/// <summary>
///This function should be called after all the vertices and polygons for each object
///have been written to the file. The function updates the following information:
///The main chunk length
///The 3D editor chunk length
///The object chunk length
///The triangular mesh chunk length
///The vertices chunk length
///The number of vertices
///The polygons chunk length
///The number of polygons
///Texture information
/// </summary>
public void MakeFinalUpdates()
{
//Copy the polygon data from the temp file to the main file
_polygonDataHandler.CopyPlgnData(ref _writer);
//Write the material information for all the objects
var faceMaterialChunkLength = MaterialChunkWriter.GetMaterialListChunkLength(_polygonDataHandler.PolygonCount);
MaterialChunkWriter.WriteMatInformationForObjFaces(_polygonDataHandler.PolygonCount, faceMaterialChunkLength, _writer);
//Copy the texture data (u,v) values from the temp file to the main file
//Store the length of the texture chunk in a variable before it is reset in the below call
var texCoodChunkLength = 0;
if (_texCoordinatesHandler.DoesTextureValueExist())
{
texCoodChunkLength = _texCoordinatesHandler.MappingCoodChunkLength();
_texCoordinatesHandler.CopyTexCoodData(ref _writer, _polygonDataHandler.PolygonCount);
}
//Calculate the length of the vertices list chunk
var vertChnkLen = (2 + (VertexCount * 3 * sizeof(float)) + 6); //6 for the usual header length
//The first two bytes are for the quantity value written after the vertices header
//Calculate the length of the polygons chunk (faces chunk)
var polsChnkLen = (6 + 2 + (_polygonDataHandler.PolygonCount * 4 * 2) + faceMaterialChunkLength);
//6 for the usual header length
//Calculate the length of the triangular mesh chunk
var meshChnkLen = 6 + vertChnkLen + polsChnkLen + texCoodChunkLength; //Header + sub-chunks
//Calculate the length of the object block chunk
var objChnkLen = 6 + ObjNameLen + meshChnkLen; //6 for header
var prevLen = _writer.BaseStream.Length - objChnkLen;
//Update the object chunk length
var offset = (int)(prevLen + 2); //2 because the chunk length is stored after the chunk id
_writer.Seek(offset, SeekOrigin.Begin);
_writer.Write(objChnkLen);
//Object name is stored at this position in the object chunk
//Update the triangular mesh chunk length
offset += 6 + ObjNameLen;
_writer.Seek(offset, SeekOrigin.Begin);
_writer.Write(meshChnkLen);
//Update the vertices chunk length
offset += 6;
_writer.Seek(offset, SeekOrigin.Begin);
_writer.Write(vertChnkLen);
//Update the number of vertices
_writer.Write(VertexCount);
//Update the polygon chunk length
offset += vertChnkLen;
_writer.Seek(offset, SeekOrigin.Begin);
_writer.Write(polsChnkLen);
//Update the number of polygons
_writer.Write(_polygonDataHandler.PolygonCount);
_polygonDataHandler = null;
_texCoordinatesHandler = null;
}
public static void ExportTo3DS(string filePath, GeometryModel3D modelData, Image textureFileData)
{
//sanity checks
if (modelData == null)
{
throw new ArgumentException("Geometry model info not supplied.");
}
if (!(modelData.Geometry != null && modelData.Geometry is MeshGeometry3D))
{
throw new ArgumentException("Passed model is not of type mesh geometry 3d");
}
//read specific values from xaml file
var modelColor = GetModelColor(modelData);
var mesh = ((MeshGeometry3D)modelData.Geometry);
var containsTextureInfo = ContainsTextureInfo(mesh);
var positionCount = mesh.Positions.Count;
var points = mesh.Positions;
var textures = mesh.TextureCoordinates;
var polygons = mesh.TriangleIndices;
//Open the 3DS file for writing
var writer = InitializeFile(filePath);
//Write Material Info
var textureFileName = MakeTextureFileName(filePath);
MaterialChunkWriter.WriteMaterialChunk(modelColor, containsTextureInfo, textureFileName, writer);
var objectCount = 0;
_3DSObjectDataHandler objHandler = null;
ushort[] setIndicesForObj = null;
bool[] isIndicesSetForObj = null;
ushort positionIndexInObj = 0;
for (var ctr = 0; ctr < polygons.Count; ctr += 3)
{
var createNewObject = objHandler == null ||
objHandler.PolygonCount >= MaxValForUnsignedShort ||
objHandler.TextureCoodCount >= MaxValForUnsignedShort ||
objHandler.VertexCount >= MaxValForUnsignedShort;
if (createNewObject)
{
if (objHandler != null)
{
objHandler.MakeFinalUpdates();
}
objectCount++;
if (objectCount > 9999)
{
throw new Exception("Error: Cannot create 3ds file.\n The number of objects into which the model can be broken down exceeds 9999");
}
objHandler = new _3DSObjectDataHandler(writer, objectCount);
setIndicesForObj = new ushort[positionCount];
isIndicesSetForObj = new bool[positionCount];
positionIndexInObj = 0;
}
var origIndices = new[] { (ushort)polygons[ctr], (ushort)polygons[ctr + 1], (ushort)polygons[ctr + 2] };
var newIndices = new List <ushort>();
foreach (var origIndex in origIndices)
{
if (isIndicesSetForObj[origIndex])
{
newIndices.Add(setIndicesForObj[origIndex]);
}
else
{//Add the new position
//Interchange y and z coordinates and change the sign of y to accomodate
//the difference in the axes orientation between the 3ds and xaml format
var origPoint = points[origIndex];
var point = new Point3D(origPoint.X, -origPoint.Z, origPoint.Y);
objHandler.AddPosition(point);
if (textures != null && textures.Count > origIndex)
{
var texCood = mesh.TextureCoordinates[origIndex];
objHandler.AddTextureIndices((float)texCood.X, (float)texCood.Y);
}
setIndicesForObj[origIndex] = positionIndexInObj;
isIndicesSetForObj[origIndex] = true;
newIndices.Add(positionIndexInObj);
positionIndexInObj++;
}
}
objHandler.AddPolygonIndices(newIndices[0], newIndices[1], newIndices[2]);
}
//Make the final updation call on object data handler
if (objHandler != null)
{
objHandler.MakeFinalUpdates();
}
//Close the 3ds file (after final updations to the header chunks)
UpdateAndCloseFile(writer);
//save the texture image data
SaveTextureImageData(filePath, textureFileData, textureFileName);
}
