/*
 * 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
 * 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.windows.wgl;

import javax.media.opengl.*;
import com.sun.opengl.impl.*;

public class WindowsOffscreenWGLDrawable extends WindowsWGLDrawable {
  private long origbitmap;
  private long hbitmap;

  public WindowsOffscreenWGLDrawable(GLDrawableFactory factory, 
                                    GLCapabilities capabilities,
                                    GLCapabilitiesChooser chooser) {
    super(factory, new NullWindow(), true, capabilities, chooser);
  }

  public GLContext createContext(GLContext shareWith) {
    return new WindowsOffscreenWGLContext(this, shareWith);
  }

  public void setSize(int newWidth, int newHeight) {
    super.setSize(newWidth, newHeight);
    destroy();
    create();
  }

  private void create() {
    getFactory().lockToolkit();
    try {
        NullWindow nw = (NullWindow) getNativeWindow();
        GLCapabilities capabilities = getCapabilities();
        int width = getWidth();
        int height = getHeight();
        BITMAPINFO info = BITMAPINFO.create();
        BITMAPINFOHEADER header = info.bmiHeader();
        int bitsPerPixel = (capabilities.getRedBits() +
                            capabilities.getGreenBits() +
                            capabilities.getBlueBits());
        header.biSize(header.size());
        header.biWidth(width);
        // NOTE: negating the height causes the DIB to be in top-down row
        // order rather than bottom-up; ends up being correct during pixel
        // readback
        header.biHeight(-1 * height);
        header.biPlanes((short) 1);
        header.biBitCount((short) bitsPerPixel);
        header.biXPelsPerMeter(0);
        header.biYPelsPerMeter(0);
        header.biClrUsed(0);
        header.biClrImportant(0);
        header.biCompression(WGL.BI_RGB);
        header.biSizeImage(width * height * bitsPerPixel / 8);

        long hdc = WGL.CreateCompatibleDC(0);
        if (hdc == 0) {
          System.out.println("LastError: " + WGL.GetLastError());
          throw new GLException("Error creating device context for offscreen OpenGL context");
        }
        nw.setSurfaceHandle(hdc);

        hbitmap = WGL.CreateDIBSection(hdc, info, WGL.DIB_RGB_COLORS, 0, 0, 0);
        if (hbitmap == 0) {
          WGL.DeleteDC(hdc);
          hdc = 0;
          throw new GLException("Error creating offscreen bitmap of width " + width +
                                ", height " + height);
        }
        if ((origbitmap = WGL.SelectObject(hdc, hbitmap)) == 0) {
          WGL.DeleteObject(hbitmap);
          hbitmap = 0;
          WGL.DeleteDC(hdc);
          hdc = 0;
          throw new GLException("Error selecting bitmap into new device context");
        }
        
        choosePixelFormat(false);
    } finally {
        getFactory().unlockToolkit();
    }
  }
  
  public void destroy() {
    getFactory().lockToolkit();
    try {
        NullWindow nw = (NullWindow) getNativeWindow();
        if (nw.getSurfaceHandle() != 0) {
          // Must destroy bitmap and device context
          WGL.SelectObject(nw.getSurfaceHandle(), origbitmap);
          WGL.DeleteObject(hbitmap);
          WGL.DeleteDC(nw.getSurfaceHandle());
          origbitmap = 0;
          hbitmap = 0;
          nw.setSurfaceHandle(0);
          setChosenGLCapabilities(null);
        }
    } finally {
        getFactory().unlockToolkit();
    }
    super.destroy();
  }
}