#include <doctest/doctest.h>

#include <light/light.hh>
#include <common/bspinfo.hh>
#include <qbsp/qbsp.hh>
#include <testmaps.hh>
#include <vis/vis.hh>
#include "test_qbsp.hh"

static testresults_t QbspVisLight_Common(const std::filesystem::path &name, std::vector<std::string> extra_qbsp_args,
    std::vector<std::string> extra_light_args, runvis_t run_vis)
{
    const bool is_q2 = std::find(extra_qbsp_args.begin(), extra_qbsp_args.end(), "-q2bsp") != extra_qbsp_args.end();
    auto map_path = std::filesystem::path(testmaps_dir) / name;

    auto bsp_path = fs::path(is_q2 ? test_quake2_maps_dir : test_quake_maps_dir) / name.filename();
    bsp_path.replace_extension(".bsp");

    auto wal_metadata_path = std::filesystem::path(testmaps_dir) / "q2_wal_metadata";

    std::vector<std::string> args{"", // the exe path, which we're ignoring in this case
        "-noverbose"};
    for (auto &extra : extra_qbsp_args) {
        args.push_back(extra);
    }
    args.push_back("-path");
    args.push_back(wal_metadata_path.string());
    args.push_back(map_path.string());
    args.push_back(bsp_path.string());

    // run qbsp

    InitQBSP(args);
    ProcessFile();

    // run vis
    if (run_vis == runvis_t::yes) {
        std::vector<std::string> vis_args{
            "", // the exe path, which we're ignoring in this case
        };
        vis_args.push_back(bsp_path.string());
        vis_main(vis_args);
    }

    // run light
    {
        std::vector<std::string> light_args{"", // the exe path, which we're ignoring in this case
            "-nodefaultpaths", // in case test_quake2_maps_dir is pointing at a real Q2 install, don't
                               // read texture data etc. from there - we want the tests to behave the same
                               // during development as they do on CI (which doesn't have a Q2 install).
            "-path", wal_metadata_path.string()};
        for (auto &arg : extra_light_args) {
            light_args.push_back(arg);
        }
        light_args.push_back(bsp_path.string());

        light_main(light_args);
    }

    // serialize obj
    {
        bspdata_t bspdata;
        LoadBSPFile(bsp_path, &bspdata);

        ConvertBSPFormat(&bspdata, &bspver_generic);

        // write to .json for inspection
        serialize_bsp(
            bspdata, std::get<mbsp_t>(bspdata.bsp), fs::path(qbsp_options.bsp_path).replace_extension(".bsp.json"));

        return {std::move(std::get<mbsp_t>(bspdata.bsp)), std::move(bspdata.bspx.entries)};
    }
}

testresults_lit_t QbspVisLight_Q1(
    const std::filesystem::path &name, std::vector<std::string> extra_light_args, runvis_t run_vis)
{
    auto res = QbspVisLight_Common(name, {}, extra_light_args, run_vis);

    // load .lit file
    auto lit_path = fs::path(test_quake_maps_dir) / name.filename();
    lit_path.replace_extension(".lit");

    std::vector<uint8_t> litdata = LoadLitFile(lit_path);

    return testresults_lit_t{.bsp = res.bsp, .bspx = res.bspx, .lit = litdata};
}

testresults_t QbspVisLight_Q2(
    const std::filesystem::path &name, std::vector<std::string> extra_light_args, runvis_t run_vis)
{
    return QbspVisLight_Common(name, {"-q2bsp"}, extra_light_args, run_vis);
}

TEST_CASE("-world_units_per_luxel, -lightgrid")
{
    auto [bsp, bspx] = QbspVisLight_Q2("q2_lightmap_custom_scale.map", {"-lightgrid"});

