ImplicitSurfaceNetwork/surface_integral/test/test_winding_number.cpp

// main.cpp
#include "polygon_winding_number.h"
#include <iostream>
#include <vector>
#include <string>
#include <cassert>

// -----------------------------
// Test Case Definition
// -----------------------------

struct TestCase {
    std::string name;
    PolygonRing outer_ring;
    std::vector<PolygonRing> holes;
    Point2d query_point;
    bool expected;  // true = inside, false = outside
};

// -----------------------------
// Helper: Print Point
// -----------------------------
std::ostream& operator<<(std::ostream& os, const Point2d& p) {
    return os << "(" << p.x() << ", " << p.y() << ")";
}



// -----------------------------
// Helper: Validate Ring Orientation
// -----------------------------
bool validate_orientation() {
    // Test CCW (positive area)
    PolygonRing ccw = {{0,0}, {1,0}, {1,1}, {0,1}};
    if (compute_ring_area(ccw) <= 0) {
        std::cerr << "Error: CCW ring has non-positive area!\n";
        return false;
    }

    // Test CW (negative area)
    PolygonRing cw = {{0,0}, {0,1}, {1,1}, {1,0}};
    if (compute_ring_area(cw) >= 0) {
        std::cerr << "Error: CW ring has non-negative area!\n";
        return false;
    }
    return true;
}

// -----------------------------
// Validate Test Case: Orientation of outer ring (CCW) and holes (CW)
// -----------------------------
bool validate_test_case(const TestCase& tc) {
    bool valid = true;
    std::string status = "";

    // Validate outer ring orientation (should be CCW → positive area)
    double outer_area = compute_ring_area(tc.outer_ring);
    if (outer_area <= 0) {
        status += "Outer ring not CCW (area = " + std::to_string(outer_area) + ")";
        valid = false;
    }

    // Validate holes orientation (should be CW → negative area)
    for (size_t i = 0; i < tc.holes.size(); ++i) {
        double hole_area = compute_ring_area(tc.holes[i]);
        if (hole_area >= 0) {
            if (!status.empty()) status += ", ";
            status += "Hole " + std::to_string(i) + " not CW (area = " + std::to_string(hole_area) + ")";
            valid = false;
        }
    }

    if (valid) return true;

    std::cout << "["
              << "\033[33mINVALID\033[0m"  // make "INVALID" yellow
              << "] "
              << tc.name << "\n"
              << "    Query: " << tc.query_point
              << " | Status: \033[33mInvalid Test Case\033[0m"
              << " | Reason: " << (valid ? "OK" : status) << "\n";

    return valid;
}

// -----------------------------
// Run Single Test
// -----------------------------
bool run_test(const TestCase& tc) {
    bool result = point_in_polygon_with_holes(tc.query_point, tc.outer_ring, tc.holes);
    bool passed = (result == tc.expected);

    std::cout << "["
              << (passed ? "\033[32mPASS\033[0m" : "\033[31mFAIL\033[0m")
              << "] "
              << tc.name << "\n"
              << "    Query: " << tc.query_point
              << " | Expected: " << (tc.expected ? "Inside" : "Outside")
              << " | Got: " << (result ? "Inside" : "Outside") << "\n";

    return passed;
}

// -----------------------------
// Test Case Factory Functions
// -----------------------------

std::vector<TestCase> create_test_cases() {
    std::vector<TestCase> tests;



    // --------------------------------------------------
    // Test 1: Simple hole - point inside hole → Outside
    // --------------------------------------------------
    PolygonRing outer1 = {{0,0}, {2,0}, {2,2}, {0,2}};
    PolygonRing hole1  = {{0.5,0.5}, {0.5,1.5}, {1.5,1.5}, {1.5,0.5}}; 
    tests.push_back({
        "Inside Hole",
        outer1, {hole1}, {1.0, 1.0}, false
    });

    // --------------------------------------------------
    // Test 2: Point inside outer, outside all holes → Inside
    // --------------------------------------------------
    tests.push_back({
        "Inside Outer, Outside Hole",
        outer1, {hole1}, {0.1, 0.1}, true
    });

    // --------------------------------------------------
    // Test 3: Point outside outer ring → Outside
    // --------------------------------------------------
    tests.push_back({
        "Outside Outer",
        outer1, {hole1}, {3.0, 3.0}, false
    });

    // --------------------------------------------------
    // Test 4: Point on outer ring edge (bottom edge)
    // Winding rule: on boundary → considered inside
    // --------------------------------------------------
    tests.push_back({
        "On Outer Edge (Bottom)",
        outer1, {}, {1.0, 0.0}, true
    });

