Do not try an orbital insertion when the ship is not moving; bug #648

git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@3259 8092fc87-c524-0410-9efc-e669fe64eaf9

sc2/ChangeLog

@@ -1,4 +1,5 @@
 Changes towards version 0.7:
+- Fixed AI ship not moving on warp in (bug #648) - Alex
 - Revert gfx settings entirely when a mode switch fails (bug #1056) - Alex
 - Fixed the Syreen lights-out scene timing (bug #1011) - Alex
 - Added a native error box for MacOSX (like we have for Windows) - Alex

sc2/src/uqm/cyborg.c

@@ -1124,13 +1124,14 @@ if (!(ShipPtr->state_flags & FINITE_LIFE)
 						ed.facing = ARCTAN (-dx, -dy);
 						if (UltraManeuverable)
 							ed.MoveState = AVOID;
-						else
+						else // Try a gravity whip
 							ed.MoveState = ENTICE;
 
 						ObjectsOfConcern[GRAVITY_MASS_INDEX] = ed;
 					}
-					else if (!UltraManeuverable)
-					{
+					else if (!UltraManeuverable &&
+							!IsVelocityZero (&Ship.velocity))
+					{	// Try an orbital insertion, don't thrust
 						++Ship.thrust_wait;
 						if (Ship.turn_wait)
 							ShipMoved = TRUE;

sc2/src/uqm/velocity.h

@@ -45,6 +45,14 @@ extern void SetVelocityComponents (VELOCITY_DESC *velocityptr, SIZE dx,
 extern void DeltaVelocityComponents (VELOCITY_DESC *velocityptr, SIZE dx,
 		SIZE dy);
 
+static inline BOOLEAN
+IsVelocityZero (VELOCITY_DESC *vptr)
+{
+	return vptr->vector.width == 0 && vptr->vector.height == 0 &&
+			vptr->incr.width == 0 && vptr->incr.height == 0 &&
+			vptr->fract.width == 0 && vptr->fract.height == 0;
+}
+
 static inline DWORD
 VelocitySquared (SIZE dx, SIZE dy)
 {