Add comprehensive geometry algorithms and examples

.github/copilot-instructions.md

@@ -15,6 +15,7 @@ Aleph-w is a comprehensive C++20 library for graph algorithms and data structure
 - **MUST**: Use `std::optional` instead of sentinel values or nullable pointers where semantically clear
 - **MUST**: Use `if constexpr` for compile-time branching in templates
 - **MUST**: Use concepts to constrain template parameters (see section below)
+- **MUST**: Use and, or, not for logical operations (instead of &&, ||, !)
 - **SHOULD**: Use `std::span` for non-owning views of contiguous sequences
 - **SHOULD**: Consider `std::variant` for type-safe unions
 - **SHOULD**: Use fold expressions for variadic template expansion

.github/workflows/ci.yml

@@ -185,16 +185,20 @@ jobs:
 
       - name: Test
         run: |
+          mkdir -p build/test_artifacts/golden_svg
+          export ALEPH_TEST_GOLDEN_DIR="$PWD/build/test_artifacts/golden_svg"
           ctest --test-dir build --output-on-failure --parallel 2 --timeout 600
 
       - name: Upload test logs on failure
         if: failure()
         uses: actions/upload-artifact@v4
         with:
           name: ctest-logs-${{ matrix.os }}-${{ matrix.compiler }}-${{ matrix.build_type }}
+          if-no-files-found: ignore
           path: |
             build/Testing/Temporary/LastTest.log
             build/CMakeCache.txt
+            build/test_artifacts/golden_svg
 
   coverage:
     name: coverage (ubuntu-24.04, gcc, Debug)
@@ -275,6 +279,8 @@ jobs:
 
       - name: Test
         run: |
+          mkdir -p build-coverage/test_artifacts/golden_svg
+          export ALEPH_TEST_GOLDEN_DIR="$PWD/build-coverage/test_artifacts/golden_svg"
           # Exclude this benchmark from coverage runs because instrumentation
           # changes timing characteristics and can make this test flaky.
           ctest --test-dir build-coverage --output-on-failure --parallel 2 --timeout 600 \
@@ -292,7 +298,7 @@ jobs:
             --gcov-ignore-errors source_not_found
             --gcov-ignore-errors no_working_dir_found
             --gcov-ignore-errors output_error
-            --gcov-ignore-parse-errors negative_hits.warn
+            --gcov-ignore-parse-errors all
             --exclude "(^|.*/)Tests/.*"
             --exclude "(^|.*/)Examples/.*"
             --exclude "(^|.*/)build-coverage/.*"
@@ -346,9 +352,11 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: ctest-logs-coverage
+          if-no-files-found: ignore
           path: |
             build-coverage/Testing/Temporary/LastTest.log
             build-coverage/CMakeCache.txt
+            build-coverage/test_artifacts/golden_svg
 
   sanitizers:
     name: sanitizers (ubuntu-24.04, gcc, Debug)
@@ -399,17 +407,21 @@ jobs:
       - name: Test
         env:
           ASAN_OPTIONS: detect_leaks=1
+          ALEPH_TEST_GOLDEN_DIR: ${{ github.workspace }}/build-asan/test_artifacts/golden_svg
         run: |
+          mkdir -p "$ALEPH_TEST_GOLDEN_DIR"
           ctest --test-dir build-asan --output-on-failure --parallel 2 --timeout 600
 
       - name: Upload test logs on failure
         if: failure()
         uses: actions/upload-artifact@v4
         with:
           name: ctest-logs-sanitizers
+          if-no-files-found: ignore
           path: |
             build-asan/Testing/Temporary/LastTest.log
             build-asan/CMakeCache.txt
+            build-asan/test_artifacts/golden_svg
 
   tsan:
     name: tsan (ubuntu-24.04, clang, Debug)
@@ -465,17 +477,21 @@ jobs:
       - name: Test
         env:
           TSAN_OPTIONS: halt_on_error=1
+          ALEPH_TEST_GOLDEN_DIR: ${{ github.workspace }}/build-tsan/test_artifacts/golden_svg
         run: |
+          mkdir -p "$ALEPH_TEST_GOLDEN_DIR"
           ctest --test-dir build-tsan --output-on-failure --parallel 2 --timeout 600
 
