assimp/code/STLExporter.cpp

/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

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All rights reserved.

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  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
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  following disclaimer in the documentation and/or other
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* Neither the name of the assimp team, nor the names of its
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  written permission of the assimp team.

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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
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*/



#if !defined(ASSIMP_BUILD_NO_EXPORT) && !defined(ASSIMP_BUILD_NO_STL_EXPORTER)

#include "STLExporter.h"
#include "../include/assimp/version.h"
#include "../include/assimp/IOSystem.hpp"
#include "../include/assimp/scene.h"
#include "../include/assimp/Exporter.hpp"
#include <boost/scoped_ptr.hpp>
#include "Exceptional.h"
#include "ByteSwapper.h"

using namespace Assimp;
namespace Assimp	{

// ------------------------------------------------------------------------------------------------
// Worker function for exporting a scene to Stereolithograpy. Prototyped and registered in Exporter.cpp
void ExportSceneSTL(const char* pFile,IOSystem* pIOSystem, const aiScene* pScene, const ExportProperties* pProperties)
{
	// invoke the exporter 
	STLExporter exporter(pFile, pScene);

	// we're still here - export successfully completed. Write the file.
	boost::scoped_ptr<IOStream> outfile (pIOSystem->Open(pFile,"wt"));
	if(outfile == NULL) {
		throw DeadlyExportError("could not open output .stl file: " + std::string(pFile));
	}

	outfile->Write( exporter.mOutput.str().c_str(), static_cast<size_t>(exporter.mOutput.tellp()),1);
}
void ExportSceneSTLBinary(const char* pFile,IOSystem* pIOSystem, const aiScene* pScene, const ExportProperties* pProperties)
{
	// invoke the exporter 
	STLExporter exporter(pFile, pScene, true);

	// we're still here - export successfully completed. Write the file.
	boost::scoped_ptr<IOStream> outfile (pIOSystem->Open(pFile,"wb"));
	if(outfile == NULL) {
		throw DeadlyExportError("could not open output .stl file: " + std::string(pFile));
	}

	outfile->Write( exporter.mOutput.str().c_str(), static_cast<size_t>(exporter.mOutput.tellp()),1);
}

} // end of namespace Assimp


// ------------------------------------------------------------------------------------------------
STLExporter :: STLExporter(const char* _filename, const aiScene* pScene, bool binary)
: filename(_filename)
, endl("\n")
{
	// make sure that all formatting happens using the standard, C locale and not the user's current locale
	const std::locale& l = std::locale("C");
	mOutput.imbue(l);
	if (binary) {
		char buf[80] = {0} ;
		buf[0] = 'A'; buf[1] = 's'; buf[2] = 's'; buf[3] = 'i'; buf[4] = 'm'; buf[5] = 'p';
		buf[6] = 'S'; buf[7] = 'c'; buf[8] = 'e'; buf[9] = 'n'; buf[10] = 'e';
		mOutput.write(buf, 80);
		unsigned int meshnum = 0;
		for(unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
			for (unsigned int j = 0; j < pScene->mMeshes[i]->mNumFaces; ++j) {
				meshnum++;
			}
		}
		AI_SWAP4(meshnum);
		mOutput.write((char *)&meshnum, 4);
		for(unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
			WriteMeshBinary(pScene->mMeshes[i]);
		}
	} else {
		const std::string& name = "AssimpScene";
	
		mOutput << "solid " << name << endl;
		for(unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
			WriteMesh(pScene->mMeshes[i]);
		}
		mOutput << "endsolid " << name << endl;
	}
}

// ------------------------------------------------------------------------------------------------
void STLExporter :: WriteMesh(const aiMesh* m)
{
	for (unsigned int i = 0; i < m->mNumFaces; ++i) {
		const aiFace& f = m->mFaces[i];

		// we need per-face normals. We specified aiProcess_GenNormals as pre-requisite for this exporter,
		// but nonetheless we have to expect per-vertex normals.
		aiVector3D nor;
		if (m->mNormals) {
			for(unsigned int a = 0; a < f.mNumIndices; ++a) {
				nor += m->mNormals[f.mIndices[a]];
			}
			nor.Normalize();
		}
		mOutput << " facet normal " << nor.x << " " << nor.y << " " << nor.z << endl;
		mOutput << "  outer loop" << endl; 
		for(unsigned int a = 0; a < f.mNumIndices; ++a) {
			const aiVector3D& v  = m->mVertices[f.mIndices[a]];
			mOutput << "  vertex " << v.x << " " << v.y << " " << v.z << endl;
		}

		mOutput << "  endloop" << endl; 
		mOutput << " endfacet" << endl << endl; 
	}
}

void STLExporter :: WriteMeshBinary(const aiMesh* m)
{
	for (unsigned int i = 0; i < m->mNumFaces; ++i) {
		const aiFace& f = m->mFaces[i];
		// we need per-face normals. We specified aiProcess_GenNormals as pre-requisite for this exporter,
		// but nonetheless we have to expect per-vertex normals.
		aiVector3D nor;
		if (m->mNormals) {
			for(unsigned int a = 0; a < f.mNumIndices; ++a) {
				nor += m->mNormals[f.mIndices[a]];
			}
			nor.Normalize();
		}
		float nx = nor.x, ny = nor.y, nz = nor.z;
		AI_SWAP4(nx); AI_SWAP4(ny); AI_SWAP4(nz);
		mOutput.write((char *)&nx, 4); mOutput.write((char *)&ny, 4); mOutput.write((char *)&nz, 4);
		for(unsigned int a = 0; a < f.mNumIndices; ++a) {
			const aiVector3D& v  = m->mVertices[f.mIndices[a]];
			float vx = v.x, vy = v.y, vz = v.z;
			AI_SWAP4(vx); AI_SWAP4(vy); AI_SWAP4(vz);
			mOutput.write((char *)&vx, 4); mOutput.write((char *)&vy, 4); mOutput.write((char *)&vz, 4);
		}
		char dummy[2] = {0};
		mOutput.write(dummy, 2);
	}
}

#endif