PolygonalDrawable * ObjIO::createPolygonalDrawable(
const ObjObject & object
, const ObjGroup & group)
{
if(group.vis.empty())
return NULL;
// TODO: this should test if all consecutive offsets are equal 3.
// The current expression could return false positives.
if(group.vis.size() / 3 != group.foffs.size())
{
qCritical("Ignore polygon with num vertices != 3 (only triangles are supported).");
return NULL;
}
const bool usesTexCoordIndices(!group.vtis.empty());
const bool usesNormalIndices(!group.vnis.empty());
PolygonalDrawable * drawable = new PolygonalDrawable();
const GLuint size(static_cast<GLuint>(group.vis.size()));
for(GLuint i = 0; i < size; ++i)
{
// add vertex and its new index based on obj index
// TODO: make use of vertex reuse!
drawable->indices().push_back(i);
drawable->vertices().push_back(object.vs[group.vis[i]]);
if(usesTexCoordIndices)
drawable->texcs().push_back(object.vts[group.vtis[i]]);
if(usesNormalIndices)
drawable->normals().push_back(object.vns[group.vnis[i]]);
}
// TODO: support other modes here!
drawable->setMode(GL_TRIANGLES);
if(!usesNormalIndices)
drawable->retrieveNormals();
return drawable;
}
PolygonalDrawable * AssimpLoader::parseMesh(const aiMesh & mesh) const
{
auto geometry = std::make_shared<PolygonalGeometry>(m_registry);
const bool usesNormalIndices(mesh.mNormals != NULL);
for (unsigned int i = 0; i < mesh.mNumVertices; i++) {
glm::vec3 vector(
mesh.mVertices[i].x, mesh.mVertices[i].y, mesh.mVertices[i].z
);
geometry->setVertex(i, vector);
}
if (usesNormalIndices) {
for (unsigned int i = 0; i < mesh.mNumVertices; i++) {
glm::vec3 vector(
mesh.mNormals[i].x, mesh.mNormals[i].y, mesh.mNormals[i].z
);
geometry->setNormal(i, vector);
}
}
unsigned int currentIndex = 0;
for (unsigned int i = 0; i < mesh.mNumFaces; i++) {
if (mesh.mFaces[i].mNumIndices != 3)
qCritical("Ignore polygon with num vertices != 3 (only triangles are supported).");
else
for (unsigned int j = 0; j < mesh.mFaces[i].mNumIndices; j++)
geometry->setIndex(currentIndex++, mesh.mFaces[i].mIndices[j]);
}
if (!usesNormalIndices)
geometry->retrieveNormals();
PolygonalDrawable * drawable = new PolygonalDrawable(mesh.mName.C_Str());
drawable->setGeometry(geometry);
drawable->setMode(GL_TRIANGLES);
return drawable;
}