    {
        INFO("back wall has texture scale 8 but still gets a luxel every 8 units");
        auto *back_wall = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {448, -84, 276}, {-1, 0, 0});
        auto back_wall_info = BSPX_DecoupledLM(bspx, Face_GetNum(&bsp, back_wall));
        auto back_wall_extents = faceextents_t(
            *back_wall, bsp, back_wall_info.lmwidth, back_wall_info.lmheight, back_wall_info.world_to_lm_space);

        // NOTE: the exact values are not critical (depends on BSP splitting) but they should be relatively large
        CHECK(75 == back_wall_extents.width());
        CHECK(43 == back_wall_extents.height());
    }

    {
        INFO("side wall func_group has _world_units_per_luxel 48, small lightmap");

        auto *side_wall = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {384, 240, 84}, {0, -1, 0});
        auto side_wall_info = BSPX_DecoupledLM(bspx, Face_GetNum(&bsp, side_wall));
        auto side_wall_extents = faceextents_t(
            *side_wall, bsp, side_wall_info.lmwidth, side_wall_info.lmheight, side_wall_info.world_to_lm_space);

        CHECK(4 == side_wall_extents.width());
        CHECK(5 == side_wall_extents.height());
    }

    {
        INFO("sky gets an optimized lightmap");

        auto *sky_face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {256, 240, 84}, {0, -1, 0});
        CHECK(sky_face->styles[0] == 255);

        auto sky_face_info = BSPX_DecoupledLM(bspx, Face_GetNum(&bsp, sky_face));
        CHECK(sky_face_info.lmwidth == 0);
        CHECK(sky_face_info.lmheight == 0);
    }
}

TEST_CASE("emissive cube artifacts")
{
    // A cube with surface flags "light", value "100", placed in a hallway.
    //
    // Generates harsh lines on the walls/ceiling due to a hack in `light` allowing
    // surface lights to emit 50% at 90 degrees off their surface normal (when physically it should be 0%).
    //
    // It's wanted in some cases (base1.map sewer lights flush with the wall, desired for them to
    // emit some lights on to their adjacent wall faces.)
    //
    // To disable the behaviour in this case with the cube lighting a hallway we have a entity key:
    //
    //     "_surflight_rescale" "0"
    //
    auto [bsp, bspx] =
        QbspVisLight_Q2("light_q2_emissive_cube.map", {"-threads", "1", "-world_units_per_luxel", "4", "-novanilla"});

    const auto start = qvec3d{1044, -1244, 880};
    const auto end = qvec3d{1044, -1272, 880};

    auto *floor = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], start, {0, 0, 1});
    auto lm_info = BSPX_DecoupledLM(bspx, Face_GetNum(&bsp, floor));

    const faceextents_t extents(*floor, bsp, lm_info.lmwidth, lm_info.lmheight, lm_info.world_to_lm_space);

    // sample the lightmap along the floor, approaching the glowing cube
    // should get brighter
    qvec3b previous_sample{};
    for (int y = start[1]; y >= end[1]; y -= 4) {
        qvec3d pos = start;
        pos[1] = y;

        auto lm_coord = extents.worldToLMCoord(pos);

        auto sample = LM_Sample(&bsp, nullptr, extents, lm_info.offset, lm_coord);
        CHECK(sample[0] >= previous_sample[0]);

        // logging::print("world: {} lm_coord: {} sample: {} lm size: {}x{}\n", pos, lm_coord, sample, lm_info.lmwidth,
        // lm_info.lmheight);

        previous_sample = sample;
    }
}

TEST_CASE("-novanilla + -world_units_per_luxel")
{
    auto [bsp, bspx] = QbspVisLight_Q2("q2_lightmap_custom_scale.map", {"-novanilla"});

    for (auto &face : bsp.dfaces) {
        CHECK(face.lightofs == -1);
    }

    // make sure no other bspx lumps are written
    CHECK(bspx.size() == 1);
    CHECK(bspx.find("DECOUPLED_LM") != bspx.end());

