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Triangulation of polygons respects its area

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- remove its_filtration
Move Flatness out of Font
This commit is contained in:
Filip Sykala 2021-09-01 11:21:05 +02:00
parent 48f1be6ccc
commit 028f04f8a1
5 changed files with 148 additions and 215 deletions
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307
src/libslic3r/Emboss.cpp
View File

@ -54,32 +54,30 @@ std::optional<Privat::Glyph> Privat::get_glyph(stbtt_fontinfo &font_info, int un
int num_verts = stbtt_GetGlyphShape(&font_info, glyph_index, &vertices);
if (num_verts <= 0) return glyph; // no shape
int * contour_lengths = NULL;
int *contour_lengths = NULL;
int num_countour = 0;
stbtt__point *points = stbtt_FlattenCurves(vertices, num_verts,
flatness,
&contour_lengths,
&num_countour,
font_info.userdata);
flatness, &contour_lengths, &num_countour, font_info.userdata);
glyph.polygons.reserve(num_countour);
size_t pi = 0; // point index
for (size_t ci = 0; ci < num_countour; ++ci) {
int length = contour_lengths[ci];
if (length <= 0) continue;
// minimal length for triangle
assert(length >= 4);
// last point is first point
--length;
Points pts;
pts.reserve(length);
for (size_t i = 0; i < length; i++) {
for (size_t i = 0; i < length; ++i) {
const stbtt__point &point = points[pi];
pi++;
++pi;
pts.emplace_back(point.x, point.y);
}
if (pts.front() == pts.back()) {
pts.pop_back();
} else {
int j = 42;
}
// last point is first point
assert(pts.front() == Point(points[pi].x, points[pi].y));
++pi;
glyph.polygons.emplace_back(pts);
}
@ -134,20 +132,20 @@ std::optional<Emboss::Font> Emboss::load_font(const char *file_path)
return res;
}
Polygons Emboss::letter2polygons(const Font &font, char letter)
Polygons Emboss::letter2polygons(const Font &font, char letter, float flatness)
{
auto font_info_opt = Privat::load_font_info(font);
if (!font_info_opt.has_value()) return Polygons();
stbtt_fontinfo *font_info = &(*font_info_opt);
auto glyph_opt = Privat::get_glyph(*font_info_opt, (int) letter, font.flatness);
auto glyph_opt = Privat::get_glyph(*font_info_opt, (int) letter, flatness);
if (!glyph_opt.has_value()) return Polygons();
return glyph_opt->polygons;
}
#include <boost\nowide\convert.hpp>
Polygons Emboss::text2polygons(const Font &font, const char *text)
Polygons Emboss::text2polygons(const Font &font, const char *text, float flatness)
{
auto font_info_opt = Privat::load_font_info(font);
if (!font_info_opt.has_value()) return Polygons();
@ -164,7 +162,7 @@ Polygons Emboss::text2polygons(const Font &font, const char *text)
continue;
}
int unicode = static_cast<int>(wc);
auto glyph_opt = Privat::get_glyph(*font_info_opt, unicode, font.flatness);
auto glyph_opt = Privat::get_glyph(*font_info_opt, unicode, flatness);
if (!glyph_opt.has_value()) continue;
// move glyph to cursor position
@ -179,163 +177,6 @@ Polygons Emboss::text2polygons(const Font &font, const char *text)
return result;
}
std::vector<Vec3i> its_create_neighbors_index_2(const indexed_triangle_set &its)
{
std::vector<Vec3i> out(its.indices.size(), Vec3i(-1, -1, -1));
// Create a mapping from triangle edge into face.
struct EdgeToFace
{
// Index of the 1st vertex of the triangle edge. vertex_low <= vertex_high.
int vertex_low;
// Index of the 2nd vertex of the triangle edge.
int vertex_high;
// Index of a triangular face.
int face;
// Index of edge in the face, starting with 1. Negative indices if the
// edge was stored reverse in (vertex_low, vertex_high).
