/* JRG, the Resource Geology Seismic Processing System for Java,
   and Viewmat for Java are Copyright 1998-2000 by John N. Louie

The software and methods here are the subject of academic research,
not commercial products. I would like to know what use you make of
my methods, and have your feedback on their success or failure.
Also, by letting me know who you are, I can inform you if bugs or
errors are discovered.
 
Please send me an email message with: your name and email address;
whether you are a student or faculty member, consultant or employee;
the name of your university or company, and department; and a sentence
or two describing what use you intend to make of these methods.
Send your message to louie@seismo.unr.edu */


import java.io.*;

public class RgFileHead
	{
	public int ntrace;		/* no. of traces in file */
	public int nt;			/* no. of samples per trace */
	public float starttime;	/* time after source initiation of 1st
				   		sample, seconds */
	public float dt;		/* time sample interval, seconds */
	
	public static final int RGFILEHEADBYTES = 16;
	
	/* Constructor */
	public RgFileHead()
		{
		dt = 1F;
		}
	/* Construct a copy */
	public RgFileHead(RgFileHead fhd)
		{
		ntrace = fhd.ntrace;
		nt = fhd.nt;
		starttime = fhd.starttime;
		dt = fhd.dt;
		}
	/* Construct a file header from FltPlane properties */
	public RgFileHead(FltPlane fp)
		{
		ntrace = fp.vecs;
		nt = fp.getNMembofDim(0);
		starttime = fp.getUnit0ofDim(0);
		dt = fp.getDUnitofDim(0);
		}

	public void copySEGYFileHead(SEGYFileHead fhd)
		{
		copySEGYFileHead(fhd, 1);
		}
	public void copySEGYFileHead(SEGYFileHead fhd, int planes)
		{
		fhd.regularize();
		this.ntrace = fhd.ntrace*planes;
		this.nt = fhd.getnt();
		this.dt = fhd.mudt/1e6F;
		this.starttime = 0F;
		}
	public void copySEGYFileHead(SEGYFileHead fhd, int planes, SEGYTraceHead thd)
		{
		thd.regularize();
		copySEGYFileHead(fhd, planes);
		this.starttime = thd.delay/1e3F;
		}
	public void copyOldRGFileHead(OldRGFileHead ofhd)
		{
		this.ntrace = ofhd.ntrace;
		this.nt = ofhd.nt;
		this.starttime = ofhd.starttime;
		}
	public String toString()
		{
		return "ntrace=" + ntrace + " nt=" + nt
			+ " starttime=" + Viewmat.getSignif("" + starttime)
			+ " dt=" + Viewmat.getSignif("" + dt);
		}
	public boolean isValid()
		{
		if (ntrace < 1 || ntrace > 1000000000
		|| nt < 1 || nt > 1000000000
		|| starttime < -1e10F || starttime > 1e10F
		|| dt < -1e10F || dt > 1e10F || dt == 0F)
			return false;
		return true;
		}
	public void readRgFileHead(String name)
		{
		FileInputStream fis = null;
		BufferedInputStream bis = null;
		DataInputStream dis = null;
		System.out.println("readRgFileHead: reading header from file " + name + " ... ");
		try {fis = new FileInputStream(name); }
		catch(FileNotFoundException fnf)
			{
			System.out.println(fnf.toString());
			return;
			}
		bis = new BufferedInputStream(fis);
		dis = new DataInputStream(bis);
		try {read(dis); }
		catch(IOException ioe)
			{
			System.out.println("Could not read RG header from file " + name);
			return;
			}
		try {fis.close(); }
		catch(IOException ioe)
			{
			System.out.println(ioe.toString());
			return;
			}
		System.out.println("readRgFileHead done.");
		}
	public void read(DataInputStream dis) throws IOException
		{
		ntrace = dis.readInt();
		nt = dis.readInt();
		starttime = dis.readFloat();
		dt = dis.readFloat();
		}
	public void write(DataOutputStream dos) throws IOException
		{
		dos.writeInt(ntrace);
		dos.writeInt(nt);
		dos.writeFloat(starttime);
		dos.writeFloat(dt);
		}
	}