Changeset 38590 in vbox

Timestamp:

Aug 31, 2011 7:36:39 PM (14 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

73785

Message:

Main/MouseImpl: try to send absolute position data that both Windows and (recent) X.Org guests interpret corrently

File:

• trunk/src/VBox/Main/src-client/MouseImpl.cpp (modified) (4 diffs)

trunk/src/VBox/Main/src-client/MouseImpl.cpp

@@ -480 +480 @@
  * validity value to false if the pair is not on an active screen and to true
  * otherwise.
+ * @note      since guests with recent versions of X.Org use a different method
+ *            to everyone else to map the valuator value to a screen pixel (they
+ *            multiply by the screen dimension, do a floating point divide by
+ *            the valuator maximum and round the result, while everyone else
+ *            does truncating integer operations) we adjust the value we send
+ *            so that it maps to the right pixel both when the result is rounded
+ *            and when it is truncated.
  *
  * @returns   COM status value
@@ -491 +498 @@
     Display *pDisplay = mParent->getDisplay();
     ComAssertRet(pDisplay, E_FAIL);
+    /** The amount to add to the result (multiplied by the screen width/height)
+     * to compensate for differences in guest methods for mapping back to
+     * pixels */
+    enum { ADJUST_RANGE = - 3 * MOUSE_RANGE / 4 };
 
     if (pfValid)
@@ -503 +514 @@
             return rc;
 
-        *pcX = displayWidth ? (x * MOUSE_RANGE - MOUSE_RANGE / 2) / (LONG) displayWidth: 0;
-        *pcY = displayHeight ? (y * MOUSE_RANGE - MOUSE_RANGE / 2) / (LONG) displayHeight: 0;
+        *pcX = displayWidth ? (x * MOUSE_RANGE + ADJUST_RANGE) / (LONG) displayWidth: 0;
+        *pcY = displayHeight ? (y * MOUSE_RANGE + ADJUST_RANGE) / (LONG) displayHeight: 0;
     }
     else
@@ -511 +522 @@
         /* Takes the display lock */
         pDisplay->getFramebufferDimensions(&x1, &y1, &x2, &y2);
-        *pcX = x1 < x2 ? ((x - x1) * MOUSE_RANGE - MOUSE_RANGE / 2) / (x2 - x1) : 0;
-        *pcY = y1 < y2 ? ((y - y1) * MOUSE_RANGE - MOUSE_RANGE / 2) / (y2 - y1) : 0;
+        *pcX = x1 < x2 ? ((x - x1) * MOUSE_RANGE + ADJUST_RANGE) / (x2 - x1) : 0;
+        *pcY = y1 < y2 ? ((y - y1) * MOUSE_RANGE + ADJUST_RANGE) / (y2 - y1) : 0;
         if (   *pcX < MOUSE_RANGE_LOWER || *pcX > MOUSE_RANGE_UPPER
             || *pcY < MOUSE_RANGE_LOWER || *pcY > MOUSE_RANGE_UPPER)