/*

 * Copyright (c) 2007, 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

 * or visit www.oracle.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.SunGraphics2D;

import sun.java2d.SurfaceData;

import sun.java2d.loops.CompositeType;

import sun.java2d.loops.MaskFill;

import sun.java2d.loops.SurfaceType;

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

/**

 * The MaskFill operation is expressed as:

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

 *

 * The OGL/D3D implementation of the MaskFill 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 BufferedMaskFill operation

 * is expressed as:

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

 *

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

 * in the following situations:

 *   - <MODE> is SrcOver

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

 *

 * Therefore, we register BufferedMaskFill primitives for only the SurfaceType

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

 * SrcNoEa case we must override the incoming composite with a SrcOver (no

 * extra alpha) instance, so that we set up the OpenGL/Direct3D blending

 * mode to match the BufferedMaskFill equation.

 */

public abstract class BufferedMaskFill extends MaskFill {

    protected final RenderQueue rq;

    protected BufferedMaskFill(RenderQueue rq,

                               SurfaceType srcType,

                               CompositeType compType,

                               SurfaceType dstType)

    {

        super(srcType, compType, dstType);

        this.rq = rq;

    }

    @Override

    public void MaskFill(SunGraphics2D sg2d, SurfaceData sData,

                         Composite comp,

                         final int x, final int y, final int w, final int h,

                         final byte[] mask,

                         final int maskoff, final int maskscan)

    {

        AlphaComposite acomp = (AlphaComposite)comp;

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

            comp = AlphaComposite.SrcOver;

        }

        rq.lock();

        try {

            validateContext(sg2d, comp, BufferedContext.USE_MASK);

            // we adjust the mask length so that the mask ends on a

            // 4-byte boundary

            int maskBytesRequired;

            if (mask != null) {

                // we adjust the mask length so that the mask ends on a

                // 4-byte boundary

                maskBytesRequired = (mask.length + 3) & (~3);

            } else {

                // mask not needed

                maskBytesRequired = 0;

            }

            int totalBytesRequired = 32 + maskBytesRequired;

            RenderBuffer buf = rq.getBuffer();

            if (totalBytesRequired <= buf.capacity()) {

                if (totalBytesRequired > buf.remaining()) {

                    // process the queue first and then enqueue the mask

                    rq.flushNow();

                }

                buf.putInt(MASK_FILL);

                // enqueue parameters

                buf.putInt(x).putInt(y).putInt(w).putInt(h);

                buf.putInt(maskoff);

                buf.putInt(maskscan);

                buf.putInt(maskBytesRequired);

                if (mask != null) {

                    // enqueue the mask

                    int padding = maskBytesRequired - mask.length;

                    buf.put(mask);

                    if (padding != 0) {

                        buf.position(buf.position() + padding);

                    }

                }

            } else {

                // queue is too small to accomodate entire mask; perform

                // the operation directly on the queue flushing thread

                rq.flushAndInvokeNow(new Runnable() {

                    public void run() {

                        maskFill(x, y, w, h,

                                 maskoff, maskscan, mask.length, mask);

                    }

                });

            }

        } finally {

            rq.unlock();

        }

    }

    /**

     * Called as a separate Runnable when the operation is too large to fit

     * on the RenderQueue.  The OGL/D3D pipelines each have their own (small)

     * native implementation of this method.

     */

    protected abstract void maskFill(int x, int y, int w, int h,

                                     int maskoff, int maskscan, int masklen,

                                     byte[] mask);

    /**

     * Validates the state in the provided SunGraphics2D object and sets up

     * any special resources for this operation (e.g. enabling gradient

     * shading).

     */

    protected abstract void validateContext(SunGraphics2D sg2d,

                                            Composite comp, int ctxflags);

}