Odin bindings for DDS, Bo Haglund and Soren Hein's double-dummy solver for the game of bridge.

A double-dummy solver computes the exact number of tricks each side can take on a given deal with all four hands visible and optimal play from everyone. DDS is the de-facto standard engine behind bridge hand analysis, par-score and par-contract calculation, and play analysis; it is fast, multi-threaded, and battle-tested.

The DDS C/C++ source is included as a git submodule under external/dds and is not modified — these bindings wrap its public C ABI (include/dll.h).

See docs/api.md for the idiomatic-Odin API guide — types, core functions, threading, and memory lifecycle. The bindings are a near 1-to-1 port, so the original DDS interface documentation also maps directly.

• Functions keep their C names: SolveBoard, CalcDDtable, Par, ... are called as dds.SolveBoard, dds.CalcDDtable, dds.Par.
• Struct/type names drop the dd prefix and are Ada_Case per Odin convention: C struct deal → dds.Deal, struct ddTableResults → dds.Table_Results, struct futureTricks → dds.Future_Tricks. (struct DDSInfo is renamed dds.DDS_Info.)
• The #define error/return codes are exposed as constants: dds.RETURN_NO_FAULT, dds.RETURN_UNKNOWN_FAULT, ...

DDS needs a one-time setup call before any other function — it sizes the per-thread transposition-table memory and builds its constant lookup tables. When DDS is used as a DLL this happens automatically from DllMain, but these bindings link a static library, which has no DllMain, so you must do it yourself:

package main

import dds ".."

main :: proc() {
	dds.SetMaxThreads(0) // 0 = let DDS pick the thread count from the core count. Call once, before anything else.
	defer dds.FreeMemory()

	deal: dds.Deal
	// ... fill in the deal ...
	fut: dds.Future_Tricks
	// target = TARGET_FIND_MAX (find the best), solutions = .All, mode = .Auto_Skip_Single.
	dds.SolveBoard(deal, dds.TARGET_FIND_MAX, .All, .Auto_Skip_Single, &fut)
}

Skipping SetMaxThreads (or SetResources) means the first DDS call dereferences unsized state and crashes. See examples/smoke.odin for a runnable smoke test (just run).

DDS never tagged 2.9.1, so the external/dds submodule is pinned to commit 7219c95 — the code-complete 2.9.1 point on the flat-layout include/+src/ tree (DDS_VERSION upstream is still 20900; the version was never bumped). This gets the 2.9.1 fixes — rimmington's transposition-table memory-freeing fixes, #include <stdbool.h> in C mode, and the SolveAllBoardsBin entry point — without the later v3 refactor that moved dll.h to library/src/api/. Validated with DDS's own dtest (0 differences across solve/calc/play/par).

The pre-built static libraries are shipped with the bindings in ./lib:

All are self-contained static archives — the whole solver folds into your one Odin executable with no shared libraries to ship. Each platform uses its native threading: WinAPI on Windows, GCD on macOS, STL on Linux (no OpenMP dependency). The Odin bindings pull in libstdc++ and libpthread on Linux/BSD automatically via foreign import.

Rebuild with:

just build-lib

On Windows this runs src/build.cmd lib external/dds (requires MSVC; auto-detected via vswhere) and stages lib/dds.lib. On Unix it runs make -C src and stages lib/dds.a or lib/darwin/dds.a. The submodule is checked out if needed.

src/build.cmd also has a dll mode (src/build.cmd dll external/dds) if you prefer a DLL on Windows — the script's header comment weighs the static-vs-DLL trade-offs in depth.

Static linking has no DllMain/constructor auto-init, so consumers must call SetMaxThreads(0) once before any other DDS call (see above). The DLL build auto-initializes but then requires shipping dds.dll (+ VCOMP140.DLL) alongside the executable.

dds.odin is generated from external/dds/include/dll.h by odin-c-bindgen using bindgen.sjson. Regenerate with:

just bindgen

A bindgen.sjson detail worth knowing: bindgen names its output after the header stem (dll.h → dll.odin), so just bindgen renames it to dds.odin.

Historical note: DDS 2.9.0's dll.h used bool without including <stdbool.h>, so bool was undefined when libclang parsed the header as C — the bindings needed a clang_defines = { "bool" = "_Bool" } override. The 2.9.1 pin (7219c95) adds that include upstream, so bool resolves on its own and the override is gone.

Hand-written additions (the foreign import block, platform selection) live in src/prelude.odin and are pasted near the top of the generated file.

Tasks are run with just (just TASK); the Windows shell is PowerShell.

• just run [name] — build and run an example (examples/<name>.odin, default smoke); e.g. just run solve_board
• just lint — type check + vet + strict style
• just format — odinfmt -w .
• just test — run all tests (they live as @(test) procs inside examples/*.odin); just test1 <name> runs one example's tests
• just build-lib — (re)build and stage the DDS static lib
• just bindgen — regenerate the bindings
• just submodules — check out / update the external/dds submodule

These bindings are provided under the terms in LICENSE. DDS itself is licensed under the Apache 2.0 license — see external/dds/LICENSE.