3 files changed, 73 insertions, 1 deletions
diff --git a/indra/llwindow/llopenglview-objc.h b/indra/llwindow/llopenglview-objc.h
index 8412621392..dd2f35aafc 100644
--- a/indra/llwindow/llopenglview-objc.h
+++ b/indra/llwindow/llopenglview-objc.h
@@ -39,4 +39,26 @@
 	unsigned int mModifiers;
 }
 
+- (NSPoint)convertToScreenFromLocalPoint:(NSPoint)point relativeToView:(NSView *)view;
+- (NSPoint)flipPoint:(NSPoint)aPoint;
+
+@end
+
+@interface NSScreen (PointConversion)
+
+/*
+ Returns the screen where the mouse resides
+ */
++ (NSScreen *)currentScreenForMouseLocation;
+
+/*
+ Allows you to convert a point from global coordinates to the current screen coordinates.
+ */
+- (NSPoint)convertPointToScreenCoordinates:(NSPoint)aPoint;
+
+/*
+ Allows to flip the point coordinates, so y is 0 at the top instead of the bottom. x remains the same
+ */
+- (NSPoint)flipPoint:(NSPoint)aPoint;
+
 @end
diff --git a/indra/llwindow/llopenglview-objc.mm b/indra/llwindow/llopenglview-objc.mm
index 25669b25d3..ca66143b78 100644
--- a/indra/llwindow/llopenglview-objc.mm
+++ b/indra/llwindow/llopenglview-objc.mm
@@ -8,6 +8,35 @@
 
 #import "llopenglview-objc.h"
 
+@implementation NSScreen (PointConversion)
+
++ (NSScreen *)currentScreenForMouseLocation
+{
+    NSPoint mouseLocation = [NSEvent mouseLocation];
+    
+    NSEnumerator *screenEnumerator = [[NSScreen screens] objectEnumerator];
+    NSScreen *screen;
+    while ((screen = [screenEnumerator nextObject]) && !NSMouseInRect(mouseLocation, screen.frame, NO))
+        ;
+    
+    return screen;
+}
+
+- (NSPoint)convertPointToScreenCoordinates:(NSPoint)aPoint
+{
+    float normalizedX = fabs(fabs(self.frame.origin.x) - fabs(aPoint.x));
+    float normalizedY = aPoint.y - self.frame.origin.y;
+    
+    return NSMakePoint(normalizedX, normalizedY);
+}
+
+- (NSPoint)flipPoint:(NSPoint)aPoint
+{
+    return NSMakePoint(aPoint.x, self.frame.size.height - aPoint.y);
+}
+
+@end
+
 @implementation LLOpenGLView
 
 - (void)viewDidMoveToWindow
@@ -349,6 +378,27 @@
 	callMouseExit();
 }
 
+- (NSPoint)convertToScreenFromLocalPoint:(NSPoint)point relativeToView:(NSView *)view
+{
+	NSScreen *currentScreen = [NSScreen currentScreenForMouseLocation];
+	if(currentScreen)
+	{
+		NSPoint windowPoint = [view convertPoint:point toView:nil];
+		NSPoint screenPoint = [[view window] convertBaseToScreen:windowPoint];
+		NSPoint flippedScreenPoint = [currentScreen flipPoint:screenPoint];
+		flippedScreenPoint.y += [currentScreen frame].origin.y;
+		
+		return flippedScreenPoint;
+	}
+	
+	return NSZeroPoint;
+}
+
+- (NSPoint)flipPoint:(NSPoint)aPoint
+{
+    return NSMakePoint(aPoint.x, self.frame.size.height - aPoint.y);
+}
+
 - (BOOL) becomeFirstResponder
 {
 	NSLog(@"Window gained focus!");
diff --git a/indra/llwindow/llwindowmacosx-objc.mm b/indra/llwindow/llwindowmacosx-objc.mm
index 1a64c94b2d..b6e5767203 100644
--- a/indra/llwindow/llwindowmacosx-objc.mm
+++ b/indra/llwindow/llwindowmacosx-objc.mm
@@ -298,7 +298,7 @@ void convertWindowToScreen(NSWindowRef window, float *coord)
 	NSPoint point;
 	point.x = coord[0];
 	point.y = coord[1];
-	point = [(LLNSWindow*)window convertBaseToScreen:point];
+	point = [(LLNSWindow*)window convertToScreenFromLocalPoint:point relativeToView:[(LLNSWindow*)window contentView]];
 	coord[0] = point.x;
 	coord[1] = point.y;
 }