path: root/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXGraphicsConfiguration.java

/*
 * Copyright (c) 2008 Sun Microsystems, Inc. All Rights Reserved.
 * Copyright (c) 2010 JogAmp Community. 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
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 * 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.
 */

package jogamp.opengl.x11.glx;

import java.util.ArrayList;
import java.util.List;

import javax.media.nativewindow.AbstractGraphicsDevice;
import javax.media.nativewindow.GraphicsConfigurationFactory;
import javax.media.opengl.DefaultGLCapabilitiesChooser;
import javax.media.opengl.GL;
import javax.media.opengl.GLCapabilities;
import javax.media.opengl.GLCapabilitiesChooser;
import javax.media.opengl.GLCapabilitiesImmutable;
import javax.media.opengl.GLContext;
import javax.media.opengl.GLDrawableFactory;
import javax.media.opengl.GLException;
import javax.media.opengl.GLProfile;

import jogamp.nativewindow.x11.X11Lib;
import jogamp.nativewindow.x11.XRenderDirectFormat;
import jogamp.nativewindow.x11.XRenderPictFormat;
import jogamp.nativewindow.x11.XVisualInfo;
import jogamp.opengl.GLGraphicsConfigurationUtil;

import com.jogamp.common.nio.PointerBuffer;
import com.jogamp.nativewindow.x11.X11GraphicsConfiguration;
import com.jogamp.nativewindow.x11.X11GraphicsScreen;

public class X11GLXGraphicsConfiguration extends X11GraphicsConfiguration implements Cloneable {
    public static final int MAX_ATTRIBS = 128;
    private GLCapabilitiesChooser chooser; 

    X11GLXGraphicsConfiguration(X11GraphicsScreen screen, 
                                X11GLCapabilities capsChosen, GLCapabilitiesImmutable capsRequested, GLCapabilitiesChooser chooser) {
        super(screen, capsChosen, capsRequested, capsChosen.getXVisualInfo());
        this.chooser=chooser;
    }

    static X11GLXGraphicsConfiguration create(GLProfile glp, X11GraphicsScreen x11Screen, int fbcfgID) {
      final AbstractGraphicsDevice device = x11Screen.getDevice();
      final long display = device.getHandle();
      if(0==display) {
          throw new GLException("Display null of "+x11Screen);
      }
      final int screen = x11Screen.getIndex();
      final long fbcfg = glXFBConfigID2FBConfig(display, screen, fbcfgID);
      if(0==fbcfg) {
          throw new GLException("FBConfig null of "+toHexString(fbcfgID));
      }
      if(null==glp) {
        glp = GLProfile.getDefault(x11Screen.getDevice());
      }
      final X11GLXDrawableFactory factory = (X11GLXDrawableFactory) GLDrawableFactory.getDesktopFactory();
      final X11GLCapabilities caps = GLXFBConfig2GLCapabilities(glp, device, fbcfg, true, true, true, factory.isGLXMultisampleAvailable(device));
      if(null==caps) {
          throw new GLException("GLCapabilities null of "+toHexString(fbcfg));
      }
      return new X11GLXGraphicsConfiguration(x11Screen, caps, caps, new DefaultGLCapabilitiesChooser());
    }

    public Object clone() {
        return super.clone();
    }

    public final long getFBConfig()   {
        return ((X11GLCapabilities)capabilitiesChosen).getFBConfig();
    }
    public final int  getFBConfigID() {
        return ((X11GLCapabilities)capabilitiesChosen).getFBConfigID();
    }

    void updateGraphicsConfiguration() {
        X11GLXGraphicsConfiguration newConfig = (X11GLXGraphicsConfiguration)
            GraphicsConfigurationFactory.getFactory(getScreen().getDevice()).chooseGraphicsConfiguration(
                getChosenCapabilities(), getRequestedCapabilities(), chooser, getScreen());
        if(null!=newConfig) {
            // FIXME: setScreen( ... );
            setXVisualInfo(newConfig.getXVisualInfo());
            setChosenCapabilities(newConfig.getChosenCapabilities());
            if(DEBUG) {
                System.err.println("updateGraphicsConfiguration: "+this);
            }
        }
    }

