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diff --git a/src/libs/graphics/dcqueue.h b/src/libs/graphics/dcqueue.h
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+/*
+ *  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.
+ */
+
+#ifndef DCQUEUE_H
+#define DCQUEUE_H
+
+// Maximum size of the DCQ.  The larger the DCQ, the larger frameskips
+// become tolerable before initiating livelock deterrence and game
+// slowdown.  Other constants for controlling the frameskip/slowdown
+// balance may be found in sdl_common.c near TFB_FlushGraphics.
+
+// Livelock deterrance constants.  Because the entire screen is rarely
+// refreshed, we may not drop draw commands on the floor with abandon.
+// Furthermore, if the main program is queuing commands at a speed
+// comparable to our processing of the commands, we never finish and
+// the game freezes.  Thus, if the queue starts out larger than
+// DCQ_FORCE_SLOWDOWN_SIZE, or DCQ_LIVELOCK_MAX commands find
+// themselves being processed in one go, livelock deterrence is
+// enabled, and TFB_FlushGraphics locks the DCQ until it has processed
+// all entries.  If batched but pending commands exceed DCQ_FORCE_BREAK_SIZE,
+// a continuity break is performed.  This will effectively slow down the 
+// game logic, a fate we seek to avoid - however, it seems to be unavoidable
+// on slower machines.  Even there, it's seems nonexistent outside of
+// communications screens.  --Michael
+
+#ifdef DCQ_OF_DOOM
+#define DCQ_MAX 512
+#define DCQ_FORCE_SLOWDOWN_SIZE 128
+#define DCQ_FORCE_BREAK_SIZE 512
+#define DCQ_LIVELOCK_MAX 256
+#else
+#define DCQ_MAX 16384
+#define DCQ_FORCE_SLOWDOWN_SIZE 4096
+#define DCQ_FORCE_BREAK_SIZE 16384
+#define DCQ_LIVELOCK_MAX 4096
+#endif
+
+extern CondVar RenderingCond;
+
+#endif
+
+