Some cleanup of M3D support

Wrap the m3d.h header
Note: C++11 support required to use in a threaded environment
Fix export memory leak (although exporter apopears to be unused)
Apply clangformat.

code/CMakeLists.txt

@@ -411,6 +411,8 @@ ADD_ASSIMP_IMPORTER( M3D
   M3D/M3DMaterials.h
   M3D/M3DImporter.h
   M3D/M3DImporter.cpp
+  M3D/M3DWrapper.h
+  M3D/M3DWrapper.cpp
   M3D/m3d.h
 )
 

code/M3D/M3DExporter.cpp

@@ -55,17 +55,19 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <string>
 #include <vector>
 
-#include <assimp/version.h> // aiGetVersion
-#include <assimp/IOSystem.hpp>
-#include <assimp/Exporter.hpp>
-#include <assimp/DefaultLogger.hpp>
-#include <assimp/StreamWriter.h> // StreamWriterLE
 #include <assimp/Exceptional.h> // DeadlyExportError
+#include <assimp/StreamWriter.h> // StreamWriterLE
 #include <assimp/material.h> // aiTextureType
-#include <assimp/scene.h>
 #include <assimp/mesh.h>
+#include <assimp/scene.h>
+#include <assimp/version.h> // aiGetVersion
+#include <assimp/DefaultLogger.hpp>
+#include <assimp/Exporter.hpp>
+#include <assimp/IOSystem.hpp>
+
 #include "M3DExporter.h"
 #include "M3DMaterials.h"
+#include "M3DWrapper.h"
 
 // RESOURCES:
 // https://gitlab.com/bztsrc/model3d/blob/master/docs/m3d_format.md
@@ -80,341 +82,331 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  - aiAnimation -> m3d_action (frame with timestamp and list of bone id, position, orientation
  *      triplets, instead of per bone timestamp + lists)
  */
-using namespace Assimp;
-
-namespace Assimp {
-
-    // ---------------------------------------------------------------------
-    // Worker function for exporting a scene to binary M3D.
-    // Prototyped and registered in Exporter.cpp
-    void ExportSceneM3D (
-        const char* pFile,
-        IOSystem* pIOSystem,
-        const aiScene* pScene,
-        const ExportProperties* pProperties
-    ){
-        // initialize the exporter
-        M3DExporter exporter(pScene, pProperties);
-
-        // perform binary export
-        exporter.doExport(pFile, pIOSystem, false);
-    }
-
-    // ---------------------------------------------------------------------
-    // Worker function for exporting a scene to ASCII A3D.
-    // Prototyped and registered in Exporter.cpp
-    void ExportSceneA3D (
-        const char* pFile,
-        IOSystem* pIOSystem,
-        const aiScene* pScene,
-        const ExportProperties* pProperties
-
-    ){
-        // initialize the exporter
-        M3DExporter exporter(pScene, pProperties);
-
-        // perform ascii export
-        exporter.doExport(pFile, pIOSystem, true);
-    }
-
-} // end of namespace Assimp
-
-// ------------------------------------------------------------------------------------------------
-M3DExporter::M3DExporter ( const aiScene* pScene, const ExportProperties* pProperties )
-: mScene(pScene)
-, mProperties(pProperties)
-, outfile()
-, m3d(nullptr) { }
 
 // ------------------------------------------------------------------------------------------------
-void M3DExporter::doExport (
-    const char* pFile,
-    IOSystem* pIOSystem,
-    bool toAscii
-){
-    // TODO: convert mProperties into M3D_EXP_* flags
-    (void)mProperties;
-
-    // open the indicated file for writing (in binary / ASCII mode)
-    outfile.reset(pIOSystem->Open(pFile, toAscii ? "wt" : "wb"));
-    if (!outfile) {
-        throw DeadlyExportError( "could not open output .m3d file: " + std::string(pFile) );
-    }
-
-    // use malloc() here because m3d_free() will call free()
-    m3d = (m3d_t*)calloc(1, sizeof(m3d_t));
-    if(!m3d) {
-        throw DeadlyExportError( "memory allocation error" );
-    }
-    m3d->name = _m3d_safestr((char*)&mScene->mRootNode->mName.data, 2);
-
-    // Create a model from assimp structures
-    aiMatrix4x4 m;
-    NodeWalk(mScene->mRootNode, m);
-
-    // serialize the structures
-    unsigned int size;
-    unsigned char *output = m3d_save(m3d, M3D_EXP_FLOAT,
-        M3D_EXP_EXTRA | (toAscii ? M3D_EXP_ASCII : 0), &size);
-    m3d_free(m3d);
-    if(!output || size < 8) {
-        throw DeadlyExportError( "unable to serialize into Model 3D" );
-    }
-
-    // Write out serialized model
-    outfile->Write(output, size, 1);
-
-    // explicitly release file pointer,
-    // so we don't have to rely on class destruction.
-    outfile.reset();
-}
-
-
+// Conversion functions
 // ------------------------------------------------------------------------------------------------
 // helper to add a vertex (private to NodeWalk)
-m3dv_t *M3DExporter::AddVrtx(m3dv_t *vrtx, uint32_t *numvrtx, m3dv_t *v, uint32_t *idx)
-{
-    if(v->x == (M3D_FLOAT)-0.0) v->x = (M3D_FLOAT)0.0;
-    if(v->y == (M3D_FLOAT)-0.0) v->y = (M3D_FLOAT)0.0;
-    if(v->z == (M3D_FLOAT)-0.0) v->z = (M3D_FLOAT)0.0;
-    if(v->w == (M3D_FLOAT)-0.0) v->w = (M3D_FLOAT)0.0;
-    vrtx = (m3dv_t*)M3D_REALLOC(vrtx, ((*numvrtx) + 1) * sizeof(m3dv_t));
-    memcpy(&vrtx[*numvrtx], v, sizeof(m3dv_t));
-    *idx = *numvrtx;
-    (*numvrtx)++;
-    return vrtx;
+m3dv_t *AddVrtx(m3dv_t *vrtx, uint32_t *numvrtx, m3dv_t *v, uint32_t *idx) {
+	if (v->x == (M3D_FLOAT)-0.0) v->x = (M3D_FLOAT)0.0;
+	if (v->y == (M3D_FLOAT)-0.0) v->y = (M3D_FLOAT)0.0;
+	if (v->z == (M3D_FLOAT)-0.0) v->z = (M3D_FLOAT)0.0;
+	if (v->w == (M3D_FLOAT)-0.0) v->w = (M3D_FLOAT)0.0;
+	vrtx = (m3dv_t *)M3D_REALLOC(vrtx, ((*numvrtx) + 1) * sizeof(m3dv_t));
+	memcpy(&vrtx[*numvrtx], v, sizeof(m3dv_t));
+	*idx = *numvrtx;
+	(*numvrtx)++;
+	return vrtx;
 }
 
 // ------------------------------------------------------------------------------------------------
 // helper to add a tmap (private to NodeWalk)
-m3dti_t *M3DExporter::AddTmap(m3dti_t *tmap, uint32_t *numtmap, m3dti_t *ti, uint32_t *idx)
-{
-    tmap = (m3dti_t*)M3D_REALLOC(tmap, ((*numtmap) + 1) * sizeof(m3dti_t));
-    memcpy(&tmap[*numtmap], ti, sizeof(m3dti_t));
-    *idx = *numtmap;
-    (*numtmap)++;
-    return tmap;
+m3dti_t *AddTmap(m3dti_t *tmap, uint32_t *numtmap, m3dti_t *ti, uint32_t *idx) {
+	tmap = (m3dti_t *)M3D_REALLOC(tmap, ((*numtmap) + 1) * sizeof(m3dti_t));
+	memcpy(&tmap[*numtmap], ti, sizeof(m3dti_t));
+	*idx = *numtmap;
+	(*numtmap)++;
+	return tmap;
 }
 
 // ------------------------------------------------------------------------------------------------
-// recursive node walker
-void M3DExporter::NodeWalk(const aiNode* pNode, aiMatrix4x4 m)
-{
-    aiMatrix4x4 nm = m * pNode->mTransformation;
-
-    for(unsigned int i = 0; i < pNode->mNumMeshes; i++) {
-        const aiMesh *mesh = mScene->mMeshes[pNode->mMeshes[i]];
-        unsigned int mi = (M3D_INDEX)-1U;
-        if(mScene->mMaterials) {
-            // get the material for this mesh
-            mi = addMaterial(mScene->mMaterials[mesh->mMaterialIndex]);
-        }
-        // iterate through the mesh faces
-        for(unsigned int j = 0; j < mesh->mNumFaces; j++) {
-            unsigned int n;
-            const aiFace* face = &(mesh->mFaces[j]);
-            // only triangle meshes supported for now
-            if(face->mNumIndices != 3) {
-                throw DeadlyExportError( "use aiProcess_Triangulate before export" );
-            }
-            // add triangle to the output
-            n = m3d->numface++;
-            m3d->face = (m3df_t*)M3D_REALLOC(m3d->face,
-                m3d->numface * sizeof(m3df_t));
-            if(!m3d->face) {
-                throw DeadlyExportError( "memory allocation error" );
-            }
-            /* set all index to -1 by default */
-            m3d->face[n].vertex[0] = m3d->face[n].vertex[1] = m3d->face[n].vertex[2] =
-            m3d->face[n].normal[0] = m3d->face[n].normal[1] = m3d->face[n].normal[2] =
-            m3d->face[n].texcoord[0] = m3d->face[n].texcoord[1] = m3d->face[n].texcoord[2] = -1U;
-            m3d->face[n].materialid = mi;
-            for(unsigned int k = 0; k < face->mNumIndices; k++) {
-                // get the vertex's index
-                unsigned int l = face->mIndices[k];
-                unsigned int idx;
-                m3dv_t vertex;
-                m3dti_t ti;
-                // multiply the position vector by the transformation matrix
-                aiVector3D v = mesh->mVertices[l];
-                v *= nm;
-                vertex.x = v.x;
-                vertex.y = v.y;
-                vertex.z = v.z;
-                vertex.w = 1.0;
-                vertex.color = 0;
-                vertex.skinid = -1U;
-                // add color if defined
-                if(mesh->HasVertexColors(0))
-                    vertex.color = mkColor(&mesh->mColors[0][l]);
-                // save the vertex to the output
-                m3d->vertex = AddVrtx(m3d->vertex, &m3d->numvertex,
-                    &vertex, &idx);
-                m3d->face[n].vertex[k] = (M3D_INDEX)idx;
-                // do we have texture coordinates?
-                if(mesh->HasTextureCoords(0)) {
-                    ti.u = mesh->mTextureCoords[0][l].x;
-                    ti.v = mesh->mTextureCoords[0][l].y;
-                    m3d->tmap = AddTmap(m3d->tmap, &m3d->numtmap, &ti, &idx);
-                    m3d->face[n].texcoord[k] = (M3D_INDEX)idx;
-                }
-                // do we have normal vectors?
-                if(mesh->HasNormals()) {
-                    vertex.x = mesh->mNormals[l].x;
-                    vertex.y = mesh->mNormals[l].y;
-                    vertex.z = mesh->mNormals[l].z;
-                    vertex.color = 0;
-                    m3d->vertex = AddVrtx(m3d->vertex, &m3d->numvertex, &vertex, &idx);
-                    m3d->face[n].normal[k] = (M3D_INDEX)idx;
-                }
-            }
-        }
-    }
-    // repeat for the children nodes
-    for (unsigned int i = 0; i < pNode->mNumChildren; i++) {
-        NodeWalk(pNode->mChildren[i], nm);
-    }
+// convert aiColor4D into uint32_t
+uint32_t mkColor(aiColor4D *c) {
+	return ((uint8_t)(c->a * 255) << 24L) |
+		   ((uint8_t)(c->b * 255) << 16L) |
+		   ((uint8_t)(c->g * 255) << 8L) |
+		   ((uint8_t)(c->r * 255) << 0L);
 }
 
 // ------------------------------------------------------------------------------------------------
-// convert aiColor4D into uint32_t
-uint32_t M3DExporter::mkColor(aiColor4D* c)
-{
-    return  ((uint8_t)(c->a*255) << 24L) |
-            ((uint8_t)(c->b*255) << 16L) |
-            ((uint8_t)(c->g*255) <<  8L) |
-            ((uint8_t)(c->r*255) <<  0L);
+// add a material property to the output
+void addProp(m3dm_t *m, uint8_t type, uint32_t value) {
+	unsigned int i;
+	i = m->numprop++;
+	m->prop = (m3dp_t *)M3D_REALLOC(m->prop, m->numprop * sizeof(m3dp_t));
+	if (!m->prop) {
+		throw DeadlyExportError("memory allocation error");
+	}
+	m->prop[i].type = type;
+	m->prop[i].value.num = value;
 }
 
