/*++

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are permitted provided that the following conditions are met:

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this list of conditions and the following disclaimer in the documentation
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DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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Abstract:

NMR_MeshExporter_STL.cpp implements the Mesh Exporter Class.
This is a derived class for Exporting the binary STL and color STL Mesh Format.

--*/

#include "Common/MeshExport/NMR_MeshExporter_STL.h" 
#include "Common/MeshImport/NMR_MeshImporter_STL.h" 
#include "Common/Math/NMR_Matrix.h" 
#include "Common/Math/NMR_Vector.h" 
#include "Common/NMR_Exception.h" 
#include <cmath>
#include <list>

namespace NMR {

	CMeshExporter_STL::CMeshExporter_STL() : CMeshExporter()
	{
		// empty on purpose
	}

	CMeshExporter_STL::CMeshExporter_STL(PExportStream pStream) : CMeshExporter(pStream)
	{
		// empty on purpose
	}

	void CMeshExporter_STL::exportMeshEx(_In_ CMesh * pMesh, _In_opt_ NMATRIX3 * pmMatrix, _In_opt_ CMeshExportEdgeMap * pExportEdgeMap)
	{
		if (!pMesh)
			throw CNMRException(NMR_ERROR_INVALIDPARAM);

		CExportStream * pStream = getStream();
		if (!pStream)
			throw CNMRException(NMR_ERROR_NOEXPORTSTREAM);

		nfUint32 nIdx, j;
		nfUint32 nFaceCount = pMesh->getFaceCount();
		MESHFACE * face;
		MESHNODE * node;

		MESHFORMAT_STL_FACET facet;
		std::list<MESHFORMAT_STL_FACET> facetdata;

		for (nIdx = 0; nIdx < nFaceCount; nIdx++) {

			face = pMesh->getFace(nIdx);
			for (j = 0; j < 3; j++) {
				node = pMesh->getNode (face->m_nodeindices[j]);
				if (pmMatrix)
					facet.m_vertices[j] = fnMATRIX3_apply(*pmMatrix, node->m_position);
				else
					facet.m_vertices[j] = node->m_position;
			}	

			// Calculate Triangle Normals
			facet.m_normal = fnVEC3_calcTriangleNormal(facet.m_vertices[0], facet.m_vertices[1], facet.m_vertices[2]);
			facet.m_attribute = 0;

			facetdata.push_back(facet);
		}

		nfByte stlheader[80];
		char HeaderMessage[34] = "STL Export by Lib3MF";
		nfUint32 nFacetCount = (nfUint32) facetdata.size();

		// Fill Header
		for (nIdx = 0; nIdx < 33; nIdx++)
			stlheader[nIdx] = (nfByte)HeaderMessage[nIdx];
		for (nIdx = 33; nIdx < 80; nIdx++)
			stlheader[nIdx] = 32;

		// Write Header
		pStream->writeBuffer(&stlheader[0], 80);
		if (isBigEndian())
			nFacetCount = swapBytes(nFacetCount);
		pStream->writeBuffer(&nFacetCount, sizeof (nFacetCount));

		std::list<MESHFORMAT_STL_FACET>::iterator iter;
		if (isBigEndian()) {
			MESHFORMAT_STL_FACET tmpFacet;
			for (iter = facetdata.begin(); iter != facetdata.end(); iter++) {
				tmpFacet = *iter;
				tmpFacet.swapByteOrder();
				pStream->writeBuffer(&tmpFacet, sizeof(MESHFORMAT_STL_FACET));
			}
		}
		else {
			for (iter = facetdata.begin(); iter != facetdata.end(); iter++) {
				pStream->writeBuffer(&(*iter), sizeof(MESHFORMAT_STL_FACET));
			}
		}
	}

}
