source: josm/trunk/src/org/openstreetmap/josm/data/projection/datum/NTV2SubGrid.java@ 8406

Last change on this file since 8406 was 8406, checked in by Don-vip, 9 years ago

Style - Method returns modified parameter
  • Property svn:eol-style set to native
File size: 13.2 KB
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1/*
2 * Copyright (c) 2003 Objectix Pty Ltd All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation.
7 *
8 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
9 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
10 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
11 * DISCLAIMED. IN NO EVENT SHALL OBJECTIX PTY LTD BE LIABLE FOR ANY
12 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
13 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
14 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
15 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
16 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
17 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
18 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
19 */
20package org.openstreetmap.josm.data.projection.datum;
21
22import java.io.IOException;
23import java.io.InputStream;
24import java.io.Serializable;
25import java.nio.charset.StandardCharsets;
26
27import org.openstreetmap.josm.Main;
28import org.openstreetmap.josm.tools.Utils;
29
30/**
31 * Models the NTv2 Sub Grid within a Grid Shift File
32 *
33 * @author Peter Yuill
34 * Modified for JOSM :
35 * - removed the RandomAccessFile mode (Pieren)
36 * - read grid file by single bytes. Workaround for a bug in some VM not supporting
37 * file reading by group of 4 bytes from a jar file.
38 */
39public class NTV2SubGrid implements Cloneable, Serializable {
40
41 private static final long serialVersionUID = 1L;
42
43 private String subGridName;
44 private String parentSubGridName;
45 private String created;
46 private String updated;
47 private double minLat;
48 private double maxLat;
49 private double minLon;
50 private double maxLon;
51 private double latInterval;
52 private double lonInterval;
53 private int nodeCount;
54
55 private int lonColumnCount;
56 private int latRowCount;
57 private float[] latShift;
58 private float[] lonShift;
59 private float[] latAccuracy;
60 private float[] lonAccuracy;
61
62 private NTV2SubGrid[] subGrid;
63
64 /**
65 * Construct a Sub Grid from an InputStream, loading the node data into
66 * arrays in this object.
67 *
68 * @param in GridShiftFile InputStream
69 * @param bigEndian is the file bigEndian?
70 * @param loadAccuracy is the node Accuracy data to be loaded?
71 * @throws IOException
72 */
73 public NTV2SubGrid(InputStream in, boolean bigEndian, boolean loadAccuracy) throws IOException {
74 byte[] b8 = new byte[8];
75 byte[] b4 = new byte[4];
76 byte[] b1 = new byte[1];
77 readBytes(in, b8);
78 readBytes(in, b8);
79 subGridName = new String(b8, StandardCharsets.UTF_8).trim();
80 readBytes(in, b8);
81 readBytes(in, b8);
82 parentSubGridName = new String(b8, StandardCharsets.UTF_8).trim();
83 readBytes(in, b8);
84 readBytes(in, b8);
85 created = new String(b8, StandardCharsets.UTF_8);
86 readBytes(in, b8);
87 readBytes(in, b8);
88 updated = new String(b8, StandardCharsets.UTF_8);
89 readBytes(in, b8);
90 readBytes(in, b8);
91 minLat = NTV2Util.getDouble(b8, bigEndian);
92 readBytes(in, b8);
93 readBytes(in, b8);
94 maxLat = NTV2Util.getDouble(b8, bigEndian);
95 readBytes(in, b8);
96 readBytes(in, b8);
97 minLon = NTV2Util.getDouble(b8, bigEndian);
98 readBytes(in, b8);
99 readBytes(in, b8);
100 maxLon = NTV2Util.getDouble(b8, bigEndian);
101 readBytes(in, b8);
102 readBytes(in, b8);
103 latInterval = NTV2Util.getDouble(b8, bigEndian);
104 readBytes(in, b8);
105 readBytes(in, b8);
106 lonInterval = NTV2Util.getDouble(b8, bigEndian);
107 lonColumnCount = 1 + (int)((maxLon - minLon) / lonInterval);
108 latRowCount = 1 + (int)((maxLat - minLat) / latInterval);
109 readBytes(in, b8);
110 readBytes(in, b8);
111 nodeCount = NTV2Util.getInt(b8, bigEndian);
112 if (nodeCount != lonColumnCount * latRowCount)
113 throw new IllegalStateException("SubGrid " + subGridName + " has inconsistent grid dimesions");
114 latShift = new float[nodeCount];
