1 files changed, 173 insertions, 0 deletions
diff --git a/src/classes/com/sun/opengl/impl/GLBufferStateTracker.java b/src/classes/com/sun/opengl/impl/GLBufferStateTracker.java
new file mode 100755
index 000000000..2c4a9963e
--- /dev/null
+++ b/src/classes/com/sun/opengl/impl/GLBufferStateTracker.java
@@ -0,0 +1,173 @@
+/*
+ * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ * - Redistribution of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * 
+ * - Redistribution in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * 
+ * Neither the name of Sun Microsystems, Inc. or the names of
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * 
+ * This software is provided "AS IS," without a warranty of any kind. ALL
+ * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
+ * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
+ * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
+ * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
+ * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
+ * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
+ * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
+ * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
+ * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
+ * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
+ * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
+ * 
+ * You acknowledge that this software is not designed or intended for use
+ * in the design, construction, operation or maintenance of any nuclear
+ * facility.
+ * 
+ * Sun gratefully acknowledges that this software was originally authored
+ * and developed by Kenneth Bradley Russell and Christopher John Kline.
+ */
+
+package com.sun.opengl.impl;
+
+import java.util.*;
+import javax.media.opengl.*;
+
+/**
+ * Tracks as closely as possible which OpenGL buffer object is bound
+ * to which binding target in the current OpenGL context.
+ * GLBufferStateTracker objects are allocated on a per-GLImpl basis,
+ * which is basically identical to a per-OpenGL-context basis
+ * (assuming correct usage of the GLImpl objects, which is checked by
+ * the DebugGL). This class is used to verify that e.g. the vertex
+ * buffer object extension is in use when the glVertexPointer variant
+ * taking a long as argument is called. <P>
+ * 
+ * Note that because the enumerated value used for the binding of a
+ * buffer object (e.g. GL_ARRAY_BUFFER) is different than that used to
+ * query the binding using glGetIntegerv (e.g.
+ * GL_ARRAY_BUFFER_BINDING), then in the face of new binding targets
+ * being added to the GL (e.g. GL_TRANSFORM_FEEDBACK_BUFFER_NV) it is
+ * impossible to set up a query of the buffer object currently bound
+ * to a particular state. It turns out that for some uses, such as
+ * finding the size of the currently bound buffer, this doesn't
+ * matter, though of course without knowing the buffer object we can't
+ * re-associate the queried size with the buffer object ID. <P>
+ *
+ * Because the namespace of buffer objects is the unsigned integers
+ * with 0 reserved by the GL, and because we have to be able to return
+ * both 0 and other integers as valid answers from
+ * getBoundBufferObject(), we need a second query, which is to ask
+ * whether we know the state of the binding for a given target. For
+ * "unknown" targets such as GL_TRANSFORM_FEEDBACK_BUFFER_NV we return
+ * false from this, but we also clear the valid bit and later refresh
+ * the binding state if glPushClientAttrib / glPopClientAttrib are
+ * called, since we don't want the complexity of tracking stacks of
+ * these attributes.
+ *
+ */
+
+public class GLBufferStateTracker {
+  private static final boolean DEBUG = Debug.debug("GLBufferStateTracker");
+
+  private static final Integer arrayBufferEnum        = new Integer(GL.GL_ARRAY_BUFFER);
+  private static final Integer elementArrayBufferEnum = new Integer(GL.GL_ELEMENT_ARRAY_BUFFER);
+  private static final Integer pixelPackBufferEnum    = new Integer(GL.GL_PIXEL_PACK_BUFFER);
+  private static final Integer pixelUnpackBufferEnum  = new Integer(GL.GL_PIXEL_UNPACK_BUFFER);
+  private static final Integer zero                   = new Integer(0);
+
+  // Maps binding targets to buffer objects. A null value indicates
+  // that the binding is unknown. A zero value indicates that it is
+  // known that no buffer is bound to the target.