       - name: Upload test logs on failure
         if: failure()
         uses: actions/upload-artifact@v4
         with:
           name: ctest-logs-tsan
+          if-no-files-found: ignore
           path: |
             build-tsan/Testing/Temporary/LastTest.log
             build-tsan/CMakeCache.txt
+            build-tsan/test_artifacts/golden_svg
 
   ci-success-push:
     name: CI Success

.github/workflows/coverity.yml

@@ -1,30 +1,22 @@
 name: Coverity Scan
 
 on:
-  # Trigger on push to workflow file and relevant source/build files
-  push:
-    paths:
-      - '.github/workflows/coverity.yml'
-      - 'src/**'
-      - 'include/**'
-      - '**/*.c'
-      - '**/*.cc'
-      - '**/*.cpp'
-      - '**/*.cxx'
-      - 'CMakeLists.txt'
-  # Weekly automatic scan on the default branch only. GitHub cron schedules run in UTC.
-  # Currently aligned to run at 06:00 UTC on Sunday, intended to be ~4 hours after the full_analysis workflow (02:00 UTC).
-  schedule:
-    - cron: '0 6 * * 0'
   # Manual trigger - can select any branch from GitHub Actions UI
   workflow_dispatch:
+  # Optional trigger for Pull Requests via label
+  pull_request:
+    types: [labeled]
 
 permissions:
   contents: read
 
 jobs:
   coverity:
     name: Coverity Static Analysis
+    # Only run if manually triggered or if the 'run-coverity' label was added to a PR
+    if: |
+      github.event_name == 'workflow_dispatch' ||
+      (github.event_name == 'pull_request' && github.event.label.name == 'run-coverity')
     runs-on: ubuntu-24.04
 
     env:

CMakeLists.txt

@@ -107,7 +107,10 @@ set(HLIST
     tpl_slist.H tpl_snode.H tpl_lhash.H tpl_dynLhash.H
     tpl_odhash.H tpl_memArray.H tpl_dynArray.H ahFuntional.H hash-dry.H
     bloom-filter.H ah-dry.H graph-dry.H tpl_con_queue.H
-    q-consumer-threads.H ah-string-utils.H ah-comb.H geom_algorithms.H
+    q-consumer-threads.H ah-string-utils.H ah-unique.H ah-comb.H geom_algorithms.H
+    tikzgeom.H
+    tikzgeom_algorithms.H
+    tikzgeom_scene.H
     tpl_fenwick_tree.H
     tpl_segment_tree.H
     tpl_cartesian_tree.H
@@ -132,7 +135,6 @@ set(LIBCCCSRCS
     hash-dry.C
     aleph-graph.C
     ahNow.C
-    point.C
     euclidian-graph-common.C
 )
 
@@ -200,4 +202,4 @@ message(STATUS "  Build type: ${CMAKE_BUILD_TYPE}")
 message(STATUS "  C++ standard: C++${CMAKE_CXX_STANDARD}")
 message(STATUS "  Build examples: ${BUILD_EXAMPLES}")
 message(STATUS "  Build tests: ${BUILD_TESTS}")
-message(STATUS "  Compiler: ${CMAKE_CXX_COMPILER_ID}")
+message(STATUS "  Compiler: ${CMAKE_CXX_COMPILER_ID}")

Examples/CMakeLists.txt

@@ -112,6 +112,39 @@ set(EXAMPLE_PROGRAMS
     cartesian_tree_example
     mo_algorithm_example
     mo_on_trees_example
+    robust_predicates_example
+    segment_segment_intersection_example
+    voronoi_clipped_cells_example
+    delaunay_voronoi_example
+    constrained_delaunay_example
+    point_in_polygon_example
+    polygon_intersection_example
+    tikz_polygons_example
+    tikz_convex_hull_example
+    tikz_intersection_example
+    tikz_voronoi_power_example
+    tikz_advanced_algorithms_example
+    tikz_funnel_animation_example
+    tikz_funnel_beamer_example
+    tikz_funnel_beamer_twocol_example
+    tikz_funnel_beamer_handout_example
+    tikz_scene_example
+    tikz_scene_beamer_example
+    tikz_scene_overlays_example
+    tikz_missing_primitives_example
+    tikz_visibility_calipers_example
+    tikz_render_features_example
+    tikz_tree_structures_example
+    halfplane_intersection_example
+    convex_hull_comparison_example
+    closest_pair_example
+    convex_polygon_distance_gjk_example
+    rotating_calipers_example
+    minimum_enclosing_circle_example
+    polygon_simplification_example
+    polygon_offset_example
+    chaikin_smoothing_example
+    trapezoidal_map_example
 )
 
