[comp.windows.x] Flaky cursor on color Sun

brad@kontron.UUCP (Brad Yearwood) (05/28/87)

I am running X V10 R4 essentially straight off the MIT tape on a Sun 3/260
color system.  Whenever the mouse cursor gets very near the left edge of the
screen, I get "mouse droppings" (leftover images of the cursor) along the
this edge.  Anyone else have the same problem, know of any fixes, or have
any suggestions on where to start looking for a bug?

Brad Yearwood
Kontron Electronics  {voder, pyramid}!kontron!brad
Mountain View, California

jromine@GREMLIN.NRTC.NORTHROP.COM (John Romine) (05/29/87)

    on a Sun 3/260 color system...  whenever the mouse cursor gets very
    near the left edge of the screen, I get "mouse droppings" (leftover
    images of the cursor) along the this edge.

Yes, I had this problem too (on 3/280 and 3/160 color systems).  The problem
is when the mouse is accelerated, it can end up at an invalid location.

Below is a context diff of the fix I installed.  Note, this doesn't totally
cure the problem, it just stops it from happening most of the time.  Also,
you will probably want to slow down the mouse acceleration using "xset m";
doing that also causes the problem to occur less often.

John Romine
Northrop Research and Technology Center
jromine@gremlin.nrtc.northrop.com
213/544-5219


*** /tmp/,RCSt1a04028	Thu May 28 10:26:21 1987
--- events.c	Fri Apr 17 17:53:48 1987
***************
*** 74,81 ****
  extern int vsdev;
  extern DEVICE *CurrentDevice;
  
! int sunthreshold = 0;
! int sunaccel = 0;
  
  #ifdef	RAW_KBD
  extern unsigned state_mask;
--- 74,81 ----
  extern int vsdev;
  extern DEVICE *CurrentDevice;
  
! int sunthreshold = 1;			/* was 0 /JLR */
! int sunaccel = 1;			/* was 0 /JLR */
  
  #ifdef	RAW_KBD
  extern unsigned state_mask;
***************
*** 326,340 ****
  		int dy = Xevent.vse_y - CurrentDevice->mouse->y;
  
  		if (sunthreshold <= (dx > 0 ? dx : -dx) + (dy > 0 ? dy : -dy)) {
! 			Xevent.vse_x = CurrentDevice->mouse->x + dx * sunaccel;
! 			Xevent.vse_y = CurrentDevice->mouse->y + dy * sunaccel;
! 		}
! 	
  	    }
- 	    SetCursorPosition((vsCursor *) &Xevent);	/* XXX - tacky */
  	}
  
! 	Xevent.vse_key;
  
  	if (Xevent.vse_type == VSE_MMOTION) {
  	    register vsBox *b = CurrentDevice->mbox;
--- 326,360 ----
  		int dy = Xevent.vse_y - CurrentDevice->mouse->y;
  
  		if (sunthreshold <= (dx > 0 ? dx : -dx) + (dy > 0 ? dy : -dy)) {
! 		    register short new_x, new_y;	/* 09Apr87/JLR */
! 
! 		    new_x = CurrentDevice->mouse->x + dx * sunaccel;
! 		    new_y = CurrentDevice->mouse->y + dy * sunaccel;
! 
! 		    /* keep cursor on screen - 09Apr98/JLR */
! 		    /* this should check against cursor->... see cursor.c */
! 		    if (new_x >= CurrentDevice->width)	/* cursor->xmax */
! 			Xevent.vse_x = CurrentDevice->width - 1;
! 		    else if (new_x < 0)			/* cursor->xmin */
! 			Xevent.vse_x = 0;
! 		    else
! 			Xevent.vse_x = (unsigned short) new_x;
! 
! 		    if (new_y >= CurrentDevice->height)	/* cursor->ymax */
! 			Xevent.vse_y = CurrentDevice->height - 1;
! 		    else if (new_y < 0)			/* cursor->ymin */
! 			Xevent.vse_y = 0;
! 		    else
! 			Xevent.vse_y = (unsigned short) new_y;
!     		}
! #ifdef	notdef
! 	fprintf (stderr, "\nMOTION: %d, %d\n", Xevent.vse_x, Xevent.vse_y);
! #endif	notdef
! 	    SetCursorPosition((vsCursor *) &Xevent);/* XXX - tacky */
  	    }
  	}
  
! 	Xevent.vse_key;					/* EH? */
  
  	if (Xevent.vse_type == VSE_MMOTION) {
  	    register vsBox *b = CurrentDevice->mbox;