/* armando modem - 2014 */

#ifdef __XC16
#include <xc.h>
#include <dsp.h>
#include <libq.h>
#elif __unix

#endif 

#include <stdint.h>

#include "modem.h"
#include "modulator.h"

#include "../peripheral/dac.h"
#include "../peripheral/gpio.h"

rotor_symbol rotor_constellation[MAX_MODULATION_ALPHABET_SIZE];
rotor_symbol silence;

// buffer dei simboli
uint8_t tx_symbol_buffer[MAX_SYMBOL_BUFFER_SIZE];
uint8_t tx_symbol_buffer_index, tx_symbol_buffer_lenght;

void modulator_setup(void) {
    // TX
#ifdef USE_GPIO
    set_tx_GPIOs();
#endif
    modulator_prepare_constellation_symbols(mod.constellation, rotor_constellation);
}

// #####################################################

// genera un buffer di campioni

void modulator_generate_sample_buffer(fractional *Q_buffer, fractional *I_buffer, uint8_t size, rotor_symbol symbol) {
    uint8_t i;

    static fractional modulator_rotor, modulator_rotor_position;
    i = 0;
    while (i < size) {
        modulator_rotor_position = modulator_rotor + symbol.offset;
        Q_buffer[i] = __builtin_mulss(_Q15sinPI(modulator_rotor_position), // non deve saturare
                symbol.gain) >> 15;

        I_buffer[i] = __builtin_mulss(_Q15cosPI(modulator_rotor_position), // non deve saturare
                symbol.gain) >> 15;

        modulator_rotor += symbol.increment; // la _Q15 satura!
        ++i;
    }

#if ! defined(__DEBUG)
    // viene riasserito dal DMA del dac, dove mettere?
    populate_tx_sample_buffer = 0; // fatto
#endif        
}

// traduce da modulazione astratta a parametri per il modulatore

void modulator_prepare_constellation_symbols(symbol *constellation, rotor_symbol *mod_constellation) {
    uint8_t i;
    for (i = 0; i < mod.alphabet_size; i++) {
        mod_constellation[i].increment = get_angular_frequency(constellation[i].frequency);
        mod_constellation[i].offset = constellation[i].phase;
        mod_constellation[i].gain = constellation[i].amplitude;
    }
}