From 13e73fa386cd7843d7079ec7c162ef43d15097c4 Mon Sep 17 00:00:00 2001
From: "Johan B. C. Engelen" <jbc.engelen@swissonline.ch>
Date: Thu, 30 Aug 2007 18:32:36 +0000
Subject: Update to 2Geom rev. 1113

(bzr r3622)
---
 src/2geom/sweep.cpp | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 src/2geom/sweep.cpp

(limited to 'src/2geom/sweep.cpp')

diff --git a/src/2geom/sweep.cpp b/src/2geom/sweep.cpp
new file mode 100644
index 000000000..4329bc559
--- /dev/null
+++ b/src/2geom/sweep.cpp
@@ -0,0 +1,104 @@
+#include "sweep.h"
+
+#include <algorithm>
+
+namespace Geom {
+
+std::vector<std::vector<unsigned> > sweep_bounds(std::vector<Rect> rs) {
+    std::vector<Event> events; events.reserve(rs.size()*2);
+    std::vector<std::vector<unsigned> > pairs(rs.size());
+    
+    for(unsigned i = 0; i < rs.size(); i++) {
+        events.push_back(Event(rs[i].left(), i, false));
+        events.push_back(Event(rs[i].right(), i, true));
+    }
+    std::sort(events.begin(), events.end());
+
+    std::vector<unsigned> open;
+    for(unsigned i = 0; i < events.size(); i++) {
+        unsigned ix = events[i].ix;
+        if(events[i].closing) {
+            std::vector<unsigned>::iterator iter = std::find(open.begin(), open.end(), ix);
+            //if(iter != open.end())
+            open.erase(iter);
+        } else {
+            for(unsigned j = 0; j < open.size(); j++) {
+                unsigned jx = open[j];
+                if(rs[jx][Y].intersects(rs[ix][Y])) {
+                    pairs[jx].push_back(ix);
+                }
+            }
+            open.push_back(ix);
+        }
+    }
+    return pairs;
+}
+
+std::vector<std::vector<unsigned> > sweep_bounds(std::vector<Rect> a, std::vector<Rect> b) {
+    std::vector<std::vector<unsigned> > pairs(a.size());
+    if(a.empty() || b.empty()) return pairs;
+    std::vector<Event> events[2];
+    events[0].reserve(a.size()*2);
+    events[1].reserve(b.size()*2);
+    
+    for(unsigned n = 0; n < 2; n++) {
+        unsigned sz = n ? b.size() : a.size();
+        events[n].reserve(sz*2);
+        for(unsigned i = 0; i < sz; i++) {
+            events[n].push_back(Event(n ? b[i].left() : a[i].left(), i, false));
+            events[n].push_back(Event(n ? b[i].right() : a[i].right(), i, true));
+        }
+        std::sort(events[n].begin(), events[n].end());
+    }
+
+    std::vector<unsigned> open[2];
+    bool n = events[1].front() < events[0].front();
+    for(unsigned i[] = {0,0}; i[n] < events[n].size();) {
+        unsigned ix = events[n][i[n]].ix;
+        bool closing = events[n][i[n]].closing;
+        //std::cout << n << "[" << ix << "] - " << (closing ? "closer" : "opener") << "\n";
+        if(closing) {
+            open[n].erase(std::find(open[n].begin(), open[n].end(), ix));
+        } else {
+            if(n) {
+                //n = 1
+                //opening a B, add to all open a
+                for(unsigned j = 0; j < open[0].size(); j++) {
+                    unsigned jx = open[0][j];
+                    if(a[jx][Y].intersects(b[ix][Y])) {
+                        pairs[jx].push_back(ix);
+                    }
+                }
+            } else {
+                //n = 0
+                //opening an A, add all open b
+                for(unsigned j = 0; j < open[1].size(); j++) {
+                    unsigned jx = open[1][j];
+                    if(b[jx][Y].intersects(a[ix][Y])) {
+                        pairs[ix].push_back(jx);
+                    }
+                }
+            }
+            open[n].push_back(ix);
+        }
+        i[n]++;
+        n = (events[!n][i[!n]] < events[n][i[n]]) ? !n : n;
+    }
+    return pairs;
+}
+
+//Fake cull, until the switch to the real sweep is made.
+std::vector<std::vector<unsigned> > fake_cull(unsigned a, unsigned b) {
+    std::vector<std::vector<unsigned> > ret;
+    
+    std::vector<unsigned> all;
+    for(unsigned j = 0; j < b; j++)
+        all.push_back(j);
+    
+    for(unsigned i = 0; i < a; i++)
+        ret.push_back(all);
+    
+    return ret;
+}
+
+}
-- 
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