Merge lp:~compiz-team/compiz-core/compiz-core.fix_874004 into lp:compiz-core/0.9.5

[Sam Spilsbury]

Fix bug 874004

[Mirco Müller (macslow)]

As mentioned on IRC this overlaps with a different commit, so just looking at scale.cpp/privates.h (rev 2881).

I would give it the seal of approval, if you'd check and protect against these edge-cases:

   priv->slot->scale == 1.0
   window->x() == -1.0 * priv->tx
   window->y() == -1.0 * priv->ty

At the moment those would still lead to a division by zero.

review: Needs Fixing

[Mirco Müller (macslow)]

Doh... fourth edge-case:

    priv->lastTargetScale == 1.0

[Sam Spilsbury (smspillaz)]

Fixing

[lp:~compiz-team/compiz-core/compiz-core.fix_874004]

2882. By Sam Spilsbury on 2011-10-17

Avoid FDIV0 in other cases too

[Mirco Müller (macslow)]

Ok now.

review: Approve

[Mikkel Kamstrup Erlandsen (kamstrup)]

Note: unless C++ contains some magic that I am unaware of then x == f0.0 is a bad idea. It may spuriously be false when x == 0.0000000001. And I *have* seen this in the real world.

[Mikkel Kamstrup Erlandsen (kamstrup)]

Ok, C++ is not different than C: http://www.parashift.com/c++-faq-lite/newbie.html#faq-29.17

=== modified file 'plugins/scale/src/privates.h'
--- plugins/scale/src/privates.h	2011-10-05 17:34:43 +0000
+++ plugins/scale/src/privates.h	2011-10-17 10:13:25 +0000
@@ -176,7 +176,7 @@
 
 	GLfloat xVelocity, yVelocity, scaleVelocity;
 	GLfloat scale;
-	GLfloat lastTargetScale;
+	GLfloat lastTargetScale, lastTargetX, lastTargetY;
 	GLfloat tx, ty;
 	float   delta;
 	bool    adjust;

=== modified file 'plugins/scale/src/scale.cpp'
--- plugins/scale/src/scale.cpp	2011-10-05 17:34:43 +0000
+++ plugins/scale/src/scale.cpp	2011-10-17 10:13:25 +0000
@@ -266,10 +266,54 @@
      * should be faded in and out */
     if (window->state () & CompWindowStateHiddenMask)
     {
+	GLfloat factor = 0;
+
 	if (priv->slot)
-	    attrib.opacity *= (1.0f - priv->scale)  / (1.0f - priv->slot->scale);
+	{
+	    GLfloat scaleFactor, xFactor, yFactor;
+
+	    /* Don't FDIV0 */
+	    if (priv->scale - priv->slot->scale == 0.0f)
+		scaleFactor = 1.0f;
+	    else
+		scaleFactor = (1.0f - priv->scale) / (1.0f - priv->slot->scale);
+
+	    if (priv->slot->x () - ((float) window->x () + priv->tx) == 0.0f)
+		xFactor = 1.0f;
+	    else
+		xFactor = priv->slot->x () / ((float) window->x () + priv->tx);
+
+	    if (priv->slot->y () - ((float) window->y () + priv->ty) == 0.0f)
+		yFactor = 1.0f;
+	    else
+		yFactor = priv->slot->y () / ((float) window->y () + priv->ty);
+
+	    factor = (scaleFactor + xFactor + yFactor) / 3.0f;
+	    attrib.opacity *= factor;
+	}
 	else
-	    attrib.opacity *= (1.0f - priv->scale) / (1.0f - priv->lastTargetScale);
+	{
+	    GLfloat scaleFactor, xFactor, yFactor;
+
+	    /* Don't FDIV0 */
+	    if (priv->scale - priv->slot->scale == 0.0f)
+		scaleFactor = 1.0f;
+	    else
+		scaleFactor = (1.0f - priv->scale) / (1.0f - priv->slot->scale);
+
+	    if (priv->lastTargetX - ((float) window->x () + priv->tx) == 0.0f)
+		xFactor = 1.0f;
+	    else
+		xFactor = priv->lastTargetX / ((float) window->x () + priv->tx);
+
+	    if (priv->lastTargetY - ((float) window->y () + priv->ty) == 0.0f)
+		yFactor = 1.0f;
+	    else
+		yFactor = priv->lastTargetY / ((float) window->y () + priv->ty);
+
+	    factor = (scaleFactor + xFactor + yFactor) / 3.0f;
+	    attrib.opacity *= factor;
+	}
     }
 
     if (priv->adjust || priv->slot)
@@ -952,11 +996,17 @@
 	    if (sw->priv->slot)
 	    {
 		sw->priv->lastTargetScale = sw->priv->slot->scale;
+		sw->priv->lastTargetX     = sw->priv->slot->x ();
+		sw->priv->lastTargetY     = sw->priv->slot->y ();
 		sw->priv->slot   = NULL;
 		sw->priv->adjust = true;
 	    }
 	    else
+	    {
 		sw->priv->lastTargetScale = 1.0f;
+		sw->priv->lastTargetX = w->x ();
+		sw->priv->lastTargetY = w->y ();
+	    }
 	}
 
 	if (state & CompAction::StateCancel)
@@ -1497,7 +1547,7 @@
 		bool       focus = false;
 		CompOption *o = screen->getOption ("click_to_focus");
 
-		if (o && o->value ().b ())
+		if (o && !o->value ().b ())
 		    focus = true;
 
 		selectWindowAt (event->xmotion.x_root,
@@ -1528,7 +1578,7 @@
 		    bool       focus = false;
 		    CompOption *o = screen->getOption ("click_to_focus");
 
-		    if (o && o->value ().b ())
+		    if (o && !o->value ().b ())
 			focus = true;
 
 		    if (w->id () == dndTarget)
@@ -1774,6 +1824,8 @@
     scaleVelocity (0.0),
     scale (1.0),
     lastTargetScale (1.0f),
+    lastTargetX (w->x ()),
+    lastTargetY (w->y ()),
     tx (0.0),
     ty (0.0),
     delta (1.0),