    static int[] GLCapabilities2AttribList(GLCapabilitiesImmutable caps,
                                           boolean forFBAttr,
                                           boolean isMultisampleAvailable,
                                           long display,
                                           int screen) 
    {
        int colorDepth = (caps.getRedBits() +
                          caps.getGreenBits() +
                          caps.getBlueBits());
        if (colorDepth < 15) {
          throw new GLException("Bit depths < 15 (i.e., non-true-color) not supported");
        }
        int[] res = new int[MAX_ATTRIBS];
        int idx = 0;

        if (forFBAttr) {
          res[idx++] = GLX.GLX_DRAWABLE_TYPE;
          res[idx++] = caps.isOnscreen() ? ( GLX.GLX_WINDOW_BIT ) : ( caps.isPBuffer() ? GLX.GLX_PBUFFER_BIT : GLX.GLX_PIXMAP_BIT ) ;
        }

        if (forFBAttr) {
          res[idx++] = GLX.GLX_RENDER_TYPE;
          res[idx++] = GLX.GLX_RGBA_BIT;
        } else {
          res[idx++] = GLX.GLX_RGBA;
        }

        // FIXME: Still a bug is Mesa: PBUFFER && GLX_STEREO==GL_FALSE ?
        if (forFBAttr) {
            res[idx++] = GLX.GLX_DOUBLEBUFFER;
            res[idx++] = caps.getDoubleBuffered()?GL.GL_TRUE:GL.GL_FALSE;
            res[idx++] = GLX.GLX_STEREO;
            res[idx++] = caps.getStereo()?GL.GL_TRUE:GL.GL_FALSE;
            res[idx++] = GLX.GLX_TRANSPARENT_TYPE;
            res[idx++] = GLX.GLX_NONE;
            /**
            res[idx++] = caps.isBackgroundOpaque()?GLX.GLX_NONE:GLX.GLX_TRANSPARENT_RGB;
            if(!caps.isBackgroundOpaque()) {
                res[idx++] = GLX.GLX_TRANSPARENT_RED_VALUE;
                res[idx++] = caps.getTransparentRedValue()>=0?caps.getTransparentRedValue():(int)GLX.GLX_DONT_CARE;
                res[idx++] = GLX.GLX_TRANSPARENT_GREEN_VALUE;
                res[idx++] = caps.getTransparentGreenValue()>=0?caps.getTransparentGreenValue():(int)GLX.GLX_DONT_CARE;
                res[idx++] = GLX.GLX_TRANSPARENT_BLUE_VALUE;
                res[idx++] = caps.getTransparentBlueValue()>=0?caps.getTransparentBlueValue():(int)GLX.GLX_DONT_CARE;
                res[idx++] = GLX.GLX_TRANSPARENT_ALPHA_VALUE;
                res[idx++] = caps.getTransparentAlphaValue()>=0?caps.getTransparentAlphaValue():(int)GLX.GLX_DONT_CARE;
            } */
        } else {
            if (caps.getDoubleBuffered()) {
              res[idx++] = GLX.GLX_DOUBLEBUFFER;
            }
            if (caps.getStereo()) {
              res[idx++] = GLX.GLX_STEREO;
            }
        }

