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* notice, this list of conditions and the following disclaimer in the
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* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
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using System;
using System.IO;
using System.Text;
using OpenSim.Region.Framework.Interfaces;
using OpenSim.Region.Framework.Scenes;
using OpenSim.Framework;
namespace OpenSim.Region.CoreModules.World.Terrain.FileLoaders
{
///
/// Terragen File Format Loader
/// Built from specification at
/// http://www.planetside.co.uk/terragen/dev/tgterrain.html
///
internal class Terragen : ITerrainLoader
{
#region ITerrainLoader Members
public ITerrainChannel LoadFile(string filename)
{
FileInfo file = new FileInfo(filename);
FileStream s = file.Open(FileMode.Open, FileAccess.Read);
ITerrainChannel retval = LoadStream(s);
s.Close();
return retval;
}
public ITerrainChannel LoadFile(string filename, int offsetX, int offsetY, int fileWidth, int fileHeight, int sectionWidth, int sectionHeight)
{
TerrainChannel retval = new TerrainChannel(sectionWidth, sectionHeight);
FileInfo file = new FileInfo(filename);
FileStream s = file.Open(FileMode.Open, FileAccess.Read);
BinaryReader bs = new BinaryReader(s);
bool eof = false;
int fileXPoints = 0;
int fileYPoints = 0;
// Terragen file
while (eof == false)
{
string tmp = Encoding.ASCII.GetString(bs.ReadBytes(4));
switch (tmp)
{
case "SIZE":
fileXPoints = bs.ReadInt16() + 1;
fileYPoints = fileXPoints;
bs.ReadInt16();
break;
case "XPTS":
fileXPoints = bs.ReadInt16();
bs.ReadInt16();
break;
case "YPTS":
fileYPoints = bs.ReadInt16();
bs.ReadInt16();
break;
case "ALTW":
eof = true;
Int16 heightScale = bs.ReadInt16();
Int16 baseHeight = bs.ReadInt16();
int currFileYOffset = 0;
// if our region isn't on the first X section of the areas to be landscaped, then
// advance to our section of the file
while (currFileYOffset < offsetY)
{
// read a whole strip of regions
int heightsToRead = sectionHeight * fileXPoints;
bs.ReadBytes(heightsToRead * 2); // because the shorts are 2 bytes in the file
currFileYOffset++;
}
for (int y = 0; y < sectionHeight; y++)
{
int currFileXOffset = 0;
// if our region isn't the first X section of the areas to be landscaped, then
// advance the stream to the X start pos of our section in the file
// i.e. eat X upto where we start
while (currFileXOffset < offsetX)
{
bs.ReadBytes(sectionWidth * 2); // 2 bytes = short
currFileXOffset++;
}
// got to our X offset, so write our regions X line
for (int x = 0; x < sectionWidth; x++)
{
// Read a strip and continue
retval[x, y] = baseHeight + bs.ReadInt16() * (float)heightScale / 65536.0f;
}
// record that we wrote it
currFileXOffset++;
// if our region isn't the last X section of the areas to be landscaped, then
// advance the stream to the end of this Y column
while (currFileXOffset < fileWidth)
{
// eat the next regions x line
bs.ReadBytes(sectionWidth * 2); // 2 bytes = short
currFileXOffset++;
}
//eat the last additional point
bs.ReadInt16();
}
break;
default:
bs.ReadInt32();
break;
}
}
bs.Close();
s.Close();
return retval;
}
public ITerrainChannel LoadStream(Stream s)
{
// Set to default size
int w = (int)Constants.RegionSize;
int h = (int)Constants.RegionSize;
// create a dummy channel (in case data is bad)
TerrainChannel retval = new TerrainChannel(w, h);
BinaryReader bs = new BinaryReader(s);
bool eof = false;
if (Encoding.ASCII.GetString(bs.ReadBytes(16)) == "TERRAGENTERRAIN ")
{
// Terragen file
while (eof == false)
{
string tmp = Encoding.ASCII.GetString(bs.ReadBytes(4));
switch (tmp)
{
case "SIZE":
w = bs.ReadInt16() + 1;
h = w;
bs.ReadInt16();
break;
case "XPTS":
w = bs.ReadInt16();
bs.ReadInt16();
