/src/assimp/code/AssetLib/Obj/ObjExporter.h

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

Copyright (c) 2006-2026, assimp team


All rights reserved.

Redistribution and use of this software in source and binary forms,
with or without modification, are permitted provided that the
following conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

* Neither the name of the assimp team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the assimp team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 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 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

----------------------------------------------------------------------
*/

/** @file ObjExporter.h
 * Declares the exporter class to write a scene to a Collada file
 */
#ifndef AI_OBJEXPORTER_H_INC
#define AI_OBJEXPORTER_H_INC

#include <assimp/types.h>
#include <sstream>
#include <vector>
#include <map>

#include <assimp/Exporter.hpp>

struct aiScene;
struct aiNode;
struct aiMesh;

namespace Assimp {

// ------------------------------------------------------------------------------------------------
/** Helper class to export a given scene to an OBJ file. */
// ------------------------------------------------------------------------------------------------
class ObjExporter final {
public:
    /// Constructor for a specific scene to export
    ObjExporter(const char* filename, const aiScene* pScene, bool noMtl=false, const ExportProperties* props = nullptr);
    ~ObjExporter();
    std::string GetMaterialLibName();
    std::string GetMaterialLibFileName();

    /// public string-streams to write all output into
    std::ostringstream mOutput, mOutputMat;

private:
    // intermediate data structures
    struct FaceVertex {
        FaceVertex()
        : vp()
        , vn()
        , vt() {
            // empty
        }

        // one-based, 0 means: 'does not exist'
        unsigned int vp, vn, vt;
    };

    struct Face {
        char kind;
        std::vector<FaceVertex> indices;
    };

    struct MeshInstance {
        std::string name, matname;
        std::vector<Face> faces;
    };

    void WriteHeader(std::ostringstream& out);
    void WriteMaterialFile();
    void WriteGeometryFile(bool noMtl=false, bool merge_identical_vertices = false);
    std::string GetMaterialName(unsigned int index);
    void AddMesh(const aiString& name, const aiMesh* m, const aiMatrix4x4& mat, bool merge_identical_vertices);
    void AddNode(const aiNode* nd, const aiMatrix4x4& mParent, bool merge_identical_vertices);

private:
    std::string filename;
    const aiScene* const pScene;

    struct vertexData {
        aiVector3D vp;
        aiColor3D vc; // OBJ does not support 4D color
        uint32_t index = 0;
    };

    std::vector<aiVector3D> vn, vt;
    std::vector<aiColor4D> vc;
    std::vector<vertexData> vp;
    bool useVc;

    struct vertexDataCompare {
        bool operator() ( const vertexData& a, const vertexData& b ) const {
            // position
            if (a.vp.x < b.vp.x) return true;
            if (a.vp.x > b.vp.x) return false;
            if (a.vp.y < b.vp.y) return true;
            if (a.vp.y > b.vp.y) return false;
            if (a.vp.z < b.vp.z) return true;
            if (a.vp.z > b.vp.z) return false;

            // color
            if (a.vc.r < b.vc.r) return true;
            if (a.vc.r > b.vc.r) return false;
            if (a.vc.g < b.vc.g) return true;
            if (a.vc.g > b.vc.g) return false;
            if (a.vc.b < b.vc.b) return true;
            if (a.vc.b > b.vc.b) return false;
            return a.index < b.index;
        }
    };

    struct aiVectorCompare {
        bool operator() (const aiVector3D& a, const aiVector3D& b) const {
            if(a.x < b.x) return true;
            if(a.x > b.x) return false;
            if(a.y < b.y) return true;
            if(a.y > b.y) return false;
            if(a.z < b.z) return true;
            return false;
        }
    };

    template <class T, class Compare = std::less<T>>
    class indexMap {
        int mNextIndex;
        typedef std::map<T, int, Compare> dataType;
        dataType vecMap;

    public:
        indexMap()
        : mNextIndex(1) {
            // empty
        }

        int getIndex(const T& key) {
            typename dataType::iterator vertIt = vecMap.find(key);
            // vertex already exists, so reference it
            if(vertIt != vecMap.end()){
                return vertIt->second;
            }
            return vecMap[key] = mNextIndex++;
        };

        void getKeys( std::vector<T>& keys ) {
            keys.resize(vecMap.size());
            for(typename dataType::iterator it = vecMap.begin(); it != vecMap.end(); ++it){
                keys[it->second-1] = it->first;
            }
        };
    };

    indexMap<aiVector3D, aiVectorCompare> mVnMap, mVtMap;
    indexMap<vertexData, vertexDataCompare> mVpMap;
    std::vector<MeshInstance> mMeshes;