        res[idx++] = GLX.GLX_RED_SIZE;
        res[idx++] = caps.getRedBits();
        res[idx++] = GLX.GLX_GREEN_SIZE;
        res[idx++] = caps.getGreenBits();
        res[idx++] = GLX.GLX_BLUE_SIZE;
        res[idx++] = caps.getBlueBits();
        if(caps.getAlphaBits()>0) {
            res[idx++] = GLX.GLX_ALPHA_SIZE;
            res[idx++] = caps.getAlphaBits();
        }
        if (caps.getStencilBits() > 0) {
          res[idx++] = GLX.GLX_STENCIL_SIZE;
          res[idx++] = caps.getStencilBits();
        }
        res[idx++] = GLX.GLX_DEPTH_SIZE;
        res[idx++] = caps.getDepthBits();
        if (caps.getAccumRedBits()   > 0 ||
            caps.getAccumGreenBits() > 0 ||
            caps.getAccumBlueBits()  > 0 ||
            caps.getAccumAlphaBits() > 0) {
          res[idx++] = GLX.GLX_ACCUM_RED_SIZE;
          res[idx++] = caps.getAccumRedBits();
          res[idx++] = GLX.GLX_ACCUM_GREEN_SIZE;
          res[idx++] = caps.getAccumGreenBits();
          res[idx++] = GLX.GLX_ACCUM_BLUE_SIZE;
          res[idx++] = caps.getAccumBlueBits();
          res[idx++] = GLX.GLX_ACCUM_ALPHA_SIZE;
          res[idx++] = caps.getAccumAlphaBits();
        }
        if (isMultisampleAvailable && caps.getSampleBuffers()) {
          res[idx++] = GLX.GLX_SAMPLE_BUFFERS;
          res[idx++] = GL.GL_TRUE;
          res[idx++] = GLX.GLX_SAMPLES;
          res[idx++] = caps.getNumSamples();
        }
        if (caps.isPBuffer()) {
          if (caps.getPbufferFloatingPointBuffers()) {
            String glXExtensions = GLX.glXQueryExtensionsString(display, screen);
            if (glXExtensions == null ||
                glXExtensions.indexOf("GLX_NV_float_buffer") < 0) {
              throw new GLException("Floating-point pbuffers on X11 currently require NVidia hardware: "+glXExtensions);
            }
            res[idx++] = GLXExt.GLX_FLOAT_COMPONENTS_NV;
            res[idx++] = GL.GL_TRUE;
          }
        }
        res[idx++] = 0;
        return res;
  }

  // FBConfig
    
  static boolean GLXFBConfigIDValid(long display, int screen, int fbcfgid) {      
    long fbcfg = X11GLXGraphicsConfiguration.glXFBConfigID2FBConfig(display, screen, fbcfgid);
    return (0 != fbcfg) ? X11GLXGraphicsConfiguration.GLXFBConfigValid( display, fbcfg ) : false ;
  }

  static boolean GLXFBConfigValid(long display, long fbcfg) {
    int[] tmp = new int[1];
    if(GLX.GLX_BAD_ATTRIBUTE == GLX.glXGetFBConfigAttrib(display, fbcfg, GLX.GLX_RENDER_TYPE, tmp, 0)) {
      return false;
    }
    return true;
  }

  static int FBCfgDrawableTypeBits(final AbstractGraphicsDevice device, GLProfile glp, final long fbcfg) {
    int val = 0;

    int[] tmp = new int[1];
    int fbtype = glXGetFBConfig(device.getHandle(), fbcfg, GLX.GLX_DRAWABLE_TYPE, tmp, 0);

    if ( 0 != ( fbtype & GLX.GLX_WINDOW_BIT ) ) {
        val |= GLGraphicsConfigurationUtil.WINDOW_BIT;
    }
    if ( 0 != ( fbtype & GLX.GLX_PIXMAP_BIT ) ) {
        val |= GLGraphicsConfigurationUtil.BITMAP_BIT;
    }
    if ( 0 != ( fbtype & GLX.GLX_PBUFFER_BIT ) ) {
        val |= GLGraphicsConfigurationUtil.PBUFFER_BIT;
    }
    if ( GLContext.isFBOAvailable(device, glp) ) {
        val |= GLGraphicsConfigurationUtil.FBO_BIT;
    }
    return val;
  }

  static X11GLCapabilities GLXFBConfig2GLCapabilities(GLProfile glp, AbstractGraphicsDevice device, long fbcfg,
                                                            boolean relaxed, boolean onscreen, boolean usePBuffer,
                                                            boolean isMultisampleAvailable) {
    ArrayList<GLCapabilitiesImmutable> bucket = new ArrayList<GLCapabilitiesImmutable>();
    final int winattrmask = GLGraphicsConfigurationUtil.getWinAttributeBits(onscreen, usePBuffer, false);
    if( GLXFBConfig2GLCapabilities(bucket, glp, device, fbcfg, winattrmask, isMultisampleAvailable) ) {
        return (X11GLCapabilities) bucket.get(0);
    } else if ( relaxed && GLXFBConfig2GLCapabilities(bucket, glp, device, fbcfg, GLGraphicsConfigurationUtil.ALL_BITS, isMultisampleAvailable) ) {
        return (X11GLCapabilities) bucket.get(0);
    }
    return null;
  }

