From 60ea578a8c5125c6ad9b5ac559b6e494207ecdd5 Mon Sep 17 00:00:00 2001
From: terminx <terminx@1a8010ca-5511-0410-912e-c29ae57300e0>
Date: Fri, 19 Apr 2019 08:31:47 +0000
Subject: [PATCH] Add support for returning the closest point in the sector to
 getsectordist()

git-svn-id: https://svn.eduke32.com/eduke32@7609 1a8010ca-5511-0410-912e-c29ae57300e0
---
 source/build/include/build.h |  4 ++--
 source/build/src/engine.cpp  | 31 +++++++++++++++++++++++--------
 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/source/build/include/build.h b/source/build/include/build.h
index 9883ccb78..c1063abc4 100644
--- a/source/build/include/build.h
+++ b/source/build/include/build.h
@@ -1176,8 +1176,8 @@ int32_t try_facespr_intersect(uspriteptr_t const spr, const vec3_t *refpos,
 
 int findwallbetweensectors(int sect1, int sect2);
 static FORCE_INLINE bool sectoradjacent(int sect1, int sect2) { return findwallbetweensectors(sect1, sect2) != -1; }
-int32_t getwalldist(vec2_t const &p, int const wallnum, vec2_t * const output = nullptr);
-int32_t getsectordist(vec2_t const &p, int const sectnum);
+int32_t getwalldist(vec2_t const &in, int const wallnum, vec2_t * const out = nullptr);
+int32_t getsectordist(vec2_t const &in, int const sectnum, vec2_t * const out = nullptr);
 extern const int16_t *chsecptr_onextwall;
 int32_t checksectorpointer(int16_t i, int16_t sectnum);
 
diff --git a/source/build/src/engine.cpp b/source/build/src/engine.cpp
index cb857c869..378cbc4e5 100644
--- a/source/build/src/engine.cpp
+++ b/source/build/src/engine.cpp
@@ -10964,18 +10964,23 @@ static inline bool inside_z_p(int32_t const x, int32_t const y, int32_t const z,
     return (z >= cz && z <= fz && inside_p(x, y, sectnum));
 }
 
-int32_t getwalldist(vec2_t const &pos, int const wallnum, vec2_t * const output)
+int32_t getwalldist(vec2_t const &in, int const wallnum, vec2_t * const out /*= nullptr*/)
 {
     vec2_t closest;
-    getclosestpointonwall_internal(pos, wallnum, &closest);
-    if (output) *output = closest;
-    return klabs(closest.x - pos.x) + klabs(closest.y - pos.y);
+    getclosestpointonwall_internal(in, wallnum, &closest);
+    if (out)
+        *out = closest;
+    return klabs(closest.x - in.x) + klabs(closest.y - in.y);
 }
 
-int32_t getsectordist(vec2_t const &pos, int const sectnum)
+int32_t getsectordist(vec2_t const &in, int const sectnum, vec2_t * const out /*= nullptr*/)
 {
-    if (inside_p(pos.x, pos.y, sectnum))
+    if (inside_p(in.x, in.y, sectnum))
+    {
+        if (out)
+            *out = in;
         return 0;
+    }
 
     int32_t distance = INT32_MAX;
 
@@ -10983,13 +10988,23 @@ int32_t getsectordist(vec2_t const &pos, int const sectnum)
     int const  startwall = sec->wallptr;
     int const  endwall   = sec->wallptr + sec->wallnum;
     auto       uwal      = (uwallptr_t)&wall[startwall];
+    vec2_t     closest = {};
 
     for (int j = startwall; j < endwall; j++, uwal++)
     {
-        int32_t const walldist = getwalldist(pos, j);
-        distance = min(walldist, distance);
+        vec2_t p;
+        int32_t const walldist = getwalldist(in, j, &p);
+
+        if (walldist < distance)
+        {
+            distance = walldist;
+            closest = p;
+        }
     }
 
+    if (out)
+        *out = closest;
+
     return distance;
 }