Updated static variable name

+ Updated DELTA variable to more suitable name:
ROTATION_DEGREES_PER_FRAME

cockatrice/src/carditem.cpp

@@ -364,11 +364,11 @@ void CardItem::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
 
 bool CardItem::animationEvent()
 {
-    int delta = DELTA;
+    int rotation = ROTATION_DEGREES_PER_FRAME;
     if (!tapped)
-        delta *= -1;
+        rotation *= -1;
 
-    tapAngle += delta;
+    tapAngle += rotation;
 
     setTransform(QTransform().translate(CARD_WIDTH_HALF, CARD_HEIGHT_HALF).rotate(tapAngle).translate(-CARD_WIDTH_HALF, -CARD_HEIGHT_HALF));
     setHovered(false);

cockatrice/src/carditem.h

@@ -14,8 +14,7 @@ class QColor;
 const int MAX_COUNTERS_ON_CARD = 999;
 const float CARD_WIDTH_HALF = CARD_WIDTH / 2;
 const float CARD_HEIGHT_HALF = CARD_HEIGHT / 2;
-// DELTA is the degrees of rotation that will animate between frames
-const int DELTA = 10;
+const int ROTATION_DEGREES_PER_FRAME = 10;
 
 class CardItem : public AbstractCardItem {
     Q_OBJECT