Reject circular arcs in convex_hull instead of silently mishandling them - #65
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convex_hull's Graham scan only looks at each element's start point, so a circular arc bulging past the chord between its endpoints was silently ignored, which could produce a hull that doesn't actually contain the input shape -- only caught after the fact by the hull-area-vs-input-area sanity check at the end, with a much less helpful error (found via fuzzing). convex_hull doesn't support arc-containing shapes yet -- for those, the intended path forward is decompose_into_basic_shapes into arc-free convex pieces first (not yet wired up to a convex-hull computation of its own). Reject them up front with a clear error instead of computing a wrong result. Also converts the test file to a parametrized suite (matching the project's usual style) with an expect_throw field, and adds a non-trivial hull-reduction case alongside the arc-rejection case.
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Summary
convex_hull's Graham scan only looks at each element's start point, so a circular arc bulging past the chord between its endpoints was silently ignored, which could produce a hull that doesn't actually contain the input shape — only caught after the fact by the hull-area-vs-input-area sanity check at the end, with a much less helpful error (found via fuzzing).convex_hulldoesn't support arc-containing shapes yet. For those, the intended path forward isdecompose_into_basic_shapesinto arc-free convex pieces first (not yet wired up to a convex-hull computation of its own — a separate follow-up). For now, reject arc-containing input up front with a clearstd::invalid_argumentinstead of computing a wrong result.Also converted the test file to a parametrized suite (matching the project's usual style), with an
expect_throwfield, and added a non-trivial hull-reduction case alongside the arc-rejection case.Test plan
ctest --test-dir build/test --output-on-failure --parallel: 480/480 tests pass (477 pre-existing + 3 in the new parametrizedConvexHullTestsuite).