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.h

@@ -25,6 +25,7 @@
 #include "common/Module.h"
 #include "common/StringMap.h"
 #include "common/math.h"
+#include "common/Optional.h"
 #include "image/ImageData.h"
 
 // C++
@@ -66,6 +67,7 @@ public:
 		SETTING_CENTERED,
 		SETTING_DISPLAY,
 		SETTING_HIGHDPI,
+		SETTING_USE_DPISCALE,
 		SETTING_REFRESHRATE,
 		SETTING_X,
 		SETTING_Y,
@@ -200,6 +202,7 @@ public:
 	virtual void DPIToWindowCoords(double *x, double *y) const = 0;
 
 	virtual double getDPIScale() const = 0;
+	virtual double getNativeDPIScale() const = 0;
 
 	virtual double toPixels(double x) const = 0;
 	virtual void toPixels(double wx, double wy, double &px, double &py) const = 0;
@@ -259,6 +262,7 @@ struct WindowSettings
 	bool centered = true;
 	int display = 0;
 	bool highdpi = false;
+	bool usedpiscale = true;
 	double refreshrate = 0.0;
 	bool useposition = false;
 	int x = 0;