    // make sure all dlightdata bytes are accounted for by the DECOUPLED_LM lump
    // and no extra was written.
    size_t expected_dlightdata_bytes = 0;
    for (auto &face : bsp.dfaces) {
        // count used styles
        size_t face_used_styles = 0;
        for (auto style : face.styles) {
            if (style != 255) {
                ++face_used_styles;
            }
        }

        // count used pixels per style
        auto lm_info = BSPX_DecoupledLM(bspx, Face_GetNum(&bsp, &face));
        const faceextents_t extents(face, bsp, lm_info.lmwidth, lm_info.lmheight, lm_info.world_to_lm_space);
        int samples_per_face = extents.numsamples() * face_used_styles;

        // round up to multiple of 4
        if (samples_per_face % 4) {
            samples_per_face += (4 - (samples_per_face % 4));
        }

        int bytes_per_face = 3 * samples_per_face;
        expected_dlightdata_bytes += bytes_per_face;
    }
    CHECK(bsp.dlightdata.size() == expected_dlightdata_bytes);
}

template<class L>
static void CheckFaceLuxels(
    const mbsp_t &bsp, const mface_t &face, L &&lambda, const std::vector<uint8_t> *lit = nullptr)
{
    // FIXME: assumes no DECOUPLED_LM lump

    const faceextents_t extents(face, bsp, LMSCALE_DEFAULT);

    for (int x = 0; x < extents.width(); ++x) {
        for (int y = 0; y < extents.height(); ++y) {
            const qvec3b sample = LM_Sample(&bsp, lit, extents, face.lightofs, {x, y});
            INFO("sample ", x, ", ", y);
            lambda(sample);
        }
    }
}

static void CheckFaceLuxelsNonBlack(const mbsp_t &bsp, const mface_t &face)
{
    CheckFaceLuxels(bsp, face, [](qvec3b sample) { CHECK(sample[0] > 0); });
}

static void CheckFaceLuxelAtPoint(const mbsp_t *bsp, const dmodelh2_t *model, const qvec3b &expected_color,
    const qvec3d &point, const qvec3d &normal = {0, 0, 0})
{
    auto *face = BSP_FindFaceAtPoint(bsp, model, point, normal);
    REQUIRE(face);

    // FIXME: assumes no DECOUPLED_LM lump

    const faceextents_t extents(*face, *bsp, LMSCALE_DEFAULT);

    const auto coord = extents.worldToLMCoord(point);

    const qvec3b sample = LM_Sample(bsp, nullptr, extents, face->lightofs, qvec2i(coord));
    INFO("sample ", coord[0], ", ", coord[1]);

    CHECK(sample == expected_color);
}

TEST_CASE("emissive lights")
{
    auto [bsp, bspx] = QbspVisLight_Q2("q2_light_flush.map", {});
    REQUIRE(bspx.empty());

    {
        INFO("the angled face on the right should not have any full black luxels");
        auto *face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {244, -92, 92});
        REQUIRE(face);
        CheckFaceLuxelsNonBlack(bsp, *face);
    }

    {
        INFO("the angled face on the left should not have any full black luxels");
        auto *left_face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {470.4, 16, 112});
        REQUIRE(left_face);
        CheckFaceLuxelsNonBlack(bsp, *left_face);
    }
}

TEST_CASE("q2_phong_doesnt_cross_contents")
{
    auto [bsp, bspx] = QbspVisLight_Q2("q2_phong_doesnt_cross_contents.map", {"-wrnormals"});
}

TEST_CASE("q2_minlight_nomottle")
{
    INFO("_minlightMottle 0 works on worldspawn");

    auto [bsp, bspx] = QbspVisLight_Q2("q2_minlight_nomottle.map", {});

    auto *face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {276, 84, 32});
    REQUIRE(face);

    CheckFaceLuxels(bsp, *face, [](qvec3b sample) { CHECK(sample == qvec3b(33, 33, 33)); });
}

TEST_CASE("q2_dirt")
{
    INFO("liquids don't cast dirt");

    auto [bsp, bspx] = QbspVisLight_Q2("q2_dirt.map", {});

    auto *face_under_lava = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {104, 112, 48});
    REQUIRE(face_under_lava);