break;
case "YPTS":
h = bs.ReadInt16();
bs.ReadInt16();
break;
case "ALTW":
eof = true;
// create new channel of proper size (now that we know it)
retval = new TerrainChannel(w, h);
float heightScale = bs.ReadInt16() / 65536.0f;
float baseHeight = bs.ReadInt16();
for (int y = 0; y < h; y++)
{
for (int x = 0; x < w; x++)
{
retval[x, y] = baseHeight + bs.ReadInt16() * heightScale;
}
}
break;
default:
bs.ReadInt32();
break;
}
}
}
bs.Close();
return retval;
}
public void SaveFile(string filename, ITerrainChannel map)
{
FileInfo file = new FileInfo(filename);
FileStream s = file.Open(FileMode.Create, FileAccess.Write);
SaveStream(s, map);
s.Close();
}
public void SaveStream(Stream stream, ITerrainChannel map)
{
BinaryWriter bs = new BinaryWriter(stream);
//find the max and min heights on the map
float heightMax = map[0,0];
float heightMin = map[0,0];
for (int y = 0; y < map.Height; y++)
{
for (int x = 0; x < map.Width; x++)
{
float current = map[x,y];
if (heightMax < current)
heightMax = current;
if (heightMin > current)
heightMin = current;
}
}
float baseHeight = (float)Math.Floor(0.5f * (heightMax + heightMin));
float horizontalScale = (float) Math.Ceiling((heightMax - heightMin));
// if we are completely flat add 1cm range to avoid NaN divisions
if (horizontalScale < 0.01f)
horizontalScale = 0.01f;
Encoding enc = Encoding.ASCII;
bs.Write(enc.GetBytes("TERRAGENTERRAIN "));
bs.Write(enc.GetBytes("SIZE"));
bs.Write(Convert.ToInt16(map.Width));
bs.Write(Convert.ToInt16(0)); // necessary padding
//The XPTS and YPTS chunks are not needed for square regions
//but L3DT won't load the terrain file properly without them.
bs.Write(enc.GetBytes("XPTS"));
bs.Write(Convert.ToInt16(map.Width));
bs.Write(Convert.ToInt16(0)); // necessary padding
bs.Write(enc.GetBytes("YPTS"));
bs.Write(Convert.ToInt16(map.Height));
bs.Write(Convert.ToInt16(0)); // necessary padding
bs.Write(enc.GetBytes("SCAL"));
bs.Write(ToLittleEndian(1f)); //we're going to say that 1 terrain unit is 1 metre
bs.Write(ToLittleEndian(1f));
bs.Write(ToLittleEndian(1f));
// as we are square and not projected on a sphere then the other
// header blocks are not required
// now write the elevation data
bs.Write(enc.GetBytes("ALTW"));
bs.Write(Convert.ToInt16(horizontalScale)); // range between max and min
bs.Write(Convert.ToInt16(baseHeight)); // base height or mid point
double factor = 65536.0 / horizontalScale; // avoid computing this on each iteration
for (int y = 0; y < map.Height; y++)
{
for (int x = 0; x < map.Width; x++)
{
float elevation = (float)((map[x,y] - baseHeight) * factor); // see LoadStream for inverse
// clamp rounding issues
if (elevation > Int16.MaxValue)
elevation = Int16.MaxValue;
else if (elevation < Int16.MinValue)
elevation = Int16.MinValue;
bs.Write(Convert.ToInt16(elevation));
}
}
//This is necessary for older versions of Terragen.
bs.Write(enc.GetBytes("EOF "));
bs.Close();
}
public string FileExtension
{
get { return ".ter"; }
}
public virtual void SaveFile(ITerrainChannel m_channel, string filename,
int offsetX, int offsetY,
int fileWidth, int fileHeight,
int regionSizeX, int regionSizeY)
{
throw new System.Exception("Not Implemented");
}
#endregion
public override string ToString()
{
return "Terragen";
}
//Returns true if this extension is supported for terrain save-tile
public bool SupportsTileSave()
{
return false;
}
///
/// terragen SCAL floats need to be written intel ordered regardless of
/// big or little endian system
///
///
///
private byte[] ToLittleEndian( float number)
{
byte[] retVal = BitConverter.GetBytes(number);
if (BitConverter.IsLittleEndian == false)
{
byte[] tmp = new byte[4];
for (int i = 3; i >= 0; i--)
{
tmp[i] = retVal[3 - i];
}
retVal = tmp;
}
return retVal ;
}
}
}