/*
 * Copyright (c) 1997, 2016, 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.BasicStroke;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.geom.Rectangle2D;
import java.util.concurrent.ConcurrentLinkedQueue;
import sun.awt.SunHints;
import sun.java2d.ReentrantContext;
import sun.java2d.ReentrantContextProvider;
import sun.java2d.ReentrantContextProviderTL;
import sun.java2d.SunGraphics2D;

This class is used to convert raw geometry into 8-bit alpha tiles
using an AATileGenerator for application by the next stage of
the pipeline.
This class sets up the Generator and computes the alpha tiles
and then passes them on to a CompositePipe object for painting.
/**
 * This class is used to convert raw geometry into 8-bit alpha tiles
 * using an AATileGenerator for application by the next stage of
 * the pipeline.
 * This class sets up the Generator and computes the alpha tiles
 * and then passes them on to a CompositePipe object for painting.
 */
public final class AAShapePipe
    implements ShapeDrawPipe, ParallelogramPipe
{
    static final RenderingEngine renderengine = RenderingEngine.getInstance();

    // Per-thread TileState (~1K very small so do not use any Weak Reference)
    private static final ReentrantContextProvider<TileState> tileStateProvider =
            new ReentrantContextProviderTL<TileState>(
                    ReentrantContextProvider.REF_HARD)
            {
                @Override
                protected TileState newContext() {
                    return new TileState();
                }
            };

    final CompositePipe outpipe;

    public AAShapePipe(CompositePipe pipe) {
        outpipe = pipe;
    }

    @Override
    public void draw(SunGraphics2D sg, Shape s) {
        final BasicStroke bs;

        if (sg.stroke instanceof BasicStroke) {
            bs = (BasicStroke) sg.stroke;
        } else {
            s = sg.stroke.createStrokedShape(s);
            bs = null;
        }

        renderPath(sg, s, bs);
    }

    @Override
    public void fill(SunGraphics2D sg, Shape s) {
        renderPath(sg, s, null);
    }

    @Override
    public void fillParallelogram(SunGraphics2D sg,
                                  double ux1, double uy1,
                                  double ux2, double uy2,
                                  double x, double y,
                                  double dx1, double dy1,
                                  double dx2, double dy2)
    {
        final TileState ts = tileStateProvider.acquire();
        try {
            final int[] abox = ts.abox;

            final AATileGenerator aatg =
                renderengine.getAATileGenerator(x, y, dx1, dy1, dx2, dy2, 0, 0,
                                                sg.getCompClip(), abox);
            if (aatg != null) {
                renderTiles(sg, ts.computeBBox(ux1, uy1, ux2, uy2),
                            aatg, abox, ts);
            }
        } finally {
            tileStateProvider.release(ts);
        }
    }

    @Override
    public void drawParallelogram(SunGraphics2D sg,
                                  double ux1, double uy1,
                                  double ux2, double uy2,
                                  double x, double y,
                                  double dx1, double dy1,
                                  double dx2, double dy2,
                                  double lw1, double lw2)
    {
        final TileState ts = tileStateProvider.acquire();
        try {
            final int[] abox = ts.abox;

            final AATileGenerator aatg =
                renderengine.getAATileGenerator(x, y, dx1, dy1, dx2, dy2, lw1,
                                                lw2, sg.getCompClip(), abox);
            if (aatg != null) {
                // Note that bbox is of the original shape, not the wide path.
                // This is appropriate for handing to Paint methods...
                renderTiles(sg, ts.computeBBox(ux1, uy1, ux2, uy2),
                            aatg, abox, ts);
            }
        } finally {
            tileStateProvider.release(ts);
        }
    }

    public void renderPath(SunGraphics2D sg, Shape s, BasicStroke bs) {
        final boolean adjust = (bs != null &&
                          sg.strokeHint != SunHints.INTVAL_STROKE_PURE);
        final boolean thin = (sg.strokeState <= SunGraphics2D.STROKE_THINDASHED);

        final TileState ts = tileStateProvider.acquire();
        try {
            final int[] abox = ts.abox;

            final AATileGenerator aatg =
                renderengine.getAATileGenerator(s, sg.transform, sg.getCompClip(),
                                                bs, thin, adjust, abox);
            if (aatg != null) {
                renderTiles(sg, s, aatg, abox, ts);
            }
        } finally {
            tileStateProvider.release(ts);
        }
    }

    public void renderTiles(SunGraphics2D sg, Shape s,
                            final AATileGenerator aatg,
                            final int[] abox, final TileState ts)
    {
        Object context = null;
        try {
            // reentrance: outpipe may also use AAShapePipe:
            context = outpipe.startSequence(sg, s,
                                            ts.computeDevBox(abox),
                                            abox);

            // copy of int[] abox as local variables for performance:
            final int x0 = abox[0];
            final int y0 = abox[1];
            final int x1 = abox[2];
            final int y1 = abox[3];

            final int tw = aatg.getTileWidth();
            final int th = aatg.getTileHeight();

            // get tile from thread local storage:
            final byte[] alpha = ts.getAlphaTile(tw * th);
            byte[] atile;

            for (int y = y0; y < y1; y += th) {
                final int h = Math.min(th, y1 - y);

                for (int x = x0; x < x1; x += tw) {
                    final int w = Math.min(tw, x1 - x);

                    final int a = aatg.getTypicalAlpha();

                    if (a == 0x00 || !outpipe.needTile(context, x, y, w, h)) {
                        aatg.nextTile();
                        outpipe.skipTile(context, x, y);
                        continue;
                    }
                    if (a == 0xff) {
                        atile = null;
                        aatg.nextTile();
                    } else {
                        atile = alpha;
                        aatg.getAlpha(alpha, 0, tw);
                    }

                    outpipe.renderPathTile(context, atile, 0, tw, x, y, w, h);
                }
            }
        } finally {
            aatg.dispose();
            if (context != null) {
                outpipe.endSequence(context);
            }
        }
    }

    // Tile state used by AAShapePipe
    static final class TileState extends ReentrantContext {
        // cached tile (32 x 32 tile by default)
        private byte[] theTile = new byte[32 * 32];
        // dirty aabox array
        final int[] abox = new int[4];
        // dirty bbox rectangle
        private final Rectangle dev = new Rectangle();
        // dirty bbox rectangle2D.Double
        private final Rectangle2D.Double bbox2D = new Rectangle2D.Double();

        byte[] getAlphaTile(int len) {
            byte[] t = theTile;
            if (t.length < len) {
                // create a larger tile and may free current theTile (too small)
                theTile = t = new byte[len];
            }
            return t;
        }

        Rectangle computeDevBox(final int[] abox) {
            final Rectangle box = this.dev;
            box.x = abox[0];
            box.y = abox[1];
            box.width = abox[2] - abox[0];
            box.height = abox[3] - abox[1];
            return box;
        }

        Rectangle2D computeBBox(double ux1, double uy1,
                                double ux2, double uy2)
        {
            if ((ux2 -= ux1) < 0.0) {
                ux1 += ux2;
                ux2 = -ux2;
            }
            if ((uy2 -= uy1) < 0.0) {
                uy1 += uy2;
                uy2 = -uy2;
            }
            final Rectangle2D.Double box = this.bbox2D;
            box.x = ux1;
            box.y = uy1;
            box.width = ux2;
            box.height = uy2;
            return box;
        }
    }
}