int face_edge;
bool operator==(const EdgeToFace &other) const
{
return vertex_low == other.vertex_low &&
vertex_high == other.vertex_high;
}
bool operator<(const EdgeToFace &other) const
{
return vertex_low < other.vertex_low ||
(vertex_low == other.vertex_low &&
vertex_high < other.vertex_high);
}
};
std::vector<EdgeToFace> edges_map;
edges_map.assign(its.indices.size() * 3, EdgeToFace());
for (uint32_t facet_idx = 0; facet_idx < its.indices.size(); ++facet_idx)
for (int i = 0; i < 3; ++i) {
EdgeToFace &e2f = edges_map[facet_idx * 3 + i];
e2f.vertex_low = its.indices[facet_idx][i];
e2f.vertex_high = its.indices[facet_idx][(i + 1) % 3];
e2f.face = facet_idx;
// 1 based indexing, to be always strictly positive.
e2f.face_edge = i + 1;
if (e2f.vertex_low > e2f.vertex_high) {
// Sort the vertices
std::swap(e2f.vertex_low, e2f.vertex_high);
// and make the face_edge negative to indicate a flipped edge.
e2f.face_edge = -e2f.face_edge;
}
}
std::sort(edges_map.begin(), edges_map.end());
// Assign a unique common edge id to touching triangle edges.
int num_edges = 0;
for (size_t i = 0; i < edges_map.size(); ++i) {
EdgeToFace &edge_i = edges_map[i];
if (edge_i.face == -1)
// This edge has been connected to some neighbor already.
continue;
// Unconnected edge. Find its neighbor with the correct orientation.
size_t j;
bool found = false;
for (j = i + 1; j < edges_map.size() && edge_i == edges_map[j]; ++j)
if (edge_i.face_edge * edges_map[j].face_edge < 0 &&
edges_map[j].face != -1) {
// Faces touching with opposite oriented edges and none of the
// edges is connected yet.
found = true;
break;
}
if (!found) {
// FIXME Vojtech: Trying to find an edge with equal orientation.
// This smells.
// admesh can assign the same edge ID to more than two facets (which is
// still topologically correct), so we have to search for a
// duplicate of this edge too in case it was already seen in this
// orientation
for (j = i + 1; j < edges_map.size() && edge_i == edges_map[j];
++j)
if (edges_map[j].face != -1) {
// Faces touching with equally oriented edges and none of
// the edges is connected yet.
found = true;
break;
}
}
// Assign an edge index to the 1st face.
// out[edge_i.face](std::abs(edge_i.face_edge) - 1) = num_edges;
if (found) {
EdgeToFace &edge_j = edges_map[j];
out[edge_i.face](std::abs(edge_i.face_edge) - 1) = edge_j.face;
out[edge_j.face](std::abs(edge_j.face_edge) - 1) = edge_i.face;
// Mark the edge as connected.
edge_j.face = -1;
}
++num_edges;
}
return out;
}
void its_remove_edge_triangles(indexed_triangle_set &its)
{
//// start, count
//std::vector<std::pair<uint32_t, uint32_t>> neighbors_vertices(its.vertices.size(), {0,0});
//// calc counts
//for (const auto &i : its.indices) {
// for (size_t j = 0; j < 3; j++)
// ++neighbors_vertices[i[j]].second;
//}
//uint32_t triangle_start = 0;
//for (auto &neighbor : neighbors_vertices) {
// neighbor.first = triangle_start;
// triangle_start += neighbor.second;
// neighbor.second = 0;
//}
//std::vector<uint32_t> neighbors_data(its.indices.size()*3);
//for (const auto &i : its.indices) {
// uint32_t index = &i - &its.indices.front();
// for (size_t j = 0; j < 3; j++) {
// auto & neighbor = neighbors_vertices[i[j]];
// size_t index_data = neighbor.second + neighbor.first;
// neighbors_data[index_data] = index;
// ++neighbor.second;
// }
//}
auto neighbors = its_create_neighbors_index_2(its);
std::set<uint32_t> remove;
std::queue<uint32_t> insert;
int no_value = -1;
for (const auto &neighbor : neighbors) {
