/*
 * 86Box	A hypervisor and IBM PC system emulator that specializes in
 *		running old operating systems and software designed for IBM
 *		PC systems and compatibles from 1981 through fairly recent
 *		system designs based on the PCI bus.
 *
 *		This file is part of the 86Box distribution.
 *
 *		Emulation of the PC speaker.
 *
 *
 *
 * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
 *		Miran Grca, <mgrca8@gmail.com>
 *
 *		Copyright 2008-2019 Sarah Walker.
 *		Copyright 2016-2019 Miran Grca.
 */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <wchar.h>
#include <86box/86box.h>
#include <86box/timer.h>
#include <86box/pit.h>
#include <86box/sound.h>
#include <86box/snd_speaker.h>


int speaker_mute = 0, speaker_gated = 0;
int speaker_enable = 0, was_speaker_enable = 0;

int gated, speakval, speakon;


static int32_t speaker_buffer[SOUNDBUFLEN];
static int speaker_pos = 0;

static uint8_t speaker_mode = 0;
static double speaker_count = 65535.0;


void
speaker_set_count(uint8_t new_m, int new_count)
{
    speaker_mode = new_m;
    speaker_count = (double) new_count;
}


void
speaker_update(void)
{
    int32_t val;
    double amplitude;

    amplitude = ((speaker_count / 64.0) * 10240.0) - 5120.0;

    if (amplitude > 5120.0)
	amplitude = 5120.0;

    if (speaker_pos < sound_pos_global) {
	for (; speaker_pos < sound_pos_global; speaker_pos++) {
		if (speaker_gated && was_speaker_enable) {
			if ((speaker_mode == 0) || (speaker_mode == 4))
				val = (int32_t) amplitude;
			else if (speaker_count < 64.0)
				val = 0xa00;
			else
				val = speakon ? 0x1400 : 0;
		} else {
			if (speaker_mode == 1)
				val = was_speaker_enable ? (int32_t) amplitude : 0;
			else
				val = was_speaker_enable ? 0x1400 : 0;
		}

		if (!speaker_enable)
			was_speaker_enable = 0;

		speaker_buffer[speaker_pos] = val;
	    }
    }
}


void
speaker_get_buffer(int32_t *buffer, int len, void *p)
{
    int32_t c, val;

    speaker_update();

    if (!speaker_mute) {
	for (c = 0; c < len * 2; c += 2) {
		val = speaker_buffer[c >> 1];
		buffer[c] += val;
		buffer[c + 1] += val;
	}
    }

    speaker_pos = 0;
}


void
speaker_init(void)
{
    memset(speaker_buffer, 0, sizeof(speaker_buffer));
    sound_add_handler(speaker_get_buffer, NULL);
    speaker_mute = 0;
}