  static XRenderDirectFormat XVisual2XRenderMask(long dpy, long visual) {
    XRenderPictFormat renderPictFmt = X11Lib.XRenderFindVisualFormat(dpy, visual);
    if(null == renderPictFmt) {
        return null;
    }
    return renderPictFmt.getDirect();
  }

  static boolean GLXFBConfig2GLCapabilities(List<GLCapabilitiesImmutable> capsBucket,
                                            GLProfile glp, AbstractGraphicsDevice device, long fbcfg,
                                            int winattrmask, boolean isMultisampleAvailable) {
    final int allDrawableTypeBits = FBCfgDrawableTypeBits(device, glp,  fbcfg);
    int drawableTypeBits = winattrmask & allDrawableTypeBits;
    
    final long display = device.getHandle(); 
    int fbcfgid = X11GLXGraphicsConfiguration.glXFBConfig2FBConfigID(display, fbcfg);
    XVisualInfo visualInfo = GLX.glXGetVisualFromFBConfig(display, fbcfg);
    if(null == visualInfo) {
        if(DEBUG) {
            System.err.println("X11GLXGraphicsConfiguration.GLXFBConfig2GLCapabilities: Null XVisualInfo for FBConfigID 0x" + Integer.toHexString(fbcfgid));
        }
        // onscreen must have an XVisualInfo
        drawableTypeBits = drawableTypeBits & ~GLGraphicsConfigurationUtil.WINDOW_BIT;
    }

    if( 0 == drawableTypeBits ) {
        return false;
    }

    int[] tmp = new int[1];
    if(GLX.GLX_BAD_ATTRIBUTE == GLX.glXGetFBConfigAttrib(display, fbcfg, GLX.GLX_RENDER_TYPE, tmp, 0)) {
      return false;
    }
    if( 0 == ( GLX.GLX_RGBA_BIT & tmp[0] ) ) {
      return false; // no RGBA -> color index not supported
    }

    GLCapabilities res = new X11GLCapabilities(visualInfo, fbcfg, fbcfgid, glp);
    res.setDoubleBuffered(glXGetFBConfig(display, fbcfg, GLX.GLX_DOUBLEBUFFER,     tmp, 0) != 0);
    res.setStereo        (glXGetFBConfig(display, fbcfg, GLX.GLX_STEREO,           tmp, 0) != 0);
    res.setHardwareAccelerated(glXGetFBConfig(display, fbcfg, GLX.GLX_CONFIG_CAVEAT, tmp, 0) != GLX.GLX_SLOW_CONFIG);
    res.setDepthBits     (glXGetFBConfig(display, fbcfg, GLX.GLX_DEPTH_SIZE,       tmp, 0));
    res.setStencilBits   (glXGetFBConfig(display, fbcfg, GLX.GLX_STENCIL_SIZE,     tmp, 0));
    res.setRedBits       (glXGetFBConfig(display, fbcfg, GLX.GLX_RED_SIZE,         tmp, 0));
    res.setGreenBits     (glXGetFBConfig(display, fbcfg, GLX.GLX_GREEN_SIZE,       tmp, 0));
    res.setBlueBits      (glXGetFBConfig(display, fbcfg, GLX.GLX_BLUE_SIZE,        tmp, 0));
    res.setAlphaBits     (glXGetFBConfig(display, fbcfg, GLX.GLX_ALPHA_SIZE,       tmp, 0));
    res.setAccumRedBits  (glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_RED_SIZE,   tmp, 0));
    res.setAccumGreenBits(glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_GREEN_SIZE, tmp, 0));
    res.setAccumBlueBits (glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_BLUE_SIZE,  tmp, 0));
    res.setAccumAlphaBits(glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_ALPHA_SIZE, tmp, 0));
    if (isMultisampleAvailable) {
      res.setSampleBuffers(glXGetFBConfig(display, fbcfg, GLX.GLX_SAMPLE_BUFFERS, tmp, 0) != 0);
      res.setNumSamples   (glXGetFBConfig(display, fbcfg, GLX.GLX_SAMPLES,        tmp, 0));
    }
    final XRenderDirectFormat xrmask = ( null != visualInfo ) ? 
                                         XVisual2XRenderMask( display, visualInfo.getVisual() ) : 
                                         null ;
    final int alphaMask = ( null != xrmask ) ? xrmask.getAlphaMask() : 0;
    res.setBackgroundOpaque( 0 >= alphaMask );
    if( !res.isBackgroundOpaque() ) {
        res.setTransparentRedValue(xrmask.getRedMask());
        res.setTransparentGreenValue(xrmask.getGreenMask());
        res.setTransparentBlueValue(xrmask.getBlueMask());
        res.setTransparentAlphaValue(alphaMask);
    }
    
