3 files changed, 43 insertions, 6 deletions

diff --git a/src/video/cocoa/cocoa_v.mm b/src/video/cocoa/cocoa_v.mm
index c1fb996de..c21edc7ac 100644
--- a/src/video/cocoa/cocoa_v.mm
+++ b/src/video/cocoa/cocoa_v.mm
@@ -322,6 +322,11 @@ void VideoDriver_Cocoa::GameSizeChanged()
 	BlitterFactory::GetCurrentBlitter()->PostResize();
 
 	::GameSizeChanged();
+
+	/* We need to store the window size as non-Retina size in
+	* the config file to get same windows size on next start. */
+	_cur_resolution.width = [ this->cocoaview frame ].size.width;
+	_cur_resolution.height = [ this->cocoaview frame ].size.height;
 }
 
 /**
@@ -491,7 +496,7 @@ void VideoDriver_Cocoa::Draw(bool force_update)
 
 		/* Normally drawRect will be automatically called by Mac OS X during next update cycle,
 		 * and then blitting will occur. If force_update is true, it will be done right now. */
-		[ this->cocoaview setNeedsDisplayInRect:dirtyrect ];
+		[ this->cocoaview setNeedsDisplayInRect:[ this->cocoaview getVirtualRect:dirtyrect ] ];
 		if (force_update) [ this->cocoaview displayIfNeeded ];
 	}
 
@@ -530,7 +535,7 @@ void VideoDriver_Cocoa::AllocateBackingStore()
 {
 	if (this->window == nil || this->cocoaview == nil || this->setup) return;
 
-	NSRect newframe = [ this->cocoaview frame ];
+	NSRect newframe = [ this->cocoaview getRealRect:[ this->cocoaview frame ] ];
 
 	this->window_width = (int)newframe.size.width;
 	this->window_height = (int)newframe.size.height;
@@ -743,6 +748,13 @@ void VideoDriver_Cocoa::GameLoop()
 	CGImageRelease(fullImage);
 }
 
+- (void)viewDidChangeBackingProperties
+{
+	[ super viewDidChangeBackingProperties ];
+
+	self.layer.contentsScale = [ driver->cocoaview getContentsScale ];
+}
+
 @end
 
 #endif /* WITH_COCOA */
diff --git a/src/video/cocoa/cocoa_wnd.h b/src/video/cocoa/cocoa_wnd.h
index fa7036396..55f0561b7 100644
--- a/src/video/cocoa/cocoa_wnd.h
+++ b/src/video/cocoa/cocoa_wnd.h
@@ -38,6 +38,9 @@ extern NSString *OTTDMainLaunchGameEngine;
 
 /** Subclass of NSView to support mouse awareness and text input. */
 @interface OTTD_CocoaView : NSView <NSTextInputClient>
+- (NSRect)getRealRect:(NSRect)rect;
+- (NSRect)getVirtualRect:(NSRect)rect;
+- (CGFloat)getContentsScale;
 - (NSPoint)mousePositionFromEvent:(NSEvent *)e;
 @end
 
diff --git a/src/video/cocoa/cocoa_wnd.mm b/src/video/cocoa/cocoa_wnd.mm
index 089bfe834..cd194f712 100644
--- a/src/video/cocoa/cocoa_wnd.mm
+++ b/src/video/cocoa/cocoa_wnd.mm
@@ -417,6 +417,30 @@ void CocoaDialog(const char *title, const char *message, const char *buttonLabel
 	float _current_magnification;
 	NSUInteger _current_mods;
 	bool _emulated_down;
+	bool _use_hidpi;
+}
+
+- (instancetype)initWithFrame:(NSRect)frameRect
+{
+	if (self = [ super initWithFrame:frameRect ]) {
+		self->_use_hidpi = [ self respondsToSelector:@selector(convertRectToBacking:) ] && [ self respondsToSelector:@selector(convertRectFromBacking:) ];
+	}
+	return self;
+}
+
+- (NSRect)getRealRect:(NSRect)rect
+{
+	return _use_hidpi ? [ self convertRectToBacking:rect ] : rect;
+}
+
+- (NSRect)getVirtualRect:(NSRect)rect
+{
+	return _use_hidpi ? [ self convertRectFromBacking:rect ] : rect;
+}
+
+- (CGFloat)getContentsScale
+{
+	return _use_hidpi && self.window != nil ? [ self.window backingScaleFactor ] : 1.0f;
 }
 
 /**
@@ -483,15 +507,13 @@ void CocoaDialog(const char *title, const char *message, const char *buttonLabel
 	if ([ e window ] == nil) pt = [ self.window convertRectFromScreen:NSMakeRect(pt.x, pt.y, 0, 0) ].origin;
 	pt = [ self convertPoint:pt fromView:nil ];
 
-	pt.y = self.bounds.size.height - pt.y;
-
-	return pt;
+	return [ self getRealRect:NSMakeRect(pt.x, self.bounds.size.height - pt.y, 0, 0) ].origin;
 }
 
 - (void)internalMouseMoveEvent:(NSEvent *)event
 {
 	if (_cursor.fix_at) {
-		_cursor.UpdateCursorPositionRelative(event.deltaX, event.deltaY);
+		_cursor.UpdateCursorPositionRelative(event.deltaX * self.getContentsScale, event.deltaY * self.getContentsScale);
 	} else {
 		NSPoint pt = [ self mousePositionFromEvent:event ];
 		_cursor.UpdateCursorPosition(pt.x, pt.y, false);