From 392880ec5ca77d63ecf27c08af62f4a1cd0ba758 Mon Sep 17 00:00:00 2001
From: ac-stef <ac_stef@users.sf.net>
Date: Sun, 12 Jul 2015 18:17:22 +0200
Subject: [PATCH] fix shot ray shortening

---
 source/src/geom.h     |  1 +
 source/src/weapon.cpp | 19 ++++++++++++-------
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/source/src/geom.h b/source/src/geom.h
index af182fef..449ab27a 100644
--- a/source/src/geom.h
+++ b/source/src/geom.h
@@ -40,6 +40,7 @@ struct vec
 
     float dist(const vec &e) const { vec t; return dist(e, t); }
     float dist(const vec &e, vec &t) const { t = *this; t.sub(e); return t.magnitude(); }
+    float squareddist(const vec &e) const { vec t = *this; t.sub(e); return t.squaredlen(); }
 
     float distxy(const vec &e) const { float dx = e.x - x, dy = e.y - y; return sqrtf(dx*dx + dy*dy); }
     float magnitudexy() const { return sqrtf(x*x + y*y); }
diff --git a/source/src/weapon.cpp b/source/src/weapon.cpp
index 8b383d11..ba508bc5 100644
--- a/source/src/weapon.cpp
+++ b/source/src/weapon.cpp
@@ -343,7 +343,7 @@ bool intersect(entity *e, const vec &from, const vec &to, vec *end)
     return intersectbox(vec(e->x, e->y, lo+mmi.h/2.0f), vec(mmi.rad, mmi.rad, mmi.h/2.0f), from, to, end);
 }
 
-playerent *intersectclosest(const vec &from, const vec &to, playerent *at, float &bestdist, int &hitzone, bool aiming = true)
+playerent *intersectclosest(const vec &from, const vec &to, const playerent *at, float &bestdist, int &hitzone, bool aiming = true)
 {
     playerent *best = NULL;
     bestdist = 1e16f;
@@ -351,14 +351,14 @@ playerent *intersectclosest(const vec &from, const vec &to, playerent *at, float
     if(at!=player1 && player1->state==CS_ALIVE && (zone = intersect(player1, from, to)))
     {
         best = player1;
-        bestdist = at->o.dist(player1->o);
+        bestdist = at->o.squareddist(player1->o);
         hitzone = zone;
     }
     loopv(players)
     {
         playerent *o = players[i];
         if(!o || o==at || (o->state!=CS_ALIVE && (aiming || (o->state!=CS_EDITING && o->state!=CS_LAGGED)))) continue;
-        float dist = at->o.dist(o->o);
+        float dist = at->o.squareddist(o->o);
         if(dist < bestdist && (zone = intersect(o, from, to)))
         {
             best = o;
@@ -587,9 +587,13 @@ void addgib(playerent *d)
     }
 }
 
-void shorten(vec &from, vec &target, float dist)
+void shorten(const vec &from, vec &target, float dist)
 {
-    target.sub(from).mul(min(1.0f, dist)).add(from);
+    target.sub(from);
+    float m = target.squaredlen();
+    if(m < 0.07f) target.add(vec(0.1f, 0.1f, 0.1f));   // if "from == target" just fake a target to avoid zero-length fx vectors
+    else target.mul(max(0.07f, sqrtf(dist / m)));
+    target.add(from);
 }
 
 void raydamage(vec &from, vec &to, playerent *d)
@@ -597,7 +601,7 @@ void raydamage(vec &from, vec &to, playerent *d)
     int dam = d->weaponsel->info.damage;
     int hitzone = -1;
     playerent *o = NULL;
-    float dist;
+    float dist, hitdist;
     bool hitted=false;
     int rayscount = 0, hitscount = 0;
     if(d->weaponsel->type==GUN_SHOTGUN)
@@ -609,7 +613,7 @@ void raydamage(vec &from, vec &to, playerent *d)
             rayscount++;
             int h = k*SGRAYS + i;
             if((hits[h] = intersectclosest(from, sgr[h].rv, d, dist, hitzone)))
-                shorten(from, sgr[h].rv, dist);
+                shorten(from, sgr[h].rv, (hitdist = dist));
         }
         loopk(3)
         loopi(SGRAYS)
@@ -684,6 +688,7 @@ void raydamage(vec &from, vec &to, playerent *d)
                 hitscount+=numhits;
             }
         }
+        if(hitscount) shorten(from, to, hitdist);
     }
     else if((o = intersectclosest(from, to, d, dist, hitzone)))
     {