 // ------------------------------------------------------------------------------------------------
 // add a material to the output
-M3D_INDEX M3DExporter::addMaterial(const aiMaterial *mat)
-{
-    unsigned int mi = -1U;
-    aiColor4D c;
-    aiString name;
-    ai_real f;
-    char *fn;
-
-    if(mat && mat->Get(AI_MATKEY_NAME, name) == AI_SUCCESS && name.length &&
-        strcmp((char*)&name.data, AI_DEFAULT_MATERIAL_NAME)) {
-        // check if we have saved a material by this name. This has to be done
-        // because only the referenced materials should be added to the output
-        for(unsigned int i = 0; i < m3d->nummaterial; i++)
-            if(!strcmp((char*)&name.data, m3d->material[i].name)) {
-                mi = i;
-                break;
-            }
-        // if not found, add the material to the output
-        if(mi == -1U) {
-            unsigned int k;
-            mi = m3d->nummaterial++;
-            m3d->material = (m3dm_t*)M3D_REALLOC(m3d->material, m3d->nummaterial
-                * sizeof(m3dm_t));
-            if(!m3d->material) {
-                throw DeadlyExportError( "memory allocation error" );
-            }
-            m3d->material[mi].name = _m3d_safestr((char*)&name.data, 0);
-            m3d->material[mi].numprop = 0;
-            m3d->material[mi].prop = NULL;
-            // iterate through the material property table and see what we got
-            for(k = 0; k < 15; k++) {
-                unsigned int j;
-                if(m3d_propertytypes[k].format == m3dpf_map)
-                    continue;
-                if(aiProps[k].pKey) {
-                    switch(m3d_propertytypes[k].format) {
-                        case m3dpf_color:
-                            if(mat->Get(aiProps[k].pKey, aiProps[k].type,
-                                aiProps[k].index, c) == AI_SUCCESS)
-                                addProp(&m3d->material[mi],
-                                    m3d_propertytypes[k].id, mkColor(&c));
-                        break;
-                        case m3dpf_float:
-                            if(mat->Get(aiProps[k].pKey, aiProps[k].type,
-                                aiProps[k].index, f) == AI_SUCCESS)
-                                    addProp(&m3d->material[mi],
-                                        m3d_propertytypes[k].id,
-                                        /* not (uint32_t)f, because we don't want to convert
+M3D_INDEX addMaterial(const Assimp::M3DWrapper &m3d, const aiMaterial *mat) {
+	unsigned int mi = -1U;
+	aiColor4D c;
+	aiString name;
+	ai_real f;
+	char *fn;
+
+	if (mat && mat->Get(AI_MATKEY_NAME, name) == AI_SUCCESS && name.length &&
+			strcmp((char *)&name.data, AI_DEFAULT_MATERIAL_NAME)) {
+		// check if we have saved a material by this name. This has to be done
+		// because only the referenced materials should be added to the output
+		for (unsigned int i = 0; i < m3d->nummaterial; i++)
+			if (!strcmp((char *)&name.data, m3d->material[i].name)) {
+				mi = i;
+				break;
+			}
+		// if not found, add the material to the output
+		if (mi == -1U) {
+			unsigned int k;
+			mi = m3d->nummaterial++;
+			m3d->material = (m3dm_t *)M3D_REALLOC(m3d->material, m3d->nummaterial * sizeof(m3dm_t));
+			if (!m3d->material) {
+				throw DeadlyExportError("memory allocation error");
+			}
+			m3d->material[mi].name = _m3d_safestr((char *)&name.data, 0);
+			m3d->material[mi].numprop = 0;
+			m3d->material[mi].prop = NULL;
+			// iterate through the material property table and see what we got
+			for (k = 0; k < 15; k++) {
+				unsigned int j;
+				if (m3d_propertytypes[k].format == m3dpf_map)
+					continue;
+				if (aiProps[k].pKey) {
+					switch (m3d_propertytypes[k].format) {
+						case m3dpf_color:
+							if (mat->Get(aiProps[k].pKey, aiProps[k].type,
+										aiProps[k].index, c) == AI_SUCCESS)
+								addProp(&m3d->material[mi],
+										m3d_propertytypes[k].id, mkColor(&c));
+							break;
+						case m3dpf_float:
+							if (mat->Get(aiProps[k].pKey, aiProps[k].type,
+										aiProps[k].index, f) == AI_SUCCESS)
+								addProp(&m3d->material[mi],
+										m3d_propertytypes[k].id,
+										/* not (uint32_t)f, because we don't want to convert
                                          * it, we want to see it as 32 bits of memory */
-                                        *((uint32_t*)&f));
-                        break;
-                        case m3dpf_uint8:
-                            if(mat->Get(aiProps[k].pKey, aiProps[k].type,
-                                aiProps[k].index, j) == AI_SUCCESS) {
-                                // special conversion for illumination model property
-                                if(m3d_propertytypes[k].id == m3dp_il) {
-                                    switch(j) {
-                                        case aiShadingMode_NoShading: j = 0; break;
-                                        case aiShadingMode_Phong: j = 2; break;
-                                        default: j = 1; break;
-                                    }
-                                }
-                                addProp(&m3d->material[mi],
-                                    m3d_propertytypes[k].id, j);
-                            }
-                        break;
-                        default:
-                            if(mat->Get(aiProps[k].pKey, aiProps[k].type,
-                                aiProps[k].index, j) == AI_SUCCESS)
-                                addProp(&m3d->material[mi],
-                                    m3d_propertytypes[k].id, j);
-                        break;
-                    }
-                }
-                if(aiTxProps[k].pKey &&
-                    mat->GetTexture((aiTextureType)aiTxProps[k].type,
-                        aiTxProps[k].index, &name, NULL, NULL, NULL,
-                        NULL, NULL) == AI_SUCCESS) {
-                        unsigned int i;
-                        for(j = name.length-1; j > 0 && name.data[j]!='.'; j++);
-                        if(j && name.data[j]=='.' &&
-                            (name.data[j+1]=='p' || name.data[j+1]=='P') &&
-                            (name.data[j+1]=='n' || name.data[j+1]=='N') &&
-                            (name.data[j+1]=='g' || name.data[j+1]=='G'))
-                                name.data[j]=0;
-                        // do we have this texture saved already?
-                        fn = _m3d_safestr((char*)&name.data, 0);
-                        for(j = 0, i = -1U; j < m3d->numtexture; j++)
-                            if(!strcmp(fn, m3d->texture[j].name)) {
-                                i = j;
-                                free(fn);
-                                break;
-                        }
-                        if(i == -1U) {
-                            i = m3d->numtexture++;
-                            m3d->texture = (m3dtx_t*)M3D_REALLOC(
-                                m3d->texture,
-                                m3d->numtexture * sizeof(m3dtx_t));
-                            if(!m3d->texture) {
-                                throw DeadlyExportError( "memory allocation error" );
-                            }
-                            // we don't need the texture itself, only its name
-                            m3d->texture[i].name = fn;
-                            m3d->texture[i].w = 0;
-                            m3d->texture[i].h = 0;
-                            m3d->texture[i].d = NULL;
-                        }
-                        addProp(&m3d->material[mi],
-                            m3d_propertytypes[k].id + 128, i);
-                }
-            }
-        }
-    }
-    return mi;
+										*((uint32_t *)&f));
+							break;
+						case m3dpf_uint8:
+							if (mat->Get(aiProps[k].pKey, aiProps[k].type,
+										aiProps[k].index, j) == AI_SUCCESS) {
+								// special conversion for illumination model property
+								if (m3d_propertytypes[k].id == m3dp_il) {
+									switch (j) {
+										case aiShadingMode_NoShading: j = 0; break;
+										case aiShadingMode_Phong: j = 2; break;
+										default: j = 1; break;
+									}
+								}
+								addProp(&m3d->material[mi],
+										m3d_propertytypes[k].id, j);
+							}
+							break;
+						default:
+							if (mat->Get(aiProps[k].pKey, aiProps[k].type,
+										aiProps[k].index, j) == AI_SUCCESS)
+								addProp(&m3d->material[mi],
+										m3d_propertytypes[k].id, j);
+							break;
+					}
+				}
+				if (aiTxProps[k].pKey &&
+						mat->GetTexture((aiTextureType)aiTxProps[k].type,
+								aiTxProps[k].index, &name, NULL, NULL, NULL,
+								NULL, NULL) == AI_SUCCESS) {
+					unsigned int i;
+					for (j = name.length - 1; j > 0 && name.data[j] != '.'; j++)
+						;
+					if (j && name.data[j] == '.' &&
+							(name.data[j + 1] == 'p' || name.data[j + 1] == 'P') &&
+							(name.data[j + 1] == 'n' || name.data[j + 1] == 'N') &&
+							(name.data[j + 1] == 'g' || name.data[j + 1] == 'G'))
+						name.data[j] = 0;
+					// do we have this texture saved already?
+					fn = _m3d_safestr((char *)&name.data, 0);
+					for (j = 0, i = -1U; j < m3d->numtexture; j++)
+						if (!strcmp(fn, m3d->texture[j].name)) {
+							i = j;
+							free(fn);
+							break;
+						}
+					if (i == -1U) {
+						i = m3d->numtexture++;
+						m3d->texture = (m3dtx_t *)M3D_REALLOC(
+								m3d->texture,
+								m3d->numtexture * sizeof(m3dtx_t));
+						if (!m3d->texture) {
+							throw DeadlyExportError("memory allocation error");
+						}
+						// we don't need the texture itself, only its name
+						m3d->texture[i].name = fn;
+						m3d->texture[i].w = 0;
+						m3d->texture[i].h = 0;
+						m3d->texture[i].d = NULL;
+					}
+					addProp(&m3d->material[mi],
+							m3d_propertytypes[k].id + 128, i);
+				}
+			}
+		}
+	}
+	return mi;
+}
+
+namespace Assimp {
+
+// ---------------------------------------------------------------------
+// Worker function for exporting a scene to binary M3D.
+// Prototyped and registered in Exporter.cpp
+void ExportSceneM3D(
+		const char *pFile,
+		IOSystem *pIOSystem,
+		const aiScene *pScene,
+		const ExportProperties *pProperties) {
+	// initialize the exporter
+	M3DExporter exporter(pScene, pProperties);
+
+	// perform binary export
+	exporter.doExport(pFile, pIOSystem, false);
+}
+
+// ---------------------------------------------------------------------
+// Worker function for exporting a scene to ASCII A3D.
+// Prototyped and registered in Exporter.cpp
+void ExportSceneA3D(
+		const char *pFile,
+		IOSystem *pIOSystem,
+		const aiScene *pScene,
+		const ExportProperties *pProperties
+
+) {
+	// initialize the exporter
+	M3DExporter exporter(pScene, pProperties);
+
+	// perform ascii export
+	exporter.doExport(pFile, pIOSystem, true);
 }
 
