dtedcoveragemanager.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

        if (proj instanceof Cylindrical)
            LineType = OMGraphic.LINETYPE_STRAIGHT;
        else
            LineType = OMGraphic.LINETYPE_RHUMB;

        if (startx > endx) {
            ret1 = getCoverageRects(startx, starty, 179, endy, LineType);
            ret2 = getCoverageRects(-180, starty, endx, endy, LineType);
            ret1[0].add(ret2[0]);
            ret1[1].add(ret2[1]);
            ret1[2].add(ret2[2]);
            return ret1;
        } else
            return getCoverageRects(startx, starty, endx, endy, LineType);
    }

    /**
     * Method looks at the coverage arrays, and returns the applicable
     * rectangles representing the frame coverages.
     * 
     * @param startx the western-most longitude.
     * @param starty the southern-most latitude.
     * @param endx the eastern-most longitude.
     * @param endy the northern-most latitude.
     * @param LineType the type of line to use on the rectangles -
     *        Cylindrical projections can use straight lines, but
     *        other projections should use Rhumb lines.
     * @return an array of lists, one for each level of dted data.
     */
    public OMGraphicList[] getCoverageRects(int startx, int starty, int endx,
                                            int endy, int LineType) {
        OMGraphicList gl0 = new OMGraphicList();
        OMGraphicList gl1 = new OMGraphicList();
        OMGraphicList gl2 = new OMGraphicList();
        OMGraphicList[] ret = new OMGraphicList[3];

        ret[0] = gl0;
        ret[1] = gl1;
        ret[2] = gl2;

        OMRect rect;

        for (int lat = starty; lat <= endy; lat++) {
            for (int lon = startx; lon <= endx; lon++) {
                if (level0Frames[lat + 90][lon + 180]) {
                    rect = new OMRect((float) lat, (float) lon, (float) lat + 1, (float) lon + 1, LineType);
                    rect.setLinePaint(level0Color);
                    if (fillRects)
                        rect.setFillPaint(level0Color);
                    gl0.add(rect);
                }

                if (level1Frames[lat + 90][lon + 180]) {
                    rect = new OMRect((float) lat + .1f, (float) lon + .1f, (float) lat + .9f, (float) lon + .9f, LineType);
                    rect.setLinePaint(level1Color);
                    if (fillRects)
                        rect.setFillPaint(level1Color);
                    gl1.add(rect);
                }

                if (level2Frames[lat + 90][lon + 180]) {
                    rect = new OMRect((float) lat + .2f, (float) lon + .2f, (float) lat + .8f, (float) lon + .8f, LineType);
                    rect.setLinePaint(level2Color);
                    if (fillRects)
                        rect.setFillPaint(level2Color);
                    gl2.add(rect);
                }
            }
        }
        return ret;
    }

    /**
     * Read in the coverage file, which is basically three
     * byte[180][360] written out to file. These are converted to
     * booleans.
     * 
     * @param coverage the path to the file.
     * @return whether the file was read! True means yes.
     */
    public boolean readCoverageFile(String coverage) {
        try {
            Debug.message("dtedcov",
                    "DTEDCoverageManager: Reading coverage file - " + coverage);
            BinaryBufferedFile binFile = new BinaryBufferedFile(coverage);
            level0Frames = new boolean[180][];
            level1Frames = new boolean[180][];
            level2Frames = new boolean[180][];

            byte[] row = new byte[360];

            for (int level = 0; level < 3; level++) {
                for (int lat = 0; lat < 180; lat++) {
                    binFile.read(row);

                    if (level == 0)
                        level0Frames[lat] = convertBytesToBooleans(row);
                    else if (level == 1)
                        level1Frames[lat] = convertBytesToBooleans(row);
                    else
                        level2Frames[lat] = convertBytesToBooleans(row);
                }
            }
            return true;

        } catch (IOException ioe) {
            Debug.message("dtedcov",
                    "DTEDCoverageManager: No coverage file - will create one at "
                            + coverage);
            level0Frames = null;
            level1Frames = null;
            level2Frames = null;
            return false;
        }

