1 files changed, 46 insertions, 2 deletions

diff --git a/src/net/java/games/jogl/impl/GLContext.java b/src/net/java/games/jogl/impl/GLContext.java
index 98b1c6065..eb7d21988 100644
--- a/src/net/java/games/jogl/impl/GLContext.java
+++ b/src/net/java/games/jogl/impl/GLContext.java
@@ -42,6 +42,7 @@ package net.java.games.jogl.impl;
 import java.awt.Component;
 import java.awt.EventQueue;
 import net.java.games.jogl.*;
+import net.java.games.gluegen.runtime.*;
 
 public abstract class GLContext {
   protected static final boolean DEBUG = false;
@@ -75,8 +76,10 @@ public abstract class GLContext {
   // All GLU interfaces eventually route calls down to gluRoot. It can be
   // static because GLU it doesn't actually need to own context, it just makes
   // GL calls and assumes some context is active.
-  protected static final GLU gluRoot = new GLUImpl();
-  protected static GLU glu = gluRoot; // this is the context's GLU interface
+  protected static final GLUProcAddressTable gluProcAddressTable = new GLUProcAddressTable();
+  protected static final GLU gluRoot = new GLUImpl(gluProcAddressTable);
+  protected static boolean haveResetGLUProcAddressTable;
+  protected GLU glu = gluRoot; // this is the context's GLU interface
   protected Thread renderingThread;
   protected Runnable deferredReshapeAction;
 
@@ -282,6 +285,13 @@ public abstract class GLContext {
    */
   protected void resetGLFunctionAvailability() {
     functionAvailability.flush();
+    if (!haveResetGLUProcAddressTable) {
+      if (DEBUG) {
+        System.err.println("!!! Initializing GLU extension address table");
+      }
+      resetProcAddressTable(gluProcAddressTable);
+      haveResetGLUProcAddressTable = true; // Only need to do this once globally
+    }
   }
 
   /**
@@ -391,6 +401,40 @@ public abstract class GLContext {
       conditions cause a GLException to be thrown. */
   protected abstract void swapBuffers() throws GLException;
 
+  /** Helper routine which resets a ProcAddressTable generated by the
+      GLEmitter by looking up anew all of its function pointers. */
+  protected void resetProcAddressTable(Object table) {
+    Class tableClass = table.getClass();
+    java.lang.reflect.Field[] fields = tableClass.getDeclaredFields();
+    
+    for (int i = 0; i < fields.length; ++i) {
+      String addressFieldName = fields[i].getName();
+      if (!addressFieldName.startsWith(ProcAddressHelper.PROCADDRESS_VAR_PREFIX)) {
+        // not a proc address variable
+        continue;
+      }
+      int startOfMethodName = ProcAddressHelper.PROCADDRESS_VAR_PREFIX.length();
+      String glFuncName = addressFieldName.substring(startOfMethodName);
+      try {
+        java.lang.reflect.Field addressField = tableClass.getDeclaredField(addressFieldName);
+        assert(addressField.getType() == Long.TYPE);
+        long newProcAddress = dynamicLookupFunction(glFuncName);
+        // set the current value of the proc address variable in the table object
+        addressField.setLong(table, newProcAddress); 
+        if (DEBUG) {
+          System.err.println(glFuncName + " = 0x" + Long.toHexString(newProcAddress));
+        }
+      } catch (Exception e) {
+        throw new GLException("Cannot get GL proc address for method \"" +
+                              glFuncName + "\": Couldn't set value of field \"" + addressFieldName +
+                              "\" in class " + tableClass.getName(), e);
+      }
+    }
+  }
+
+  /** Dynamically looks up the given function. */
+  protected abstract long dynamicLookupFunction(String glFuncName);
+  
   //----------------------------------------------------------------------
   // Internals only below this point
   //