added 3dengfx into the repo, probably not the correct version for this

[summerhack] / src / 3dengfx / src / common / psort.hpp

diff --git a/src/3dengfx/src/common/psort.hpp b/src/3dengfx/src/common/psort.hpp
new file mode 100644 (file)
index 0000000..3944753
--- /dev/null
+++ b/src/3dengfx/src/common/psort.hpp
@@ -0,0 +1,77 @@
+/*
+Copyright (C) 2005 John Tsiombikas <nuclear@siggraph.org>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+/* Priority sort template function
+ * 
+ * Author: Mihalis Georgoulopoulos 2005
+ */
+
+#include <cstring>
+#include <algorithm>
+
+#ifndef _PSORT_HEADER_
+#define _PSORT_HEADER_
+
+#define SORT_LOHI      false
+#define SORT_HILO      true
+
+template <class T> int less(const T* a, const T* b)
+{
+       return (*a < *b);
+}
+
+template <class T> int greater(const T* a, const T* b)
+{
+       return !(*a < *b);
+}
+
+template <class T, class P> void sort(T *elements, P *priorities, unsigned int n, bool hilo)
+{
+       int (*criterion)(const P*, const P*);
+
+       if (hilo)
+               criterion = greater;
+       else
+               criterion = less;
+
+       P **pointers = new P*[n];
+       for (unsigned int i=0; i<n; i++)
+               pointers[i] = priorities + i;
+
+       // sort priority pointers
+       std::sort(pointers, pointers + n, criterion);
+       
+       // collect sorted items
+       T *sorted_el = new T[n];
+       P *sorted_pr = new P[n];
+       for (unsigned int i=0; i<n; i++)
+       {
+               sorted_el[i] = elements[pointers[i] - priorities];
+               sorted_pr[i] = *pointers[i];
+       }
+
+       memcpy(elements, sorted_el, n * sizeof(T));
+       memcpy(priorities, sorted_pr, n * sizeof(P));
+       
+       // cleanup
+       delete [] pointers;
+       delete [] sorted_el;
+       delete [] sorted_pr;
+}
+
+#endif // ndef _PSORT_HEADER_