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

[summerhack] / src / 3dengfx / src / gfx / timeline.cpp

diff --git a/src/3dengfx/src/gfx/timeline.cpp b/src/3dengfx/src/gfx/timeline.cpp
new file mode 100644 (file)
index 0000000..fbce4f3
--- /dev/null
+++ b/src/3dengfx/src/gfx/timeline.cpp
@@ -0,0 +1,71 @@
+/*
+This file is part of the graphics core library.
+
+Copyright (c) 2004, 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
+*/
+
+#include "timeline.hpp"
+
+template <class T>
+static inline T wrap(T n, T low, T high) {
+       n -= low;
+       
+       while(n < 0) {
+               n += high;
+       }
+       if(high) n %= high;
+       
+       return n + low;
+}
+
+template <class T>
+static inline T bounce(T n, T low, T high) {
+       T interval = high - low;
+       T offs = n % interval;
+       
+       if((n / interval) % 2) {
+               // descent
+               return high - offs;
+       } else {
+               return low + offs;
+       }
+}
+
+
+unsigned long get_timeline_time(unsigned long time, unsigned long start, unsigned long end, TimelineMode mode) {
+       switch(mode) {
+       case TIME_WRAP:
+               time = wrap(time, start, end);
+               break;
+
+       case TIME_BOUNCE:
+               time = bounce(time, start, end);
+               break;
+
+       case TIME_CLAMP:
+               if(time < start) time = start;
+               if(time > end) time = end;
+               break;
+
+       case TIME_FREE:
+       default:
+               break;
+       }
+
+       return time;
+}
+