    CheckFaceLuxels(bsp, *face_under_lava, [](qvec3b sample) { CHECK(sample == qvec3b(96)); });
}

TEST_CASE("q2_light_translucency")
{
    INFO("liquids cast translucent colored shadows (sampling texture) by default");

    auto [bsp, bspx] = QbspVisLight_Q2("q2_light_translucency.map", {});

    {
        auto *face_under_water = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {152, -96, 32});
        REQUIRE(face_under_water);

        CheckFaceLuxels(bsp, *face_under_water, [](qvec3b sample) {
            INFO("green color from the texture");
            CHECK(sample == qvec3b(100, 150, 100));
        });
    }

    {
        INFO("under _light_alpha 0 is not tinted");

        auto *under_alpha_0_glass = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {-296, -96, 40});
        REQUIRE(under_alpha_0_glass);

        CheckFaceLuxels(bsp, *under_alpha_0_glass, [](qvec3b sample) { CHECK(sample == qvec3b(150)); });
    }

    {
        INFO("under _light_alpha 1 is fully tinted");

        auto *under_alpha_1_glass = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {-616, -96, 40});
        REQUIRE(under_alpha_1_glass);

        CheckFaceLuxels(bsp, *under_alpha_1_glass, [](qvec3b sample) { CHECK(sample == qvec3b(0, 150, 0)); });
    }

    {
        INFO("alpha test works");

        auto *in_light = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {-976, -316, 184});
        REQUIRE(in_light);

        CheckFaceLuxels(bsp, *in_light, [](qvec3b sample) { CHECK(sample == qvec3b(150)); });

        auto *in_shadow = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {-976, -316, 88});
        REQUIRE(in_shadow);

        CheckFaceLuxels(bsp, *in_shadow, [](qvec3b sample) { CHECK(sample == qvec3b(0)); });
    }
}

TEST_CASE("-visapprox vis with opaque liquids")
{
    INFO("opaque liquids block vis, but don't cast shadows by default.");
    INFO("make sure '-visapprox vis' doesn't wrongly cull rays that should illuminate the level.");

    const std::vector<std::string> maps{
        "q2_light_visapprox.map", // light in liquid
        "q2_light_visapprox2.map" // light outside of liquid
    };

    for (const auto &map : maps) {
        SUBCASE(map.c_str())
        {
            auto [bsp, bspx] = QbspVisLight_Q2(map, {"-visapprox", "vis"}, runvis_t::yes);

            auto *ceil_face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {968, 1368, 1248});
            REQUIRE(ceil_face);

            CheckFaceLuxels(bsp, *ceil_face, [](qvec3b sample) {
                INFO("ceiling above player start receiving light");
                REQUIRE(sample[0] > 200);
            });
        }
    }
}

TEST_CASE("negative lights work")
{
    const std::vector<std::string> maps{"q2_light_negative.map", "q2_light_negative_bounce.map"};

    for (const auto &map : maps) {
        SUBCASE(map.c_str())
        {
            auto [bsp, bspx] = QbspVisLight_Q2(map, {});

            auto *face_under_negative_light = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {632, 1304, 960});
            REQUIRE(face_under_negative_light);

            CheckFaceLuxels(bsp, *face_under_negative_light, [](qvec3b sample) { CHECK(sample == qvec3b(0)); });
        }
    }
}

TEST_CASE("light channel mask (_object_channel_mask, _light_channel_mask, _shadow_channel_mask)")
{
    auto [bsp, bspx] = QbspVisLight_Q2("q2_light_group.map", {});
    REQUIRE(4 == bsp.dmodels.size());

    {
        INFO("world doesn't receive light from the light ent with _light_channel_mask 2");

        auto *face_under_light = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {680, 1224, 944});
        REQUIRE(face_under_light);

        CheckFaceLuxels(bsp, *face_under_light, [](qvec3b sample) { CHECK(sample == qvec3b(64)); });
    }

