{ config, lib, stdenv, fetchFromGitHub, cmake, pkg-config, xorg, libGLU
, libGL, glew, ocl-icd, python3
, cudaSupport ? config.cudaSupport
, cudaPackages
, openclSupport ? !cudaSupport
, darwin
}:

stdenv.mkDerivation rec {
  pname = "opensubdiv";
  version = "3.5.1";

  src = fetchFromGitHub {
    owner = "PixarAnimationStudios";
    repo = "OpenSubdiv";
    rev = "v${lib.replaceStrings ["."] ["_"] version}";
    sha256 = "sha256-uDKCT0Uoa5WQekMUFm2iZmzm+oWAZ6IWMwfpchkUZY0=";
  };

  outputs = [ "out" "dev" ];

  nativeBuildInputs = [
    cmake
    pkg-config
  ] ++ lib.optional cudaSupport [
    cudaPackages.cuda_nvcc
  ];
  buildInputs =
    [ libGLU libGL python3
      # FIXME: these are not actually needed, but the configure script wants them.
      glew xorg.libX11 xorg.libXrandr xorg.libXxf86vm xorg.libXcursor
      xorg.libXinerama xorg.libXi
    ]
    ++ lib.optional (openclSupport && !stdenv.isDarwin) ocl-icd
    ++ lib.optionals stdenv.isDarwin (with darwin.apple_sdk.frameworks; [OpenCL Cocoa CoreVideo IOKit AppKit AGL ])
    ++ lib.optional cudaSupport [
      cudaPackages.cuda_cudart
    ];

  # It's important to set OSD_CUDA_NVCC_FLAGS,
  # because otherwise OSD might piggyback unwanted architectures:
  # https://github.com/PixarAnimationStudios/OpenSubdiv/blob/7d0ab5530feef693ac0a920585b5c663b80773b3/CMakeLists.txt#L602
  preConfigure = lib.optionalString cudaSupport ''
    cmakeFlagsArray+=(
      -DOSD_CUDA_NVCC_FLAGS="${lib.concatStringsSep " " cudaPackages.cudaFlags.gencode}"
    )
  '';

  cmakeFlags =
    [ "-DNO_TUTORIALS=1"
      "-DNO_REGRESSION=1"
      "-DNO_EXAMPLES=1"
      "-DNO_METAL=1" # don’t have metal in apple sdk
      (lib.cmakeBool "NO_OPENCL" (!openclSupport))
      (lib.cmakeBool "NO_CUDA" (!cudaSupport))
    ] ++ lib.optionals (!stdenv.isDarwin) [
      "-DGLEW_INCLUDE_DIR=${glew.dev}/include"
      "-DGLEW_LIBRARY=${glew.dev}/lib"
    ] ++ lib.optionals cudaSupport [
    ] ++ lib.optionals (!openclSupport) [
    ];

  preBuild = let maxBuildCores = 16; in lib.optionalString cudaSupport ''
    # https://github.com/PixarAnimationStudios/OpenSubdiv/issues/1313
    NIX_BUILD_CORES=$(( NIX_BUILD_CORES < ${toString maxBuildCores} ? NIX_BUILD_CORES : ${toString maxBuildCores} ))
  '';

  postInstall = "rm $out/lib/*.a";

  meta = {
    description = "An Open-Source subdivision surface library";
    homepage = "http://graphics.pixar.com/opensubdiv";
    broken = openclSupport && cudaSupport;
    platforms = lib.platforms.unix;
    maintainers = [ lib.maintainers.eelco ];
    license = lib.licenses.asl20;
  };
}