 // ------------------------------------------------------------------------------------------------
-// add a material property to the output
-void M3DExporter::addProp(m3dm_t *m, uint8_t type, uint32_t value)
-{
-    unsigned int i;
-    i = m->numprop++;
-    m->prop = (m3dp_t*)M3D_REALLOC(m->prop, m->numprop * sizeof(m3dp_t));
-    if(!m->prop) { throw DeadlyExportError( "memory allocation error" ); }
-    m->prop[i].type = type;
-    m->prop[i].value.num = value;
+M3DExporter::M3DExporter(const aiScene *pScene, const ExportProperties *pProperties) :
+		mScene(pScene),
+		mProperties(pProperties),
+		outfile() {}
+
+// ------------------------------------------------------------------------------------------------
+void M3DExporter::doExport(
+		const char *pFile,
+		IOSystem *pIOSystem,
+		bool toAscii) {
+	// TODO: convert mProperties into M3D_EXP_* flags
+	(void)mProperties;
+
+	// open the indicated file for writing (in binary / ASCII mode)
+	outfile.reset(pIOSystem->Open(pFile, toAscii ? "wt" : "wb"));
+	if (!outfile) {
+		throw DeadlyExportError("could not open output .m3d file: " + std::string(pFile));
+	}
+
+	M3DWrapper m3d;
+	if (!m3d) {
+		throw DeadlyExportError("memory allocation error");
+	}
+	m3d->name = _m3d_safestr((char *)&mScene->mRootNode->mName.data, 2);
+
+	// Create a model from assimp structures
+	aiMatrix4x4 m;
+	NodeWalk(m3d, mScene->mRootNode, m);
+
+	// serialize the structures
+	unsigned int size;
+	unsigned char *output = m3d.Save(M3D_EXP_FLOAT, M3D_EXP_EXTRA | (toAscii ? M3D_EXP_ASCII : 0), size);
+
+	if (!output || size < 8) {
+		throw DeadlyExportError("unable to serialize into Model 3D");
+	}
+
+	// Write out serialized model
+	outfile->Write(output, size, 1);
+
+	// explicitly release file pointer,
+	// so we don't have to rely on class destruction.
+	outfile.reset();
+}
+
+// ------------------------------------------------------------------------------------------------
+// recursive node walker
+void M3DExporter::NodeWalk(const M3DWrapper &m3d, const aiNode *pNode, aiMatrix4x4 m) {
+	aiMatrix4x4 nm = m * pNode->mTransformation;
+
+	for (unsigned int i = 0; i < pNode->mNumMeshes; i++) {
+		const aiMesh *mesh = mScene->mMeshes[pNode->mMeshes[i]];
+		unsigned int mi = (M3D_INDEX)-1U;
+		if (mScene->mMaterials) {
+			// get the material for this mesh
+			mi = addMaterial(m3d, mScene->mMaterials[mesh->mMaterialIndex]);
+		}
+		// iterate through the mesh faces
+		for (unsigned int j = 0; j < mesh->mNumFaces; j++) {
+			unsigned int n;
+			const aiFace *face = &(mesh->mFaces[j]);
+			// only triangle meshes supported for now
+			if (face->mNumIndices != 3) {
+				throw DeadlyExportError("use aiProcess_Triangulate before export");
+			}
+			// add triangle to the output
+			n = m3d->numface++;
+			m3d->face = (m3df_t *)M3D_REALLOC(m3d->face,
+					m3d->numface * sizeof(m3df_t));
+			if (!m3d->face) {
+				throw DeadlyExportError("memory allocation error");
+			}
+			/* set all index to -1 by default */
+			m3d->face[n].vertex[0] = m3d->face[n].vertex[1] = m3d->face[n].vertex[2] =
+					m3d->face[n].normal[0] = m3d->face[n].normal[1] = m3d->face[n].normal[2] =
+							m3d->face[n].texcoord[0] = m3d->face[n].texcoord[1] = m3d->face[n].texcoord[2] = -1U;
+			m3d->face[n].materialid = mi;
+			for (unsigned int k = 0; k < face->mNumIndices; k++) {
+				// get the vertex's index
+				unsigned int l = face->mIndices[k];
+				unsigned int idx;
+				m3dv_t vertex;
+				m3dti_t ti;
+				// multiply the position vector by the transformation matrix
+				aiVector3D v = mesh->mVertices[l];
+				v *= nm;
+				vertex.x = v.x;
+				vertex.y = v.y;
+				vertex.z = v.z;
+				vertex.w = 1.0;
+				vertex.color = 0;
+				vertex.skinid = -1U;
+				// add color if defined
+				if (mesh->HasVertexColors(0))
+					vertex.color = mkColor(&mesh->mColors[0][l]);
+				// save the vertex to the output
+				m3d->vertex = AddVrtx(m3d->vertex, &m3d->numvertex,
+						&vertex, &idx);
+				m3d->face[n].vertex[k] = (M3D_INDEX)idx;
+				// do we have texture coordinates?
+				if (mesh->HasTextureCoords(0)) {
+					ti.u = mesh->mTextureCoords[0][l].x;
+					ti.v = mesh->mTextureCoords[0][l].y;
+					m3d->tmap = AddTmap(m3d->tmap, &m3d->numtmap, &ti, &idx);
+					m3d->face[n].texcoord[k] = (M3D_INDEX)idx;
+				}
+				// do we have normal vectors?
+				if (mesh->HasNormals()) {
+					vertex.x = mesh->mNormals[l].x;
+					vertex.y = mesh->mNormals[l].y;
+					vertex.z = mesh->mNormals[l].z;
+					vertex.color = 0;
+					m3d->vertex = AddVrtx(m3d->vertex, &m3d->numvertex, &vertex, &idx);
+					m3d->face[n].normal[k] = (M3D_INDEX)idx;
+				}
+			}
+		}
+	}
+	// repeat for the children nodes
+	for (unsigned int i = 0; i < pNode->mNumChildren; i++) {
+		NodeWalk(m3d, pNode->mChildren[i], nm);
+	}
 }
+} // namespace Assimp
 
 #endif // ASSIMP_BUILD_NO_M3D_EXPORTER
 #endif // ASSIMP_BUILD_NO_EXPORT

code/M3D/M3DExporter.h

@@ -48,8 +48,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef ASSIMP_BUILD_NO_M3D_EXPORTER
 
-#include "m3d.h"
-
 #include <assimp/types.h>
 //#include <assimp/material.h>
 #include <assimp/StreamWriter.h> // StreamWriterLE
@@ -68,6 +66,8 @@ namespace Assimp
     class IOStream;
     class ExportProperties;
 
+    class M3DWrapper;
+
     // ---------------------------------------------------------------------
     /** Helper class to export a given scene to an M3D file. */
     // ---------------------------------------------------------------------
@@ -83,15 +83,9 @@ namespace Assimp
         const aiScene* mScene; // the scene to export
         const ExportProperties* mProperties; // currently unused
         std::shared_ptr<IOStream> outfile; // file to write to
-        m3d_t *m3d; // model for the C library to convert to
 
         // helper to do the recursive walking
-        void NodeWalk(const aiNode* pNode, aiMatrix4x4 m);
-        m3dv_t *AddVrtx(m3dv_t *vrtx, uint32_t *numvrtx, m3dv_t *v, uint32_t *idx);
-        m3dti_t *AddTmap(m3dti_t *tmap, uint32_t *numtmap, m3dti_t *ti, uint32_t *idx);
-        uint32_t mkColor(aiColor4D* c);
-        M3D_INDEX addMaterial(const aiMaterial *mat);
-        void addProp(m3dm_t *m, uint8_t type, uint32_t value);
+        void NodeWalk(const M3DWrapper &m3d, const aiNode* pNode, aiMatrix4x4 m);
     };
 }
 

code/M3D/M3DImporter.cpp

@@ -44,20 +44,22 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #define M3D_IMPLEMENTATION
 #define M3D_ASCII
-#define M3D_NONORMALS       /* leave the post-processing to Assimp */
+#define M3D_NONORMALS /* leave the post-processing to Assimp */
 #define M3D_NOWEIGHTS
 #define M3D_NOANIMATION
 
-#include <assimp/IOStreamBuffer.h>
-#include <memory>
 #include <assimp/DefaultIOSystem.h>
-#include <assimp/Importer.hpp>
-#include <assimp/scene.h>
+#include <assimp/IOStreamBuffer.h>
 #include <assimp/ai_assert.h>
-#include <assimp/DefaultLogger.hpp>
 #include <assimp/importerdesc.h>
+#include <assimp/scene.h>
+#include <assimp/DefaultLogger.hpp>
+#include <assimp/Importer.hpp>
+#include <memory>
+
 #include "M3DImporter.h"
 #include "M3DMaterials.h"
+#include "M3DWrapper.h"
 
 // RESOURCES:
 // https://gitlab.com/bztsrc/model3d/blob/master/docs/m3d_format.md
@@ -85,682 +87,656 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
 static const aiImporterDesc desc = {
-    "Model 3D Importer",
-    "",
-    "",
-    "",
-    aiImporterFlags_SupportBinaryFlavour,
-    0,
-    0,
-    0,
-    0,
-    "m3d a3d"
+	"Model 3D Importer",
+	"",
+	"",
+	"",
+	aiImporterFlags_SupportTextFlavour | aiImporterFlags_SupportBinaryFlavour,
+	0,
+	0,
+	0,
+	0,
+	"m3d a3d"
 };
 
-// workaround: the SDK expects a C callback, but we want to use Assimp::IOSystem to implement that
-extern "C" {
-    void* m3dimporter_pIOHandler;
-
-    unsigned char *m3dimporter_readfile(char *fn, unsigned int *size) {
-        ai_assert( nullptr != fn );
-        ai_assert( nullptr != size );
-        std::string file(fn);
-        std::unique_ptr<Assimp::IOStream> pStream(
-            (reinterpret_cast<Assimp::IOSystem*>(m3dimporter_pIOHandler))->Open( file, "rb"));
-        size_t fileSize = 0;
-        unsigned char *data = NULL;
-        // sometimes pStream is nullptr for some reason (should be an empty object returning nothing I guess)
-        if(pStream) {
-            fileSize = pStream->FileSize();
-            // should be allocated with malloc(), because the library will call free() to deallocate
-            data = (unsigned char*)malloc(fileSize);
-            if( !data || !pStream.get() || !fileSize || fileSize != pStream->Read(data,1,fileSize)) {
-                pStream.reset();
-                *size = 0;
-                // don't throw a deadly exception, it's not fatal if we can't read an external asset
-                return nullptr;
-            }
-            pStream.reset();
-        }
-        *size = (int)fileSize;
-        return data;
-    }
-}
-
 namespace Assimp {
 
 using namespace std;
 
 // ------------------------------------------------------------------------------------------------
 //  Default constructor
-M3DImporter::M3DImporter()
-: mScene(nullptr)
-, m3d(nullptr) { }
-
-// ------------------------------------------------------------------------------------------------
-//  Destructor.
-M3DImporter::~M3DImporter() {}
+M3DImporter::M3DImporter() :
+		mScene(nullptr) {}
 
 // ------------------------------------------------------------------------------------------------
 //  Returns true, if file is a binary or ASCII Model 3D file.
-bool M3DImporter::CanRead(const std::string& pFile, IOSystem*  pIOHandler , bool checkSig) const {
-    const std::string extension = GetExtension(pFile);
-
-    if (extension == "m3d" || extension == "a3d")
-        return true;
-    else if (!extension.length() || checkSig)   {
-        if (!pIOHandler) {
-            return true;
-        }
-        /*
+bool M3DImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool checkSig) const {
+	const std::string extension = GetExtension(pFile);
+
+	if (extension == "m3d" || extension == "a3d")
+		return true;
+	else if (!extension.length() || checkSig) {
+		if (!pIOHandler) {
+			return true;
+		}
+		/*
          * don't use CheckMagicToken because that checks with swapped bytes too, leading to false
          * positives. This magic is not uint32_t, but char[4], so memcmp is the best way
 
         const char* tokens[] = {"3DMO", "3dmo"};
         return CheckMagicToken(pIOHandler,pFile,tokens,2,0,4);
         */
-        std::unique_ptr<IOStream> pStream (pIOHandler->Open(pFile, "rb"));
-        unsigned char data[4];
-        if(4 != pStream->Read(data,1,4)) {
-            return false;
-        }
-        return !memcmp(data, "3DMO", 4) /* bin */ || !memcmp(data, "3dmo", 4) /* ASCII */;
-    }
-    return false;
+		std::unique_ptr<IOStream> pStream(pIOHandler->Open(pFile, "rb"));
+		unsigned char data[4];
+		if (4 != pStream->Read(data, 1, 4)) {
+			return false;
+		}
+		return !memcmp(data, "3DMO", 4) /* bin */ || !memcmp(data, "3dmo", 4) /* ASCII */;
+	}
+	return false;
 }
 
 // ------------------------------------------------------------------------------------------------
-const aiImporterDesc* M3DImporter::GetInfo() const {
-    return &desc;
+const aiImporterDesc *M3DImporter::GetInfo() const {
+	return &desc;
 }
 
