From 8c7ecb3838a71dffc5c998cfe605ef62e0f9d329 Mon Sep 17 00:00:00 2001
From: Fabio Pellacini <fabio.pellacini@gmail.com>
Date: Mon, 29 Jan 2024 11:55:05 +0100
Subject: [PATCH] Remove vertex welding

---
 libs/yocto/yocto_shape.cpp | 154 -------------------------------------
 libs/yocto/yocto_shape.h   |  31 --------
 2 files changed, 185 deletions(-)

diff --git a/libs/yocto/yocto_shape.cpp b/libs/yocto/yocto_shape.cpp
index 9e6f8d9d5..1d07df4d0 100644
--- a/libs/yocto/yocto_shape.cpp
+++ b/libs/yocto/yocto_shape.cpp
@@ -395,51 +395,6 @@ shape_data add_normals(const shape_data& shape) {
   transformed.normals = compute_normals(shape);
   return transformed;
 }
-shape_data weld_vertices(
-    const shape_data& shape, float threshold, bool normals, bool others) {
-  auto transform_vert = [](auto&& old_verts, const vector<int>& old_indices) {
-    if (old_verts.empty()) return old_verts;
-    using T    = typename std::remove_cvref_t<decltype(old_verts[0])>;
-    auto verts = vector<T>(old_indices.size());
-    for (auto&& [idx, vert] : enumerate(verts))
-      vert = old_verts[old_indices[idx]];
-    return verts;
-  };
-  auto transform_elem = [](auto&& elems_, const vector<int>& new_indices) {
-    auto elems = std::move(elems_);
-    for (auto& elem : elems)
-      if constexpr (std::is_same_v<std::remove_cvref_t<decltype(elem)>, int>) {
-        elem = new_indices[elem];
-      } else {
-        for (auto& vid : elem) vid = new_indices[vid];
-      }
-    return elems;
-  };
-
-  auto [old_indices, new_indices] = weld_indices(shape.positions, threshold);
-  auto transformed                = shape;
-  transformed.positions = transform_vert(transformed.positions, old_indices);
-  if (normals) {
-    transformed.normals = transform_vert(transformed.normals, old_indices);
-  } else {
-    transformed.normals = {};
-  }
-  if (others) {
-    transformed.texcoords = transform_vert(transformed.texcoords, old_indices);
-    transformed.colors    = transform_vert(transformed.colors, old_indices);
-    transformed.radius    = transform_vert(transformed.radius, old_indices);
-  } else {
-    transformed.texcoords = {};
-    transformed.colors    = {};
-    transformed.radius    = {};
-  }
-  transformed.tangents  = transform_vert(transformed.tangents, old_indices);
-  transformed.points    = transform_elem(transformed.points, new_indices);
-  transformed.lines     = transform_elem(transformed.lines, new_indices);
-  transformed.triangles = transform_elem(transformed.triangles, new_indices);
-  transformed.quads     = transform_elem(transformed.quads, new_indices);
-  return transformed;
-}
 
 vector<string> shape_stats(const shape_data& shape, bool verbose) {
   auto format = [](auto num) {
@@ -2490,115 +2445,6 @@ void split_facevarying(vector<vec4i>& split_quads,
   }
 }
 
