From 7411f21b59ab6f98e78a3e4d98e2794e57d45f31 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Tue, 23 Aug 2022 21:49:25 +0200
Subject: [PATCH] rogueviz:: parallelize moved from flocking to rogueviz.h

---
 rogueviz/flocking.cpp | 26 --------------------------
 rogueviz/rogueviz.h   | 19 +++++++++++++++++++
 2 files changed, 19 insertions(+), 26 deletions(-)

diff --git a/rogueviz/flocking.cpp b/rogueviz/flocking.cpp
index 384138b5..b38710b8 100644
--- a/rogueviz/flocking.cpp
+++ b/rogueviz/flocking.cpp
@@ -16,30 +16,6 @@
 
 // press 'o' when flocking active to change the parameters.
 
-#ifdef USE_THREADS
-#include <thread>
-int threads = 1;
-#endif
-
-template<class T> auto parallelize(long long N, T action) -> decltype(action(0,0)) {
-#ifndef USE_THREADS
-  return action(0,N);
-#else
-  if(threads == 1) return action(0,N);
-  std::vector<std::thread> v;
-  typedef decltype(action(0,0)) Res;
-  std::vector<Res> results(threads);
-  for(int k=0; k<threads; k++)
-    v.emplace_back([&,k] () { 
-      results[k] = action(N*k/threads, N*(k+1)/threads); 
-      });
-  for(std::thread& t:v) t.join();
-  Res res = 0;
-  for(Res r: results) res += r;
-  return res;
-#endif
-  }
-
 #include "rogueviz.h"
 
 namespace rogueviz {
@@ -372,11 +348,9 @@ namespace flocking {
       shift(); ini_speed = argf();
       shift(); max_speed = argf();
       }
-    #ifdef USE_THREADS
     else if(argis("-threads")) {
       shift(); threads = argi();
       }
-    #endif
     else return 1;
     return 0;
     }
diff --git a/rogueviz/rogueviz.h b/rogueviz/rogueviz.h
index c4cd20a9..7e72e283 100644
--- a/rogueviz/rogueviz.h
+++ b/rogueviz/rogueviz.h
@@ -342,6 +342,25 @@ namespace objmodels {
 #define addHook_slideshows(x, y) 0
 #define addHook_rvtour(x, y) 0
 #endif
+
+  /* parallelize a computation */
+  inline int threads = 1;
+
+  template<class T> auto parallelize(long long N, T action) -> decltype(action(0,0)) {
+    if(threads == 1) return action(0,N);
+    std::vector<std::thread> v;
+    typedef decltype(action(0,0)) Res;
+    std::vector<Res> results(threads);
+    for(int k=0; k<threads; k++)
+      v.emplace_back([&,k] () { 
+        results[k] = action(N*k/threads, N*(k+1)/threads); 
+        });
+    for(std::thread& t:v) t.join();
+    Res res = 0;
+    for(Res r: results) res += r;
+    return res;
+    }
+
   }
 
 #endif