1.1 --- a/src/video/x11/SDL_x11mouse.c	Wed Oct 29 22:44:35 2014 +0100
     1.2 +++ b/src/video/x11/SDL_x11mouse.c	Wed Oct 29 22:55:40 2014 -0400
     1.3 @@ -382,8 +382,14 @@
     1.4                  retval |= (mask & Button1Mask) ? SDL_BUTTON_LMASK : 0;
     1.5                  retval |= (mask & Button2Mask) ? SDL_BUTTON_MMASK : 0;
     1.6                  retval |= (mask & Button3Mask) ? SDL_BUTTON_RMASK : 0;
     1.7 -                *x = data->x + rootx;
     1.8 -                *y = data->y + rooty;
     1.9 +                /* SDL_DisplayData->x,y point to screen origin, and adding them to mouse coordinates relative to root window doesn't do the right thing
    1.10 +                 * (observed on dual monitor setup with primary display being the rightmost one - mouse was offset to the right).
    1.11 +                 *
    1.12 +                 * Adding root position to root-relative coordinates seems to be a better way to get absolute position. */
    1.13 +                XWindowAttributes root_attrs;
    1.14 +                X11_XGetWindowAttributes(display, root, &root_attrs);
    1.15 +                *x = root_attrs.x + rootx;
    1.16 +                *y = root_attrs.y + rooty;
    1.17                  return retval;
    1.18              }
    1.19          }