86Box/src/sound/snd_opl.c

/* Copyright holders: Sarah Walker, SA1988
   see COPYING for more details
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <wchar.h>
#include "../86box.h"
#include "../cpu/cpu.h"
#include "../io.h"
#include "../timer.h"
#include "sound.h"
#include "snd_opl.h"
#include "snd_dbopl.h"


/*Interfaces between 86Box and the actual OPL emulator*/


uint8_t opl2_read(uint16_t a, void *priv)
{
        opl_t *opl = (opl_t *)priv;

        sub_cycles((int)(isa_timing * 8));
        opl2_update2(opl);
        return opl_read(0, a);
}
void opl2_write(uint16_t a, uint8_t v, void *priv)
{
        opl_t *opl = (opl_t *)priv;

        opl2_update2(opl);
        opl_write(0, a, v);
        opl_write(1, a, v);
}

uint8_t opl2_l_read(uint16_t a, void *priv)
{
        opl_t *opl = (opl_t *)priv;

        sub_cycles((int)(isa_timing * 8));
        opl2_update2(opl);
        return opl_read(0, a);
}
void opl2_l_write(uint16_t a, uint8_t v, void *priv)
{
        opl_t *opl = (opl_t *)priv;

        opl2_update2(opl);
        opl_write(0, a, v);
}

uint8_t opl2_r_read(uint16_t a, void *priv)
{
        opl_t *opl = (opl_t *)priv;

        sub_cycles((int)(isa_timing * 8));
        opl2_update2(opl);
        return opl_read(1, a);
}
void opl2_r_write(uint16_t a, uint8_t v, void *priv)
{
        opl_t *opl = (opl_t *)priv;

        opl2_update2(opl);
        opl_write(1, a, v);
}

uint8_t opl3_read(uint16_t a, void *priv)
{
        opl_t *opl = (opl_t *)priv;

        sub_cycles((int)(isa_timing * 8));
        opl3_update2(opl);
        return opl_read(0, a);
}
void opl3_write(uint16_t a, uint8_t v, void *priv)
{
        opl_t *opl = (opl_t *)priv;
        
        opl3_update2(opl);
        opl_write(0, a, v);
}


void opl2_update2(opl_t *opl)
{
        if (opl->pos < sound_pos_global)
        {
                opl2_update(0, &opl->buffer[opl->pos*2], sound_pos_global - opl->pos);
                opl2_update(1, &opl->buffer[opl->pos*2 + 1], sound_pos_global - opl->pos);
                for (; opl->pos < sound_pos_global; opl->pos++)
                {
                        opl->filtbuf[0] = opl->buffer[opl->pos*2]   = (opl->buffer[opl->pos*2]   / 2);
                        opl->filtbuf[1] = opl->buffer[opl->pos*2+1] = (opl->buffer[opl->pos*2+1] / 2);
                }
        }
}

void opl3_update2(opl_t *opl)
{
        if (opl->pos < sound_pos_global)
        {
                opl3_update(0, &opl->buffer[opl->pos*2], sound_pos_global - opl->pos);
                for (; opl->pos < sound_pos_global; opl->pos++)
                {
                        opl->filtbuf[0] = opl->buffer[opl->pos*2]   = (opl->buffer[opl->pos*2]   / 2);
                        opl->filtbuf[1] = opl->buffer[opl->pos*2+1] = (opl->buffer[opl->pos*2+1] / 2);
                }
        }
}

void ym3812_timer_set_0(void *param, int timer, uint64_t period)
{
        opl_t *opl = (opl_t *)param;
        
		if (period)
			timer_set_delay_u64(&opl->timers[0][timer], period * TIMER_USEC * 20);
		else
			timer_disable(&opl->timers[0][timer]);
}
void ym3812_timer_set_1(void *param, int timer, uint64_t period)
{
        opl_t *opl = (opl_t *)param;

		if (period)
			timer_set_delay_u64(&opl->timers[1][timer], period * TIMER_USEC * 20);
		else
			timer_disable(&opl->timers[1][timer]);
}

void ymf262_timer_set(void *param, int timer, uint64_t period)
{
        opl_t *opl = (opl_t *)param;

		if (period)
			timer_set_delay_u64(&opl->timers[0][timer], period * TIMER_USEC * 20);
		else
			timer_disable(&opl->timers[0][timer]);
}

static void opl_timer_callback00(void *p)
{
        opl_timer_over(0, 0);
}
static void opl_timer_callback01(void *p)
{
        opl_timer_over(0, 1);
}
static void opl_timer_callback10(void *p)
{
        opl_timer_over(1, 0);
}
static void opl_timer_callback11(void *p)
{
        opl_timer_over(1, 1);
}
        
void opl2_init(opl_t *opl)
{
        opl_init(ym3812_timer_set_0, opl, 0, 0);
        opl_init(ym3812_timer_set_1, opl, 1, 0);
		timer_add(&opl->timers[0][0], opl_timer_callback00, (void *)opl, 0);
		timer_add(&opl->timers[0][1], opl_timer_callback01, (void *)opl, 0);
		timer_add(&opl->timers[1][0], opl_timer_callback10, (void *)opl, 0);
		timer_add(&opl->timers[1][1], opl_timer_callback11, (void *)opl, 0);
}

void opl3_init(opl_t *opl)
{
        opl_init(ymf262_timer_set, opl, 0, 1);
		timer_add(&opl->timers[0][0], opl_timer_callback00, (void *)opl, 0);
		timer_add(&opl->timers[0][1], opl_timer_callback01, (void *)opl, 0);
}