 // ------------------------------------------------------------------------------------------------
 //  Model 3D import implementation
-void M3DImporter::InternReadFile( const std::string &file, aiScene* pScene, IOSystem* pIOHandler) {
-    // Read file into memory
-    std::unique_ptr<IOStream> pStream( pIOHandler->Open( file, "rb"));
-    if( !pStream.get() ) {
-        throw DeadlyImportError( "Failed to open file " + file + "." );
-    }
-
-    // Get the file-size and validate it, throwing an exception when fails
-    size_t fileSize = pStream->FileSize();
-    if( fileSize < 8 ) {
-        throw DeadlyImportError( "M3D-file " + file + " is too small." );
-    }
-    std::unique_ptr<unsigned char[]> _buffer (new unsigned char[fileSize]);
-    unsigned char *data( _buffer.get() );
-    if(fileSize != pStream->Read(data,1,fileSize)) {
-        throw DeadlyImportError( "Failed to read the file " + file + "." );
-    }
-
-    // Get the path for external assets
-    std::string  folderName( "./" );
-    std::string::size_type pos = file.find_last_of( "\\/" );
-    if ( pos != std::string::npos ) {
-        folderName = file.substr( 0, pos );
-        if ( !folderName.empty() ) {
-            pIOHandler->PushDirectory( folderName );
-        }
-    }
-    // pass this IOHandler to the C callback
-    m3dimporter_pIOHandler = pIOHandler;
+void M3DImporter::InternReadFile(const std::string &file, aiScene *pScene, IOSystem *pIOHandler) {
+	// Read file into memory
+	std::unique_ptr<IOStream> pStream(pIOHandler->Open(file, "rb"));
+	if (!pStream.get()) {
+		throw DeadlyImportError("Failed to open file " + file + ".");
+	}
+
+	// Get the file-size and validate it, throwing an exception when fails
+	size_t fileSize = pStream->FileSize();
+	if (fileSize < 8) {
+		throw DeadlyImportError("M3D-file " + file + " is too small.");
+	}
+	std::vector<unsigned char> buffer(fileSize);
+	if (fileSize != pStream->Read(buffer.data(), 1, fileSize)) {
+		throw DeadlyImportError("Failed to read the file " + file + ".");
+	}
+
+	// Get the path for external assets
+	std::string folderName("./");
+	std::string::size_type pos = file.find_last_of("\\/");
+	if (pos != std::string::npos) {
+		folderName = file.substr(0, pos);
+		if (!folderName.empty()) {
+			pIOHandler->PushDirectory(folderName);
+		}
+	}
 
     //DefaultLogger::create("/dev/stderr", Logger::VERBOSE);
-    ASSIMP_LOG_DEBUG_F("M3D: loading ", file);
-
-    // let the C SDK do the hard work for us
-    m3d = m3d_load(&data[0], m3dimporter_readfile, free, nullptr);
-    m3dimporter_pIOHandler = nullptr;
-    if( !m3d ) {
-        throw DeadlyImportError( "Unable to parse " + file + " as M3D." );
-    }
-
-    // create the root node
-    pScene->mRootNode = new aiNode;
-    pScene->mRootNode->mName = aiString(std::string(std::string(m3d->name)));
-    pScene->mRootNode->mTransformation = aiMatrix4x4();
-    pScene->mRootNode->mNumChildren = 0;
-    mScene = pScene;
-
-    ASSIMP_LOG_DEBUG("M3D: root node " + std::string(m3d->name));
-
-    // now we just have to fill up the Assimp structures in pScene
-    importMaterials();
-    importTextures();
-    importBones(-1U, pScene->mRootNode);
-    importMeshes();
-    importAnimations();
-
-    // we don't need the SDK's version any more
-    m3d_free(m3d);
-
-    // Pop directory stack
-    if ( pIOHandler->StackSize() > 0 ) {
-        pIOHandler->PopDirectory();
-    }
+	ASSIMP_LOG_DEBUG_F("M3D: loading ", file);
+
+	// let the C SDK do the hard work for us
+	M3DWrapper m3d(pIOHandler, buffer);
+
+	
+	if (!m3d) {
+		throw DeadlyImportError("Unable to parse " + file + " as M3D.");
+	}
+
+	// create the root node
+	pScene->mRootNode = new aiNode;
+	pScene->mRootNode->mName = aiString(m3d.Name());
+	pScene->mRootNode->mTransformation = aiMatrix4x4();
+	pScene->mRootNode->mNumChildren = 0;
+	mScene = pScene;
+
+	ASSIMP_LOG_DEBUG("M3D: root node " + m3d.Name());
+
+	// now we just have to fill up the Assimp structures in pScene
+	importMaterials(m3d);
+    importTextures(m3d);
+	importBones(m3d, -1U, pScene->mRootNode);
+	importMeshes(m3d);
+	importAnimations(m3d);
+
+	// Pop directory stack
+	if (pIOHandler->StackSize() > 0) {
+		pIOHandler->PopDirectory();
+	}
 }
 
 // ------------------------------------------------------------------------------------------------
 // convert materials. properties are converted using a static table in M3DMaterials.h
-void M3DImporter::importMaterials()
-{
-    unsigned int i, j, k, l, n;
-    m3dm_t *m;
-    aiString name = aiString(AI_DEFAULT_MATERIAL_NAME);
-    aiColor4D c;
-    ai_real f;
-
-    ai_assert(mScene != nullptr);
-    ai_assert(m3d != nullptr);
-
-    mScene->mNumMaterials = m3d->nummaterial + 1;
-    mScene->mMaterials = new aiMaterial*[ m3d->nummaterial + 1 ];
-
-    ASSIMP_LOG_DEBUG_F("M3D: importMaterials ", mScene->mNumMaterials);
-
-    // add a default material as first
-    aiMaterial* mat = new aiMaterial;
-    mat->AddProperty( &name, AI_MATKEY_NAME );
-    c.a = 1.0; c.b = c.g = c.r = 0.6;
-    mat->AddProperty( &c, 1, AI_MATKEY_COLOR_DIFFUSE);
-    mScene->mMaterials[0] = mat;
-
-    for(i = 0; i < m3d->nummaterial; i++) {
-        m = &m3d->material[i];
-        aiMaterial* mat = new aiMaterial;
-        name.Set(std::string(m->name));
-        mat->AddProperty( &name, AI_MATKEY_NAME );
-        for(j = 0; j < m->numprop; j++) {
-            // look up property type
-            // 0 - 127 scalar values,
-            // 128 - 255 the same properties but for texture maps
-            k = 256;
-            for(l = 0; l < sizeof(m3d_propertytypes)/sizeof(m3d_propertytypes[0]); l++)
-                if(m->prop[j].type == m3d_propertytypes[l].id ||
-                    m->prop[j].type == m3d_propertytypes[l].id + 128) {
-                        k = l;
-                        break;
-                    }
-            // should never happen, but be safe than sorry
-            if(k == 256) continue;
-
-            // scalar properties
-            if(m->prop[j].type < 128 && aiProps[k].pKey) {
-                switch(m3d_propertytypes[k].format) {
-                    case m3dpf_color:
-                        c = mkColor(m->prop[j].value.color);
-                        mat->AddProperty(&c, 1, aiProps[k].pKey, aiProps[k].type, aiProps[k].index);
-                    break;
-                    case m3dpf_float:
-                        f = m->prop[j].value.fnum;
-                        mat->AddProperty(&f, 1, aiProps[k].pKey, aiProps[k].type, aiProps[k].index);
-                    break;
-                    default:
-                        n = m->prop[j].value.num;
-                        if(m->prop[j].type == m3dp_il) {
-                            switch(n) {
-                                case 0:  n = aiShadingMode_NoShading; break;
-                                case 2:  n = aiShadingMode_Phong; break;
-                                default: n = aiShadingMode_Gouraud; break;
-                            }
-                        }
-                        mat->AddProperty(&n, 1, aiProps[k].pKey, aiProps[k].type, aiProps[k].index);
-                    break;
-                }
-            }
-            // texture map properties
-            if(m->prop[j].type >= 128 && aiTxProps[k].pKey &&
-                // extra check, should never happen, do we have the refered texture?
-                m->prop[j].value.textureid < m3d->numtexture &&
-                m3d->texture[m->prop[j].value.textureid].name) {
-                    name.Set(std::string(std::string(m3d->texture[m->prop[j].value.textureid].name) + ".png"));
-                    mat->AddProperty(&name, aiTxProps[k].pKey, aiTxProps[k].type, aiTxProps[k].index);
-                    n = 0;
-                    mat->AddProperty(&n, 1, _AI_MATKEY_UVWSRC_BASE, aiProps[k].type, aiProps[k].index);
-            }
-        }
-        mScene->mMaterials[i + 1] = mat;
-    }
+void M3DImporter::importMaterials(const M3DWrapper &m3d_wrap) {
+	unsigned int i, j, k, l, n;
+	m3dm_t *m;
+	aiString name = aiString(AI_DEFAULT_MATERIAL_NAME);
+	aiColor4D c;
+	ai_real f;
+
+	ai_assert(mScene != nullptr);
+	ai_assert(m3d_wrap);
+
+	mScene->mNumMaterials = m3d_wrap->nummaterial + 1;
+	mScene->mMaterials = new aiMaterial *[mScene->mNumMaterials];
+
+	ASSIMP_LOG_DEBUG_F("M3D: importMaterials ", mScene->mNumMaterials);
+
+	// add a default material as first
+	aiMaterial *mat = new aiMaterial;
+	mat->AddProperty(&name, AI_MATKEY_NAME);
+	c.a = 1.0f;
+	c.b = c.g = c.r = 0.6f;
+	mat->AddProperty(&c, 1, AI_MATKEY_COLOR_DIFFUSE);
+	mScene->mMaterials[0] = mat;
+
+	for (i = 0; i < m3d_wrap->nummaterial; i++) {
+		m = &m3d_wrap->material[i];
+		aiMaterial *mat = new aiMaterial;
+		name.Set(std::string(m->name));
+		mat->AddProperty(&name, AI_MATKEY_NAME);
+		for (j = 0; j < m->numprop; j++) {
+			// look up property type
+			// 0 - 127 scalar values,
+			// 128 - 255 the same properties but for texture maps
+			k = 256;
+			for (l = 0; l < sizeof(m3d_propertytypes) / sizeof(m3d_propertytypes[0]); l++)
+				if (m->prop[j].type == m3d_propertytypes[l].id ||
+						m->prop[j].type == m3d_propertytypes[l].id + 128) {
+					k = l;
+					break;
+				}
+			// should never happen, but be safe than sorry
+			if (k == 256) continue;
+
+			// scalar properties
+			if (m->prop[j].type < 128 && aiProps[k].pKey) {
+				switch (m3d_propertytypes[k].format) {
+					case m3dpf_color:
+						c = mkColor(m->prop[j].value.color);
+						mat->AddProperty(&c, 1, aiProps[k].pKey, aiProps[k].type, aiProps[k].index);
+						break;
+					case m3dpf_float:
+						f = m->prop[j].value.fnum;
+						mat->AddProperty(&f, 1, aiProps[k].pKey, aiProps[k].type, aiProps[k].index);
+						break;
+					default:
+						n = m->prop[j].value.num;
+						if (m->prop[j].type == m3dp_il) {
+							switch (n) {
+								case 0: n = aiShadingMode_NoShading; break;
+								case 2: n = aiShadingMode_Phong; break;
+								default: n = aiShadingMode_Gouraud; break;
+							}
+						}
+						mat->AddProperty(&n, 1, aiProps[k].pKey, aiProps[k].type, aiProps[k].index);
+						break;
+				}
+			}
+			// texture map properties
+			if (m->prop[j].type >= 128 && aiTxProps[k].pKey &&
+					// extra check, should never happen, do we have the refered texture?
+					m->prop[j].value.textureid < m3d_wrap->numtexture &&
+					m3d_wrap->texture[m->prop[j].value.textureid].name) {
+				name.Set(std::string(std::string(m3d_wrap->texture[m->prop[j].value.textureid].name) + ".png"));
+				mat->AddProperty(&name, aiTxProps[k].pKey, aiTxProps[k].type, aiTxProps[k].index);
+				n = 0;
+				mat->AddProperty(&n, 1, _AI_MATKEY_UVWSRC_BASE, aiProps[k].type, aiProps[k].index);
+			}
+		}
+		mScene->mMaterials[i + 1] = mat;
+	}
 }
 