    try { 
        res.setPbufferFloatingPointBuffers(glXGetFBConfig(display, fbcfg, GLXExt.GLX_FLOAT_COMPONENTS_NV, tmp, 0) != GL.GL_FALSE);
    } catch (Exception e) {}

    return GLGraphicsConfigurationUtil.addGLCapabilitiesPermutations(capsBucket, res, drawableTypeBits );
  }

  private static String glXGetFBConfigErrorCode(int err) {
    switch (err) {
      case GLX.GLX_NO_EXTENSION:  return "GLX_NO_EXTENSION";
      case GLX.GLX_BAD_ATTRIBUTE: return "GLX_BAD_ATTRIBUTE";
      default:                return "Unknown error code " + err;
    }
  }

  static int glXGetFBConfig(long display, long cfg, int attrib, int[] tmp, int tmp_offset) {
    if (display == 0) {
      throw new GLException("No display connection");
    }
    int res = GLX.glXGetFBConfigAttrib(display, cfg, attrib, tmp, tmp_offset);
    if (res != 0) {
      throw new GLException("glXGetFBConfig("+toHexString(attrib)+") failed: error code " + glXGetFBConfigErrorCode(res));
    }
    return tmp[tmp_offset];
  }

  static int glXFBConfig2FBConfigID(long display, long cfg) {
      int[] tmpID = new int[1];
      return glXGetFBConfig(display, cfg, GLX.GLX_FBCONFIG_ID, tmpID, 0);
  }

  static long glXFBConfigID2FBConfig(long display, int screen, int id) {
      int[] attribs = new int[] { GLX.GLX_FBCONFIG_ID, id, 0 };
      int[] count = { -1 };
      PointerBuffer fbcfgsL = GLX.glXChooseFBConfig(display, screen, attribs, 0, count, 0);
      if (fbcfgsL == null || fbcfgsL.limit()<1) {
          return 0;
      }
      return fbcfgsL.get(0);
  }

  // Visual Info

  static XVisualInfo XVisualID2XVisualInfo(long display, long visualID) {
      int[] count = new int[1];
      XVisualInfo template = XVisualInfo.create();
      template.setVisualid(visualID);
      XVisualInfo[] infos = X11Lib.XGetVisualInfo(display, X11Lib.VisualIDMask, template, count, 0);
      if (infos == null || infos.length == 0) {
            return null;
      }  
      XVisualInfo res = XVisualInfo.create(infos[0]);
      if (DEBUG) {
        System.err.println("Fetched XVisualInfo for visual ID " + toHexString(visualID));
        System.err.println("Resulting XVisualInfo: visualid = " + toHexString(res.getVisualid()));
      }
      return res;
  }

  static boolean XVisualInfo2GLCapabilities(List<GLCapabilitiesImmutable> capsBucket,
                                            GLProfile glp, long display, XVisualInfo info,
                                            final int winattrmask, boolean isMultisampleEnabled) {
    final int allDrawableTypeBits = GLGraphicsConfigurationUtil.WINDOW_BIT | GLGraphicsConfigurationUtil.BITMAP_BIT ;
    final int drawableTypeBits = winattrmask & allDrawableTypeBits;

    if( 0 == drawableTypeBits ) {
        return false;
    }

    int[] tmp = new int[1];
    int val = glXGetConfig(display, info, GLX.GLX_USE_GL, tmp, 0);
    if (val == 0) {
      if(DEBUG) {
        System.err.println("Visual ("+toHexString(info.getVisualid())+") does not support OpenGL");
      }
      return false;
    }
    val = glXGetConfig(display, info, GLX.GLX_RGBA, tmp, 0);
    if (val == 0) {
      if(DEBUG) {
        System.err.println("Visual ("+toHexString(info.getVisualid())+") does not support RGBA");
      }
      return false;
    }

