/*

 * Copyright 2007 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.java2d.pipe;

import java.awt.AlphaComposite;

import java.awt.Composite;

import sun.java2d.SurfaceData;

import sun.java2d.loops.Blit;

import sun.java2d.loops.CompositeType;

import sun.java2d.loops.MaskBlit;

import sun.java2d.loops.SurfaceType;

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

/**

 * The MaskBlit operation is expressed as:

 *   dst = ((src <MODE> dst) * pathA) + (dst * (1 - pathA))

 *

 * The OGL/D3D implementation of the MaskBlit operation differs from the above

 * equation because it is not possible to perform such a complex operation in

 * OpenGL/Direct3D (without the use of advanced techniques like fragment

 * shaders and multitexturing).  Therefore, the BufferedMaskBlit operation

 * is expressed as:

 *   dst = (src * pathA) <SrcOver> dst

 *

 * This simplified formula is only equivalent to the "true" MaskBlit equation

 * in the following situations:

 *   - <MODE> is SrcOver

 *   - <MODE> is Src, extra alpha == 1.0, and the source surface is opaque

 *

 * Therefore, we register BufferedMaskBlit primitives for only the SurfaceType

 * and CompositeType restrictions mentioned above.  In addition for the Src

 * case, we must override the composite with a SrcOver (no extra alpha)

 * instance, so that we set up the OpenGL/Direct3D blending mode to match the

 * BufferedMaskBlit equation.

 */

public abstract class BufferedMaskBlit extends MaskBlit {

    private static final int ST_INT_ARGB     = 0;

    private static final int ST_INT_ARGB_PRE = 1;

    private static final int ST_INT_RGB      = 2;

    private static final int ST_INT_BGR      = 3;

    private final RenderQueue rq;

    private final int srcTypeVal;

    private Blit blitop;

    protected BufferedMaskBlit(RenderQueue rq,

                               SurfaceType srcType,

                               CompositeType compType,

                               SurfaceType dstType)

    {

        super(srcType, compType, dstType);

        this.rq = rq;

        if (srcType == SurfaceType.IntArgb) {

            this.srcTypeVal = ST_INT_ARGB;

        } else if (srcType == SurfaceType.IntArgbPre) {

            this.srcTypeVal = ST_INT_ARGB_PRE;

        } else if (srcType == SurfaceType.IntRgb) {

            this.srcTypeVal = ST_INT_RGB;

        } else if (srcType == SurfaceType.IntBgr) {

            this.srcTypeVal = ST_INT_BGR;

        } else {

            throw new InternalError("unrecognized source surface type");

        }

    }

    @Override

    public void MaskBlit(SurfaceData src, SurfaceData dst,

                         Composite comp, Region clip,

                         int srcx, int srcy,

                         int dstx, int dsty,

                         int width, int height,

                         byte[] mask, int maskoff, int maskscan)

    {

        if (width <= 0 || height <= 0) {

            return;

        }

        if (mask == null) {

            // no mask involved; delegate to regular blit loop

            if (blitop == null) {

                blitop = Blit.getFromCache(src.getSurfaceType(),

                                           CompositeType.AnyAlpha,

                                           this.getDestType());

            }

            blitop.Blit(src, dst,

                        comp, clip,

                        srcx, srcy, dstx, dsty,

                        width, height);

            return;

        }

        AlphaComposite acomp = (AlphaComposite)comp;

        if (acomp.getRule() != AlphaComposite.SRC_OVER) {

            comp = AlphaComposite.SrcOver;

        }

        rq.lock();

        try {

            validateContext(dst, comp, clip);

            RenderBuffer buf = rq.getBuffer();

            int totalBytesRequired = 20 + (width * height * 4);

            /*

             * REMIND: we should fix this so that it works with tiles that

             *         are larger than the entire buffer, but the native

             *         OGL/D3DMaskBlit isn't even prepared for tiles larger

             *         than 32x32 pixels, so there's no urgency here...

             */

            rq.ensureCapacity(totalBytesRequired);

            // enqueue parameters and tile pixels

            int newpos = enqueueTile(buf.getAddress(), buf.position(),

                                     src, src.getNativeOps(), srcTypeVal,

                                     mask, mask.length, maskoff, maskscan,

                                     srcx, srcy, dstx, dsty,

                                     width, height);

            buf.position(newpos);

        } finally {

            rq.unlock();

        }

    }

    private native int enqueueTile(long buf, int bpos,

                                   SurfaceData srcData,

                                   long pSrcOps, int srcType,

                                   byte[] mask, int masklen,

                                   int maskoff, int maskscan,

                                   int srcx, int srcy, int dstx, int dsty,

                                   int width, int height);

    /**

     * Validates the context state using the given destination surface

     * and composite/clip values.

     */

    protected abstract void validateContext(SurfaceData dstData,

                                            Composite comp, Region clip);

}