Re: PATCH: XWin multiwindow+multiscreen for negative screen coordinates

["Earle F. Philhower III" <earle at ziplabel dot com>]

Howdy, I'm happy to help out (especially when it helps me too).  I got 
hooked on
multiple monitors back on a Mac way too many years ago, and today at work I use
a 3-head "cockpit" setup, so I feel sort of constrained even when using my
2-screen home machine now.

Please find below the diff -U3 against the 20030501 dump referenced in your
message:
------------8<--------------------------------
--- winmultiwindowwindow.c      2003-05-11 14:59:52.000000000 -0700
+++ /tmp/winmultiwindowwindow.c 2003-05-01 09:56:46.000000000 -0700
@@ -202,10 +202,6 @@
   iX = pWin->drawable.x;
   iY = pWin->drawable.y;

-  /* Root coord (0,0) is really screen coord (-X, -Y) */
-  iX += GetSystemMetrics(SM_XVIRTUALSCREEN);
-  iY += GetSystemMetrics(SM_YVIRTUALSCREEN);
-
   /* Get the height and width of the X window */
   iWidth = pWin->drawable.width;
   iHeight = pWin->drawable.height;
@@ -813,10 +809,6 @@
       /* Translate the client area mouse coordinates to screen coordinates */
       ClientToScreen (hwnd, &ptMouse);

-      /* Screen coord (-X,-Y) maps to root window (0,0) */
-      ptMouse.x -= GetSystemMetrics(SM_XVIRTUALSCREEN);
-      ptMouse.y -= GetSystemMetrics(SM_YVIRTUALSCREEN);
-
       /* We can't do anything without privates */
       if (s_pScreenPriv == NULL || s_pScreenInfo->fIgnoreInput)
        break;
@@ -946,10 +938,6 @@
       /* Translate the client area mouse coordinates to screen coordinates */
       ClientToScreen (hwnd, &ptMouse);

-      /* Screen Coords from (-X,-Y) => Root Window (0,0) */
-      ptMouse.left -= GetSystemMetrics(SM_XVIRTUALSCREEN);
-      ptMouse.top  -= GetSystemMetrics(SM_YVIRTUALSCREEN);
-
       /* Pass the message to the root window */
       SendMessage (hwndScreen, message, wParam, MAKELONG(ptMouse.x, 
ptMouse.y));
       return  0;
@@ -1097,10 +1085,9 @@
       ErrorF ("\t(%d, %d)\n", pWinPriv->iX, pWinPriv->iY);
 #endif

-      /* Map from screen (-X,-Y) to (0,0) root coords */
       winMoveXWindow (pWin,
-                     LOWORD(lParam) - wBorderWidth (pWin) - 
GetSystemMetrics(SM_XVIRTUALSCREEN),
-                     HIWORD(lParam) - wBorderWidth (pWin) - 
GetSystemMetrics(SM_YVIRTUALSCREEN));
+                     LOWORD(lParam) - wBorderWidth (pWin),
+                     HIWORD(lParam) - wBorderWidth (pWin));
       return 0;

     case WM_SHOWWINDOW:
@@ -1259,10 +1246,9 @@
            }


-         /* Map from screen (-X,-Y) to (0,0) root coords */
          (s_pScreen->ResizeWindow) (pWin,
-                                    pWinPriv->iX - wBorderWidth (pWin) - 
GetSystemMetrics(SM_XVIRTUALSCREEN),
-                                    pWinPriv->iY - wBorderWidth (pWin) - 
GetSystemMetrics(SM_YVIRTUALSCREEN),
+                                    pWinPriv->iX - wBorderWidth (pWin),
+                                    pWinPriv->iY - wBorderWidth (pWin),
                                     pWinPriv->iWidth,
                                     pWinPriv->iHeight,
                                     pWin->nextSib);
@@ -1304,10 +1290,6 @@
          /* Get the current position of the mouse cursor */
          GetCursorPos (&point);

-         /* Map from screen (-x,-y) to root (0,0) */
-         point.x -= GetSystemMetrics(SM_XVIRTUALSCREEN);
-         point.y -= GetSystemMetrics(SM_YVIRTUALSCREEN);
-
          /* Deliver absolute cursor position to X Server */
          miPointerAbsoluteCursor (point.x, point.y,
                                   g_c32LastInputEventTime = GetTickCount ());
@@ -1350,10 +1332,6 @@
   iX = pWin->drawable.x;
   iY = pWin->drawable.y;

-  /* Map from root coord (0,0) to screen (-X, -Y) */
-  iX += GetSystemMetrics(SM_XVIRTUALSCREEN);
-  iY += GetSystemMetrics(SM_YVIRTUALSCREEN);
-
   iWidth = pWin->drawable.width;
   iHeight = pWin->drawable.height;
------------8<--------------------------------




Thanks,


At 05:08 PM 5/11/2003 -0400, you wrote:
> Earle,
> I like the patch.
> However, I have two problems (easily fixable) with it:
> 1) It is against an old version of winmultiwindowwindow.c.  The newest 
> version can be downloaded here:
> http://www.msu.edu/~huntharo/xwin/shadow/xwin-20030501-1250.tar.bz2
> http://xfree86.cygwin.com/devel/shadow/changelog.html
> 2) Please run ``diff -U3''.  I need the extra info that that format 
> provides so I can figure out what is happening.
> Other than that I thank you for stepping up to fix this problem.  I don't 
> have multiple monitors so I can't really fix these sorts of things on my own.
> Thanks for contributing,
> Harold
> Earle F. Philhower III wrote:
> > There is a bug in the way XWin handles Windows screen coordinates when
> > it's run on a system with legal negative position values.  That is, there
> > is a monitor to the left of the primary monitor, whose screen coords are
> > (-xxx,0), and the global screen coords are from (-xxx,0) to (+xxx,0).  You
> > can reproduce this on a 2 head system by setting the rightmost head to be
> > the Control Panel->Display Settings->Settings->Use this device as my
> > primary monitor, and then running "XWin.exe -multiwindow -multiplemonitors"
> > The fix is to offset screen coords by SM_XVIRTUALSCREEN/SM_YVIRTUALSCREEN
> > whenever you are mapping to/from root window coords (window positioning,
> > mouse movements).
>
> -Earle F. Philhower, III
>  earle@ziplabel.com
>  cdrlabel - ZipLabel - FlpLabel
>  http://www.cdrlabel.com