+  private Map/*<Integer,Integer>*/ bindingMap = new HashMap/*<Integer,Integer>*/();
+
+  private int[] bufTmp = new int[1];
+
+  public GLBufferStateTracker() {
+    // Start with known unbound targets for known keys
+    bindingMap.put(arrayBufferEnum,        zero);
+    bindingMap.put(elementArrayBufferEnum, zero);
+    bindingMap.put(pixelPackBufferEnum,    zero);
+    bindingMap.put(pixelUnpackBufferEnum,  zero);
+  }
+
+  public void setBoundBufferObject(int target, int buffer) {
+    Integer key = box(target);
+    bindingMap.put(key, box(buffer));
+  }
+
+  /** Note: returns an unspecified value if the binding for the
+      specified target (e.g. GL_ARRAY_BUFFER) is currently unknown.
+      You must use isBoundBufferObjectKnown() to see whether the
+      return value is valid. */
+  public int getBoundBufferObject(int target, GL caller) {
+    Integer key = box(target);
+    Integer value = (Integer) bindingMap.get(key);
+    if (value == null) {
+      // User probably either called glPushClientAttrib /
+      // glPopClientAttrib or is querying an unknown target. See
+      // whether we know how to fetch this state.
+      boolean gotQueryTarget = true;
+      int queryTarget = 0;
+      switch (target) {
+        case GL.GL_ARRAY_BUFFER:          queryTarget = GL.GL_ARRAY_BUFFER_BINDING;         break;
+        case GL.GL_ELEMENT_ARRAY_BUFFER:  queryTarget = GL.GL_ELEMENT_ARRAY_BUFFER_BINDING; break;
+        case GL.GL_PIXEL_PACK_BUFFER:     queryTarget = GL.GL_PIXEL_PACK_BUFFER_BINDING;    break;
+        case GL.GL_PIXEL_UNPACK_BUFFER:   queryTarget = GL.GL_PIXEL_UNPACK_BUFFER_BINDING;  break;
+        default:                          gotQueryTarget = false; break;
+      }
+      if (gotQueryTarget) {
+        caller.glGetIntegerv(queryTarget, bufTmp, 0);
+        if (DEBUG) {
+          System.err.println("GLBufferStateTracker.getBoundBufferObject(): queried bound buffer " +
+                             bufTmp[0] +
+                             " for query target 0x" + Integer.toHexString(queryTarget));
+        }
+        setBoundBufferObject(target, bufTmp[0]);
+        // Try once more
+        return getBoundBufferObject(target, caller);
+      }
+      return 0;
+    }
+    return value.intValue();
+  }
+
+  /** Indicates whether the binding state for the specified target is
+      currently known. Should be called after getBoundBufferObject()
+      because that method may change the answer for a given target. */
+  public boolean isBoundBufferObjectKnown(int target) {
+    return (bindingMap.get(box(target)) != null);
+  }
+
+  /** Clears out the known/unknown state of the various buffer object
+      binding states. These will be refreshed later on an as-needed
+      basis. This is called by the implementations of
+      glPushClientAttrib / glPopClientAttrib. Might want to call this
+      from GLContext.makeCurrent() in the future to possibly increase
+      the robustness of these caches in the face of external native
+      code manipulating OpenGL state. */
+  public void clearBufferObjectState() {
+    bindingMap.clear();
+  }
+
+  // FIXME: could largely remove this and use Integer.valueOf() in JDK 5
+  private static Integer box(int key) {
+    switch (key) {
+      case 0:                          return zero;
+      case GL.GL_ARRAY_BUFFER:         return arrayBufferEnum;
+      case GL.GL_ELEMENT_ARRAY_BUFFER: return elementArrayBufferEnum;
+      case GL.GL_PIXEL_PACK_BUFFER:    return pixelPackBufferEnum;
+      case GL.GL_PIXEL_UNPACK_BUFFER:  return pixelUnpackBufferEnum;
+      default:                         return new Integer(key);
+    }
+  }
+}