Initial revision

git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/svn-server-sync/jogl/trunk@3 232f8b59-042b-4e1e-8c03-345bb8c30851

1 files changed, 294 insertions, 0 deletions

diff --git a/src/net/java/games/jogl/impl/FunctionAvailabilityCache.java b/src/net/java/games/jogl/impl/FunctionAvailabilityCache.java
new file mode 100644
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+++ b/src/net/java/games/jogl/impl/FunctionAvailabilityCache.java
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+/*
+ * Copyright (c) 2003 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
+ * MIDROSYSTEMS, 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 net.java.games.jogl.impl;
+
+import net.java.games.jogl.*;
+import java.util.*;
+import java.awt.Canvas;
+import java.awt.Graphics;
+import java.awt.GraphicsConfiguration;
+import java.lang.reflect.*;
+
+/**
+ * A utility object intended to be used by implementations to act as a cache
+ * of which OpenGL functions are currently available on both the host machine
+ * and display.
+ */
+public final class FunctionAvailabilityCache {
+
+  FunctionAvailabilityCache(GLContext context)
+  {
+    this.context = context;
+  }
+
+  /**
+   * Flush the cache. The cache will be rebuilt lazily as calls to {@link
+   * #isFunctionAvailable(String)} are received.
+   */
+  public void flush()
+  {
+    availabilityCache.clear();
+    availableExtensionCache.clear();
+  }
+
+  public boolean isFunctionAvailable(String glFunctionName)
+  {
+    //System.err.println("!!! CHECKING FOR AVAILABILITY OF: "+glFunctionName);
+
+    Boolean available = (Boolean)availabilityCache.get(glFunctionName);
+
+    if (available == null) // not in availabilityCache
+    {
+      if (isPartOfAvailableExtensions(glFunctionName) ||
+          isPartOfGLCore(context.getGL().glGetString(GL.GL_VERSION), glFunctionName))
+      {
+        available = Boolean.TRUE;
+      }
+      else
+      {
+        available = Boolean.FALSE;
+      }
+      
+      availabilityCache.put(glFunctionName, available);
+    }
+
+    return available.booleanValue();
+  }
+
+  public boolean isExtensionAvailable(String glExtensionName) {
+    initAvailableExtensions();
+    return availableExtensionCache.contains(glExtensionName);
+  }
+
+  protected void initAvailableExtensions() {
+    // if hash is empty (meaning it was flushed), pre-cache it with the list
+    // of extensions that are in the GL_EXTENSIONS string
+    if (availableExtensionCache.isEmpty()) {
+      GL gl = context.getGL();
+      //System.err.println("!!! Pre-caching extension availability");
+      String allAvailableExtensions =
+        gl.glGetString(GL.GL_EXTENSIONS) + " " + context.getPlatformExtensionsString();
+      StringTokenizer tok = new StringTokenizer(allAvailableExtensions);
+      while (tok.hasMoreTokens()) {
+        String availableExt = tok.nextToken().trim();
+        availableExt = availableExt.intern();
+        availableExtensionCache.add(availableExt);
+        //System.err.println("!!!   Available: " + availableExt);
+      }
+
+      // put a dummy var in here so that the cache is no longer empty even if
+      // no extensions are in the GL_EXTENSIONS string
+      availableExtensionCache.add("<INTERNAL_DUMMY_PLACEHOLDER>");
+    }
+  }
+
+  protected boolean isPartOfAvailableExtensions(String glFunctionName)
+  {    
+    initAvailableExtensions();
+
+    // First, find the extension to which the function corresponds
+    String extensionName = getExtensionCorrespondingToFunction(glFunctionName);
+
+    // Now see if that extension is available
+    boolean extensionAvailable = availableExtensionCache.contains(extensionName);
+
+    return extensionAvailable;
+  }
+
+  /**
+   * Returns true if the given OpenGL function is part of the OpenGL core
+   * that corresponds to the give OpenGL version string.
+   *
+   * @param versionString must be of the form "X" or "X.Y" or "X.Y.Z", where
+   * X, Y, and Z are integers
+   @ @exception GLException if the glFunctionName passed in is
+   * not the name of any known OpenGL extension function. 
+   */
+  public static boolean isPartOfGLCore(String glVersionString, String glFunctionName)
+  {
+    String funcCoreVersionString =
+      StaticGLInfo.getFunctionAssociation(glFunctionName);
+
+    if (funcCoreVersionString == null) {
+      // No extension string was found in the glext.h/wglext.h/glxext.h
+      // headers when building the StaticGLInfo class. So either it's a new
+      // extension that's not in those headers, or it's not an opengl
+      // extension. Either way it's an illegal argument.
+      throw new GLException(