uint32_t index = &neighbor - &neighbors.front();
auto it = remove.find(index);
if (it != remove.end()) continue; // already removed
if (neighbor[0] != no_value &&
neighbor[1] != no_value &&
neighbor[2] != no_value)
continue;
insert.push(index);
while (!insert.empty()) {
uint32_t i = insert.front();
insert.pop();
if (remove.find(i) != remove.end()) continue;
remove.insert(i);
for (size_t j = 0; j < 3; j++) {
if (neighbor[j] == no_value) continue;
uint32_t i2 = static_cast<uint32_t>(neighbor[j]);
insert.push(i2);
}
}
}
std::vector<uint32_t> rem(remove.begin(), remove.end());
std::sort(rem.begin(), rem.end());
uint32_t offset = 0;
for (uint32_t i : rem) {
its.indices.erase(its.indices.begin() + (i - offset));
++offset;
}
}
indexed_triangle_set Emboss::polygons2model(const Polygons &shape2d,
const IProject &projection)
{
@ -387,18 +228,14 @@ indexed_triangle_set Emboss::polygons2model(const Polygons &shape2d,
}
polygon_offset += polygon_points;
}
// remove bad triangulated faces
its_remove_edge_triangles(result);
return result;
}
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Constrained_Delaunay_triangulation_2.h>
#include <CGAL/Triangulation_vertex_base_with_info_2.h>
std::vector<Vec3i> Emboss::triangulate(
const Points& points,
const std::set<std::pair<uint32_t, uint32_t>> &edges)
Emboss::Indices Emboss::triangulate(const Points & points,
const HalfEdges &half_edges)
{
// IMPROVE use int point insted of float !!!
@ -410,19 +247,20 @@ std::vector<Vec3i> Emboss::triangulate(
// construct a constrained triangulation
CDT cdt;
std::map<CDT::Vertex_handle, int> map; // for indices
std::map<CDT::Vertex_handle, uint32_t> map; // for indices
std::vector<CDT::Vertex_handle> vertices_handle; // for constriants
vertices_handle.reserve(points.size());
for (const auto& p: points) {
Point cdt_p(p.x(), p.y());
auto handl = cdt.insert(cdt_p);
vertices_handle.push_back(handl);
size_t i = &p - &points.front();
map[handl] = i;
// point index
uint32_t pi = &p - &points.front();
map[handl] = pi;
}
// triangle can not contain forbiden edge
for (const std::pair<uint32_t, uint32_t> &edge : edges) {
for (const std::pair<uint32_t, uint32_t> &edge : half_edges) {
const CDT::Vertex_handle& vh1 = vertices_handle[edge.first];
const CDT::Vertex_handle& vh2 = vertices_handle[edge.second];
cdt.insert_constraint(vh1, vh2);
@ -432,33 +270,33 @@ std::vector<Vec3i> Emboss::triangulate(
std::vector<Vec3i> indices;
indices.reserve(faces.size());
for (CDT::Face_handle face : faces) {
auto v0 = face->vertex(0);
auto v1 = face->vertex(1);
auto v2 = face->vertex(2);
uint32_t i0 = map[v0];
uint32_t i1 = map[v1];
uint32_t i2 = map[v2];
// point indices
std::array<uint32_t, 3> pi;
for (size_t i = 0; i < 3; ++i)
pi[i] = map[face->vertex(i)];
// check forbiden triangle edge - opposit order
if (edges.find(std::make_pair(i0, i1)) != edges.end()) continue;
if (edges.find(std::make_pair(i1, i2)) != edges.end()) continue;
if (edges.find(std::make_pair(i2, i0)) != edges.end()) continue;
// Do not use triangles with opposit edges
if (half_edges.find(std::make_pair(pi[0], pi[1])) != half_edges.end()) continue;
if (half_edges.find(std::make_pair(pi[1], pi[2])) != half_edges.end()) continue;
if (half_edges.find(std::make_pair(pi[2], pi[0])) != half_edges.end()) continue;
indices.emplace_back(map[v0], map[v1], map[v2]);
indices.emplace_back(pi[0], pi[1], pi[2]);
}
return indices;
}
std::vector<Vec3i> Emboss::triangulate(const Polygon &polygon)
Emboss::Indices Emboss::triangulate(const Polygon &polygon)
{
const Points & pts = polygon.points;