115 lonShift = new float[nodeCount];
116 if (loadAccuracy) {
117 latAccuracy = new float[nodeCount];
118 lonAccuracy = new float[nodeCount];
119 }
120
121 for (int i = 0; i < nodeCount; i++) {
122 // Read the grid file byte after byte. This is a workaround about a bug in
123 // certain VM which are not able to read byte blocks when the resource file is
124 // in a .jar file (Pieren)
125 readBytes(in, b1); b4[0] = b1[0];
126 readBytes(in, b1); b4[1] = b1[0];
127 readBytes(in, b1); b4[2] = b1[0];
128 readBytes(in, b1); b4[3] = b1[0];
129 latShift[i] = NTV2Util.getFloat(b4, bigEndian);
130 readBytes(in, b1); b4[0] = b1[0];
131 readBytes(in, b1); b4[1] = b1[0];
132 readBytes(in, b1); b4[2] = b1[0];
133 readBytes(in, b1); b4[3] = b1[0];
134 lonShift[i] = NTV2Util.getFloat(b4, bigEndian);
135 readBytes(in, b1); b4[0] = b1[0];
136 readBytes(in, b1); b4[1] = b1[0];
137 readBytes(in, b1); b4[2] = b1[0];
138 readBytes(in, b1); b4[3] = b1[0];
139 if (loadAccuracy) {
140 latAccuracy[i] = NTV2Util.getFloat(b4, bigEndian);
141 }
142 readBytes(in, b1); b4[0] = b1[0];
143 readBytes(in, b1); b4[1] = b1[0];
144 readBytes(in, b1); b4[2] = b1[0];
145 readBytes(in, b1); b4[3] = b1[0];
146 if (loadAccuracy) {
147 lonAccuracy[i] = NTV2Util.getFloat(b4, bigEndian);
148 }
149 }
150 }
151
152 private void readBytes(InputStream in, byte[] b) throws IOException {
153 if (in.read(b) < b.length) {
154 Main.error("Failed to read expected amount of bytes ("+ b.length +") from stream");
155 }
156 }
157
158 /**
159 * Tests if a specified coordinate is within this Sub Grid
160 * or one of its Sub Grids. If the coordinate is outside
161 * this Sub Grid, null is returned. If the coordinate is
162 * within this Sub Grid, but not within any of its Sub Grids,
163 * this Sub Grid is returned. If the coordinate is within
164 * one of this Sub Grid's Sub Grids, the method is called
165 * recursively on the child Sub Grid.
166 *
167 * @param lon Longitude in Positive West Seconds
168 * @param lat Latitude in Seconds
169 * @return the Sub Grid containing the Coordinate or null
170 */
171 public NTV2SubGrid getSubGridForCoord(double lon, double lat) {
172 if (isCoordWithin(lon, lat)) {
173 if (subGrid == null)
174 return this;
175 else {
176 for (NTV2SubGrid aSubGrid : subGrid) {
177 if (aSubGrid.isCoordWithin(lon, lat))
178 return aSubGrid.getSubGridForCoord(lon, lat);
179 }
180 return this;
181 }
182 } else
183 return null;
184 }
185
186 /**
187 * Tests if a specified coordinate is within this Sub Grid.
188 * A coordinate on either outer edge (maximum Latitude or
189 * maximum Longitude) is deemed to be outside the grid.
190 *
191 * @param lon Longitude in Positive West Seconds
192 * @param lat Latitude in Seconds
193 * @return true or false
194 */
195 private boolean isCoordWithin(double lon, double lat) {
196 return (lon >= minLon) && (lon < maxLon) && (lat >= minLat) && (lat < maxLat);
197 }
198
199 /**
200 * Bi-Linear interpolation of four nearest node values as described in
201 * 'GDAit Software Architecture Manual' produced by the <a
202 * href='http://www.dtpli.vic.gov.au/property-and-land-titles/geodesy/geocentric-datum-of-australia-1994-gda94/gda94-useful-tools'>
203 * Geomatics Department of the University of Melbourne</a>
204 * @param a value at the A node
205 * @param b value at the B node
206 * @param c value at the C node
207 * @param d value at the D node
208 * @param x Longitude factor
209 * @param y Latitude factor
210 * @return interpolated value
211 */
212 private final double interpolate(float a, float b, float c, float d, double x, double y) {
213 return a + (((double)b - (double)a) * x) + (((double)c - (double)a) * y) +
214 (((double)a + (double)d - b - c) * x * y);
215 }
216
217 /**
218 * Interpolate shift and accuracy values for a coordinate in the 'from' datum
219 * of the GridShiftFile. The algorithm is described in
220 * 'GDAit Software Architecture Manual' produced by the <a
221 * href='http://www.dtpli.vic.gov.au/property-and-land-titles/geodesy/geocentric-datum-of-australia-1994-gda94/gda94-useful-tools'>
222 * Geomatics Department of the University of Melbourne</a>
223 * <p>This method is thread safe for both memory based and file based node data.
