Merge lp:~samuel-thibault/compiz/xysync2 into lp:compiz/0.9.13

[Samuel thibault]

[Alberts Muktupāvels (muktupavels)]

Code/change looks good to me, but no idea about math part... Does that really produce expected result?

For example xdiff = 2.5 and ydiff = 3.5. With current code xamount = 2.5 and yamount = 3.5, but with your change amount is now 4.301162634. Is that expected?

[lp:~samuel-thibault/compiz/xysync2]

4145. By Samuel thibault on 2018-07-14

Normalize combination of xdiff and ydiff

4146. By Samuel thibault on 2018-07-14

No need to use the double version of sqrt

[Samuel thibault (samuel-thibault)]

I, right, I missed normalizing by dividing by sqrt(2), I have now done so.

[Samuel thibault (samuel-thibault)]

Mmm, but then with e.g. xdiff == 0 the value is then not correct, I have to rethink that.

Unmerged revisions

4146. By Samuel thibault on 2018-07-14

No need to use the double version of sqrt

4145. By Samuel thibault on 2018-07-14

Normalize combination of xdiff and ydiff

4144. By Samuel thibault on 2018-06-11

Synchronize X and Y translation capping

Capping X and Y separately brings some discontinuity visual effect: instead of
terminating the translation at the same time, the axis getting capped (e.g. X)
will terminate the translation later, so that at the point when the other axis
(here, Y) is finished translating, there is a discontinuity in the movement: we
suddenly have only X translation, and no Y translation any more. This does not
look very smooth.

This changes it by simply capping both axis at the same time.

=== modified file 'plugins/ezoom/src/ezoom.cpp'
--- plugins/ezoom/src/ezoom.cpp	2017-12-05 14:45:06 +0000
+++ plugins/ezoom/src/ezoom.cpp	2018-07-14 08:18:26 +0000
@@ -308,23 +308,17 @@
 
     float xadjust = xdiff * 0.002f;
     float yadjust = ydiff * 0.002f;
-    float xamount = fabs (xdiff);
-    float yamount = fabs (ydiff);
-
-    if (xamount < 1.0f)
-	xamount = 1.0f;
-    else if (xamount > 5.0)
-	xamount = 5.0f;
-
-    if (yamount < 1.0f)
-	yamount = 1.0f;
-    else if (yamount > 5.0)
-	yamount = 5.0f;
+    float amount = sqrtf (xdiff * xdiff + ydiff * ydiff) / sqrtf (2.);
+
+    if (amount < 1.0f)
+	amount = 1.0f;
+    else if (amount > 5.0)
+	amount = 5.0f;
 
     zooms.at (out).xVelocity =
-	(xamount * zooms.at (out).xVelocity + xadjust) / (xamount + 1.0f);
+	(amount * zooms.at (out).xVelocity + xadjust) / (amount + 1.0f);
     zooms.at (out).yVelocity =
-	(yamount * zooms.at (out).yVelocity + yadjust) / (yamount + 1.0f);
+	(amount * zooms.at (out).yVelocity + yadjust) / (amount + 1.0f);
 
     if ((fabs(xdiff) < 0.1f && fabs (zooms.at (out).xVelocity) < 0.005f) &&
 	(fabs(ydiff) < 0.1f && fabs (zooms.at (out).yVelocity) < 0.005f))