 // ------------------------------------------------------------------------------------------------
 // import textures, this is the simplest of all
-void M3DImporter::importTextures()
-{
-    unsigned int i;
-    const char *formatHint[] = { "rgba0800", "rgba0808", "rgba8880", "rgba8888" };
-    m3dtx_t *t;
-
-    ai_assert(mScene != nullptr);
-    ai_assert(m3d != nullptr);
-
-    mScene->mNumTextures = m3d->numtexture;
-    ASSIMP_LOG_DEBUG_F("M3D: importTextures ", mScene->mNumTextures);
-
-    if(!m3d->numtexture)
-        return;
-
-    mScene->mTextures = new aiTexture*[m3d->numtexture];
-    for(i = 0; i < m3d->numtexture; i++) {
-        unsigned int j, k;
-        t = &m3d->texture[i];
-        if(!t->w || !t->h || !t->f || !t->d) continue;
-        aiTexture *tx = new aiTexture;
-        strcpy(tx->achFormatHint, formatHint[t->f - 1]);
-        tx->mFilename = aiString(std::string(t->name) + ".png");
-        tx->mWidth = t->w;
-        tx->mHeight = t->h;
-        tx->pcData = new aiTexel[ tx->mWidth*tx->mHeight ];
-        for(j = k = 0; j < tx->mWidth*tx->mHeight; j++) {
-            switch(t->f) {
-                case 1: tx->pcData[j].g = t->d[k++]; break;
-                case 2: tx->pcData[j].g = t->d[k++]; tx->pcData[j].a = t->d[k++]; break;
-                case 3:
-                    tx->pcData[j].r = t->d[k++]; tx->pcData[j].g = t->d[k++];
-                    tx->pcData[j].b = t->d[k++]; tx->pcData[j].a = 255;
-                break;
-                case 4:
-                    tx->pcData[j].r = t->d[k++]; tx->pcData[j].g = t->d[k++];
-                    tx->pcData[j].b = t->d[k++]; tx->pcData[j].a = t->d[k++];
-                break;
-            }
-        }
-        mScene->mTextures[i] = tx;
-    }
+void M3DImporter::importTextures(const M3DWrapper &m3d) {
+	unsigned int i;
+	const char *formatHint[] = { "rgba0800", "rgba0808", "rgba8880", "rgba8888" };
+	m3dtx_t *t;
+
+	ai_assert(mScene != nullptr);
+	ai_assert(m3d);
+
+	mScene->mNumTextures = m3d->numtexture;
+	ASSIMP_LOG_DEBUG_F("M3D: importTextures ", mScene->mNumTextures);
+
+	if (!m3d->numtexture)
+		return;
+
+	mScene->mTextures = new aiTexture *[m3d->numtexture];
+	for (i = 0; i < m3d->numtexture; i++) {
+		unsigned int j, k;
+		t = &m3d->texture[i];
+		if (!t->w || !t->h || !t->f || !t->d) continue;
+		aiTexture *tx = new aiTexture;
+		strcpy(tx->achFormatHint, formatHint[t->f - 1]);
+		tx->mFilename = aiString(std::string(t->name) + ".png");
+		tx->mWidth = t->w;
+		tx->mHeight = t->h;
+		tx->pcData = new aiTexel[tx->mWidth * tx->mHeight];
+		for (j = k = 0; j < tx->mWidth * tx->mHeight; j++) {
+			switch (t->f) {
+				case 1: tx->pcData[j].g = t->d[k++]; break;
+				case 2:
+					tx->pcData[j].g = t->d[k++];
+					tx->pcData[j].a = t->d[k++];
+					break;
+				case 3:
+					tx->pcData[j].r = t->d[k++];
+					tx->pcData[j].g = t->d[k++];
+					tx->pcData[j].b = t->d[k++];
+					tx->pcData[j].a = 255;
+					break;
+				case 4:
+					tx->pcData[j].r = t->d[k++];
+					tx->pcData[j].g = t->d[k++];
+					tx->pcData[j].b = t->d[k++];
+					tx->pcData[j].a = t->d[k++];
+					break;
+			}
+		}
+		mScene->mTextures[i] = tx;
+	}
 }
 
 // ------------------------------------------------------------------------------------------------
 // this is tricky. M3D has a global vertex and UV list, and faces are indexing them
 // individually. In assimp there're per mesh vertex and UV lists, and they must be
 // indexed simultaneously.
-void M3DImporter::importMeshes()
-{
-    unsigned int i, j, k, l, numpoly = 3, lastMat = -2U;
-    std::vector<aiMesh*> *meshes = new std::vector<aiMesh*>();
-    std::vector<aiFace> *faces = nullptr;
-    std::vector<aiVector3D> *vertices = nullptr;
-    std::vector<aiVector3D> *normals = nullptr;
-    std::vector<aiVector3D> *texcoords = nullptr;
-    std::vector<aiColor4D> *colors = nullptr;
-    std::vector<unsigned int> *vertexids = nullptr;
-    aiMesh *pMesh = nullptr;
-
-    ai_assert(mScene != nullptr);
-    ai_assert(m3d != nullptr);
-    ai_assert(mScene->mRootNode != nullptr);
-
-    ASSIMP_LOG_DEBUG_F("M3D: importMeshes ", m3d->numface);
-
-    for(i = 0; i < m3d->numface; i++) {
-        // we must switch mesh if material changes
-        if(lastMat != m3d->face[i].materialid) {
-            lastMat = m3d->face[i].materialid;
-            if(pMesh && vertices && vertices->size() && faces && faces->size()) {
-                populateMesh(pMesh, faces, vertices, normals, texcoords, colors, vertexids);
-                meshes->push_back(pMesh);
-                delete faces;
-                delete vertices;
-                delete normals;
-                delete texcoords;
-                delete colors;
-                delete vertexids;   // this is not stored in pMesh, just to collect bone vertices
-            }
-            pMesh = new aiMesh;
-            pMesh->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;
-            pMesh->mMaterialIndex = lastMat + 1;
-            faces = new std::vector<aiFace>();
-            vertices = new std::vector<aiVector3D>();
-            normals = new std::vector<aiVector3D>();
-            texcoords = new std::vector<aiVector3D>();
-            colors = new std::vector<aiColor4D>();
-            vertexids = new std::vector<unsigned int>();
-        }
-        // add a face to temporary vector
-        aiFace *pFace = new aiFace;
-        pFace->mNumIndices = numpoly;
-        pFace->mIndices = new unsigned int[numpoly];
-        for(j = 0; j < numpoly; j++) {
-            aiVector3D pos, uv, norm;
-            k = vertices->size();
-            pFace->mIndices[j] = k;
-            l = m3d->face[i].vertex[j];
-            pos.x = m3d->vertex[l].x;
-            pos.y = m3d->vertex[l].y;
-            pos.z = m3d->vertex[l].z;
-            vertices->push_back(pos);
-            colors->push_back(mkColor(m3d->vertex[l].color));
-            // add a bone to temporary vector
-            if(m3d->vertex[l].skinid != -1U &&m3d->vertex[l].skinid != -2U && m3d->skin && m3d->bone) {
-                // this is complicated, because M3D stores a list of bone id / weight pairs per
-                // vertex but assimp uses lists of local vertex id/weight pairs per local bone list
-                vertexids->push_back(l);
-            }
-            l = m3d->face[i].texcoord[j];
-            if(l != -1U) {
-                uv.x = m3d->tmap[l].u;
-                uv.y = m3d->tmap[l].v;
-                uv.z = 0.0;
-                texcoords->push_back(uv);
-            }
-            l = m3d->face[i].normal[j];
-            if(l != -1U) {
-                norm.x = m3d->vertex[l].x;
-                norm.y = m3d->vertex[l].y;
-                norm.z = m3d->vertex[l].z;
-                normals->push_back(norm);
-            }
-        }
-        faces->push_back(*pFace);
-        delete pFace;
-    }
-    // if there's data left in the temporary vectors, flush them
-    if(pMesh && vertices->size() && faces->size()) {
-        populateMesh(pMesh, faces, vertices, normals, texcoords, colors, vertexids);
-        meshes->push_back(pMesh);
-    }
-
-    // create global mesh list in scene
-    mScene->mNumMeshes = meshes->size();
-    mScene->mMeshes = new aiMesh*[mScene->mNumMeshes];
-    std::copy(meshes->begin(), meshes->end(), mScene->mMeshes);
-
-    // create mesh indeces in root node
-    mScene->mRootNode->mNumMeshes = meshes->size();
-    mScene->mRootNode->mMeshes = new unsigned int[meshes->size()];
-    for(i = 0; i < meshes->size(); i++) {
-        mScene->mRootNode->mMeshes[i] = i;
-    }
-
-    delete meshes;
-    if(faces)       delete faces;
-    if(vertices)    delete vertices;
-    if(normals)     delete normals;
-    if(texcoords)   delete texcoords;
-    if(colors)      delete colors;
-    if(vertexids)   delete vertexids;
+void M3DImporter::importMeshes(const M3DWrapper &m3d) {
+	unsigned int i, j, k, l, numpoly = 3, lastMat = -2U;
+	std::vector<aiMesh *> *meshes = new std::vector<aiMesh *>();
+	std::vector<aiFace> *faces = nullptr;
+	std::vector<aiVector3D> *vertices = nullptr;
+	std::vector<aiVector3D> *normals = nullptr;
+	std::vector<aiVector3D> *texcoords = nullptr;
+	std::vector<aiColor4D> *colors = nullptr;
+	std::vector<unsigned int> *vertexids = nullptr;
+	aiMesh *pMesh = nullptr;
+
+	ai_assert(mScene != nullptr);
+	ai_assert(m3d);
+	ai_assert(mScene->mRootNode != nullptr);
+
+	ASSIMP_LOG_DEBUG_F("M3D: importMeshes ", m3d->numface);
+
+	for (i = 0; i < m3d->numface; i++) {
+		// we must switch mesh if material changes
+		if (lastMat != m3d->face[i].materialid) {
+			lastMat = m3d->face[i].materialid;
+			if (pMesh && vertices && vertices->size() && faces && faces->size()) {
+				populateMesh(m3d, pMesh, faces, vertices, normals, texcoords, colors, vertexids);
+				meshes->push_back(pMesh);
+				delete faces;
+				delete vertices;
+				delete normals;
+				delete texcoords;
+				delete colors;
+				delete vertexids; // this is not stored in pMesh, just to collect bone vertices
+			}
+			pMesh = new aiMesh;
+			pMesh->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;
+			pMesh->mMaterialIndex = lastMat + 1;
+			faces = new std::vector<aiFace>();
+			vertices = new std::vector<aiVector3D>();
+			normals = new std::vector<aiVector3D>();
+			texcoords = new std::vector<aiVector3D>();
+			colors = new std::vector<aiColor4D>();
+			vertexids = new std::vector<unsigned int>();
+		}
+		// add a face to temporary vector
+		aiFace *pFace = new aiFace;
+		pFace->mNumIndices = numpoly;
+		pFace->mIndices = new unsigned int[numpoly];
+		for (j = 0; j < numpoly; j++) {
+			aiVector3D pos, uv, norm;
+			k = static_cast<unsigned int>(vertices->size());
+			pFace->mIndices[j] = k;
+			l = m3d->face[i].vertex[j];
+			pos.x = m3d->vertex[l].x;
+			pos.y = m3d->vertex[l].y;
+			pos.z = m3d->vertex[l].z;
+			vertices->push_back(pos);
+			colors->push_back(mkColor(m3d->vertex[l].color));
+			// add a bone to temporary vector
+			if (m3d->vertex[l].skinid != -1U && m3d->vertex[l].skinid != -2U && m3d->skin && m3d->bone) {
+				// this is complicated, because M3D stores a list of bone id / weight pairs per
+				// vertex but assimp uses lists of local vertex id/weight pairs per local bone list
+				vertexids->push_back(l);
+			}
+			l = m3d->face[i].texcoord[j];
+			if (l != -1U) {
+				uv.x = m3d->tmap[l].u;
+				uv.y = m3d->tmap[l].v;
+				uv.z = 0.0;
+				texcoords->push_back(uv);
+			}
+			l = m3d->face[i].normal[j];
+			if (l != -1U) {
+				norm.x = m3d->vertex[l].x;
+				norm.y = m3d->vertex[l].y;
+				norm.z = m3d->vertex[l].z;
+				normals->push_back(norm);
+			}
+		}
+		faces->push_back(*pFace);
+		delete pFace;
+	}
+	// if there's data left in the temporary vectors, flush them
+	if (pMesh && vertices->size() && faces->size()) {
+		populateMesh(m3d, pMesh, faces, vertices, normals, texcoords, colors, vertexids);
+		meshes->push_back(pMesh);
+	}
+
+	// create global mesh list in scene
+	mScene->mNumMeshes = static_cast<unsigned int>(meshes->size());
+	mScene->mMeshes = new aiMesh *[mScene->mNumMeshes];
+	std::copy(meshes->begin(), meshes->end(), mScene->mMeshes);
+
+	// create mesh indeces in root node
+	mScene->mRootNode->mNumMeshes = static_cast<unsigned int>(meshes->size());
+	mScene->mRootNode->mMeshes = new unsigned int[meshes->size()];
+	for (i = 0; i < meshes->size(); i++) {
+		mScene->mRootNode->mMeshes[i] = i;
+	}
+
+	delete meshes;
+	if (faces) delete faces;
+	if (vertices) delete vertices;
+	if (normals) delete normals;
+	if (texcoords) delete texcoords;
+	if (colors) delete colors;
+	if (vertexids) delete vertexids;
 }
 