    // this endl() doesn't flush() the stream
    const std::string endl;
};

}

#endif

Line	Count	Source
1		/*
2		Open Asset Import Library (assimp)
3		----------------------------------------------------------------------
4
5		Copyright (c) 2006-2026, assimp team
6
7
8		All rights reserved.
9
10		Redistribution and use of this software in source and binary forms,
11		with or without modification, are permitted provided that the
12		following conditions are met:
13
14		* Redistributions of source code must retain the above
15		copyright notice, this list of conditions and the
16		following disclaimer.
17
18		* Redistributions in binary form must reproduce the above
19		copyright notice, this list of conditions and the
20		following disclaimer in the documentation and/or other
21		materials provided with the distribution.
22
23		* Neither the name of the assimp team, nor the names of its
24		contributors may be used to endorse or promote products
25		derived from this software without specific prior
26		written permission of the assimp team.
27
28		THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29		"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30		LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31		A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32		OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33		SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34		LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35		DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36		THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37		(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38		OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39
40		----------------------------------------------------------------------
41		*/
42
43		/** @file ObjExporter.h
44		* Declares the exporter class to write a scene to a Collada file
45		*/
46		#ifndef AI_OBJEXPORTER_H_INC
47		#define AI_OBJEXPORTER_H_INC
48
49		#include <assimp/types.h>
50		#include <sstream>
51		#include <vector>
52		#include <map>
53
54		#include <assimp/Exporter.hpp>
55
56		struct aiScene;
57		struct aiNode;
58		struct aiMesh;
59
60		namespace Assimp {
61
62		// ------------------------------------------------------------------------------------------------
63		/** Helper class to export a given scene to an OBJ file. */
64		// ------------------------------------------------------------------------------------------------
65		class ObjExporter final {
66		public:
67		/// Constructor for a specific scene to export
68		ObjExporter(const char* filename, const aiScene* pScene, bool noMtl=false, const ExportProperties* props = nullptr);
69		~ObjExporter();
70		std::string GetMaterialLibName();
71		std::string GetMaterialLibFileName();
72
73		/// public string-streams to write all output into
74		std::ostringstream mOutput, mOutputMat;
75
76		private:
77		// intermediate data structures
78		struct FaceVertex {
79		FaceVertex()
80		: vp()
81		, vn()
82	0	, vt() {
83		// empty
84	0	}
85
86		// one-based, 0 means: 'does not exist'
87		unsigned int vp, vn, vt;
88		};
89
90		struct Face {
91		char kind;
92		std::vector<FaceVertex> indices;
93		};
94
95		struct MeshInstance {
96		std::string name, matname;
97		std::vector<Face> faces;
98		};
99
100		void WriteHeader(std::ostringstream& out);
101		void WriteMaterialFile();
102		void WriteGeometryFile(bool noMtl=false, bool merge_identical_vertices = false);
103		std::string GetMaterialName(unsigned int index);
104		void AddMesh(const aiString& name, const aiMesh* m, const aiMatrix4x4& mat, bool merge_identical_vertices);
