-////////////////////////////////////////////////////////////////////////////////
-
-struct Vec3
-{
- GLfloat x, y, z;
- bool operator!=(const Vec3& rhs) const
- {
- return x != rhs.x || y != rhs.y || z != rhs.z;
- }
- bool operator<(const Vec3& rhs) const
- {
- if (x != rhs.x) return x < rhs.x;
- else if (y != rhs.y) return y < rhs.y;
- else if (z != rhs.z) return z < rhs.z;
- else return false;
- }
-};
-
-typedef std::pair<Vec3, GLuint> Vec3i;
-
-////////////////////////////////////////////////////////////////////////////////
-
-Mesh* Mesh::load_stl(const QString& filename)
-{
- QFile file(filename);
- file.open(QIODevice::ReadOnly);
-
- QDataStream data(&file);
- data.setByteOrder(QDataStream::LittleEndian);
- data.setFloatingPointPrecision(QDataStream::SinglePrecision);
-
- // Skip .stl file header
- data.skipRawData(80);
-
- // Load the triangle count from the .stl file
- uint32_t tri_count;
- data >> tri_count;
-
- // Extract vertices into an array of xyz, unsigned pairs
- QVector<Vec3i> verts(tri_count*3);
-
- // Dummy array, because readRawData is faster than skipRawData
- char buffer[sizeof(float)*3];
-
- // Store vertices in the array, processing one triangle at a time.
- for (auto v=verts.begin(); v != verts.end(); v += 3)
- {
- // Skip face's normal vector
- data.readRawData(buffer, 3*sizeof(float));
-
- // Load vertex data from .stl file into vertices
- data >> v[0].first.x >> v[0].first.y >> v[0].first.z;
- data >> v[1].first.x >> v[1].first.y >> v[1].first.z;
- data >> v[2].first.x >> v[2].first.y >> v[2].first.z;
-
- // Skip face attribute
- data.readRawData(buffer, sizeof(uint16_t));
- }
-
- // Save indicies as the second element in the array
- // (so that we can reconstruct triangle order after sorting)
- for (size_t i=0; i < tri_count*3; ++i)
- {
- verts[i].second = i;
- }
-
- // Sort the set of vertices (to deduplicate)
- std::sort(verts.begin(), verts.end());
-
- // This vector will store triangles as sets of 3 indices
- std::vector<GLuint> indices(tri_count*3);
-
- // Go through the sorted vertex list, deduplicating and creating
- // an indexed geometry representation for the triangles.
- // Unique vertices are moved so that they occupy the first vertex_count
- // positions in the verts array.
- size_t vertex_count = 0;
- for (auto v : verts)
- {
- if (!vertex_count || v.first != verts[vertex_count-1].first)
- {
- verts[vertex_count++] = v;
- }
- indices[v.second] = vertex_count - 1;
- }
- verts.resize(vertex_count);
-
- std::vector<GLfloat> flat_verts;
- flat_verts.reserve(vertex_count*3);
- for (auto v : verts)
- {
- flat_verts.push_back(v.first.x);
- flat_verts.push_back(v.first.y);
- flat_verts.push_back(v.first.z);
- }
-
- return new Mesh(flat_verts, indices);
-}