224 * @param gs GridShift object containing the coordinate to shift and the shift values
225 */
226 public void interpolateGridShift(NTV2GridShift gs) {
227 int lonIndex = (int)((gs.getLonPositiveWestSeconds() - minLon) / lonInterval);
228 int latIndex = (int)((gs.getLatSeconds() - minLat) / latInterval);
229
230 double x = (gs.getLonPositiveWestSeconds() - (minLon + (lonInterval * lonIndex))) / lonInterval;
231 double y = (gs.getLatSeconds() - (minLat + (latInterval * latIndex))) / latInterval;
232
233 // Find the nodes at the four corners of the cell
234
235 int indexA = lonIndex + (latIndex * lonColumnCount);
236 int indexB = indexA + 1;
237 int indexC = indexA + lonColumnCount;
238 int indexD = indexC + 1;
239
240 gs.setLonShiftPositiveWestSeconds(interpolate(
241 lonShift[indexA], lonShift[indexB], lonShift[indexC], lonShift[indexD], x, y));
242
243 gs.setLatShiftSeconds(interpolate(
244 latShift[indexA], latShift[indexB], latShift[indexC], latShift[indexD], x, y));
245
246 if (lonAccuracy == null) {
247 gs.setLonAccuracyAvailable(false);
248 } else {
249 gs.setLonAccuracyAvailable(true);
250 gs.setLonAccuracySeconds(interpolate(
251 lonAccuracy[indexA], lonAccuracy[indexB], lonAccuracy[indexC], lonAccuracy[indexD], x, y));
252 }
253
254 if (latAccuracy == null) {
255 gs.setLatAccuracyAvailable(false);
256 } else {
257 gs.setLatAccuracyAvailable(true);
258 gs.setLatAccuracySeconds(interpolate(
259 latAccuracy[indexA], latAccuracy[indexB], latAccuracy[indexC], latAccuracy[indexD], x, y));
260 }
261 }
262
263 public String getParentSubGridName() {
264 return parentSubGridName;
265 }
266
267 public String getSubGridName() {
268 return subGridName;
269 }
270
271 public int getNodeCount() {
272 return nodeCount;
273 }
274
275 public int getSubGridCount() {
276 return (subGrid == null) ? 0 : subGrid.length;
277 }
278
279 public NTV2SubGrid getSubGrid(int index) {
280 return (subGrid == null) ? null : subGrid[index];
281 }
282
283 /**
284 * Set an array of Sub Grids of this sub grid
285 * @param subGrid
286 */
287 public void setSubGridArray(NTV2SubGrid[] subGrid) {
288 this.subGrid = Utils.copyArray(subGrid);
289 }
290
291 @Override
292 public String toString() {
293 return subGridName;
294 }
295
296 /**
297 * Returns textual details about the sub grid.
298 * @return textual details about the sub grid
299 */
300 public String getDetails() {
301 StringBuilder buff = new StringBuilder("Sub Grid : ");
302 buff.append(subGridName)
303 .append("\nParent : ")
304 .append(parentSubGridName)
305 .append("\nCreated : ")
306 .append(created)
307 .append("\nUpdated : ")
308 .append(updated)
309 .append("\nMin Lat : ")
310 .append(minLat)
311 .append("\nMax Lat : ")
312 .append(maxLat)
313 .append("\nMin Lon : ")
314 .append(minLon)
315 .append("\nMax Lon : ")
316 .append(maxLon)
317 .append("\nLat Intvl: ")
318 .append(latInterval)
319 .append("\nLon Intvl: ")
320 .append(lonInterval)
321 .append("\nNode Cnt : ")
322 .append(nodeCount);
323 return buff.toString();
324 }
325
326 /**
327 * Make a deep clone of this Sub Grid
328 */
329 @Override
330 public Object clone() {
331 NTV2SubGrid clone = null;
332 try {
333 clone = (NTV2SubGrid)super.clone();
334 // Do a deep clone of the sub grids
335 if (subGrid != null) {
336 clone.subGrid = new NTV2SubGrid[subGrid.length];
337 for (int i = 0; i < subGrid.length; i++) {
338 clone.subGrid[i] = (NTV2SubGrid)subGrid[i].clone();
339 }
340 }
341 } catch (CloneNotSupportedException cnse) {
342 Main.warn(cnse);
343 }
344 return clone;
345 }
346 /**
347 * Get maximum latitude value
348 * @return maximum latitude
349 */
350 public double getMaxLat() {
351 return maxLat;
352 }
353
354 /**
355 * Get maximum longitude value
356 * @return maximum longitude
357 */
358 public double getMaxLon() {
359 return maxLon;
360 }
361
362 /**
363 * Get minimum latitude value
364 * @return minimum latitude
365 */
366 public double getMinLat() {
367 return minLat;
368 }
369
370 /**
371 * Get minimum longitude value
372 * @return minimum longitude
373 */
374 public double getMinLon() {
375 return minLon;
376 }
377}
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