Add 'usedpiscale' boolean (true by default) to love.window.setMode's settings table and love.conf's t.window table. Add love.window.getNativeDPIScale.

When usedpiscale=false, love will no longer automatically scale coordinates by the screen's DPI scale factor (so all coordinates will be in pixels), even when highdpi=true. love.window.getDPIScale will return 1, love.graphics.newCanvas will default to a dpi scale of 1 instead of the screen's dpi scale, etc.

love.window.getNativeDPIScale() will return the screen's DPI scale as reported by the OS no matter what usedpiscale is set to.

src/modules/window/Window.cpp

@@ -104,6 +104,7 @@ StringMap<Window::Setting, Window::SETTING_MAX_ENUM>::Entry Window::settingEntri
 	{"centered", SETTING_CENTERED},
 	{"display", SETTING_DISPLAY},
 	{"highdpi", SETTING_HIGHDPI},
+	{"usedpiscale", SETTING_USE_DPISCALE},
 	{"refreshrate", SETTING_REFRESHRATE},
 	{"x", SETTING_X},
 	{"y", SETTING_Y},