    GLCapabilities res = new X11GLCapabilities(info, glp);

    res.setDoubleBuffered(glXGetConfig(display, info, GLX.GLX_DOUBLEBUFFER,     tmp, 0) != 0);
    res.setStereo        (glXGetConfig(display, info, GLX.GLX_STEREO,           tmp, 0) != 0);
    // Note: use of hardware acceleration is determined by
    // glXCreateContext, not by the XVisualInfo. Optimistically claim
    // that all GLCapabilities have the capability to be hardware
    // accelerated.
    res.setHardwareAccelerated(true);
    res.setDepthBits     (glXGetConfig(display, info, GLX.GLX_DEPTH_SIZE,       tmp, 0));
    res.setStencilBits   (glXGetConfig(display, info, GLX.GLX_STENCIL_SIZE,     tmp, 0));
    res.setRedBits       (glXGetConfig(display, info, GLX.GLX_RED_SIZE,         tmp, 0));
    res.setGreenBits     (glXGetConfig(display, info, GLX.GLX_GREEN_SIZE,       tmp, 0));
    res.setBlueBits      (glXGetConfig(display, info, GLX.GLX_BLUE_SIZE,        tmp, 0));
    res.setAlphaBits     (glXGetConfig(display, info, GLX.GLX_ALPHA_SIZE,       tmp, 0));
    res.setAccumRedBits  (glXGetConfig(display, info, GLX.GLX_ACCUM_RED_SIZE,   tmp, 0));
    res.setAccumGreenBits(glXGetConfig(display, info, GLX.GLX_ACCUM_GREEN_SIZE, tmp, 0));
    res.setAccumBlueBits (glXGetConfig(display, info, GLX.GLX_ACCUM_BLUE_SIZE,  tmp, 0));
    res.setAccumAlphaBits(glXGetConfig(display, info, GLX.GLX_ACCUM_ALPHA_SIZE, tmp, 0));
    if (isMultisampleEnabled) {
      res.setSampleBuffers(glXGetConfig(display, info, GLX.GLX_SAMPLE_BUFFERS, tmp, 0) != 0);
      res.setNumSamples   (glXGetConfig(display, info, GLX.GLX_SAMPLES,        tmp, 0));
    }
    final XRenderDirectFormat xrmask = ( null != info ) ? 
                                         XVisual2XRenderMask( display, info.getVisual() ) : 
                                         null ;
    final int alphaMask = ( null != xrmask ) ? xrmask.getAlphaMask() : 0;
    res.setBackgroundOpaque( 0 >= alphaMask );
    if( !res.isBackgroundOpaque() ) {
        res.setTransparentRedValue(xrmask.getRedMask());
        res.setTransparentGreenValue(xrmask.getGreenMask());
        res.setTransparentBlueValue(xrmask.getBlueMask());
        res.setTransparentAlphaValue(alphaMask);
    }

    return GLGraphicsConfigurationUtil.addGLCapabilitiesPermutations(capsBucket, res, drawableTypeBits);
  }

  private static String glXGetConfigErrorCode(int err) {
    switch (err) {
      case GLX.GLX_NO_EXTENSION:  return "GLX_NO_EXTENSION";
      case GLX.GLX_BAD_SCREEN:    return "GLX_BAD_SCREEN";
      case GLX.GLX_BAD_ATTRIBUTE: return "GLX_BAD_ATTRIBUTE";
      case GLX.GLX_BAD_VISUAL:    return "GLX_BAD_VISUAL";
      default:                return "Unknown error code " + err;
    }
  }

  static int glXGetConfig(long display, XVisualInfo info, int attrib, int[] tmp, int tmp_offset) {
    if (display == 0) {
      throw new GLException("No display connection");
    }
    int res = GLX.glXGetConfig(display, info, attrib, tmp, tmp_offset);
    if (res != 0) {
      throw new GLException("glXGetConfig("+toHexString(attrib)+") failed: error code " + glXGetConfigErrorCode(res));
    }
    return tmp[tmp_offset];
  }

  public String toString() {
    return "X11GLXGraphicsConfiguration["+getScreen()+", visualID " + toHexString(getXVisualID()) + ", fbConfigID " + toHexString(getFBConfigID()) +
                                        ",\n\trequested " + getRequestedCapabilities()+
                                        ",\n\tchosen    " + getChosenCapabilities()+
                                        "]";
  }
}