SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package javax.microedition.khronos.egl;

import cc.squirreljme.runtime.cldc.annotation.Api;
import cc.squirreljme.runtime.opengles.DefaultEGL;
import java.lang.ref.Reference;
import java.lang.ref.WeakReference;
import javax.microedition.khronos.opengles.GL;

/**
 * This class encapsulates the OpenGL context which is used to obtain instances
 * of OpenGL ES and OpenGL rasterizers.
 *
 * To create a context use {@link EGL10#eglCreateContext(EGLDisplay, EGLConfig,
 * EGLContext, int[])} method.
 *
 * To destroy a context use {@link EGL10#eglDestroyContext(EGLDisplay,
 * EGLContext)}.
 *
 * For compatibility with the standard API this class should not be extended,
 * unless the class extending is internal to SquirrelJME.
 *
 * @since 2016/10/10
 */
@Api
public abstract class EGLContext
{
    /** The single instance of EGL, shared by everything. */
    private static Reference<EGL> _EGL;
    
    /**
     * Returns an instance of an object which is used to provide access to
     * the underlying OpenGL ES rasterization API.
     *
     * @return The OpenGL ES rasterization API accessor.
     * @since 2016/10/10
     */
    @Api
    public abstract GL getGL();
    
    /**
     * This returns an instance of an object that implements the {@link EGL}
     * interface which is used to initialize the rasterizer for drawing.
     *
     * @return An instance of the OpenGL ES rasterizer.
     * @since 2016/10/10
     */
    @Api
    public static EGL getEGL()
    {
        // Get
        Reference<EGL> ref = EGLContext._EGL;
        EGL rv;
        
        // Create?
        if (ref == null || null == (rv = ref.get()))
            EGLContext._EGL = new WeakReference<>((rv = new DefaultEGL()));
        
        // Return it
        return rv;
    }
}