/*

 * Copyright (c) 2004, 2015, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package sun.java2d.opengl;

import sun.java2d.pipe.BufferedContext;

import sun.java2d.pipe.RenderBuffer;

import sun.java2d.pipe.RenderQueue;

import sun.java2d.pipe.hw.ContextCapabilities;

import static sun.java2d.pipe.BufferedOpCodes.*;

import static sun.java2d.pipe.hw.ContextCapabilities.*;

import java.lang.annotation.Native;

/**

 * Note that the RenderQueue lock must be acquired before calling any of

 * the methods in this class.

 */

public class OGLContext extends BufferedContext {

    private final OGLGraphicsConfig config;

    OGLContext(RenderQueue rq, OGLGraphicsConfig config) {

        super(rq);

        this.config = config;

    }

    /**

     * Convenience method that delegates to setScratchSurface() below.

     */

    static void setScratchSurface(OGLGraphicsConfig gc) {

        setScratchSurface(gc.getNativeConfigInfo());

    }

    /**

     * Makes the given GraphicsConfig's context current to its associated

     * "scratch surface".  Each GraphicsConfig maintains a native context

     * (GLXContext on Unix, HGLRC on Windows) as well as a native pbuffer

     * known as the "scratch surface".  By making the context current to the

     * scratch surface, we are assured that we have a current context for

     * the relevant GraphicsConfig, and can therefore perform operations

     * depending on the capabilities of that GraphicsConfig.  For example,

     * if the GraphicsConfig supports the GL_ARB_texture_non_power_of_two

     * extension, then we should be able to make a non-pow2 texture for this

     * GraphicsConfig once we make the context current to the scratch surface.

     *

     * This method should be used for operations with an OpenGL texture

     * as the destination surface (e.g. a sw->texture blit loop), or in those

     * situations where we may not otherwise have a current context (e.g.

     * when disposing a texture-based surface).

     */

    static void setScratchSurface(long pConfigInfo) {

        // assert OGLRenderQueue.getInstance().lock.isHeldByCurrentThread();

        // invalidate the current context

        currentContext = null;

        // set the scratch context

        OGLRenderQueue rq = OGLRenderQueue.getInstance();

        RenderBuffer buf = rq.getBuffer();

        rq.ensureCapacityAndAlignment(12, 4);

        buf.putInt(SET_SCRATCH_SURFACE);

        buf.putLong(pConfigInfo);

    }

    /**

     * Invalidates the currentContext field to ensure that we properly

     * revalidate the OGLContext (make it current, etc.) next time through

     * the validate() method.  This is typically invoked from methods

     * that affect the current context state (e.g. disposing a context or

     * surface).

     */

    static void invalidateCurrentContext() {

        // assert OGLRenderQueue.getInstance().lock.isHeldByCurrentThread();

        // invalidate the current Java-level context so that we

        // revalidate everything the next time around

        if (currentContext != null) {

            currentContext.invalidateContext();

            currentContext = null;

        }

        // invalidate the context reference at the native level, and

        // then flush the queue so that we have no pending operations

        // dependent on the current context

        OGLRenderQueue rq = OGLRenderQueue.getInstance();

        rq.ensureCapacity(4);

        rq.getBuffer().putInt(INVALIDATE_CONTEXT);

        rq.flushNow();

    }

    public RenderQueue getRenderQueue() {

        return OGLRenderQueue.getInstance();

    }

    /**

     * Returns a string representing adapter id (vendor, renderer, version).

     * Must be called on the rendering thread.

     *

     * @return an id string for the adapter

     */

    static final native String getOGLIdString();

    @Override

    public void saveState() {

        // assert rq.lock.isHeldByCurrentThread();

        // reset all attributes of this and current contexts

        invalidateContext();

        invalidateCurrentContext();

        setScratchSurface(config);

        // save the state on the native level

        rq.ensureCapacity(4);

        buf.putInt(SAVE_STATE);

        rq.flushNow();

    }

    @Override

    public void restoreState() {

        // assert rq.lock.isHeldByCurrentThread();

        // reset all attributes of this and current contexts

        invalidateContext();

        invalidateCurrentContext();

        setScratchSurface(config);

        // restore the state on the native level

        rq.ensureCapacity(4);

        buf.putInt(RESTORE_STATE);

        rq.flushNow();

    }

    static class OGLContextCaps extends ContextCapabilities {

        /**

         * Indicates the presence of the GL_EXT_framebuffer_object extension.

         * This cap will only be set if the fbobject system property has been

         * enabled and we are able to create an FBO with depth buffer.

         */

        @Native

        static final int CAPS_EXT_FBOBJECT     =

                (CAPS_RT_TEXTURE_ALPHA | CAPS_RT_TEXTURE_OPAQUE);

        /** Indicates that the context is doublebuffered. */

        @Native

        static final int CAPS_DOUBLEBUFFERED   = (FIRST_PRIVATE_CAP << 0);

        /**

         * Indicates the presence of the GL_ARB_fragment_shader extension.

         * This cap will only be set if the lcdshader system property has been

         * enabled and the hardware supports the minimum number of texture units

         */

        @Native

        static final int CAPS_EXT_LCD_SHADER   = (FIRST_PRIVATE_CAP << 1);

        /**

         * Indicates the presence of the GL_ARB_fragment_shader extension.

         * This cap will only be set if the biopshader system property has been

         * enabled and the hardware meets our minimum requirements.

         */

        @Native

        static final int CAPS_EXT_BIOP_SHADER  = (FIRST_PRIVATE_CAP << 2);

        /**

         * Indicates the presence of the GL_ARB_fragment_shader extension.

         * This cap will only be set if the gradshader system property has been

         * enabled and the hardware meets our minimum requirements.

         */

        @Native

        static final int CAPS_EXT_GRAD_SHADER  = (FIRST_PRIVATE_CAP << 3);

        /** Indicates the presence of the GL_ARB_texture_rectangle extension. */

        @Native

        static final int CAPS_EXT_TEXRECT      = (FIRST_PRIVATE_CAP << 4);

        /** Indicates the presence of the GL_NV_texture_barrier extension. */

        @Native

        static final int CAPS_EXT_TEXBARRIER = (FIRST_PRIVATE_CAP << 5);

        OGLContextCaps(int caps, String adapterId) {

            super(caps, adapterId);

        }

        @Override

        public String toString() {

            StringBuilder sb = new StringBuilder(super.toString());

            if ((caps & CAPS_EXT_FBOBJECT) != 0) {

                sb.append("CAPS_EXT_FBOBJECT|");

            }

            if ((caps & CAPS_DOUBLEBUFFERED) != 0) {

                sb.append("CAPS_DOUBLEBUFFERED|");

            }

            if ((caps & CAPS_EXT_LCD_SHADER) != 0) {

                sb.append("CAPS_EXT_LCD_SHADER|");

            }

            if ((caps & CAPS_EXT_BIOP_SHADER) != 0) {

                sb.append("CAPS_BIOP_SHADER|");

            }

            if ((caps & CAPS_EXT_GRAD_SHADER) != 0) {

                sb.append("CAPS_EXT_GRAD_SHADER|");

            }

            if ((caps & CAPS_EXT_TEXRECT) != 0) {

                sb.append("CAPS_EXT_TEXRECT|");

            }

            if ((caps & CAPS_EXT_TEXBARRIER) != 0) {

                sb.append("CAPS_EXT_TEXBARRIER|");

            }

            return sb.toString();

        }

    }

}