 // ------------------------------------------------------------------------------------------------
 // a reentrant node parser. Otherwise this is simple
-void M3DImporter::importBones(unsigned int parentid, aiNode *pParent)
-{
-    unsigned int i, n;
-
-    ai_assert(pParent != nullptr);
-    ai_assert(mScene != nullptr);
-    ai_assert(m3d != nullptr);
-
-    ASSIMP_LOG_DEBUG_F("M3D: importBones ", m3d->numbone, " parentid ", (int)parentid);
-
-    for(n = 0, i = parentid + 1; i < m3d->numbone; i++)
-        if(m3d->bone[i].parent == parentid) n++;
-    pParent->mChildren = new aiNode*[n];
-
-    for(i = parentid + 1; i < m3d->numbone; i++) {
-        if(m3d->bone[i].parent == parentid) {
-            aiNode *pChild = new aiNode;
-            pChild->mParent = pParent;
-            pChild->mName = aiString(std::string(m3d->bone[i].name));
-            convertPose(&pChild->mTransformation, m3d->bone[i].pos, m3d->bone[i].ori);
-            pChild->mNumChildren = 0;
-            pParent->mChildren[pParent->mNumChildren] = pChild;
-            pParent->mNumChildren++;
-            importBones(i, pChild);
-        }
-    }
+void M3DImporter::importBones(const M3DWrapper &m3d, unsigned int parentid, aiNode *pParent) {
+	unsigned int i, n;
+
+	ai_assert(pParent != nullptr);
+	ai_assert(mScene != nullptr);
+	ai_assert(m3d);
+
+	ASSIMP_LOG_DEBUG_F("M3D: importBones ", m3d->numbone, " parentid ", (int)parentid);
+
+	for (n = 0, i = parentid + 1; i < m3d->numbone; i++)
+		if (m3d->bone[i].parent == parentid) n++;
+	pParent->mChildren = new aiNode *[n];
+
+	for (i = parentid + 1; i < m3d->numbone; i++) {
+		if (m3d->bone[i].parent == parentid) {
+			aiNode *pChild = new aiNode;
+			pChild->mParent = pParent;
+			pChild->mName = aiString(std::string(m3d->bone[i].name));
+			convertPose(m3d, &pChild->mTransformation, m3d->bone[i].pos, m3d->bone[i].ori);
+			pChild->mNumChildren = 0;
+			pParent->mChildren[pParent->mNumChildren] = pChild;
+			pParent->mNumChildren++;
+			importBones(m3d, i, pChild);
+		}
+	}
 }
 
 // ------------------------------------------------------------------------------------------------
 // this is another headache. M3D stores list of changed bone id/position/orientation triplets and
 // a timestamp per frame, but assimp needs timestamp and lists of position, orientation lists per
 // bone, so we have to convert between the two conceptually different representation forms
-void M3DImporter::importAnimations()
-{
-    unsigned int i, j, k, l, pos, ori;
-    double t;
-    m3da_t *a;
-
-    ai_assert(mScene != nullptr);
-    ai_assert(m3d != nullptr);
-
-    mScene->mNumAnimations = m3d->numaction;
-
-    ASSIMP_LOG_DEBUG_F("M3D: importAnimations ", mScene->mNumAnimations);
-
-    if(!m3d->numaction || !m3d->numbone)
-        return;
-
-    mScene->mAnimations = new aiAnimation*[m3d->numaction];
-    for(i = 0; i < m3d->numaction; i++) {
-        a = &m3d->action[i];
-        aiAnimation *pAnim = new aiAnimation;
-        pAnim->mName = aiString(std::string(a->name));
-        pAnim->mDuration = ((double)a->durationmsec) / 10;
-        pAnim->mTicksPerSecond = 100;
-        // now we know how many bones are referenced in this animation
-        pAnim->mNumChannels = m3d->numbone;
-        pAnim->mChannels = new aiNodeAnim*[pAnim->mNumChannels];
-        for(l = 0; l < m3d->numbone; l++) {
-            unsigned int n;
-            pAnim->mChannels[l] = new aiNodeAnim;
-            pAnim->mChannels[l]->mNodeName = aiString(std::string(m3d->bone[l].name));
-            // now n is the size of positions / orientations arrays
-            pAnim->mChannels[l]->mNumPositionKeys = pAnim->mChannels[l]->mNumRotationKeys = a->numframe;
-            pAnim->mChannels[l]->mPositionKeys = new aiVectorKey[a->numframe];
-            pAnim->mChannels[l]->mRotationKeys = new aiQuatKey[a->numframe];
-            pos = m3d->bone[l].pos;
-            ori = m3d->bone[l].ori;
-            for(j = n = 0; j < a->numframe; j++) {
-                t = ((double)a->frame[j].msec) / 10;
-                for(k = 0; k < a->frame[j].numtransform; k++) {
-                    if(a->frame[j].transform[k].boneid == l) {
-                        pos = a->frame[j].transform[k].pos;
-                        ori = a->frame[j].transform[k].ori;
-                    }
-                }
-                m3dv_t *v = &m3d->vertex[pos];
-                m3dv_t *q = &m3d->vertex[ori];
-                pAnim->mChannels[l]->mPositionKeys[j].mTime = t;
-                pAnim->mChannels[l]->mPositionKeys[j].mValue.x = v->x;
-                pAnim->mChannels[l]->mPositionKeys[j].mValue.y = v->y;
-                pAnim->mChannels[l]->mPositionKeys[j].mValue.z = v->z;
-                pAnim->mChannels[l]->mRotationKeys[j].mTime = t;
-                pAnim->mChannels[l]->mRotationKeys[j].mValue.w = q->w;
-                pAnim->mChannels[l]->mRotationKeys[j].mValue.x = q->x;
-                pAnim->mChannels[l]->mRotationKeys[j].mValue.y = q->y;
-                pAnim->mChannels[l]->mRotationKeys[j].mValue.z = q->z;
-            }// foreach frame
-        }// foreach bones
-        mScene->mAnimations[i] = pAnim;
-    }
+void M3DImporter::importAnimations(const M3DWrapper &m3d) {
+	unsigned int i, j, k, l, pos, ori;
+	double t;
+	m3da_t *a;
+
+	ai_assert(mScene != nullptr);
+	ai_assert(m3d);
+
+	mScene->mNumAnimations = m3d->numaction;
+
+	ASSIMP_LOG_DEBUG_F("M3D: importAnimations ", mScene->mNumAnimations);
+
+	if (!m3d->numaction || !m3d->numbone)
+		return;
+
+	mScene->mAnimations = new aiAnimation *[m3d->numaction];
+	for (i = 0; i < m3d->numaction; i++) {
+		a = &m3d->action[i];
+		aiAnimation *pAnim = new aiAnimation;
+		pAnim->mName = aiString(std::string(a->name));
+		pAnim->mDuration = ((double)a->durationmsec) / 10;
+		pAnim->mTicksPerSecond = 100;
+		// now we know how many bones are referenced in this animation
+		pAnim->mNumChannels = m3d->numbone;
+		pAnim->mChannels = new aiNodeAnim *[pAnim->mNumChannels];
+		for (l = 0; l < m3d->numbone; l++) {
+			unsigned int n;
+			pAnim->mChannels[l] = new aiNodeAnim;
+			pAnim->mChannels[l]->mNodeName = aiString(std::string(m3d->bone[l].name));
+			// now n is the size of positions / orientations arrays
+			pAnim->mChannels[l]->mNumPositionKeys = pAnim->mChannels[l]->mNumRotationKeys = a->numframe;
+			pAnim->mChannels[l]->mPositionKeys = new aiVectorKey[a->numframe];
+			pAnim->mChannels[l]->mRotationKeys = new aiQuatKey[a->numframe];
+			pos = m3d->bone[l].pos;
+			ori = m3d->bone[l].ori;
+			for (j = n = 0; j < a->numframe; j++) {
+				t = ((double)a->frame[j].msec) / 10;
+				for (k = 0; k < a->frame[j].numtransform; k++) {
+					if (a->frame[j].transform[k].boneid == l) {
+						pos = a->frame[j].transform[k].pos;
+						ori = a->frame[j].transform[k].ori;
+					}
+				}
+				m3dv_t *v = &m3d->vertex[pos];
+				m3dv_t *q = &m3d->vertex[ori];
+				pAnim->mChannels[l]->mPositionKeys[j].mTime = t;
+				pAnim->mChannels[l]->mPositionKeys[j].mValue.x = v->x;
+				pAnim->mChannels[l]->mPositionKeys[j].mValue.y = v->y;
+				pAnim->mChannels[l]->mPositionKeys[j].mValue.z = v->z;
+				pAnim->mChannels[l]->mRotationKeys[j].mTime = t;
+				pAnim->mChannels[l]->mRotationKeys[j].mValue.w = q->w;
+				pAnim->mChannels[l]->mRotationKeys[j].mValue.x = q->x;
+				pAnim->mChannels[l]->mRotationKeys[j].mValue.y = q->y;
+				pAnim->mChannels[l]->mRotationKeys[j].mValue.z = q->z;
+			} // foreach frame
+		} // foreach bones
+		mScene->mAnimations[i] = pAnim;
+	}
 }
 
 // ------------------------------------------------------------------------------------------------
 // convert uint32_t into aiColor4D
 aiColor4D M3DImporter::mkColor(uint32_t c) {
-    aiColor4D color;
-    color.a = ((float)((c >> 24)&0xff)) / 255;
-    color.b = ((float)((c >> 16)&0xff)) / 255;
-    color.g = ((float)((c >>  8)&0xff)) / 255;
-    color.r = ((float)((c >>  0)&0xff)) / 255;
-    return color;
+	aiColor4D color;
+	color.a = ((float)((c >> 24) & 0xff)) / 255;
+	color.b = ((float)((c >> 16) & 0xff)) / 255;
+	color.g = ((float)((c >> 8) & 0xff)) / 255;
+	color.r = ((float)((c >> 0) & 0xff)) / 255;
+	return color;
 }
 
 // ------------------------------------------------------------------------------------------------
 // convert a position id and orientation id into a 4 x 4 transformation matrix
-void M3DImporter::convertPose(aiMatrix4x4 *m, unsigned int posid, unsigned int orientid)
-{
-    ai_assert(m != nullptr);
-    ai_assert(m3d != nullptr);
-    ai_assert(posid != -1U && posid < m3d->numvertex);
-    ai_assert(orientid != -1U && orientid < m3d->numvertex);
-    m3dv_t *p = &m3d->vertex[posid];
-    m3dv_t *q = &m3d->vertex[orientid];
-
-    /* quaternion to matrix. Do NOT use aiQuaternion to aiMatrix3x3, gives bad results */
-    if(q->x == 0.0 && q->y == 0.0 && q->z >= 0.7071065 && q->z <= 0.7071075 && q->w == 0.0) {
-        m->a2 = m->a3 = m->b1 = m->b3 = m->c1 = m->c2 = 0.0;
-        m->a1 = m->b2 = m->c3 = -1.0;
-    } else {
-        m->a1 = 1 - 2 * (q->y * q->y + q->z * q->z); if(m->a1 > -M3D_EPSILON && m->a1 < M3D_EPSILON) m->a1 = 0.0;
-        m->a2 = 2 * (q->x * q->y - q->z * q->w);     if(m->a2 > -M3D_EPSILON && m->a2 < M3D_EPSILON) m->a2 = 0.0;
-        m->a3 = 2 * (q->x * q->z + q->y * q->w);     if(m->a3 > -M3D_EPSILON && m->a3 < M3D_EPSILON) m->a3 = 0.0;
-        m->b1 = 2 * (q->x * q->y + q->z * q->w);     if(m->b1 > -M3D_EPSILON && m->b1 < M3D_EPSILON) m->b1 = 0.0;
-        m->b2 = 1 - 2 * (q->x * q->x + q->z * q->z); if(m->b2 > -M3D_EPSILON && m->b2 < M3D_EPSILON) m->b2 = 0.0;
-        m->b3 = 2 * (q->y * q->z - q->x * q->w);     if(m->b3 > -M3D_EPSILON && m->b3 < M3D_EPSILON) m->b3 = 0.0;
-        m->c1 = 2 * (q->x * q->z - q->y * q->w);     if(m->c1 > -M3D_EPSILON && m->c1 < M3D_EPSILON) m->c1 = 0.0;
-        m->c2 = 2 * (q->y * q->z + q->x * q->w);     if(m->c2 > -M3D_EPSILON && m->c2 < M3D_EPSILON) m->c2 = 0.0;
-        m->c3 = 1 - 2 * (q->x * q->x + q->y * q->y); if(m->c3 > -M3D_EPSILON && m->c3 < M3D_EPSILON) m->c3 = 0.0;
-    }
-
-    /* set translation */
-    m->a4 = p->x; m->b4 = p->y; m->c4 = p->z;
-
-    m->d1 = 0; m->d2 = 0; m->d3 = 0; m->d4 = 1;
+void M3DImporter::convertPose(const M3DWrapper &m3d, aiMatrix4x4 *m, unsigned int posid, unsigned int orientid) {
+	ai_assert(m != nullptr);
+	ai_assert(m3d);
+	ai_assert(posid != -1U && posid < m3d->numvertex);
+	ai_assert(orientid != -1U && orientid < m3d->numvertex);
+	m3dv_t *p = &m3d->vertex[posid];
+	m3dv_t *q = &m3d->vertex[orientid];
+
+	/* quaternion to matrix. Do NOT use aiQuaternion to aiMatrix3x3, gives bad results */
+	if (q->x == 0.0 && q->y == 0.0 && q->z >= 0.7071065 && q->z <= 0.7071075 && q->w == 0.0) {
+		m->a2 = m->a3 = m->b1 = m->b3 = m->c1 = m->c2 = 0.0;
+		m->a1 = m->b2 = m->c3 = -1.0;
+	} else {
+		m->a1 = 1 - 2 * (q->y * q->y + q->z * q->z);
+		if (m->a1 > -M3D_EPSILON && m->a1 < M3D_EPSILON) m->a1 = 0.0;
+		m->a2 = 2 * (q->x * q->y - q->z * q->w);
+		if (m->a2 > -M3D_EPSILON && m->a2 < M3D_EPSILON) m->a2 = 0.0;
+		m->a3 = 2 * (q->x * q->z + q->y * q->w);
+		if (m->a3 > -M3D_EPSILON && m->a3 < M3D_EPSILON) m->a3 = 0.0;
+		m->b1 = 2 * (q->x * q->y + q->z * q->w);
+		if (m->b1 > -M3D_EPSILON && m->b1 < M3D_EPSILON) m->b1 = 0.0;
+		m->b2 = 1 - 2 * (q->x * q->x + q->z * q->z);
+		if (m->b2 > -M3D_EPSILON && m->b2 < M3D_EPSILON) m->b2 = 0.0;
+		m->b3 = 2 * (q->y * q->z - q->x * q->w);
+		if (m->b3 > -M3D_EPSILON && m->b3 < M3D_EPSILON) m->b3 = 0.0;
+		m->c1 = 2 * (q->x * q->z - q->y * q->w);
+		if (m->c1 > -M3D_EPSILON && m->c1 < M3D_EPSILON) m->c1 = 0.0;
+		m->c2 = 2 * (q->y * q->z + q->x * q->w);
+		if (m->c2 > -M3D_EPSILON && m->c2 < M3D_EPSILON) m->c2 = 0.0;
+		m->c3 = 1 - 2 * (q->x * q->x + q->y * q->y);
+		if (m->c3 > -M3D_EPSILON && m->c3 < M3D_EPSILON) m->c3 = 0.0;
+	}
+
+	/* set translation */
+	m->a4 = p->x;
+	m->b4 = p->y;
+	m->c4 = p->z;
+
+	m->d1 = 0;
+	m->d2 = 0;
+	m->d3 = 0;
+	m->d4 = 1;
 }
 