std::set<std::pair<uint32_t, uint32_t>> edges;
for (uint32_t i = 1; i < pts.size(); ++i) edges.insert({i - 1, i});
edges.insert({(uint32_t)pts.size() - 1, uint32_t(0)});
return triangulate(pts, edges);
Emboss::Indices indices = triangulate(pts, edges);
remove_outer(indices, edges);
return indices;
}
std::vector<Vec3i> Emboss::triangulate(const Polygons &polygons)
Emboss::Indices Emboss::triangulate(const Polygons &polygons)
{
size_t count = count_points(polygons);
Points points;
@ -480,7 +318,76 @@ std::vector<Vec3i> Emboss::triangulate(const Polygons &polygons)
edges.insert({offset + size - 1, offset});
offset += size;
}
return triangulate(points, edges);
Emboss::Indices indices = triangulate(points, edges);
remove_outer(indices, edges);
return indices;
}
void Emboss::remove_outer(Indices &indices, const HalfEdges &half_edges) {
uint32_t no_triangle = indices.size();
std::map<HalfEdge, uint32_t> edge2triangle;
// triangles with all edges out of half_edge, candidate to remove
std::vector<uint32_t> triangles_to_check;
triangles_to_check.reserve(indices.size()/3);
for (const auto& t : indices) {
uint32_t index = &t - &indices.front();
bool is_border = false;
for (size_t j = 0; j < 3; ++j) {
size_t j2 = (j == 0) ? 2 : (j - 1);
HalfEdge he(t[j], t[j2]);
if (half_edges.find(he) != half_edges.end())
is_border = true;
else
edge2triangle[he] = index;
}
if (!is_border) {
triangles_to_check.push_back(index);
}
}
std::set<uint32_t> remove;
std::queue<uint32_t> insert;
for (uint32_t index : triangles_to_check) {
auto it = remove.find(index);
if (it != remove.end()) continue; // already removed
bool is_edge = false;
const Vec3i &t = indices[index];
for (size_t j = 0; j < 3; ++j) {
size_t j2 = (j == 0) ? 2 : (j - 1);
// opposit
HalfEdge he(t[j2], t[j]);
if (edge2triangle.find(he) == edge2triangle.end()) is_edge = true;
}
if (!is_edge) continue; // correct
insert.push(index);
while (!insert.empty()) {
uint32_t i = insert.front();
insert.pop();
if (remove.find(i) != remove.end()) continue;
remove.insert(i);
for (size_t j = 0; j < 3; ++j) {
size_t j2 = (j == 0) ? 2 : (j - 1);
// opposit
HalfEdge he(t[j2], t[j]);
auto it = edge2triangle.find(he);
if (it == edge2triangle.end()) continue; // edge
insert.push(it->second);
}
}
}
// remove indices
std::vector<uint32_t> rem(remove.begin(), remove.end());
std::sort(rem.begin(), rem.end());
uint32_t offset = 0;
for (uint32_t i : rem) {
indices.erase(indices.begin() + (i - offset));
++offset;
}
}
std::pair<Vec3f, Vec3f> Emboss::ProjectZ::project(const Point &p) const

29
src/libslic3r/Emboss.hpp
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@ -38,9 +38,6 @@ public:
// unscaled precision of lettter outline curve in conversion to lines
float flatness = 2.;
// change size of font
float scale = 1.;
// enum class Align: center/left/right
};
@ -56,16 +53,18 @@ public:
/// </summary>
/// <param name="font">Define fonts</param>
/// <param name="letter">One character to convert</param>
/// <param name="flatness">Precision of lettter outline curve in conversion to lines</param>
/// <returns>inner polygon ccw(outer cw)</returns>
static Polygons letter2polygons(const Font &font, char letter);
static Polygons letter2polygons(const Font &font, char letter, float flatness);
/// <summary>
/// Convert text into polygons
/// </summary>
/// <param name="font">Define fonts</param>
/// <param name="text">Characters to convert</param>
/// <returns>inner polygon ccw(outer cw)</returns>
static Polygons text2polygons(const Font &font, const char *text);