    {
        INFO("pillar with _object_channel_mask 2 is receiving light");

        auto *face_on_pillar = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[1], {680, 1248, 1000});
        REQUIRE(face_on_pillar);

        CheckFaceLuxels(bsp, *face_on_pillar, [](qvec3b sample) { CHECK(sample == qvec3b(255, 0, 0)); });
    }

    {
        INFO("_object_channel_mask 2 implicitly makes bmodels cast shadow in channel 2");

        auto *occluded_face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[1], {680, 1280, 1000});
        REQUIRE(occluded_face);

        CheckFaceLuxels(bsp, *occluded_face, [](qvec3b sample) { CHECK(sample == qvec3b(0)); });
    }

    {
        INFO("ensure AABB culling isn't breaking light channels");

        auto *unoccluded_face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[1], {680, 1280, 1088});
        REQUIRE(unoccluded_face);

        CheckFaceLuxels(bsp, *unoccluded_face, [](qvec3b sample) { CHECK(sample[0] > 100); });
    }

    {
        INFO("sunlight doesn't cast on _object_channel_mask 4 bmodel");

        auto *face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[2], {904, 1248, 1016});
        REQUIRE(face);

        CheckFaceLuxels(bsp, *face, [](qvec3b sample) { CHECK(sample == qvec3b(0, 255, 0)); });
    }

    {
        INFO("surface light doesn't cast on _object_channel_mask 8 bmodel");

        auto *face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[3], {1288, 1248, 1016});
        REQUIRE(face);

        CheckFaceLuxels(bsp, *face, [](qvec3b sample) { CHECK(sample == qvec3b(0, 0, 255)); });
    }

    {
        INFO("_object_channel_mask 8 bmodel doesn't occlude luxels of a (channel 1) worldspawn brush touching it");

        auto *face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {1290, 1264, 1014});
        REQUIRE(face);

        INFO("should be receiving orange light from surface light");
        CheckFaceLuxels(bsp, *face, [](qvec3b sample) {
            qvec3i delta = qv::abs(qvec3i(sample) - qvec3i{255, 127, 64});
            CHECK(delta[0] <= 2);
            CHECK(delta[1] <= 2);
            CHECK(delta[2] <= 2);
        });
    }

    {
        INFO("check that _object_channel_mask 8 func_group receives _light_channel_mask 8");

        auto *face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {1480, 1248, 1004});
        REQUIRE(face);

        CheckFaceLuxels(bsp, *face, [](qvec3b sample) { CHECK(sample == qvec3b(0, 0, 255)); });
    }

    {
        INFO("_object_channel_mask 8 func_group doesn't cast shadow on default channel");

        auto *face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {1484, 1280, 1016});
        REQUIRE(face);

        CheckFaceLuxels(bsp, *face, [](qvec3b sample) {
            qvec3i delta = qv::abs(qvec3i(sample) - qvec3i{255, 127, 64});
            CHECK(delta[0] <= 2);
            CHECK(delta[1] <= 2);
            CHECK(delta[2] <= 2);
        });
    }
}

TEST_CASE("light channel mask / dirt interaction")
{
    auto [bsp, bspx] = QbspVisLight_Q2("q2_light_group_dirt.map", {});

    REQUIRE(2 == bsp.dmodels.size());

    INFO("worldspawn has dirt in the corner");
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {26, 26, 26}, {1432, 1480, 944});

    INFO("worldspawn not receiving dirt from func_wall on different channel");
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {62, 62, 62}, {1212, 1272, 1014});

    INFO("func_wall on different channel not receiving dirt from worldspawn");
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[1], {64, 64, 64}, {1216, 1266, 1014});

    INFO("func_wall on different channel is receiving dirt from itself");
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[1], {19, 19, 19}, {1236, 1308, 960});
}

TEST_CASE("surface lights minlight")
{
    auto [bsp, bspx, lit] = QbspVisLight_Q1("q1_surflight_minlight.map", {});