 // ------------------------------------------------------------------------------------------------
 // find a node by name
-aiNode *M3DImporter::findNode(aiNode *pNode, aiString name)
-{
-    unsigned int i;
-
-    ai_assert(pNode != nullptr);
-    ai_assert(mScene != nullptr);
-
-    if(pNode->mName == name)
-        return pNode;
-    for(i = 0; i < pNode->mNumChildren; i++) {
-        aiNode *pChild = findNode(pNode->mChildren[i], name);
-        if(pChild) return pChild;
-    }
-    return nullptr;
+aiNode *M3DImporter::findNode(aiNode *pNode, aiString name) {
+	unsigned int i;
+
+	ai_assert(pNode != nullptr);
+	ai_assert(mScene != nullptr);
+
+	if (pNode->mName == name)
+		return pNode;
+	for (i = 0; i < pNode->mNumChildren; i++) {
+		aiNode *pChild = findNode(pNode->mChildren[i], name);
+		if (pChild) return pChild;
+	}
+	return nullptr;
 }
 
 // ------------------------------------------------------------------------------------------------
 // fills up offsetmatrix in mBones
-void M3DImporter::calculateOffsetMatrix(aiNode *pNode, aiMatrix4x4 *m)
-{
-    ai_assert(pNode != nullptr);
-    ai_assert(mScene != nullptr);
-
-    if(pNode->mParent) {
-        calculateOffsetMatrix(pNode->mParent, m);
-        *m *= pNode->mTransformation;
-    } else {
-        *m = pNode->mTransformation;
-    }
+void M3DImporter::calculateOffsetMatrix(aiNode *pNode, aiMatrix4x4 *m) {
+	ai_assert(pNode != nullptr);
+	ai_assert(mScene != nullptr);
+
+	if (pNode->mParent) {
+		calculateOffsetMatrix(pNode->mParent, m);
+		*m *= pNode->mTransformation;
+	} else {
+		*m = pNode->mTransformation;
+	}
 }
 
 // ------------------------------------------------------------------------------------------------
 // because M3D has a global mesh, global vertex ids and stores materialid on the face, we need
 // temporary lists to collect data for an aiMesh, which requires local arrays and local indeces
 // this function fills up an aiMesh with those temporary lists
-void M3DImporter::populateMesh(aiMesh *pMesh, std::vector<aiFace> *faces, std::vector<aiVector3D> *vertices,
-    std::vector<aiVector3D> *normals, std::vector<aiVector3D> *texcoords, std::vector<aiColor4D> *colors,
-    std::vector<unsigned int> *vertexids) {
-
-    ai_assert(pMesh != nullptr);
-    ai_assert(faces != nullptr);
-    ai_assert(vertices != nullptr);
-    ai_assert(normals != nullptr);
-    ai_assert(texcoords != nullptr);
-    ai_assert(colors != nullptr);
-    ai_assert(vertexids != nullptr);
-    ai_assert(m3d != nullptr);
-
-    ASSIMP_LOG_DEBUG_F("M3D: populateMesh numvertices ", vertices->size(), " numfaces ", faces->size(),
-        " numnormals ", normals->size(), " numtexcoord ", texcoords->size(), " numbones ", m3d->numbone);
-
-    if(vertices->size() && faces->size()) {
-        pMesh->mNumFaces = faces->size();
-        pMesh->mFaces = new aiFace[pMesh->mNumFaces];
-        std::copy(faces->begin(), faces->end(), pMesh->mFaces);
-        pMesh->mNumVertices = vertices->size();
-        pMesh->mVertices = new aiVector3D[pMesh->mNumVertices];
-        std::copy(vertices->begin(), vertices->end(), pMesh->mVertices);
-        if(normals->size() == vertices->size()) {
-            pMesh->mNormals = new aiVector3D[pMesh->mNumVertices];
-            std::copy(normals->begin(), normals->end(), pMesh->mNormals);
-        }
-        if(texcoords->size() == vertices->size()) {
-            pMesh->mTextureCoords[0] = new aiVector3D[pMesh->mNumVertices];
-            std::copy(texcoords->begin(), texcoords->end(), pMesh->mTextureCoords[0]);
-            pMesh->mNumUVComponents[0] = 2;
-        }
-        if(colors->size() == vertices->size()) {
-            pMesh->mColors[0] = new aiColor4D[pMesh->mNumVertices];
-            std::copy(colors->begin(), colors->end(), pMesh->mColors[0]);
-        }
-        // this is complicated, because M3D stores a list of bone id / weight pairs per
-        // vertex but assimp uses lists of local vertex id/weight pairs per local bone list
-        pMesh->mNumBones = m3d->numbone;
-        /* we need aiBone with mOffsetMatrix for bones without weights as well */
-        if(pMesh->mNumBones) {
-            pMesh->mBones = new aiBone*[pMesh->mNumBones];
-            for(unsigned int i = 0; i < m3d->numbone; i++) {
-                aiNode *pNode;
-                pMesh->mBones[i] = new aiBone;
-                pMesh->mBones[i]->mName = aiString(std::string(m3d->bone[i].name));
-                pMesh->mBones[i]->mNumWeights = 0;
-                pNode = findNode(mScene->mRootNode, pMesh->mBones[i]->mName);
-                if(pNode) {
-                    calculateOffsetMatrix(pNode, &pMesh->mBones[i]->mOffsetMatrix);
-                    pMesh->mBones[i]->mOffsetMatrix.Inverse();
-                } else
-                    pMesh->mBones[i]->mOffsetMatrix = aiMatrix4x4();
-            }
-            if(vertexids->size()) {
-                unsigned int i, j;
-                // first count how many vertices we have per bone
-                for(i = 0; i < vertexids->size(); i++) {
-                    unsigned int s = m3d->vertex[vertexids->at(i)].skinid;
-                    if(s != -1U && s!= -2U) {
-                        for(unsigned int k = 0; k < M3D_NUMBONE && m3d->skin[s].weight[k] > 0.0; k++) {
-                                aiString name = aiString(std::string(m3d->bone[m3d->skin[s].boneid[k]].name));
-                                for(j = 0; j < pMesh->mNumBones; j++) {
-                                    if(pMesh->mBones[j]->mName == name) {
-                                        pMesh->mBones[j]->mNumWeights++;
-                                        break;
-                                    }
-                                }
-                        }
-                    }
-                }
-                // allocate mWeights
-                for(j = 0; j < pMesh->mNumBones; j++) {
-                    aiBone *pBone = pMesh->mBones[j];
-                    if(pBone->mNumWeights) {
-                        pBone->mWeights = new aiVertexWeight[pBone->mNumWeights];
-                        pBone->mNumWeights = 0;
-                    }
-                }
-                // fill up with data
-                for(i = 0; i < vertexids->size(); i++) {
-                    unsigned int s = m3d->vertex[vertexids->at(i)].skinid;
-                    if(s != -1U && s!= -2U) {
-                        for(unsigned int k = 0; k < M3D_NUMBONE && m3d->skin[s].weight[k] > 0.0; k++) {
-                                aiString name = aiString(std::string(m3d->bone[m3d->skin[s].boneid[k]].name));
-                                for(j = 0; j < pMesh->mNumBones; j++) {
-                                    if(pMesh->mBones[j]->mName == name) {
-                                        aiBone *pBone = pMesh->mBones[j];
-                                        pBone->mWeights[pBone->mNumWeights].mVertexId = i;
-                                        pBone->mWeights[pBone->mNumWeights].mWeight = m3d->skin[s].weight[k];
-                                        pBone->mNumWeights++;
-                                        break;
-                                    }
-                                }
-                        } // foreach skin
-                    }
-                } // foreach vertexids
-            }
-        }
-    }
+void M3DImporter::populateMesh(const M3DWrapper &m3d, aiMesh *pMesh, std::vector<aiFace> *faces, std::vector<aiVector3D> *vertices,
+		std::vector<aiVector3D> *normals, std::vector<aiVector3D> *texcoords, std::vector<aiColor4D> *colors,
+		std::vector<unsigned int> *vertexids) {
+
+	ai_assert(pMesh != nullptr);
+	ai_assert(faces != nullptr);
+	ai_assert(vertices != nullptr);
+	ai_assert(normals != nullptr);
+	ai_assert(texcoords != nullptr);
+	ai_assert(colors != nullptr);
+	ai_assert(vertexids != nullptr);
+	ai_assert(m3d);
+
+	ASSIMP_LOG_DEBUG_F("M3D: populateMesh numvertices ", vertices->size(), " numfaces ", faces->size(),
+			" numnormals ", normals->size(), " numtexcoord ", texcoords->size(), " numbones ", m3d->numbone);
+
+	if (vertices->size() && faces->size()) {
+		pMesh->mNumFaces = static_cast<unsigned int>(faces->size());
+		pMesh->mFaces = new aiFace[pMesh->mNumFaces];
+		std::copy(faces->begin(), faces->end(), pMesh->mFaces);
+		pMesh->mNumVertices = static_cast<unsigned int>(vertices->size());
+		pMesh->mVertices = new aiVector3D[pMesh->mNumVertices];
+		std::copy(vertices->begin(), vertices->end(), pMesh->mVertices);
+		if (normals->size() == vertices->size()) {
+			pMesh->mNormals = new aiVector3D[pMesh->mNumVertices];
+			std::copy(normals->begin(), normals->end(), pMesh->mNormals);
+		}
+		if (texcoords->size() == vertices->size()) {
+			pMesh->mTextureCoords[0] = new aiVector3D[pMesh->mNumVertices];
+			std::copy(texcoords->begin(), texcoords->end(), pMesh->mTextureCoords[0]);
+			pMesh->mNumUVComponents[0] = 2;
+		}
+		if (colors->size() == vertices->size()) {
+			pMesh->mColors[0] = new aiColor4D[pMesh->mNumVertices];
+			std::copy(colors->begin(), colors->end(), pMesh->mColors[0]);
+		}
+		// this is complicated, because M3D stores a list of bone id / weight pairs per
+		// vertex but assimp uses lists of local vertex id/weight pairs per local bone list
+		pMesh->mNumBones = m3d->numbone;
+		/* we need aiBone with mOffsetMatrix for bones without weights as well */
+		if (pMesh->mNumBones) {
+			pMesh->mBones = new aiBone *[pMesh->mNumBones];
+			for (unsigned int i = 0; i < m3d->numbone; i++) {
+				aiNode *pNode;
+				pMesh->mBones[i] = new aiBone;
+				pMesh->mBones[i]->mName = aiString(std::string(m3d->bone[i].name));
+				pMesh->mBones[i]->mNumWeights = 0;
+				pNode = findNode(mScene->mRootNode, pMesh->mBones[i]->mName);
+				if (pNode) {
+					calculateOffsetMatrix(pNode, &pMesh->mBones[i]->mOffsetMatrix);
+					pMesh->mBones[i]->mOffsetMatrix.Inverse();
+				} else
+					pMesh->mBones[i]->mOffsetMatrix = aiMatrix4x4();
+			}
+			if (vertexids->size()) {
+				unsigned int i, j;
+				// first count how many vertices we have per bone
+				for (i = 0; i < vertexids->size(); i++) {
+					unsigned int s = m3d->vertex[vertexids->at(i)].skinid;
+					if (s != -1U && s != -2U) {
+						for (unsigned int k = 0; k < M3D_NUMBONE && m3d->skin[s].weight[k] > 0.0; k++) {
+							aiString name = aiString(std::string(m3d->bone[m3d->skin[s].boneid[k]].name));
+							for (j = 0; j < pMesh->mNumBones; j++) {
+								if (pMesh->mBones[j]->mName == name) {
+									pMesh->mBones[j]->mNumWeights++;
+									break;
+								}
+							}
+						}
+					}
+				}
+				// allocate mWeights
+				for (j = 0; j < pMesh->mNumBones; j++) {
+					aiBone *pBone = pMesh->mBones[j];
+					if (pBone->mNumWeights) {
+						pBone->mWeights = new aiVertexWeight[pBone->mNumWeights];
+						pBone->mNumWeights = 0;
+					}
+				}
+				// fill up with data
+				for (i = 0; i < vertexids->size(); i++) {
+					unsigned int s = m3d->vertex[vertexids->at(i)].skinid;
+					if (s != -1U && s != -2U) {
+						for (unsigned int k = 0; k < M3D_NUMBONE && m3d->skin[s].weight[k] > 0.0; k++) {
+							aiString name = aiString(std::string(m3d->bone[m3d->skin[s].boneid[k]].name));
+							for (j = 0; j < pMesh->mNumBones; j++) {
+								if (pMesh->mBones[j]->mName == name) {
+									aiBone *pBone = pMesh->mBones[j];
+									pBone->mWeights[pBone->mNumWeights].mVertexId = i;
+									pBone->mWeights[pBone->mNumWeights].mWeight = m3d->skin[s].weight[k];
+									pBone->mNumWeights++;
+									break;
+								}
+							}
+						} // foreach skin
+					}
+				} // foreach vertexids
+			}
+		}
+	}
 }
 
