_DPI_AWARENESS"
/**
* \brief Uses DPI-scaled points as the SDL coordinate system on Windows.
*
* This changes the SDL coordinate system units to be DPI-scaled points, rather than pixels everywhere.
* This means windows will be appropriately sized, even when created on high-DPI displays with scaling.
*
* e.g. requesting a 640x480 window from SDL, on a display with 125% scaling in Windows display settings,
* will create a window with an 800x600 client area (in pixels).
*
* Setting this to "1" implicitly requests process DPI awareness (setting SDL_WINDOWS_DPI_AWARENESS is unnecessary),
* and forces SDL_WINDOW_ALLOW_HIGHDPI on all windows.
*
* This variable can be set to the following values:
* "0" - SDL coordinates equal Windows coordinates. No automatic window resizing when dragging
* between monitors with different scale factors (unless this is performed by
* Windows itself, which is the case when the process is DPI unaware).
* "1" - SDL coordinates are in DPI-scaled points. Automatically resize windows as needed on
* displays with non-100% scale factors.
*/
#define SDL_HINT_WINDOWS_DPI_SCALING "SDL_WINDOWS_DPI_SCALING"
/**
* \brief A variable controlling whether the window frame and title bar are interactive when the cursor is hidden
*