/// <param name="flatness">Precision of lettter outline curve in conversion to lines</param>
/// <returns>Inner polygon ccw(outer cw)</returns>
static Polygons text2polygons(const Font &font, const char *text, float flatness);
/// <summary>
/// Project 2d point into space
@ -94,15 +93,27 @@ public:
/// <returns>Projected shape into space</returns>
static indexed_triangle_set polygons2model(const Polygons &shape2d, const IProject& projection);
// define oriented connection of 2 vertices(defined by its index)
using HalfEdge = std::pair<uint32_t, uint32_t>;
using HalfEdges = std::set<HalfEdge>;
using Indices = std::vector<Vec3i>;
/// <summary>
/// Connect points by triangulation to create filled surface by triangle indices
/// </summary>
/// <param name="points">Points to connect</param>
/// <param name="edges">Constraint for edges, pair is from point(first) to point(second)</param>
/// <returns>Triangles</returns>
static std::vector<Vec3i> triangulate(const Points &points, const std::set<std::pair<uint32_t, uint32_t>> &edges);
static std::vector<Vec3i> triangulate(const Polygon &polygon);
static std::vector<Vec3i> triangulate(const Polygons &polygons);
static Indices triangulate(const Points &points, const HalfEdges &half_edges);
static Indices triangulate(const Polygon &polygon);
static Indices triangulate(const Polygons &polygons);
/// <summary>
/// Filter out triagles without both side edge or inside half edges
/// Main purpose: Filter out triangles which lay outside of ExPolygon given to triangulation
/// </summary>
/// <param name="indices">Triangles</param>
/// <param name="half_edges">Only outer edges</param>
static void remove_outer(Indices &indices, const HalfEdges &half_edges);
class ProjectZ : public IProject
{

4
src/slic3r/GUI/Gizmos/GLGizmoEmboss.cpp
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@ -24,6 +24,7 @@ GLGizmoEmboss::GLGizmoEmboss(GLCanvas3D & parent,
, m_text(new char[m_text_size])
, m_scale(0.01f)
, m_emboss(5.f)
, m_flatness(2.f)
{
load_font();
// TODO: suggest to use https://fontawesome.com/
@ -86,6 +87,7 @@ void GLGizmoEmboss::on_render_input_window(float x, float y, float bottom_limit)
ImGui::InputFloat("Scale", &m_scale);
ImGui::InputFloat("Emboss", &m_emboss);
ImGui::InputFloat("Flatness", &m_flatness);
m_imgui->disabled_begin(!m_font.has_value());
if (ImGui::Button("Preview")) process();
m_imgui->disabled_end();
@ -160,7 +162,7 @@ void GLGizmoEmboss::process() {
auto project = std::make_unique<Emboss::ProjectScale>(
std::make_unique<Emboss::ProjectZ>(m_emboss/m_scale), m_scale);
Polygons polygons = Emboss::text2polygons(*m_font, m_text.get());
Polygons polygons = Emboss::text2polygons(*m_font, m_text.get(), m_flatness);
if (polygons.empty()) return;
indexed_triangle_set its = Emboss::polygons2model(polygons, *project);

1
src/slic3r/GUI/Gizmos/GLGizmoEmboss.hpp
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@ -64,6 +64,7 @@ private:
float m_scale;
float m_emboss;
float m_flatness;
};
} // namespace GUI

12
tests/libslic3r/test_indexed_triangle_set.cpp
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@ -288,3 +288,15 @@ TEST_CASE("Simplify trouble case", "[its]")
its_quadric_edge_collapse(tm.its, wanted_count, &max_error);
CHECK(tm.its.indices.size() <= 8);
}
TEST_CASE("Neighbors in cube", "[its]")
{
auto its = its_make_cube(1, 2, 3);
auto neighbors = its_face_neighbors(its);
int no_value = -1;
for (auto &neighbor : neighbors) {
for (size_t i = 0; i < 3; i++) {
CHECK(neighbor[i] != no_value);
}
}
}