Files
86Box/src/game/joystick_sw_pad.c
2022-02-20 16:26:40 -05:00

282 lines
8.1 KiB
C

/*
* VARCem Virtual ARchaeological Computer EMulator.
* An emulator of (mostly) x86-based PC systems and devices,
* using the ISA,EISA,VLB,MCA and PCI system buses, roughly
* spanning the era between 1981 and 1995.
*
* This file is part of the VARCem Project.
*
* Implementation of a Side Winder GamePad.
*
* Notes: - Write to 0x201 starts packet transfer (5*N or 15*N bits)
* - Currently alternates between Mode A and Mode B (is there
* any way of actually controlling which is used?)
* - Windows 9x drivers require Mode B when more than 1 pad
* connected
* - Packet preceeded by high data (currently 50us), and
* followed by low data (currently 160us) - timings are
* probably wrong, but good enough for everything I've tried
* - Analog inputs are only used to time ID packet request.
* If A0 timing out is followed after ~64us by another 0x201
* write then an ID packet is triggered
* - Sidewinder game pad ID is 'H0003'
* - ID is sent in Mode A (1 bit per clock), but data bit 2
* must change during ID packet transfer, or Windows 9x
* drivers won't use Mode B. I don't know if it oscillates,
* mirrors the data transfer, or something else - the drivers
* only check that it changes at least 10 times during the
* transfer
* - Some DOS stuff will write to 0x201 while a packet is
* being transferred. This seems to be ignored.
*
*
*
* Authors: Miran Grca, <mgrca8@gmail.com>
* Sarah Walker, <tommowalker@tommowalker.co.uk>
*
* Copyright 2016-2018 Miran Grca.
* Copyright 2008-2018 Sarah Walker.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the:
*
* Free Software Foundation, Inc.
* 59 Temple Place - Suite 330
* Boston, MA 02111-1307
* USA.
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <wchar.h>
#include <86box/86box.h>
#include <86box/device.h>
#include <86box/timer.h>
#include <86box/gameport.h>
#include <86box/joystick_sw_pad.h>
typedef struct
{
pc_timer_t poll_timer;
int poll_left;
int poll_clock;
uint64_t poll_data;
int poll_mode;
pc_timer_t trigger_timer;
int data_mode;
} sw_data;
static void sw_timer_over(void *p)
{
sw_data *sw = (sw_data *)p;
sw->poll_clock = !sw->poll_clock;
if (sw->poll_clock)
{
sw->poll_data >>= (sw->poll_mode ? 3 : 1);
sw->poll_left--;
}
if (sw->poll_left == 1 && !sw->poll_clock)
timer_advance_u64(&sw->poll_timer, TIMER_USEC * 160);
else if (sw->poll_left)
timer_advance_u64(&sw->poll_timer, TIMER_USEC * 5);
else
timer_disable(&sw->poll_timer);
}
static void sw_trigger_timer_over(void *p)
{
sw_data *sw = (sw_data *)p;
timer_disable(&sw->trigger_timer);
}
static int sw_parity(uint16_t data)
{
int bits_set = 0;
while (data)
{
bits_set++;
data &= (data - 1);
}
return bits_set & 1;
}
static void *sw_init(void)
{
sw_data *sw = (sw_data *)malloc(sizeof(sw_data));
memset(sw, 0, sizeof(sw_data));
timer_add(&sw->poll_timer, sw_timer_over, sw, 0);
timer_add(&sw->trigger_timer, sw_trigger_timer_over, sw, 0);
return sw;
}
static void sw_close(void *p)
{
sw_data *sw = (sw_data *)p;
free(sw);
}
static uint8_t sw_read(void *p)
{
sw_data *sw = (sw_data *)p;
uint8_t temp = 0;
if (!JOYSTICK_PRESENT(0))
return 0xff;
if (timer_is_enabled(&sw->poll_timer))
{
if (sw->poll_clock)
temp |= 0x10;
if (sw->poll_mode)
temp |= (sw->poll_data & 7) << 5;
else
{
temp |= ((sw->poll_data & 1) << 5) | 0xc0;
if (sw->poll_left > 31 && !(sw->poll_left & 1))
temp &= ~0x80;
}
}
else
temp |= 0xf0;
return temp;
}
static void sw_write(void *p)
{
sw_data *sw = (sw_data *)p;
int64_t time_since_last = timer_get_remaining_us(&sw->trigger_timer);
if (!JOYSTICK_PRESENT(0))
return;
timer_process();
if (!sw->poll_left)
{
sw->poll_clock = 1;
timer_set_delay_u64(&sw->poll_timer, TIMER_USEC * 50);
if (time_since_last > 9900 && time_since_last < 9940)
{
sw->poll_mode = 0;
sw->poll_left = 49;
sw->poll_data = 0x2400ull | (0x1830ull << 15) | (0x19b0ull << 30);
}
else
{
int c;
sw->poll_mode = sw->data_mode;
sw->data_mode = !sw->data_mode;
if (sw->poll_mode)
{
sw->poll_left = 1;
sw->poll_data = 7;
}
else
{
sw->poll_left = 1;
sw->poll_data = 1;
}
for (c = 0; c < 4; c++)
{
uint16_t data = 0x3fff;
int b;
if (!JOYSTICK_PRESENT(c))
break;
if (joystick_state[c].axis[1] < -16383)
data &= ~1;
if (joystick_state[c].axis[1] > 16383)
data &= ~2;
if (joystick_state[c].axis[0] > 16383)
data &= ~4;
if (joystick_state[c].axis[0] < -16383)
data &= ~8;
for (b = 0; b < 10; b++)
{
if (joystick_state[c].button[b])
data &= ~(1 << (b + 4));
}
if (sw_parity(data))
data |= 0x4000;
if (sw->poll_mode)
{
sw->poll_left += 5;
sw->poll_data |= (data << (c*15 + 3));
}
else
{
sw->poll_left += 15;
sw->poll_data |= (data << (c*15 + 1));
}
}
}
}
timer_disable(&sw->trigger_timer);
}
static int sw_read_axis(void *p, int axis)
{
if (!JOYSTICK_PRESENT(0))
return AXIS_NOT_PRESENT;
return 0; /*No analogue support on Sidewinder game pad*/
}
static void sw_a0_over(void *p)
{
sw_data *sw = (sw_data *)p;
timer_set_delay_u64(&sw->trigger_timer, TIMER_USEC * 10000);
}
const joystick_if_t joystick_sw_pad =
{
"Microsoft SideWinder Pad",
"sidewinder_pad",
sw_init,
sw_close,
sw_read,
sw_write,
sw_read_axis,
sw_a0_over,
2,
10,
0,
4,
{"X axis", "Y axis"},
{"A", "B", "C", "X", "Y", "Z", "L", "R", "Start", "M"}
};