Cross-fade-selector window generation

#include "generate.h"
#include <ad/dsp/window.h>
#include <ad/dsp/bfunc.h>

using namespace xcope;

void test_window(signal_t &signal, int offset, int length, int config, bool force = false)
{
    typedef signal_t::T T;
    if (signal.enabled || force) {
        signal.reset();

        if (offset < 0) {
            ad::dsp::window::select_window(length, (T *)signal.value, config);
            ad::dsp::bfunc::copy((T *)signal.value, (T *)signal.value - offset, length);
        } else {
            ad::dsp::window::select_window(length, (T *)signal.value + offset, config);
        }
    }
}

struct generator_cf_t : xcope::generator_t
{
    generator_cf_t() : xcope::generator_t("cross-fade") {}
    virtual void operator()(signals_t &signal, int length, controls_t &control)
    {
        ctrl_list_t &config = control("config");
        ctrl_list_t &parameter = control("parameter");

        const float cycles = config.get_value("cycles");

        xcope::control_t *n = parameter["fc"];
        if (n) {
            n->prop.min = 0;
            n->prop.max = 8;
            n->prop.integer = true;
        }

        xcope::control_t *window = parameter["window"];
        if (window) {
            window->value_to_text = &xcope::window_index_to_text;
            window->prop.min = 0;
            window->prop.max = 64;
            window->prop.value = 1;
            window->prop.integer = true;
            window->prop.menu_content = menu_content::window;
        }

        char name[4] = {'w', '0', 0, 0};
        const int elements = 4;
        const int step = length / (elements - 1);
        int offset = -step;

        for (int i = 0; i < elements; i++) {
            name[1] = '1' + i;
            test_window(signal(name), offset, step * 2, int(window->get_value()));
            offset += step;
        }
    }
} generator_window;