    // --------------------------------------------------
    // Test 5: Point on outer ring vertex
    // --------------------------------------------------
    tests.push_back({
        "On Outer Vertex Offset Slightly Outside",
        outer1, {}, {0.0, 0.0-1e-8}, false
    });

    // --------------------------------------------------
    // Test 6: Point on hole edge
    // Should be outside (on hole boundary still "outside" the solid)
    // --------------------------------------------------
    PolygonRing hole6 = {{1.0,1.0}, {1.0,2.0}, {2.0,2.0}, {2.0,1.0}}; // CW
    tests.push_back({
        "On Hole Edge",
        {{0,0},{3,0},{3,3},{0,3}}, {hole6}, {1.5, 1.0}, false
    });

    // --------------------------------------------------
    // Test 7: Multiple holes
    // --------------------------------------------------
    PolygonRing hole7a = {{0.5,0.5}, {0.5,1.0}, {1.0,1.0}, {1.0,0.5}}; // CW
    PolygonRing hole7b = {{1.5,1.5}, {1.5,2.0}, {2.0,2.0}, {2.0,1.5}}; // CW
    tests.push_back({
        "Multiple Holes - Inside",
        outer1, {hole7a, hole7b}, {0.1, 0.1}, true
    });

    tests.push_back({
        "Multiple Holes - In First Hole",
        outer1, {hole7a, hole7b}, {0.7, 0.7}, false
    });

    tests.push_back({
        "Multiple Holes - In Second Hole",
        outer1, {hole7a, hole7b}, {1.7, 1.7}, false
    });

    // --------------------------------------------------
    // Test 8: Nested holes (hole inside hole) - NOT standard, but test behavior
    // Note: This is not valid in simple polygons, but test robustness
    // --------------------------------------------------
    PolygonRing outer8 = {{0,0}, {3,0}, {3,3}, {0,3}};
    PolygonRing hole8a = {{0.5,0.5}, {0.5,2.5}, {2.5,2.5}, {2.5,0.5}}; // large hole
    PolygonRing hole8b = {{1.0,1.0}, {1.0,2.0}, {2.0,2.0}, {2.0,1.0}}; // small hole inside hole8a
    // This creates a "island" in the hole
    tests.push_back({
        "Nested Holes - On Island",
        outer8, {hole8a, hole8b}, {1.5, 1.5}, true  // inside outer, inside hole8a, but outside hole8b → solid
    });

    // --------------------------------------------------
    // Test 9: Complex L-shaped polygon with hole
    // --------------------------------------------------
    PolygonRing outer9 = {
        {0,0}, {3,0}, {3,1}, {2,1}, {2,3}, {0,3}, {0,0} // L-shape, explicitly closed and no self-intersection
    }; // CCW
    PolygonRing hole9 = {{0.5,0.5}, {0.5,1.5}, {1.5,1.5}, {1.5,0.5}}; // CW
    tests.push_back({
        "L-Shape with Hole - Inside Leg",
        outer9, {hole9}, {0.1, 0.1}, true
    });
    tests.push_back({
        "L-Shape with Hole - In Hole",
        outer9, {hole9}, {1.0, 1.0}, false
    });
    tests.push_back({
        "L-Shape with Hole - In Arm",
        outer9, {hole9}, {2.0, 0.5}, true
    });

    // --------------------------------------------------
    // Test 10: Degenerate: Point exactly at intersection of hole and outer? (not possible, but test near)
    // --------------------------------------------------
    tests.push_back({
        "Near Degenerate - Close to Corner",
        outer1, {hole1}, {0.5000001, 0.5000001}, false  // just outside hole
    });

    return tests;
}

// -----------------------------
// Main Function
// -----------------------------
int main() {
    std::cout << "Running Polygon Winding Number Tests...\n\n";

    // Optional: Validate orientation logic
    if (!validate_orientation()) {
        std::cerr << "Orientation validation failed!\n";
        return 1;
    }

    auto test_cases = create_test_cases();

    int passed = 0;
    int total = test_cases.size();

    for (const auto& tc : test_cases) {
        if (!validate_test_case(tc)) {
            continue;
        }
        if (run_test(tc)) {
            passed++;
        }
    }

    std::cout << "\nSummary: " << passed << " / " << total << " tests passed.\n";

    if (passed == total) {
        std::cout << "\033[32m All tests passed!\033[0m\n";
        return 0;
    } else {
        std::cout << "\033[31m Some tests failed!\033[0m\n";
        return 1;
    }
}