rocket guiding: handle the case of thisdir == -goaldir without returning the zero...

diff --git a/qcsrc/server/w_rocketlauncher.qc b/qcsrc/server/w_rocketlauncher.qc
index 723389e7121e5d7536f5f7bf07aec65847548092..42ae90d7466e84c0a46740c9ec2cef614ce873ef 100644 (file)
--- a/qcsrc/server/w_rocketlauncher.qc
+++ b/qcsrc/server/w_rocketlauncher.qc
@@ -63,58 +63,6 @@ void W_Rocket_DoRemoteExplode ()
        remove (self);
 }
 
-entity FindLaserTarget(entity e, float dist_variance, float dot_variance)
-{
-       entity head, selected;
-       vector dir;
-       float dist, maxdist,// bestdist,
-               dot,// bestdot,
-               points, bestpoints;
-       //bestdist = 9999;
-       //bestdot = -2;
-       bestpoints = 0;
-       maxdist = 800;
-       selected = world;
-
-       makevectors(e.angles);
-
-       head = find(world, classname, "laser_target");
-       while(head)
-       {
-               points = 0;
-               dir = normalize(head.origin - self.origin);
-               dot = dir * v_forward;
-               dist = vlen(head.origin - self.origin);
-               if(dist > maxdist)
-                       dist = maxdist;
-
-               // gain points for being in front
-               points = points + ((dot+1)*0.5) * 500
-                       * (1 + crandom()*dot_variance);
-               // gain points for being close away
-               points = points + (1 - dist/maxdist) * 1000
-                       * (1 + crandom()*dot_variance);
-
-               traceline(e.origin, head.origin, TRUE, self);
-               if(trace_fraction < 1)
-               {
-                       points = 0;
-               }
-
-               if(points > bestpoints)//random() > 0.5)//
-               {
-                       bestpoints = points;
-                       selected = head;
-               }
-
-               head = find(head, classname, "laser_target");
-       }
-
-       //bprint(selected.realowner.netname);
-       //bprint("\n");
-       return selected;
-}
-
 void W_Rocket_RemoteExplode()
 {
        if(self.realowner.deadflag == DEAD_NO)
@@ -134,6 +82,8 @@ vector rocket_steerto(vector thisdir, vector goaldir, float maxturn_cos)
 {
        if(thisdir * goaldir > maxturn_cos)
                return goaldir;
+       if(thisdir * goaldir < -0.9998) // less than 1 degree and opposite
+               return thisdir; // refuse to guide (better than letting a numerical error happen)
        float f, m2;
        vector v;
        // solve:
@@ -151,6 +101,15 @@ vector rocket_steerto(vector thisdir, vector goaldir, float maxturn_cos)
        v = solve_quadratic(m2 - f * f, 2 * f * (m2 - 1), m2 - 1);
        return normalize(thisdir + goaldir * v_y); // the larger solution!
 }
+// assume thisdir == -goaldir:
+//   f == -1
+//   v = solve_qadratic(m2 - 1, -2 * (m2 - 1), m2 - 1)
+//   (m2 - 1) x^2 - 2 * (m2 - 1) * x + (m2 - 1) = 0
+//   x^2 - 2 * x + 1 = 0
+//   (x - 1)^2 = 0
+//   x = 1
+//   normalize(thisdir + goaldir)
+//   normalize(0)
 
 void W_Rocket_Think (void)
 {