Added a utility class that encapsulates our display mode jockeying.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@1280 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/media/util/ModeUtil.java

@@ -0,0 +1,73 @@
+//
+// $Id: ModeUtil.java,v 1.1 2002/04/19 00:38:44 mdb Exp $
+
+package com.threerings.media.util;
+
+import java.awt.DisplayMode;
+import java.awt.GraphicsDevice;
+
+import java.util.Comparator;
+import java.util.TreeSet;
+
+/**
+ * Display mode related utilities.
+ */
+public class ModeUtil
+{
+    /**
+     * Gets a display mode that matches the specified parameters. The
+     * screen resolution must match the specified resolution exactly, the
+     * specified desired depth will be used if it is available, and if
+     * not, the highest depth greater than or equal to the specified
+     * minimum depth is used. The highest refresh rate available for the
+     * desired mode is also used.
+     */
+    public static DisplayMode getDisplayMode (
+        GraphicsDevice gd, int width, int height,
+        int desiredDepth, int minimumDepth)
+    {
+        DisplayMode[] modes = gd.getDisplayModes();
+        final int ddepth = desiredDepth;
+
+        // we sort modes in order of desirability
+        Comparator mcomp = new Comparator () {
+            public int compare (Object o1, Object o2) {
+                DisplayMode m1 = (DisplayMode)o1;
+                DisplayMode m2 = (DisplayMode)o2;
+                int bd1 = m1.getBitDepth(), bd2 = m2.getBitDepth();
+                int rr1 = m1.getRefreshRate(), rr2 = m2.getRefreshRate();
+
+                // prefer the desired depth
+                if (bd1 == ddepth && bd2 != ddepth) {
+                    return -1;
+                } else if (bd2 == ddepth && bd1 != ddepth) {
+                    return 1;
+                }
+
+                // otherwise prefer higher bitrates
+                if (bd1 != bd2) {
+                    return bd1 - bd2;
+                }
+
+                // for same bitrates, prefer higher refresh rates
+                return rr1 - rr2;
+            }
+
+            public boolean equals (Object obj) {
+                return this == obj;
+            }
+        };
+
+        // but we only add modes that meet our minimum requirements
+        TreeSet mset = new TreeSet(mcomp);
+        for (int i = 0; i < modes.length; i++) {
+            if (modes[i].getWidth() == 800 &&
+                modes[i].getHeight() == 600 &&
+                modes[i].getBitDepth() >= minimumDepth) {
+                mset.add(modes[i]);
+            }
+        }
+
+        return (mset.size() > 0) ? (DisplayMode)mset.first() : null;
+    }
+}