/**
* Swap the grid header, avoiding strings
*
* @param gh grid header to swap
*/
private void swapGridHeader(int[] gh) {
McIDASUtil.flip(gh, 0, 5);
McIDASUtil.flip(gh, 7, 7);
McIDASUtil.flip(gh, 9, 10);
McIDASUtil.flip(gh, 12, 14);
McIDASUtil.flip(gh, 32, 51);
}
/**
* Initialize this reader. Get the Grid specific info
*
* @param fullCheck for a full check reading grids
* @return true if successful
* @throws IOException problem reading the data
*/
protected boolean init(boolean fullCheck) throws IOException {
if (rf == null) {
logError("File is null");
return false;
}
gridIndex = new GridIndex(rf.getLocation());
rf.order(RandomAccessFile.BIG_ENDIAN);
int numEntries = Math.abs(readInt(10));
if (numEntries > 1000000) {
needToSwap = true;
numEntries = Math.abs(McIDASUtil.swbyt4(numEntries));
}
if (numEntries > MAX_GRIDS) {
return false;
}
// System.out.println("need to Swap = " + needToSwap);
// System.out.println("number entries="+numEntries);
// go back to the beginning
rf.seek(0);
// read the fileheader
String label = rf.readString(32);
// GEMPAK too closely like McIDAS
if (label.indexOf("GEMPAK DATA MANAGEMENT FILE") >= 0) {
logError("label indicates this is a GEMPAK grid");
return false;
} else { // check that they are all printable ASCII chars
for (int i = 0; i < label.length(); i++) {
String s0 = label.substring(i, i + 1);
if (!(0 <= s0.compareTo(" ") && s0.compareTo("~") <= 0)) {
logError("bad label, not a McIDAS grid");
return false;
}
}
}
// System.out.println("label = " + label);
int project = readInt(8);
// System.out.println("Project = " + project);
int date = readInt(9);
// dates are supposed to be yyyddd, but account for ccyyddd up to year 4000
if ((date < 10000) || (date > 400000)) {
logError("date wrong, not a McIDAS grid");
return false;
}
// System.out.println("date = " + date);
int[] entries = new int[numEntries];
for (int i = 0; i < numEntries; i++) {
entries[i] = readInt(i + 11);
// sanity check that this is indeed a McIDAS Grid file
if (entries[i] < -1) {
logError("bad grid offset " + i + ": " + entries[i]);
return false;
}
}
if (!fullCheck) {
return true;
}
// Don't swap:
rf.order(RandomAccessFile.BIG_ENDIAN);
for (int i = 0; i < numEntries; i++) {
if (entries[i] == -1) {
continue;
}
int[] header = new int[64];
rf.seek(entries[i] * 4);
rf.readInt(header, 0, 64);
if (needToSwap) {
swapGridHeader(header);
}
try {
McIDASGridRecord gr = new McIDASGridRecord(entries[i], header);
// if (gr.getGridDefRecordId().equals("CONF X:93 Y:65")) {
// if (gr.getGridDefRecordId().equals("CONF X:54 Y:47")) {
// figure out how to handle Mercator projections
// if ( !(gr.getGridDefRecordId().startsWith("MERC"))) {
gridIndex.addGridRecord(gr);
if (gdsMap.get(gr.getGridDefRecordId()) == null) {
McGridDefRecord mcdef = gr.getGridDefRecord();
// System.out.println("new nav " + mcdef.toString());
gdsMap.put(mcdef.toString(), mcdef);
gridIndex.addHorizCoordSys(mcdef);
}
// }
} catch (McIDASException me) {
logError("problem creating grid dir");
return false;
}
}
// check to see if there are any grids that we can handle
if (gridIndex.getGridRecords().isEmpty()) {
logError("no grids found");
return false;
}
return true;
}