/** <title>NSOpenGLView.m </title>

   <abstract>Context for openGL drawing</abstract>

   Copyright (C) 1996 Free Software Foundation, Inc.

   Author:  Frederic De Jaeger
   Date: 2002

   This file is part of the GNUstep GUI Library.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; see the file COPYING.LIB.
   If not, write to the Free Software Foundation,
   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/

#include <Foundation/NSDebug.h>
#include <Foundation/NSException.h>
#include <Foundation/NSNotification.h>
#include "AppKit/NSOpenGL.h"
#include "AppKit/NSOpenGLView.h"



/**
  <unit>
  <heading>NSOpenGLView</heading>

  <p>
  This class is simply a view with a NSOpenGLContext attached to it.
  This is the simplest way to initialize a GL context within GNUstep.
  </p>

  
  <p>
  There is a mechanism to update the context when the view is moved
  or resize.
  </p>

  </unit>
*/
@implementation NSOpenGLView
/**
   return a standard NSOpenGLPixelFormat you can pass to the 
   initWithFrame: pixelFormat: method
 */
+ (NSOpenGLPixelFormat*)defaultPixelFormat
{
  NSOpenGLPixelFormat *fmt;
  NSOpenGLPixelFormatAttribute attrs[] =
    {	
      NSOpenGLPFADoubleBuffer,
      NSOpenGLPFADepthSize, 16,
      NSOpenGLPFAColorSize, 1,
      0
    };
//   NSOpenGLPixelFormatAttribute attrs[] =
//     {
//       NSOpenGLPFADoubleBuffer,
//       NSOpenGLPFADepthSize, 32,
//       0
//     };
  
  fmt = [[NSOpenGLPixelFormat alloc] initWithAttributes: attrs];
  if (fmt)
    return AUTORELEASE(fmt);
  else
    {
      NSWarnMLog(@"could not find a reasonable pixel format...");
      return nil;
    }
}
  
/**
   detach from the current context.  You should call it before releasing this 
   object.
 */
- (void)clearGLContext
{
  if (glcontext)
    {
      [glcontext clearDrawable];
      DESTROY(glcontext);
    }
}

- (void)setOpenGLContext:(NSOpenGLContext*)context
{
  [self clearGLContext];
  ASSIGN(glcontext, context);
  attached = NO;
}

/**
   return the current gl context associated with this view
*/
- (NSOpenGLContext*)openGLContext
{
  if (glcontext == nil)
    {
      glcontext = [[NSOpenGLContext alloc] initWithFormat: pixel_format
				 shareContext: nil];
      attached = NO;
    }
  return glcontext;
}


-(id) initWithFrame: (NSRect)frameRect
{  
  return [self initWithFrame: frameRect
	         pixelFormat: [[self class] defaultPixelFormat]];
  
}

/** default initializer.  Can be passed [NSOpenGLContext defaultPixelFormat] 
    as second argument
*/
- (id)initWithFrame:(NSRect)frameRect 
	pixelFormat:(NSOpenGLPixelFormat*)format
{
  [super initWithFrame: frameRect];
  ASSIGN(pixel_format, format);

  [self setPostsFrameChangedNotifications: YES];
  [[NSNotificationCenter defaultCenter] 
    addObserver: self
    selector: @selector(_frameChanged:)
    name: NSViewFrameDidChangeNotification
    object: self];

  return self;
}

- (void) dealloc
{
  [[NSNotificationCenter defaultCenter] removeObserver: self];
  RELEASE(pixel_format);
  RELEASE(glcontext);
  NSDebugMLLog(@"GL", @"deallocating");
  [super dealloc];
}

- (NSOpenGLPixelFormat*)pixelFormat
{
  return pixel_format;
}

- (void)setPixelFormat:(NSOpenGLPixelFormat*)pixelFormat
{
  ASSIGN(pixel_format, pixelFormat);
}

- (void) reshape
{
}

- (void) update
{
  [glcontext update];
}

- (void) _frameChanged: (NSNotification *) aNot
{
  NSDebugMLLog(@"GL", @"our frame has changed");
  [self update];
  [self reshape];
}

- (void) lockFocusInRect: (NSRect) aRect
{
  [super lockFocusInRect: aRect];
  if (!glcontext)
    {
      [self openGLContext];
      NSAssert(glcontext, NSInternalInconsistencyException);
    }
  if (attached == NO && glcontext != nil)
    {
      NSDebugMLLog(@"GL", @"Attaching context to the view");
      [glcontext setView: self];
      attached = YES;
    }
}
@end