-// Weld vertices within a threshold.
-pair<vector<vec3f>, vector<int>> weld_vertices(
-    const vector<vec3f>& positions, float threshold) {
-  auto indices   = vector<int>(positions.size());
-  auto welded    = vector<vec3f>{};
-  auto grid      = make_hash_grid(threshold);
-  auto neighbors = vector<int>{};
-  for (auto vertex : range(positions.size())) {
-    auto& position = positions[vertex];
-    find_neighbors(grid, neighbors, position, threshold);
-    if (neighbors.empty()) {
-      welded.push_back(position);
-      indices[vertex] = (int)welded.size() - 1;
-      insert_vertex(grid, position);
-    } else {
-      indices[vertex] = neighbors.front();
-    }
-  }
-  return {welded, indices};
-}
-inline pair<vector<int>, vector<int>> weld_indices(
-    const vector<vec3f>& positions, float threshold) {
-  auto new_indices = vector<int>(positions.size());
-  auto old_indices = vector<int>();
-  auto grid        = make_hash_grid(threshold);
-  auto neighbors   = vector<int>{};
-  for (auto vertex : range(positions.size())) {
-    auto& position = positions[vertex];
-    find_neighbors(grid, neighbors, position, threshold);
-    if (neighbors.empty()) {
-      old_indices.push_back((int)vertex);
-      new_indices[vertex] = (int)old_indices.size() - 1;
-      insert_vertex(grid, position);
-    } else {
-      new_indices[vertex] = neighbors.front();
-    }
-  }
-  return {old_indices, new_indices};
-}
-pair<vector<vec3i>, vector<vec3f>> weld_triangles(
-    const vector<vec3i>& triangles, const vector<vec3f>& positions,
-    float threshold) {
-  auto [wpositions, indices] = weld_vertices(positions, threshold);
-  auto wtriangles            = triangles;
-  for (auto& t : wtriangles) t = {indices[t.x], indices[t.y], indices[t.z]};
-  return {wtriangles, wpositions};
-}
-pair<vector<vec4i>, vector<vec3f>> weld_quads(const vector<vec4i>& quads,
-    const vector<vec3f>& positions, float threshold) {
-  auto [wpositions, indices] = weld_vertices(positions, threshold);
-  auto wquads                = quads;
-  for (auto& q : wquads)
-    q = {
-        indices[q.x],
-        indices[q.y],
-        indices[q.z],
-        indices[q.w],
-    };
-  return {wquads, wpositions};
-}
-
-// Merge shape elements
-void merge_lines(vector<vec2i>& lines, vector<vec3f>& positions,
-    vector<vec3f>& tangents, vector<vec2f>& texcoords, vector<float>& radius,
-    const vector<vec2i>& merge_lines, const vector<vec3f>& merge_positions,
-    const vector<vec3f>& merge_tangents,
-    const vector<vec2f>& merge_texturecoords,
-    const vector<float>& merge_radius) {
-  auto merge_verts = (int)positions.size();
-  for (auto& l : merge_lines)
-    lines.push_back({l.x + merge_verts, l.y + merge_verts});
-  positions.insert(
-      positions.end(), merge_positions.begin(), merge_positions.end());
-  tangents.insert(tangents.end(), merge_tangents.begin(), merge_tangents.end());
-  texcoords.insert(
-      texcoords.end(), merge_texturecoords.begin(), merge_texturecoords.end());
-  radius.insert(radius.end(), merge_radius.begin(), merge_radius.end());
-}
-void merge_triangles(vector<vec3i>& triangles, vector<vec3f>& positions,
-    vector<vec3f>& normals, vector<vec2f>& texcoords,
-    const vector<vec3i>& merge_triangles, const vector<vec3f>& merge_positions,
-    const vector<vec3f>& merge_normals,
-    const vector<vec2f>& merge_texturecoords) {
-  auto merge_verts = (int)positions.size();
-  for (auto& t : merge_triangles)
-    triangles.push_back(
-        {t.x + merge_verts, t.y + merge_verts, t.z + merge_verts});
-  positions.insert(
-      positions.end(), merge_positions.begin(), merge_positions.end());
-  normals.insert(normals.end(), merge_normals.begin(), merge_normals.end());
-  texcoords.insert(
-      texcoords.end(), merge_texturecoords.begin(), merge_texturecoords.end());
-}
-void merge_quads(vector<vec4i>& quads, vector<vec3f>& positions,
-    vector<vec3f>& normals, vector<vec2f>& texcoords,
-    const vector<vec4i>& merge_quads, const vector<vec3f>& merge_positions,
-    const vector<vec3f>& merge_normals,
-    const vector<vec2f>& merge_texturecoords) {
-  auto merge_verts = (int)positions.size();
-  for (auto& q : merge_quads)
-    quads.push_back({q.x + merge_verts, q.y + merge_verts, q.z + merge_verts,
-        q.w + merge_verts});
-  positions.insert(
-      positions.end(), merge_positions.begin(), merge_positions.end());
-  normals.insert(normals.end(), merge_normals.begin(), merge_normals.end());
-  texcoords.insert(
-      texcoords.end(), merge_texturecoords.begin(), merge_texturecoords.end());
-}
-
 }  // namespace yocto
 
 // -----------------------------------------------------------------------------
diff --git a/libs/yocto/yocto_shape.h b/libs/yocto/yocto_shape.h
index 1d887b2f7..da3e2fc1a 100644
--- a/libs/yocto/yocto_shape.h
+++ b/libs/yocto/yocto_shape.h
@@ -142,8 +142,6 @@ shape_data flipyz_shape(const shape_data& shape);
 // Manipulate vertex data
 shape_data remove_normals(const shape_data& shape);
 shape_data add_normals(const shape_data& shape);
-shape_data weld_vertices(const shape_data& shape, float threshold,
-    bool normals = false, bool others = false);
 
 // Merge a shape into another
 void merge_shape_inplace(shape_data& shape, const shape_data& merge);
@@ -571,35 +569,6 @@ void split_facevarying(vector<vec4i>& split_quads,
     const vector<vec3f>& positions, const vector<vec3f>& normals,
     const vector<vec2f>& texcoords);
 
-// Weld vertices within a threshold.
-pair<vector<vec3f>, vector<int>> weld_vertices(
-    const vector<vec3f>& positions, float threshold);
-pair<vector<int>, vector<int>> weld_indices(
-    const vector<vec3f>& positions, float threshold);
-pair<vector<vec3i>, vector<vec3f>> weld_triangles(
-    const vector<vec3i>& triangles, const vector<vec3f>& positions,
-    float threshold);
-pair<vector<vec4i>, vector<vec3f>> weld_quads(const vector<vec4i>& quads,
-    const vector<vec3f>& positions, float threshold);
-
-// Merge shape elements
-void merge_lines(vector<vec2i>& lines, vector<vec3f>& positions,
-    vector<vec3f>& tangents, vector<vec2f>& texcoords, vector<float>& radius,
-    const vector<vec2i>& merge_lines, const vector<vec3f>& merge_positions,
-    const vector<vec3f>& merge_tangents,
-    const vector<vec2f>& merge_texturecoords,
-    const vector<float>& merge_radius);
-void merge_triangles(vector<vec3i>& triangles, vector<vec3f>& positions,
-    vector<vec3f>& normals, vector<vec2f>& texcoords,
-    const vector<vec2i>& merge_triangles, const vector<vec3f>& merge_positions,
-    const vector<vec3f>& merge_normals,
-    const vector<vec2f>& merge_texturecoords);
-void merge_quads(vector<vec4i>& quads, vector<vec3f>& positions,
-    vector<vec3f>& normals, vector<vec2f>& texcoords,
-    const vector<vec4i>& merge_quads, const vector<vec3f>& merge_positions,
-    const vector<vec3f>& merge_normals,
-    const vector<vec2f>& merge_texturecoords);
-
 }  // namespace yocto
 
 // -----------------------------------------------------------------------------