Rev 231 | Blame | Compare with Previous | Last modification | View Log | RSS feed
/** Copyright (C) 2010.** This program is free software; you can redistribute it and/or modify* it under the terms of the GNU General Public License version 3 as* published by the Free Software Foundation.** This program 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 for more details.*/package test.display;import uk.me.parabola.imgfmt.app.ImgFileReader;/*** Standalone program to display the DEM file. This stores a* digital elevation model used to display shaded surface and profiles of tracks.** @author Ronny Klier**/public class DemDisplay extends CommonDisplay {private class DemTile {private DemSection section;private int tileNumberLat;private int tileNumberLon;private int offset; // offset from section.dataOffset2private int dataLength; // number of bytes for compressed elevation dataprivate short baseHeight; // base or minimum height in this tileprivate short differenceHeight; // maximum height above baseHeight (elevation?)DemTile(DemSection parent, int numLat, int numLon) {section = parent;tileNumberLat = numLat;tileNumberLon = numLon;}void readHeader(ImgFileReader reader, int baseOffset) {Displayer d = new Displayer(reader);d.setTitle("DEM Tile Header");DisplayItem item = d.item();item.addText("Tile row %1$s column %2$s", tileNumberLat, tileNumberLon);reader.position(section.dataOffset + (section.tilesLon * tileNumberLat + tileNumberLon) * section.tileDescSize);switch (section.offsetSize) {case 1:offset = d.byteValue("offset in data section");break;case 2:offset = d.shortValue("offset in data section");break;case 3:offset = d.int3Value("offset in data section");break;}offset += baseOffset;if (1 == section.baseSize) {baseHeight = d.byteValue("minimum height");} else {baseHeight = d.shortValue("minimum height");}if (1 == section.differenceSize) {differenceHeight = d.byteValue("elevation");} else {differenceHeight = d.shortValue("elevation");}d.print(outStream);}void setDataLength(int nextOffset) {dataLength = nextOffset - offset;if (dataLength < 0)dataLength = 0;}public void printRawData(ImgFileReader reader) {reader.position(offset);Displayer d = new Displayer(reader);d.setTitle(String.format("Raw data for tile row %1$s column %2$s", tileNumberLat, tileNumberLon));d.rawValue(dataLength, "real DEM data");d.print(outStream);}}private class DemSection {private int num;private int pointsPerLat;private int pointsPerLon;private int tilesLat;private int tilesLon;private byte offsetSize;private byte baseSize;private byte differenceSize;private short tileDescSize;private int dataOffset;private int dataOffset2;private int pointsDistanceLat;private int pointsDistanceLon;private int top;private int left;private DemTile[] tiles;protected void print(ImgFileReader reader) {readHeader(reader);}private void readHeader(ImgFileReader reader) {Displayer d = new Displayer(reader);d.setTitle("DEM Sector Header");num = d.shortValue("#"); //0x00 - 0x01pointsPerLat = d.intValue("Points per tile (latitude"); //0x02 - 0x05pointsPerLon = d.intValue("Points per tile (longitude)");//0x06 - 0x09d.intValue("unknown integer1"); //0x0a - 0x0dd.intValue("unknown integer2"); //0x0e - 0x11d.shortValue("unknown short"); //0x12 - 0x13tilesLon = d.intValue("Tiles per longitude") + 1; //0x14 - 0x17tilesLat = d.intValue("Tiles per latitude") + 1; //0x18 - 0x1Bshort recordDesc = d.shortValue("Flags for tile description"); //0x1C - 0x1DDisplayItem item = d.item();offsetSize = (byte)((recordDesc & 3) + 1);baseSize = (byte)(((recordDesc & 4) >> 2) + 1);differenceSize = (byte)(((recordDesc & 8) >> 3) + 1);item.addText("Data offset has %s bytes", offsetSize);item.addText("Base height has %s bytes", baseSize);item.addText("Height difference has %s bytes", differenceSize);tileDescSize = d.shortValue("Size of tile description");//0x1E - 0x1FdataOffset = d.intValue("offset of first tile description");// 0x20 - 0x23dataOffset2 = d.intValue("offset of first tiles data"); //0x24 - 0x27left = d.intValue("western bound"); //0x28-0x2Btop = d.intValue("northern bound"); //0x2C - 0x2Fd.item().addText("In degrees lat,lon: %.4f,%.4f",DemDisplay.toDegrees(top),DemDisplay.toDegrees(left));pointsDistanceLat = d.intValue("map units between points (latitude)"); //0x30 - 0x33pointsDistanceLon = d.intValue("map units between points (longitude)"); //0x34 - 0x37d.shortValue("minimum height"); //0x38 - 0x39d.shortValue("maximum height"); //0x3A - 0x3Bd.print(outStream);tiles = new DemTile[tilesLat * tilesLon];// now read the tile descriptionfor (int i = 0; i < tiles.length; ++i) {tiles[i] = new DemTile(this, i / tilesLon, i % tilesLon);tiles[i].readHeader(reader, dataOffset2);if (i != 0) {tiles[i-1].setDataLength(tiles[i].offset);}// data length of last tile has to be set after reading next section}}private void setLastDataLength(int nextSectionOffset) {tiles[tiles.length -1].setDataLength(nextSectionOffset);}public void printRawData(ImgFileReader reader) {Displayer d = new Displayer(reader);d.setTitle(String.format("Printing raw data of sector %s", num));for (int i = 0; i < tiles.length; ++i) {tiles[i].printRawData(reader);}d.print(outStream);}}private DemSection[] sections;private int sectionOffset;private short sectionSize;private boolean useMeters;@Overrideprotected void print() {readCommonHeader();readFileHeader();}private void readFileHeader() {Displayer d = new Displayer(reader);d.setTitle("DEM Header");useMeters = 1 != (d.intValue("Flags ?") & 1);DisplayItem item = d.item();if (useMeters) {item.addText("elevation is given in meters");} else {item.addText("elevation is given in feet");}sections = new DemSection[d.shortValue("Number of zoom levels/sectors")];d.intValue("unknown integer");sectionSize = d.shortValue("size of sector headers");sectionOffset = d.intValue("offset of first sector header");if (getHeaderLen() > 0x25) {d.intValue("unknown integer at 0x25");}d.print(outStream);reader.position(sectionOffset);for (int i = 0; i < sections.length; i++) {reader.position(sectionOffset + sectionSize * i);sections[i] = new DemSection();sections[i].print(reader);if (i != 0) {// data of last tile of previous section ends before first tile of this sectionsections[i-1].setLastDataLength(sections[i].dataOffset2);}if (i - 1 == sections.length) {// data of last tile of last section ends before begin of section descriptionsections[i].setLastDataLength(sectionOffset);}}// now iterate a second time over section and tiles and print out raw datafor (int i = 0; i < sections.length; ++i) {sections[i].printRawData(reader);}}private static double toDegrees(int val) {return (double) val * (360.0 / 4294967296.0);}public static void main(String[] args) {if (args.length < 1) {System.err.println("Usage: demdisplay <filename>");System.exit(1);}CommonDisplay td = new DemDisplay();td.display(args[0],"DEM");}}