From 9687e576666b94aa6e18386643ae5c3adac5b987 Mon Sep 17 00:00:00 2001
From: Simon Brooke <simon@journeyman.cc>
Date: Wed, 3 Jun 2020 19:12:08 +0100
Subject: [PATCH] Woohoo! Now I can meaningfully search a superstructure!

---
 project.clj                    |  1 +
 src/walkmap/microworld.clj     |  4 +++-
 src/walkmap/polygon.clj        |  9 +++++++-
 src/walkmap/superstructure.clj | 38 ++++++++++++++++++++++++++++++++++
 src/walkmap/utils.clj          | 10 +++++++++
 5 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/project.clj b/project.clj
index 4ac438a..577dc87 100644
--- a/project.clj
+++ b/project.clj
@@ -5,6 +5,7 @@
           :output-path "docs/codox"
           :source-uri "https://github.com/simon-brooke/walkmap/blob/master/{filepath}#L{line}"}
   :dependencies [[org.clojure/algo.generic "0.1.3"]
+                 [org.clojure/core.memoize "1.0.236"]
                  [org.clojure/clojure "1.8.0"]
                  [org.clojure/data.zip "1.0.0"]
                  [org.clojure/math.numeric-tower "0.0.4"]
diff --git a/src/walkmap/microworld.clj b/src/walkmap/microworld.clj
index 43d5684..5b88a99 100644
--- a/src/walkmap/microworld.clj
+++ b/src/walkmap/microworld.clj
@@ -92,4 +92,6 @@
          polys)
        polys))))
 
-;; (load-microworld-edn "../MicroWorld/mw-cli/isle_of_man.edn" nil {})
+
+
+
diff --git a/src/walkmap/polygon.clj b/src/walkmap/polygon.clj
index d5bd83a..2b52167 100644
--- a/src/walkmap/polygon.clj
+++ b/src/walkmap/polygon.clj
@@ -73,7 +73,14 @@
         vse (vertex (:x vne)
                     (:y vsw)
                     (/ (reduce + (map #(or (:z %) 0) [vsw vne])) 2))]
-    (t/tag (polygon vsw vnw vne vse) :rectangle)))
+    (t/tag
+      (assoc
+        (polygon vsw vnw vne vse)
+        :centre
+        (vertex (+ (:x vsw) (/ (- (:x vne) (:x vsw)) 2))
+                (+ (:x vsw) (/ (- (:y vne) (:y vsw)) 2))
+                (:z vse)))
+      :rectangle)))
 
 ;; (rectangle (vertex 1 2 3) (vertex 7 9 4))
 
diff --git a/src/walkmap/superstructure.clj b/src/walkmap/superstructure.clj
index 50ad5b9..dab1075 100644
--- a/src/walkmap/superstructure.clj
+++ b/src/walkmap/superstructure.clj
@@ -2,6 +2,7 @@
   "single indexing structure for walkmap objects"
   (:require [clojure.walk :refer [postwalk]]
             [taoensso.timbre :as l]
+            [walkmap.edge :refer [edge length]]
             [walkmap.path :as p]
             [walkmap.polygon :as q]
             [walkmap.utils :as u]
@@ -180,4 +181,41 @@
        #(v/within-box? % minv maxv)
        (filter #(= (:kind %) :vertex) (vals s))))))
 
+(defn find-nearest
+  "Search superstructure `s` for the nearest object matching `filter-fn` to
+  the `target` vertex. Searches only with `radius` (slight misnomer, area
+  actually searched is a cube). Returns one object, or `nil` if no matching
+  object found.
+
+  WARNING: currently only returns objects which have a defined `:centre`
+  (but most of the significant objects we have do)."
+  [s target filter-fn radius]
+  (let [minv (v/vertex
+               (- (:x (v/check-vertex target)) radius)
+               (- (:y target) radius) (- (or (:z target) 0) radius))
+        maxv (v/vertex
+               (+ (:x target) 0.5) (+ (:y target) 0.5)
+               (+ (or (:z target) 0) 0.5))]
+    ;; filter those objects with the filter function, then sort that list
+    ;; by the edge distance from the target to the `:centre` of the object
+    ;; and take the first
+    (first
+      (sort-by
+        #(length (edge target (:centre %)))
+        (filter
+          :centre
+          (map #(retrieve % s)
+               ;; for each vertex id in vids, get the objects associated with that id
+               ;; in the vertex index as a single flat list
+               (reduce
+                 concat
+                 (remove
+                   nil?
+                   (map
+                     #(-> s ::vertex-index % keys)
+                     ;; get all the vertex ids within radius of the target
+                     (set
+                       (map
+                         :walkmap.id/id
+                         (search-vertices s minv maxv))))))))))))
 
diff --git a/src/walkmap/utils.clj b/src/walkmap/utils.clj
index 1295676..427194e 100644
--- a/src/walkmap/utils.clj
+++ b/src/walkmap/utils.clj
@@ -99,3 +99,13 @@
             ")"])))
      ~s)))
 
+(defn load-edn
+  "Load edn from an io/reader source (filename or io/resource)."
+  [source]
+  (try
+    (with-open [r (io/reader source)]
+      (edn/read (java.io.PushbackReader. r)))
+    (catch java.io.IOException e
+      (printf "Couldn't open '%s': %s\n" source (.getMessage e)))
+    (catch RuntimeException e
+      (printf "Error parsing edn file '%s': %s\n" source (.getMessage e)))))