Function test_encode_from_preprocessed

tests/test_phase3.cpp:440–587

// ═══════════════════════════════════════════════════════════════════════════════

static void test_encode_from_preprocessed(const std::string & model_path,
                                           const std::string & ref_dir,
                                           int & n_pass, int & n_fail) {
    fprintf(stderr, "\n╔══════════════════════════════════════════╗\n");
    fprintf(stderr, "║  Test: ViT Numerics (Python preprocess)  ║\n");
    fprintf(stderr, "╚══════════════════════════════════════════╝\n");

    // Load Python-preprocessed image (CHW layout, [1, 3, 1008, 1008])
    auto preproc = load_ref(ref_dir + "/preprocessed");
    if (preproc.data.empty()) {
        fprintf(stderr, "  [SKIP] No preprocessed reference data\n");
        return;
    }
    fprintf(stderr, "  Loaded preprocessed image: shape=[");
    for (size_t i = 0; i < preproc.shape.size(); ++i) {
        if (i > 0) fprintf(stderr, ", ");
        fprintf(stderr, "%d", preproc.shape[i]);
    }
    fprintf(stderr, "] numel=%d\n", preproc.numel());

    // The preprocessed data is [1, 3, 1008, 1008] in PyTorch NCHW layout.
    // For ggml, the input tensor is [W=1008, H=1008, C=3, B=1].
    // ggml flat index: x + y*W + c*W*H = same as CHW[c*H*W + y*W + x].
    // So the CHW data can be uploaded directly.
    const float * chw_data = preproc.data.data();
    int img_size = preproc.shape[2];  // 1008

    sam3_params params;
    params.model_path = model_path;
    params.use_gpu = false;
    params.n_threads = 4;

    auto model = sam3_load_model(params);
    if (!model) {
        fprintf(stderr, "  FATAL: Failed to load model\n");
        n_fail++;
        return;
    }

    auto state = sam3_create_state(*model, params);
    if (!state) {
        fprintf(stderr, "  FATAL: Failed to create state\n");
        n_fail++;
        return;
    }

    bool ok = sam3_encode_image_from_preprocessed(*state, *model, chw_data, img_size);
    if (!ok) {
        fprintf(stderr, "  FATAL: sam3_encode_image_from_preprocessed failed\n");
        n_fail++;
        return;
    }

    std::string dump_dir = ref_dir + "/cpp_out_from_preproc";
    {
        std::string cmd = "mkdir -p " + dump_dir;
        (void)system(cmd.c_str());
    }