Add puGL API to query HiDPI backing-scale factor

This is mainly relevant for Apple's high-resolution displays, where rendering should be upsampled.
x42 · Jul 30, 2022 · f7e3821 · f7e3821
1 parent 57473a3
commit f7e3821
Show file tree

Hide file tree

Showing 5 changed files with 19 additions and 0 deletions.
diff --git a/pugl/pugl.h b/pugl/pugl.h
@@ -273,6 +273,12 @@ puglGetHandle(PuglView* view);
 PUGL_API uint32_t
 puglGetEventTimestamp(PuglView* view);
 
+/**
+   Return the hardware backing scale
+*/
+PUGL_API float
+puglGetHWSurfaceScale(PuglView* view);
+
 /**
    Get the currently active modifiers (PuglMod flags).
 

diff --git a/pugl/pugl_internal.h b/pugl/pugl_internal.h
@@ -54,6 +54,7 @@ struct PuglViewImpl {
 	bool     set_window_hints;
 	bool     ontop;
 	bool     resize;
+	float    ui_scale;
 	uint32_t event_timestamp_ms;
 };
 
@@ -75,6 +76,12 @@ puglGetEventTimestamp(PuglView* view)
 	return view->event_timestamp_ms;
 }
 
+float
+puglGetHWSurfaceScale(PuglView* view)
+{
+	return view->ui_scale;;
+}
+
 int
 puglGetModifiers(PuglView* view)
 {

diff --git a/pugl/pugl_osx.mm b/pugl/pugl_osx.mm
@@ -430,6 +430,7 @@ - (void) flagsChanged:(NSEvent*)event
 	view->width  = width;
 	view->height = height;
 	view->ontop  = ontop;
+	view->ui_scale  = 1.0;
 	view->user_resizable = resizable; // unused
 
 	[NSAutoreleasePool new];
@@ -501,6 +502,9 @@ void set_value (id) { }
 		} else {
 			p.set_value ([[NSScreen mainScreen] backingScaleFactor]);
 		}
+		if (p._f >= 1.f && p._f <= 4.f) {
+			view->ui_scale = p._f;
+		}
 	}
 #endif
 	return view;

diff --git a/pugl/pugl_win.cpp b/pugl/pugl_win.cpp
@@ -75,6 +75,7 @@ puglCreate(PuglNativeWindow parent,
 	view->width  = width;
 	view->height = height;
 	view->ontop  = ontop;
+	view->ui_scale  = 1.0;
 	view->user_resizable = resizable && !parent;
 	view->impl->keep_aspect = min_width != width;
 

diff --git a/pugl/pugl_x11.c b/pugl/pugl_x11.c
@@ -124,6 +124,7 @@ puglCreate(PuglNativeWindow parent,
 	view->width  = width;
 	view->height = height;
 	view->ontop  = ontop;
+	view->ui_scale  = 1.0;
 	view->set_window_hints = true;
 	view->user_resizable = resizable;