 # Function to get source file from program name

Examples/chaikin_smoothing_example.cc

@@ -0,0 +1,145 @@
+/*
+                          Aleph_w
+
+  Data structures & Algorithms
+  version 2.0.0b
+  https://github.com/lrleon/Aleph-w
+
+  This file is part of Aleph-w library
+
+  Copyright (c) 2002-2026 Leandro Rabindranath Leon
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in all
+  copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+  SOFTWARE.
+*/
+
+/// @file chaikin_smoothing_example.cc
+/// @brief Demonstrates Chaikin corner-cutting polygon smoothing with TikZ output.
+
+# include <tikzgeom_algorithms.H>
+# include <cassert>
+# include <cmath>
+# include <iostream>
+# include <fstream>
+
+using namespace std;
+using namespace Aleph;
+
+/// Build a 5-pointed star polygon centered at the origin.
+static Polygon make_star(double outer_r = 10.0, double inner_r = 4.0)
+{
+  Polygon poly;
+  for (int i = 0; i < 10; ++i)
+    {
+      double angle = M_PI / 2.0 + 2.0 * M_PI * i / 10.0;
+      double r = (i % 2 == 0) ? outer_r : inner_r;
+      poly.add_vertex(Point(r * cos(angle), r * sin(angle)));
+    }
+  poly.close();
+  return poly;
+}
+
+/// Build an L-shaped polygon.
+static Polygon make_L_shape()
+{
+  Polygon poly;
+  poly.add_vertex(Point(0, 0));
+  poly.add_vertex(Point(6, 0));
+  poly.add_vertex(Point(6, 3));
+  poly.add_vertex(Point(3, 3));
+  poly.add_vertex(Point(3, 8));
+  poly.add_vertex(Point(0, 8));
+  poly.close();
+  return poly;
+}
+
+int main()
+{
+  // 1. Star polygon
+  Polygon star = make_star();
+  auto star_verts = GeomPolygonUtils::extract_vertices(star);
+  cout << "Star: " << star_verts.size() << " vertices" << endl;
+
+  // Smooth at 1..4 iterations
+  for (size_t k = 1; k <= 4; ++k)
+    {
+      Polygon smoothed = ChaikinSmoothing::smooth_polygon(star, k);
+      auto sv = GeomPolygonUtils::extract_vertices(smoothed);
+      cout << "  iter " << k << ": " << sv.size() << " vertices" << endl;
+    }
+
+  // 2. L-shaped polygon
+  Polygon lshape = make_L_shape();
+  auto l_verts = GeomPolygonUtils::extract_vertices(lshape);
+  cout << "L-shape: " << l_verts.size() << " vertices" << endl;
+
+  for (size_t k = 1; k <= 3; ++k)
+    {
+      Polygon smoothed = ChaikinSmoothing::smooth_polygon(lshape, k);
+      auto sv = GeomPolygonUtils::extract_vertices(smoothed);
+      cout << "  iter " << k << ": " << sv.size() << " vertices" << endl;
+    }
+
+  // 3. TikZ output
+  ofstream tex("chaikin_smoothing_output.tex");
+  tex << "\\documentclass[border=5mm]{standalone}\n"
+      << "\\usepackage{tikz}\n"
+      << "\\usepackage{subcaption}\n"
+      << "\\begin{document}\n"
+      << "\\begin{figure}\n";
+
+  auto draw_subfig = [&](const char * caption, const Polygon & original,
+                          const Polygon & smoothed)
+    {
+      Tikz_Plane plane(60, 60);
+      put_smoothing_result(plane, original, smoothed);
+      tex << "\\begin{minipage}{0.45\\textwidth}\\centering\n";
+      plane.draw(tex);
+      tex << "\\captionof{subfigure}{" << caption << "}\n"
+          << "\\end{minipage}\\hfill\n";
+    };
+
+  // Star: original, 1, 2, 4 iterations
+  draw_subfig("Star original", star, star);
+  Polygon star1 = ChaikinSmoothing::smooth_polygon(star, 1);
+  draw_subfig("Star iter=1", star, star1);
+  tex << "\n\\medskip\n\n";
+  Polygon star2 = ChaikinSmoothing::smooth_polygon(star, 2);
+  draw_subfig("Star iter=2", star, star2);
+  Polygon star4 = ChaikinSmoothing::smooth_polygon(star, 4);
+  draw_subfig("Star iter=4", star, star4);
+
+  tex << "\n\\bigskip\n\n";
+
+  // L-shape: original, 1, 2, 3 iterations
+  draw_subfig("L-shape original", lshape, lshape);
+  Polygon l1 = ChaikinSmoothing::smooth_polygon(lshape, 1);
+  draw_subfig("L-shape iter=1", lshape, l1);
+  tex << "\n\\medskip\n\n";
+  Polygon l2 = ChaikinSmoothing::smooth_polygon(lshape, 2);
+  draw_subfig("L-shape iter=2", lshape, l2);
+  Polygon l3 = ChaikinSmoothing::smooth_polygon(lshape, 3);
+  draw_subfig("L-shape iter=3", lshape, l3);
+
+  tex << "\\end{figure}\n"
+      << "\\end{document}\n";
+
+  cout << "TikZ output written to chaikin_smoothing_output.tex" << endl;
+
+  return 0;
+}