BitmapArranger Stress Test Harness

Standalone test harness for the concave bitmap arrangement algorithm in OrcaSlicer. Compiles outside the OrcaSlicer build tree, linking against a pre-built libslic3r.lib. No OrcaSlicer source code is redistributed — this project only contains test scenarios and build configuration.

What it does

Exercises BitmapArranger::arrange() with synthetic part geometries (rectangles, L-shapes, crescents, T-shapes, U-channels, circles) in realistic combinations: tight packing, overflow, mixed sizes, edge cases, and stress loads. Reports placement counts, plate usage, timing, and overlap detection.

Prerequisites

1. OrcaSlicer source and build — You need a built copy of the feature/concave-arrange branch:

   git clone https://github.com/thereprocase/OrcaSlicer.git
   cd OrcaSlicer
   git checkout feature/concave-arrange
   

   Follow OrcaSlicer's build instructions to compile deps and the slicer. On Windows:

   build_release_vs.bat
   

   The harness needs these artifacts from the OrcaSlicer build:

   • build/src/libslic3r/Release/libslic3r.lib
   • deps/build/OrcaSlicer_dep/usr/local/ (Boost, TBB, GMP, MPFR, OpenSSL, zlib, etc.)
   • deps/build/dep_OCCT-prefix/src/dep_OCCT-build/lib/occt/ (OpenCASCADE import libs)
   • Source headers in src/ and deps_src/

2. Build tools:

   • CMake 3.13+ (pip install cmake works)
   • Ninja (pip install ninja works)
   • MSVC (Visual Studio 2022 Build Tools or full VS)

Setup

1. Clone this repo

git clone <this-repo-url>
cd OrcaTestHarness

2. Set the OrcaSlicer path

Edit CMakeLists.txt line 8 — set ORCA_ROOT to your OrcaSlicer source directory:

set(ORCA_ROOT "F:/your/path/to/OrcaSlicer")

3. Build

Windows (CMD or PowerShell):

build.bat

Or manually:

call "C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools\VC\Auxiliary\Build\vcvarsall.bat" x64
mkdir build && cd build
cmake .. -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build . --config Release

4. Run

run.bat --all

Or run individual scenarios:

run.bat --scenario stress_50_mixed

Usage

arrange_stress [--all] [--scenario NAME] [--verbose]

• --all — Run all scenarios (default if no args)
• --scenario NAME — Run one named scenario
• --verbose — Extra output (not yet implemented)

Results are logged to logs/stress_YYYYMMDD_HHMMSS.log.

Scenarios

Category	Scenario	What it tests
Sanity	single_rect, empty_input, single_oversized	Basic placement, empty input, too-large item
Packing	6_rects_one_plate, tight_pack_25_squares, tight_pack_26_squares	Density and overflow boundary
Concave	L_shapes_interlock, crescents_nest, T_shapes, U_channels	Concave shape nesting advantage
Competition	large_blocks_small_bed, ordering_matters, barely_fits, barely_doesnt_fit	Size conflicts, BLF ordering, boundary cases
Multi-plate	overflow_3_plates	Overflow to multiple plates
Mixed	mixed_sizes	Heterogeneous part sizes
Stress	stress_100_rects, stress_50_mixed	Volume and timing
Edge	zero_area_item, very_thin_item, no_spacing	Degenerate input handling

Adding scenarios

Add a new entry in build_scenarios() in src/arrange_stress.cpp:

scenarios["my_test"] = [=]() {
    std::vector<ArrangePolygon> items;
    items.push_back(make_ap(make_rect(50, 50)));
    // ... add more items
    return run_scenario("my_test", items, bed, params, true, "description");
};

Rebuild and run: build.bat && run.bat --scenario my_test

Known limitations

• No concave_triangles — Test shapes use ExPolygon (Clipper rasterization path), not the concave triangle path used in real OrcaSlicer. Tests that expect concave interlocking (L-shapes on small beds) may underperform.
• Overlap checker is approximate — Uses vertex sampling, not full bitmap intersection. May produce false positives on shapes with few vertices (circles, crescents).
• Windows only — Build scripts assume MSVC. CMakeLists.txt is cross-platform in principle but only tested on Windows.

License

This test harness contains no OrcaSlicer source code. It links against libslic3r.lib at build time, which is licensed under AGPLv3. See OrcaSlicer's license for details.

Test harness code (src/arrange_stress.cpp, CMakeLists.txt, build scripts) is provided under the same AGPLv3 license for compatibility.