+        "Function \"" + glFunctionName + "\" does not " +
+        "correspond to any known OpenGL extension or core version.");
+    }
+
+    Version actualVersion;
+    try
+    {
+      actualVersion = new Version(funcCoreVersionString);
+    }
+    catch (IllegalArgumentException e)
+    {      
+      // funcCoreVersionString is not an OpenGL version identifier (i.e., not
+      // of the form GL_VERSION_XXX).
+      //
+      // Since the association string returned from
+      // StaticGLInfo.getFunctionAssociation() was not null, this function
+      // must be an OpenGL extension function.
+      //
+      // Therefore this function can't be part of any OpenGL core.
+      return false;
+    }
+    
+    Version versionToCheck;
+    try
+    {
+      versionToCheck = new Version(glVersionString);
+    }
+    catch (IllegalArgumentException e)
+    {
+      // user did not supply a valid OpenGL version identifier
+      throw new IllegalArgumentException(
+          "Illegally formatted OpenGL version identifier: \"" + glVersionString + "\"");
+    }
+    
+    // See if the version number of glVersionString is less than or equal to
+    // the OpenGL specification number to which the given function actually
+    // belongs.
+    if (actualVersion.compareTo(versionToCheck) <= 0)
+    {
+      System.err.println(
+        glFunctionName + " is in core OpenGL " + glVersionString +
+        " because it is in OpenGL " + funcCoreVersionString);
+      return true;
+    }
+    
+    System.err.println(
+      glFunctionName + " is NOT a part of the OpenGL " + glVersionString + " core" +
+      "; it is part of OpenGL " + funcCoreVersionString);
+
+    return false;
+  }
+
+  /** Returns the extension name that corresponds to the given extension
+   * function. For example, it will return "GL_EXT_vertex_array" when the
+   * argument is "glNormalPointerEXT".
+   *
+   * Please see http://oss.sgi.com/projects/ogl-sample/registry/index.html for
+   * a list of extension names and the functions they expose.
+   */
+  protected static String getExtensionCorrespondingToFunction(String glFunctionName)
+  {
+    // HACK: FIXME!!! return something I know is supported so I can test other
+    // functions. 
+    return StaticGLInfo.getFunctionAssociation(glFunctionName);
+  }
+
+  //----------------------------------------------------------------------
+  // Internals only below this point
+  //
+
+  private HashMap availabilityCache = new HashMap(50); 
+  private HashSet availableExtensionCache = new HashSet(50);
+  private GLContext context;
+
+  /**
+   * A class for storing and comparing revision version numbers.
+   */
+  private static class Version implements Comparable
+  {
+    private int major, minor, sub;
+    public Version(int majorRev, int minorRev, int subMinorRev)
+    {
+      major = majorRev;
+      minor = minorRev;
+      sub = subMinorRev;
+    }
+
+    /**
+     * @param versionString must be of the form "GL_VERSION_X" or
+     * "GL_VERSION_X_Y" or "GL_VERSION_X_Y_Z", where X, Y, and Z are integers.
+     *
+     * @exception IllegalArgumentException if the argument is not a valid
+     * OpenGL version identifier
+     */
+    public Version(String versionString)
+    {
+      if (! versionString.startsWith("GL_VERSION_"))
+      {
+        // not a version string
+        throw new IllegalArgumentException(
+          "Illegal version identifier \"" + versionString +
+          "\"; does not start with \"GL_VERSION_\"");
+      }
+      
+      try
+      {
+        StringTokenizer tok = new StringTokenizer(versionString, "_");
+
+        tok.nextToken(); // GL_
+        tok.nextToken(); // VERSION_ 
+        if (!tok.hasMoreTokens()) { major = 0; return; }
+        major = Integer.valueOf(tok.nextToken()).intValue();
+        if (!tok.hasMoreTokens()) { minor = 0; return; }
+        minor = Integer.valueOf(tok.nextToken()).intValue();
+        if (!tok.hasMoreTokens()) { sub = 0; return; }
+        sub = Integer.valueOf(tok.nextToken()).intValue();
+      }
+      catch (Exception e)
+      {
+        throw new IllegalArgumentException(
+          "Illegally formatted version identifier: \"" + versionString + "\"");
+      }
+    }
+
+    public int compareTo(Object o)
+    {
+      Version vo = (Version)o;
+      if (major > vo.major) return 1; 
+      else if (major < vo.major) return -1; 
+      else if (minor > vo.minor) return 1; 
+      else if (minor < vo.minor) return -1; 
+      else if (sub > vo.sub) return 1; 
+      else if (sub < vo.sub) return -1; 
+
+      return 0; // they are equal
+    }
+    
+  } // end class Version
+}
+