/** \brief This function constructs a heuristic coloring for the
graph and returns the number of colors */
size_t compute_coloring() {
// Reset the colors
#pragma omp parallel for
for(int v = 0; v < (int)num_vertices(); ++v) set_color(v, 0);
// Recolor
size_t max_color = 0;
std::set<vertex_color_type> neighbor_colors;
for(vertex_id_type vid = 0; vid < num_vertices(); ++vid) {
neighbor_colors.clear();
// Get the neighbor colors
foreach(vertex_id_type neighbor_vid, in_vertices(vid)){
const vertex_color_type& neighbor_color = get_color(neighbor_vid);
neighbor_colors.insert(neighbor_color);
}
foreach(vertex_id_type neighbor_vid, out_vertices(vid)){
const vertex_color_type& neighbor_color = get_color(neighbor_vid);
neighbor_colors.insert(neighbor_color);
}
vertex_color_type vertex_color = 0;
foreach(vertex_color_type neighbor_color, neighbor_colors) {
if(vertex_color != neighbor_color) break;
else vertex_color++;
// Ensure no wrap around
ASSERT_NE(vertex_color, 0);
}
set_color(vid, vertex_color);
max_color = std::max(max_color, size_t(vertex_color) );
}
// Return the NUMBER of colors
propagate_coloring();
ncolors = max_color + 1;
return max_color + 1;
}
void indexVBO(std::vector<natVec3<>>& vertices, std::vector<natVec2<>>& uvs, std::vector<natVec3<>>& normals, std::vector<unsigned short>& out_indices)
{
out_indices.clear();
std::vector<natVec3<>> out_vertices(vertices);
std::vector<natVec2<>> out_uvs(uvs);
std::vector<natVec3<>> out_normals(normals);
std::map<PackedVertex, nuShort> VertexToOutIndex;
nuInt count = static_cast<nuInt>(std::min({ vertices.size(), uvs.size(), normals.size() }));
for (nuInt i = 0u; i < count; ++i)
{
PackedVertex packed = { vertices[i], uvs[i], normals[i] };
// Try to find a similar vertex in out_XXXX
nuShort index;
if (getSimilarVertexIndex(packed, VertexToOutIndex, index))
{
// A similar vertex is already in the VBO, use it instead !
out_indices.push_back(index);
}
else
{
// If not, it needs to be added in the output data.
out_vertices.push_back(vertices[i]);
out_uvs.push_back(uvs[i]);
out_normals.push_back(normals[i]);
unsigned short newindex = static_cast<unsigned short>(out_vertices.size()) - 1;
out_indices.push_back(newindex);
VertexToOutIndex[packed] = newindex;
}
}
/*vertices.swap(out_vertices);
uvs.swap(out_uvs);
normals.swap(out_normals);*/
vertices.assign(out_vertices.begin(), out_vertices.end());
uvs.assign(out_uvs.begin(), out_uvs.end());
normals.assign(out_normals.begin(), out_normals.end());
}