 // ------------------------------------------------------------------------------------------------
 
-}   // Namespace Assimp
+} // Namespace Assimp
 
 #endif // !! ASSIMP_BUILD_NO_M3D_IMPORTER

code/M3D/M3DImporter.h

@@ -48,7 +48,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef ASSIMP_BUILD_NO_M3D_IMPORTER
 
-#include "m3d.h"
 #include <assimp/BaseImporter.h>
 #include <assimp/material.h>
 #include <vector>
@@ -60,43 +59,41 @@ struct aiFace;
 
 namespace Assimp {
 
+class M3DWrapper;
+
 class M3DImporter : public BaseImporter {
 public:
-    /// \brief  Default constructor
-    M3DImporter();
-
-    /// \brief  Destructor
-    ~M3DImporter();
+	/// \brief  Default constructor
+	M3DImporter();
 
 public:
-    /// \brief  Returns whether the class can handle the format of the given file.
-    /// \remark See BaseImporter::CanRead() for details.
-    bool CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const;
+	/// \brief  Returns whether the class can handle the format of the given file.
+	/// \remark See BaseImporter::CanRead() for details.
+	bool CanRead(const std::string &pFile, IOSystem *pIOHandler, bool checkSig) const;
 
 private:
-    aiScene* mScene; // the scene to import to
-    m3d_t *m3d; // model for the C library to convert from
-
-    //! \brief  Appends the supported extension.
-    const aiImporterDesc* GetInfo () const;
-
-    //! \brief  File import implementation.
-    void InternReadFile(const std::string& pFile, aiScene* pScene, IOSystem* pIOHandler);
-
-    void importMaterials();
-    void importTextures();
-    void importMeshes();
-    void importBones(unsigned int parentid, aiNode *pParent);
-    void importAnimations();
-
-    // helper functions
-    aiColor4D mkColor(uint32_t c);
-    void convertPose(aiMatrix4x4 *m, unsigned int posid, unsigned int orientid);
-    aiNode *findNode(aiNode *pNode, aiString name);
-    void calculateOffsetMatrix(aiNode *pNode, aiMatrix4x4 *m);
-    void populateMesh(aiMesh *pMesh, std::vector<aiFace> *faces, std::vector<aiVector3D> *verteces,
-        std::vector<aiVector3D> *normals, std::vector<aiVector3D> *texcoords, std::vector<aiColor4D> *colors,
-        std::vector<unsigned int> *vertexids);
+	aiScene *mScene = nullptr; // the scene to import to
+
+	//! \brief  Appends the supported extension.
+	const aiImporterDesc *GetInfo() const;
+
+	//! \brief  File import implementation.
+	void InternReadFile(const std::string &pFile, aiScene *pScene, IOSystem *pIOHandler);
+
+	void importMaterials(const M3DWrapper &m3d);
+	void importTextures(const M3DWrapper &m3d);
+	void importMeshes(const M3DWrapper &m3d);
+	void importBones(const M3DWrapper &m3d, unsigned int parentid, aiNode *pParent);
+	void importAnimations(const M3DWrapper &m3d);
+
+	// helper functions
+	aiColor4D mkColor(uint32_t c);
+	void convertPose(const M3DWrapper &m3d, aiMatrix4x4 *m, unsigned int posid, unsigned int orientid);
+	aiNode *findNode(aiNode *pNode, aiString name);
+	void calculateOffsetMatrix(aiNode *pNode, aiMatrix4x4 *m);
+	void populateMesh(const M3DWrapper &m3d, aiMesh *pMesh, std::vector<aiFace> *faces, std::vector<aiVector3D> *verteces,
+			std::vector<aiVector3D> *normals, std::vector<aiVector3D> *texcoords, std::vector<aiColor4D> *colors,
+			std::vector<unsigned int> *vertexids);
 };
 
 } // Namespace Assimp

code/M3D/M3DWrapper.cpp

@@ -0,0 +1,136 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+Copyright (c) 2019 bzt
+
+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.
+
+----------------------------------------------------------------------
+*/
+
+#if !(ASSIMP_BUILD_NO_EXPORT || ASSIMP_BUILD_NO_M3D_EXPORTER) && !ASSIMP_BUILD_NO_M3D_IMPORTER
+
+#include "M3DWrapper.h"
+
+#include <assimp/DefaultIOSystem.h>
+#include <assimp/IOStreamBuffer.h>
+#include <assimp/ai_assert.h>
+
+#if (__cplusplus >= 201103L) || (_MSC_VER >= 1915) || defined(AI_M3D_USE_STDMUTEX) // C++11 and MSVC that mostly supports it
+#define AI_M3D_USE_STDMUTEX
+#include <mutex>
+#endif
+
+// workaround: the M3D SDK expects a C callback, but we want to use Assimp::IOSystem to implement that
+// This makes it non-rentrant so lock a mutex (requires C++11)
+
+std::mutex file_mutex;
+
+extern "C" {
+void *m3dimporter_pIOHandler;
+
+unsigned char *m3dimporter_readfile(char *fn, unsigned int *size) {
+	ai_assert(nullptr != fn);
+	ai_assert(nullptr != size);
+	std::string file(fn);
+	std::unique_ptr<Assimp::IOStream> pStream(
+			(reinterpret_cast<Assimp::IOSystem *>(m3dimporter_pIOHandler))->Open(file, "rb"));
+	size_t fileSize = 0;
+	unsigned char *data = NULL;
+	// sometimes pStream is nullptr for some reason (should be an empty object returning nothing I guess)
+	if (pStream) {
+		fileSize = pStream->FileSize();
+		// should be allocated with malloc(), because the library will call free() to deallocate
+		data = (unsigned char *)malloc(fileSize);
+		if (!data || !pStream.get() || !fileSize || fileSize != pStream->Read(data, 1, fileSize)) {
+			pStream.reset();
+			*size = 0;
+			// don't throw a deadly exception, it's not fatal if we can't read an external asset
+			return nullptr;
+		}
+		pStream.reset();
+	}
+	*size = (int)fileSize;
+	return data;
+}
+}
+
+namespace Assimp {
+M3DWrapper::M3DWrapper() {
+	// use malloc() here because m3d_free() will call free()
+	m3d_ = (m3d_t *)calloc(1, sizeof(m3d_t));
+}
+
+M3DWrapper::M3DWrapper(IOSystem *pIOHandler, const std::vector<unsigned char> &buffer) {
+#ifdef AI_M3D_USE_STDMUTEX
+	// M3D is NOT thread-safe, so lock the global mutex
+	const std::lock_guard<std::mutex> lock(file_mutex);
+#endif
+	// pass this IOHandler to the C callback
+	m3dimporter_pIOHandler = pIOHandler;
+	m3d_ = m3d_load(const_cast<unsigned char *>(buffer.data()), m3dimporter_readfile, free, nullptr);
+	// Clear the C callback
+	m3dimporter_pIOHandler = nullptr;
+}
+
+M3DWrapper::~M3DWrapper() {
+	reset();
+}
+
+void M3DWrapper::reset() {
+	ClearSave();
+	if (m3d_)
+		m3d_free(m3d_);
+	m3d_ = nullptr;
+}
+
+unsigned char *M3DWrapper::Save(int quality, int flags, unsigned int &size) {
+#if (!(ASSIMP_BUILD_NO_EXPORT || ASSIMP_BUILD_NO_M3D_EXPORTER))
+	ClearSave();
+	saved_output_ = m3d_save(m3d_, quality, flags, &size);
+	return saved_output_;
+#else
+	return nullptr;
+#endif
+}
+
+void M3DWrapper::ClearSave() {
+	if (saved_output_)
+		M3D_FREE(saved_output_);
+	saved_output_ = nullptr;
+}
+} // namespace Assimp
+
+#endif

code/M3D/M3DWrapper.h

@@ -0,0 +1,96 @@
+#pragma once
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+Copyright (c) 2019 bzt
+
+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 M3DWrapper.h
+*   @brief Declares a class to wrap the C m3d SDK
+*/
+#ifndef AI_M3DWRAPPER_H_INC
+#define AI_M3DWRAPPER_H_INC
+#if !(ASSIMP_BUILD_NO_EXPORT || ASSIMP_BUILD_NO_M3D_EXPORTER) && !ASSIMP_BUILD_NO_M3D_IMPORTER
+
+#include <memory>
+#include <vector>
+
+#include "m3d.h"
+
+namespace Assimp {
+class IOSystem;
+
+class M3DWrapper {
+	m3d_t *m3d_ = nullptr;
+	unsigned char *saved_output_ = nullptr;
+
+public:
+	// Construct an empty M3D model
+	explicit M3DWrapper();
+
+	// Construct an M3D model from provided buffer
+	// NOTE: The m3d.h SDK function does not mark the data as const. Have assumed it does not write.
+	// BUG: SECURITY: The m3d.h SDK cannot be informed of the buffer size. BUFFER OVERFLOW IS CERTAIN
+	explicit M3DWrapper(IOSystem *pIOHandler, const std::vector<unsigned char> &buffer);
+
+	~M3DWrapper();
+
+	void reset();
+
+	// Name
+	inline std::string Name() const {
+		if (m3d_) return std::string(m3d_->name);
+		return std::string();
+	}
+
+	// Execute a save
+	unsigned char *Save(int quality, int flags, unsigned int &size);
+	void ClearSave();
+
+	inline explicit operator bool() const { return m3d_ != nullptr; }
+
+	// Allow direct access to M3D API
+	inline m3d_t *operator->() const { return m3d_; }
+	inline m3d_t *M3D() const { return m3d_; }
+};
+} // namespace Assimp
+
+#endif
+
+#endif // AI_M3DWRAPPER_H_INC