    {
        INFO("there's a point entity in the void, but it has _nofill 1 so it should be ignored by filling");
        CheckFilled(bsp);
    }

    auto *surflight = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {-3264, -1664, -560});
    REQUIRE(surflight);

    const auto l = [](qvec3b sample) {
        // "light" key is 100, color is (1, 0.5, 0), but values get halved due to overbright

        CHECK(sample[0] <= 75);
        CHECK(sample[0] >= 50);

        CHECK(sample[1] <= 35);
        CHECK(sample[1] >= 25);

        CHECK(sample[2] == 0);
    };

    CheckFaceLuxels(bsp, *surflight, l, &lit);

    INFO("same but with liquid");

    auto *liquid_face = BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {-3264, -1456, -560}, {-1, 0, 0});
    REQUIRE(liquid_face);

    CheckFaceLuxels(bsp, *liquid_face, l, &lit);
}

static void CheckSpotCutoff(const mbsp_t &bsp, const qvec3d &position)
{
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {0, 0, 0}, position + qvec3d{16, 0, 0});
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {243, 243, 243}, position - qvec3d{16, 0, 0});
}

TEST_CASE("q2_light_cone")
{
    auto [bsp, bspx] = QbspVisLight_Q2("q2_light_cone.map", {});

    // lights are 256 units from wall
    // all 3 lights have a 10 degree cone radius
    // radius on wall should be 256 * sin(10 degrees) = 44.45 units

    CheckSpotCutoff(bsp, {948, 1472, 952});
    CheckSpotCutoff(bsp, {1092, 1472, 952});
    CheckSpotCutoff(bsp, {1236, 1472, 952});
}

TEST_CASE("q2_light_sunlight_default_mangle")
{
    auto [bsp, bspx] = QbspVisLight_Q2("q2_light_sunlight_default_mangle.map", {});

    INFO("sunlight should be shining directly down if unspecified");
    const qvec3d shadow_pos{1112, 1248, 944};
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {0, 0, 0}, shadow_pos);

    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {100, 100, 100}, shadow_pos + qvec3d{48, 0, 0});
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {100, 100, 100}, shadow_pos + qvec3d{-48, 0, 0});
}

TEST_CASE("q2_light_sun")
{
    auto [bsp, bspx] = QbspVisLight_Q2("q2_light_sun.map", {});

    INFO("sun entity shines at target");
    const qvec3d shadow_pos{1084, 1284, 944};
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {0, 0, 0}, shadow_pos);

    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {220, 0, 0}, shadow_pos + qvec3d{128, 0, 0});
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {220, 0, 0}, shadow_pos + qvec3d{-128, 0, 0});
}

TEST_CASE("q2_light_origin_brush_shadow")
{
    auto [bsp, bspx] = QbspVisLight_Q2("q2_light_origin_brush_shadow.map", {});

    const qvec3d under_shadow_bmodel{-320, 176, 1};
    const qvec3d under_nonshadow_bmodel{-432, 176, 1};

    const qvec3d under_nodraw_shadow_bmodel = under_shadow_bmodel - qvec3d(0, 96, 0);
    const qvec3d under_nodraw_nonshadow_bmodel = under_nonshadow_bmodel - qvec3d(0, 96, 0);

    const qvec3d at_origin{0, 0, 1};

    INFO("ensure expected shadow");
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {0, 0, 0}, under_shadow_bmodel);
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {0, 0, 0}, under_nodraw_shadow_bmodel);

    INFO("ensure no spurious shadow under non-_shadow 1 bmodel");
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {100, 100, 100}, under_nonshadow_bmodel);
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {100, 100, 100}, under_nodraw_nonshadow_bmodel);

    INFO("ensure no spurious shadow at the world origin (would happen if we didn't apply model offset)");
    CheckFaceLuxelAtPoint(&bsp, &bsp.dmodels[0], {100, 100, 100}, at_origin);
}