X11: Fixed SDL_GetGlobalMouseState() to work better with multimonitor configs. Fixes Bugzilla #2770. Thanks to Epic Games for contributing this fix.
diff --git a/src/video/x11/SDL_x11mouse.c b/src/video/x11/SDL_x11mouse.c
index 02d96da..d3ec619 100644
--- a/src/video/x11/SDL_x11mouse.c
+++ b/src/video/x11/SDL_x11mouse.c
@@ -382,8 +382,14 @@ X11_GetGlobalMouseState(int *x, int *y)
retval |= (mask & Button1Mask) ? SDL_BUTTON_LMASK : 0;
retval |= (mask & Button2Mask) ? SDL_BUTTON_MMASK : 0;
retval |= (mask & Button3Mask) ? SDL_BUTTON_RMASK : 0;
- *x = data->x + rootx;
- *y = data->y + rooty;
+ /* SDL_DisplayData->x,y point to screen origin, and adding them to mouse coordinates relative to root window doesn't do the right thing
+ * (observed on dual monitor setup with primary display being the rightmost one - mouse was offset to the right).
+ *
+ * Adding root position to root-relative coordinates seems to be a better way to get absolute position. */
+ XWindowAttributes root_attrs;
+ X11_XGetWindowAttributes(display, root, &root_attrs);
+ *x = root_attrs.x + rootx;
+ *y = root_attrs.y + rooty;
return retval;
}
}