public Mesh ExtractMesh(IEnumerable <int> geom_ids)
{
/* Returns a single Mesh containing all geometry from the geom_ids (except the UV
* coordinates). The mesh consists of two submeshes: the triangles, and the stems.
* We fill them with dummies if they are empty, to simplify the callers.
*/
CallRegularUpdate();
lock (geometries_lock)
{
var extractor = new MeshExtractor();
extractor.vertices = new Vector3[mgos.Count][];
extractor.normals = new Vector3[mgos.Count][];
foreach (var geom_id in geom_ids)
{
Geom geom = geometries[geom_id];
uint gmask = geom.gindex & GINDEX_MASK;
if (gmask != GINDEX_FREE)
{
int renderer_index = (int)(geom.gindex >> GINDEX_SHIFT);
var mgo = mgos[renderer_index];
if (mgo != null)
{
mgo._ExtractMeshGeometry(extractor, geom, renderer_index);
}
}
}
if (extractor.out_vertices.Count == 0)
{
extractor.out_vertices.Add(Vector3.zero);
extractor.out_normals.Add(Vector3.zero);
}
if (extractor.out_triangles.Count == 0)
{
extractor.out_triangles.Add(0);
extractor.out_triangles.Add(0);
extractor.out_triangles.Add(0);
}
if (extractor.out_stems.Count == 0)
{
extractor.out_stems.Add(0);
extractor.out_stems.Add(0);
}
var mesh = new Mesh();
if (extractor.out_vertices.Count >= 0xFFE0)
{
mesh.indexFormat = UnityEngine.Rendering.IndexFormat.UInt32;
}
mesh.SetVertices(extractor.out_vertices);
mesh.SetNormals(extractor.out_normals);
mesh.subMeshCount = 2;
mesh.SetTriangles(extractor.out_triangles, 0, calculateBounds: false);
mesh.SetIndices(extractor.out_stems.ToArray(), MeshTopology.Lines, 1, calculateBounds: false);
mesh.RecalculateBounds();
return(mesh);
}
}
internal void _ExtractMeshGeometry(MeshExtractor extractor, Geom geom, int renderer_index)
{
var vertices = extractor.vertices[renderer_index];
if (vertices == null)
{
vertices = extractor.vertices[renderer_index] = mesh.vertices;
}
var normals = extractor.normals[renderer_index];
if (normals == null)
{
normals = extractor.normals[renderer_index] = mesh.normals;
}
int tstart, tstop;
tstart = geom.triangle_start * 3;
tstop = geom.triangle_stop * 3;
if (tstop == 0xFFFF * 3)
{
tstop = all_triangles.Length;
}
int sstart, sstop;
sstart = geom.stem_start * 2;
sstop = geom.stem_stop * 2;
if (sstop == 0xFFFF * 2)
{
sstop = all_stems.Length;
}
/* xxx this assumes that each independent geom_id was built from its
* own set of new vertices, without reusing any of the previous vertices;
* otherwise, we're going to get large ranges in min,max and a lot of
* duplication if we're extracting a mesh with many geom_ids */
int min = 0x7fffffff, max = -1;
for (int j = tstart; j < tstop; j++)
{
if (all_triangles[j] < min)
{
min = all_triangles[j];
}
if (all_triangles[j] > max)
{
max = all_triangles[j];
}
}
for (int j = sstart; j < sstop; j++)
{
if (all_stems[j] < min)
{
min = all_stems[j];
}
if (all_stems[j] > max)
{
max = all_stems[j];
}
}
int diff = extractor.out_vertices.Count - min;
for (int i = min; i <= max; i++)
{
extractor.out_vertices.Add(vertices[i]);
extractor.out_normals.Add(i < normals.Length ? normals[i] : Vector3.zero);
}
for (int j = tstart; j < tstop; j++)
{
extractor.out_triangles.Add(all_triangles[j] + diff);
}
for (int j = sstart; j < sstop; j++)
{
extractor.out_stems.Add(all_stems[j] + diff);
}
}
