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 * 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.
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 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 *
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package sun.awt.image;

import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;
import java.awt.image.ByteLookupTable;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;
import java.awt.image.LookupOp;
import java.awt.image.LookupTable;
import java.awt.image.RasterOp;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;
import java.security.AccessController;
import java.security.PrivilegedAction;

This class provides a hook to access platform-specific
imaging code.
If the implementing class cannot handle the op, tile format or
image format, the method will return null;
If there is an error when processing the
data, the implementing class may either return null
(in which case our java code will be executed) or may throw
an exception.
/**
 * This class provides a hook to access platform-specific
 * imaging code.
 *
 * If the implementing class cannot handle the op, tile format or
 * image format, the method will return null;
 * If there is an error when processing the
 * data, the implementing class may either return null
 * (in which case our java code will be executed) or may throw
 * an exception.
 */
public class ImagingLib {

    static boolean useLib = true;
    static boolean verbose = false;

    private static final int NUM_NATIVE_OPS = 3;
    private static final int LOOKUP_OP   = 0;
    private static final int AFFINE_OP   = 1;
    private static final int CONVOLVE_OP = 2;

    private static Class<?>[] nativeOpClass = new Class<?>[NUM_NATIVE_OPS];

    
Returned value indicates whether the library initailization was
succeded.
There could be number of reasons to failure:
- failed to load library.
- failed to get all required entry points.
/**
     * Returned value indicates whether the library initailization was
     * succeded.
     *
     * There could be number of reasons to failure:
     * - failed to load library.
     * - failed to get all required entry points.
     */
    private static native boolean init();

    public static native int transformBI(BufferedImage src, BufferedImage dst,
                                         double[] matrix, int interpType);
    public static native int transformRaster(Raster src, Raster dst,
                                             double[] matrix,
                                             int interpType);
    public static native int convolveBI(BufferedImage src, BufferedImage dst,
                                        Kernel kernel, int edgeHint);
    public static native int convolveRaster(Raster src, Raster dst,
                                            Kernel kernel, int edgeHint);
    public static native int lookupByteBI(BufferedImage src, BufferedImage dst,
                                        byte[][] table);
    public static native int lookupByteRaster(Raster src, Raster dst,
                                              byte[][] table);

    static {

        PrivilegedAction<Boolean> doMlibInitialization =
            new PrivilegedAction<Boolean>() {
                public Boolean run() {
                    String arch = System.getProperty("os.arch");

                    try {
                        System.loadLibrary("mlib_image");
                    } catch (UnsatisfiedLinkError e) {
                        return Boolean.FALSE;
                    }
                    boolean success = init();
                    return Boolean.valueOf(success);
                }
            };

        useLib = AccessController.doPrivileged(doMlibInitialization);

        //
        // Cache the class references of the operations we know about
        // at the time this class is initially loaded.
        //
        try {
            nativeOpClass[LOOKUP_OP] =
                Class.forName("java.awt.image.LookupOp");
        } catch (ClassNotFoundException e) {
            System.err.println("Could not find class: "+e);
        }
        try {
            nativeOpClass[AFFINE_OP] =
                Class.forName("java.awt.image.AffineTransformOp");
        } catch (ClassNotFoundException e) {
            System.err.println("Could not find class: "+e);
        }
        try {
            nativeOpClass[CONVOLVE_OP] =
                Class.forName("java.awt.image.ConvolveOp");
        } catch (ClassNotFoundException e) {
            System.err.println("Could not find class: "+e);
        }

    }

    private static int getNativeOpIndex(Class<?> opClass) {
        //
        // Search for this class in cached list of
        // classes supplying native acceleration
        //
        int opIndex = -1;
        for (int i=0; i<NUM_NATIVE_OPS; i++) {
            if (opClass == nativeOpClass[i]) {
                opIndex = i;
                break;
            }
        }
        return opIndex;
    }


    public static WritableRaster filter(RasterOp op, Raster src,
                                        WritableRaster dst) {
        if (useLib == false) {
            return null;
        }

        // Create the destination tile
        if (dst == null) {
            dst = op.createCompatibleDestRaster(src);
        }


        WritableRaster retRaster = null;
        switch (getNativeOpIndex(op.getClass())) {

          case LOOKUP_OP:
            // REMIND: Fix this!
            LookupTable table = ((LookupOp)op).getTable();
            if (table.getOffset() != 0) {
                // Right now the native code doesn't support offsets
                return null;
            }
            if (table instanceof ByteLookupTable) {
                ByteLookupTable bt = (ByteLookupTable) table;
                if (lookupByteRaster(src, dst, bt.getTable()) > 0) {
                    retRaster = dst;
                }
            }
            break;

          case AFFINE_OP:
            AffineTransformOp bOp = (AffineTransformOp) op;
            double[] matrix = new double[6];
            bOp.getTransform().getMatrix(matrix);
            if (transformRaster(src, dst, matrix,
                                bOp.getInterpolationType()) > 0) {
                retRaster =  dst;
            }
            break;

          case CONVOLVE_OP:
            ConvolveOp cOp = (ConvolveOp) op;
            if (convolveRaster(src, dst,
                               cOp.getKernel(), cOp.getEdgeCondition()) > 0) {
                retRaster = dst;
            }
            break;

          default:
            break;
        }

        if (retRaster != null) {
            SunWritableRaster.markDirty(retRaster);
        }

        return retRaster;
    }


    public static BufferedImage filter(BufferedImageOp op, BufferedImage src,
                                       BufferedImage dst)
    {
        if (verbose) {
            System.out.println("in filter and op is "+op
                               + "bufimage is "+src+" and "+dst);
        }

        if (useLib == false) {
            return null;
        }

        // Create the destination image
        if (dst == null) {
            dst = op.createCompatibleDestImage(src, null);
        }

        BufferedImage retBI = null;
        switch (getNativeOpIndex(op.getClass())) {

          case LOOKUP_OP:
            // REMIND: Fix this!
            LookupTable table = ((LookupOp)op).getTable();
            if (table.getOffset() != 0) {
                // Right now the native code doesn't support offsets
                return null;
            }
            if (table instanceof ByteLookupTable) {
                ByteLookupTable bt = (ByteLookupTable) table;
                if (lookupByteBI(src, dst, bt.getTable()) > 0) {
                    retBI = dst;
                }
            }
            break;

          case AFFINE_OP:
            AffineTransformOp bOp = (AffineTransformOp) op;
            double[] matrix = new double[6];
            AffineTransform xform = bOp.getTransform();
            bOp.getTransform().getMatrix(matrix);

            if (transformBI(src, dst, matrix,
                            bOp.getInterpolationType())>0) {
                retBI = dst;
            }
            break;

          case CONVOLVE_OP:
            ConvolveOp cOp = (ConvolveOp) op;
            if (convolveBI(src, dst, cOp.getKernel(),
                           cOp.getEdgeCondition()) > 0) {
                retBI = dst;
            }
            break;

          default:
            break;
        }

        if (retBI != null) {
            SunWritableRaster.markDirty(retBI);
        }

        return retBI;
    }
}