105		void AddNode(const aiNode* nd, const aiMatrix4x4& mParent, bool merge_identical_vertices);
106
107		private:
108		std::string filename;
109		const aiScene* const pScene;
110
111		struct vertexData {
112		aiVector3D vp;
113		aiColor3D vc; // OBJ does not support 4D color
114		uint32_t index = 0;
115		};
116
117		std::vector<aiVector3D> vn, vt;
118		std::vector<aiColor4D> vc;
119		std::vector<vertexData> vp;
120		bool useVc;
121
122		struct vertexDataCompare {
123	0	bool operator() ( const vertexData& a, const vertexData& b ) const {
124		// position
125	0	if (a.vp.x < b.vp.x) return true;
126	0	if (a.vp.x > b.vp.x) return false;
127	0	if (a.vp.y < b.vp.y) return true;
128	0	if (a.vp.y > b.vp.y) return false;
129	0	if (a.vp.z < b.vp.z) return true;
130	0	if (a.vp.z > b.vp.z) return false;
131
132		// color
133	0	if (a.vc.r < b.vc.r) return true;
134	0	if (a.vc.r > b.vc.r) return false;
135	0	if (a.vc.g < b.vc.g) return true;
136	0	if (a.vc.g > b.vc.g) return false;
137	0	if (a.vc.b < b.vc.b) return true;
138	0	if (a.vc.b > b.vc.b) return false;
139	0	return a.index < b.index;
140	0	}
141		};
142
143		struct aiVectorCompare {
144	0	bool operator() (const aiVector3D& a, const aiVector3D& b) const {
145	0	if(a.x < b.x) return true;
146	0	if(a.x > b.x) return false;
147	0	if(a.y < b.y) return true;
148	0	if(a.y > b.y) return false;
149	0	if(a.z < b.z) return true;
150	0	return false;
151	0	}
152		};
153
154		template <class T, class Compare = std::less<T>>
155		class indexMap {
156		int mNextIndex;
157		typedef std::map<T, int, Compare> dataType;
158		dataType vecMap;
159
160		public:
161		indexMap()
162	0	: mNextIndex(1) {
163		// empty
164	0	} Unexecuted instantiation: Assimp::ObjExporter::indexMap<aiVector3t<float>, Assimp::ObjExporter::aiVectorCompare>::indexMap() Unexecuted instantiation: Assimp::ObjExporter::indexMap<Assimp::ObjExporter::vertexData, Assimp::ObjExporter::vertexDataCompare>::indexMap()
165
166	0	int getIndex(const T& key) {
167	0	typename dataType::iterator vertIt = vecMap.find(key);
168		// vertex already exists, so reference it
169	0	if(vertIt != vecMap.end()){
170	0	return vertIt->second;
171	0	}
172	0	return vecMap[key] = mNextIndex++;
173	0	}; Unexecuted instantiation: Assimp::ObjExporter::indexMap<Assimp::ObjExporter::vertexData, Assimp::ObjExporter::vertexDataCompare>::getIndex(Assimp::ObjExporter::vertexData const&) Unexecuted instantiation: Assimp::ObjExporter::indexMap<aiVector3t<float>, Assimp::ObjExporter::aiVectorCompare>::getIndex(aiVector3t<float> const&)
174
175	0	void getKeys( std::vector<T>& keys ) {
176	0	keys.resize(vecMap.size());
177	0	for(typename dataType::iterator it = vecMap.begin(); it != vecMap.end(); ++it){
178	0	keys[it->second-1] = it->first;
179	0	}
180	0	}; Unexecuted instantiation: Assimp::ObjExporter::indexMap<Assimp::ObjExporter::vertexData, Assimp::ObjExporter::vertexDataCompare>::getKeys(std::__1::vector<Assimp::ObjExporter::vertexData, std::__1::allocator<Assimp::ObjExporter::vertexData> >&) Unexecuted instantiation: Assimp::ObjExporter::indexMap<aiVector3t<float>, Assimp::ObjExporter::aiVectorCompare>::getKeys(std::__1::vector<aiVector3t<float>, std::__1::allocator<aiVector3t<float> > >&)
181		};
182
183		indexMap<aiVector3D, aiVectorCompare> mVnMap, mVtMap;
184		indexMap<vertexData, vertexDataCompare> mVpMap;
185		std::vector<MeshInstance> mMeshes;
186
187		// this endl() doesn't flush() the stream
188		const std::string endl;
189		};
190
191		}
192
193		#endif

Coverage Report

Created: 2026-06-15 06:20