    }

    /**
     * Read in the coverage file, which is basically three
     * byte[180][360] written out to file. These are converted to
     * booleans.
     * 
     * @param urlCov an url to a coverage file, if available. Should
     *        be null if not used.
     * @param coverage the path to the file.
     * @return whether the file was read! True means yes.
     */
    protected boolean readCoverageFile(String urlCov, String coverage) {
        URL url = null;
        BufferedInputStream bin = null;
        BinaryBufferedFile binFile = null;

        level0Frames = null;
        level1Frames = null;
        level2Frames = null;

        if (urlCov != null) {
            Debug.message("dtedcov",
                    "DTEDCoverageManager: Reading coverage file from URL - "
                            + urlCov);
            try {
                url = new URL(urlCov);
                bin = new BufferedInputStream(url.openStream());
            } catch (MalformedURLException mue) {
                System.err.println("DTEDCoverageManager: Weird URL given : \""
                        + urlCov + "\"");
                bin = null;
            } catch (java.io.IOException e) {
                System.err.println("DTEDCoverageManager: Unable to read coverage file at \""
                        + urlCov + "\"");
                bin = null;
            }
        }

        if (bin == null && coverage != null) {
            try {
                Debug.message("dtedcov",
                        "DTEDCoverageManager: Reading coverage file - "
                                + coverage);
                binFile = new BinaryBufferedFile(coverage);
            } catch (java.io.IOException e) {
                System.err.println("DTEDCoverageManager: Unable to read coverage file at \""
                        + coverage + "\"");
            }
        }

        if (bin != null || binFile != null) {
            try {
                level0Frames = new boolean[180][];
                level1Frames = new boolean[180][];
                level2Frames = new boolean[180][];

                byte[] row = new byte[360];

                for (int level = 0; level < 3; level++) {
                    for (int lat = 0; lat < 180; lat++) {

                        if (bin != null) {
                            for (int k = 0; k < row.length; k++) {
                                row[k] = (byte) bin.read();
                            }
                        } else
                            binFile.read(row);

                        if (level == 0)
                            level0Frames[lat] = convertBytesToBooleans(row);
                        else if (level == 1)
                            level1Frames[lat] = convertBytesToBooleans(row);
                        else
                            level2Frames[lat] = convertBytesToBooleans(row);
                    }
                }
                return true;

            } catch (IOException ioe) {
                System.err.println("DTECoverageLayer: Error reading coverage.");

                level0Frames = null;
                level1Frames = null;
                level2Frames = null;
            }
        }

        if (level0Frames == null) {
            System.err.println("DTEDCoverageManager: Error reading coverage file - will try to create a valid one at "
                    + coverage);
        }
        return false;
    }

    /**
     * Convert the bytes read in to the file to the booleans used in
     * the coverage arrays.
     * 
     * @param row array of bytes
     * @return array of booleans
     */
    protected boolean[] convertBytesToBooleans(byte[] row) {
        boolean[] ret = new boolean[row.length];
        for (int i = 0; i < row.length; i++)
            ret[i] = (row[i] == 0) ? false : true;
        return ret;
    }

    /**
     * Convert the booleans to write out to bytes.
     * 
     * @param row the input array of booleans
     * @return an array of bytes.
     */
    protected byte[] convertBooleansToBytes(boolean[] row) {
        byte[] ret = new byte[row.length];
        for (int i = 0; i < row.length; i++)
            ret[i] = (row[i]) ? (byte) 1 : (byte) 0;
        return ret;
    }

    /**
     * Write the coverage summary to a file.
     * 
     * @param covFilename the file name to write the arrays into.
     */
    public void writeCoverageFile(String covFilename) {
        try {
            Debug.message("dtedcov",
                    "DTEDCoverageManager: Writing coverage summary file...");

            FileOutputStream binFile = new FileOutputStream(covFilename);

            byte[] row;

            for (int level = 0; level < 3; level++) {
                if (Debug.debugging("dtedcov")) {
                    Debug.output("-- level " + level);
                }
                for (int lat = 0; lat < 180; lat++) {

                    if (level == 0) {
                        row = convertBooleansToBytes(level0Frames[lat]);
                    } else if (level == 1) {
                        row = convertBooleansToBytes(level1Frames[lat]);
                    } else {
                        row = convertBooleansToBytes(level2Frames[lat]);
                    }

                    binFile.write(row);
                    if (Debug.debugging("dtedcov")) {
                        Debug.output("--- latitude " + lat);
                    }
                }
            }

            binFile.close();

        } catch (IOException ioe) {
            System.err.println("DTEDCoverageManager: Error writing coverage file!");
        }
    }

    /**
     * Add a ProgressListener that will display build progress.
     */
    public void addProgressListener(ProgressListener list) {
        progressSupport.addProgressListener(list);
    }

    /**
     * Remove a ProgressListener that displayed build progress.
     */
    public void removeProgressListener(ProgressListener list) {
        progressSupport.removeProgressListener(list);
    }

    /**
     * Clear all progress listeners.
     */
    public void clearProgressListeners() {
        progressSupport.removeAll();
    }

    /**
     * Fire an build update to progress listeners.
     * 
     * @param frameNumber the current frame count
     * @param totalFrames the total number of frames.
     */
    protected void fireProgressUpdate(int type, String task, int frameNumber,
                                      int totalFrames) {
        progressSupport.fireUpdate(type, task, totalFrames, frameNumber);
    }

}