idac: add ffb emulation

board/config.c

@@ -93,3 +93,11 @@ void vfd_config_load(struct vfd_config *cfg, const wchar_t *filename)
     cfg->port = GetPrivateProfileIntW(L"vfd", L"portNo", 0, filename);
     cfg->utf_conversion = GetPrivateProfileIntW(L"vfd", L"utfConversion", 0, filename);
 }
+
+void ffb_config_load(struct ffb_config *cfg, const wchar_t *filename)
+{
+    assert(cfg != NULL);
+    assert(filename != NULL);
+
+    cfg->enable = GetPrivateProfileIntW(L"ffb", L"enable", 1, filename);
+}

board/config.h

@@ -6,7 +6,9 @@
 #include "board/io4.h"
 #include "board/sg-reader.h"
 #include "board/vfd.h"
+#include "board/ffb.h"
 
 void aime_config_load(struct aime_config *cfg, const wchar_t *filename);
 void io4_config_load(struct io4_config *cfg, const wchar_t *filename);
 void vfd_config_load(struct vfd_config *cfg, const wchar_t *filename);
+void ffb_config_load(struct ffb_config *cfg, const wchar_t *filename);

board/ffb.c

@@ -0,0 +1,234 @@
+/*
+    Force Feedback Board (FFB)
+
+    This board is used by many SEGA games to provide force feedback to the player.
+    It is driven by the game software over a serial connection and is used by many
+    games such as SEGA World Drivers Championship, Initial D Arcade, ...
+
+    Part number in schematics is "838-15069 MOTOR DRIVE BD RS232/422 Board".
+
+    Some observations:
+    The maximal strength for any effect is 127, except Damper which maxes out at 40.
+    The period for rumble effects is in the range 0-40.
+*/
+
+#include "board/ffb.h"
+
+#include <assert.h>
+#include <stdint.h>
+#include <windows.h>
+
+#include "hook/iohook.h"
+#include "hooklib/uart.h"
+#include "util/dprintf.h"
+#include "util/dump.h"
+
+
+// request format:
+// 0x?? - sync + command
+// 0x?? - direction/additional command
+// 0x?? - strength
+// 0x?? - checksum (sum of everything except the sync byte)
+
+enum {
+    FFB_CMD_TOGGLE = 0x80,
+    FFB_CMD_CONSTANT_FORCE = 0x84,
+    FFB_CMD_RUMBLE = 0x85,
+    FFB_CMD_DAMPER = 0x86,
+};
+
+struct ffb_hdr {
+    uint8_t cmd;
+};
+
+union ffb_req_any {
+    struct ffb_hdr hdr;
+    uint8_t bytes[3];
+};
+
+static HRESULT ffb_handle_irp(struct irp *irp);
+
+static HRESULT ffb_req_dispatch(const union ffb_req_any *req);
+static HRESULT ffb_req_toggle(const uint8_t *bytes);
+static HRESULT ffb_req_constant_force(const uint8_t *bytes);
+static HRESULT ffb_req_rumble(const uint8_t *bytes);
+static HRESULT ffb_req_damper(const uint8_t *bytes);
+
+static const struct ffb_ops *ffb_ops;
+static struct uart ffb_uart;
+
+static bool ffb_started;
+static HRESULT ffb_start_hr;
+static uint8_t ffb_written[4];
+static uint8_t ffb_readable[4];
+
+/* Static variables to store maximum strength values */
+static uint8_t max_constant_force = 0;
+static uint8_t max_rumble = 0;
+static uint8_t max_period = 0;
+static uint8_t max_damper = 0;
+
+HRESULT ffb_hook_init(
+        const struct ffb_config *cfg,
+        const struct ffb_ops *ops,
+        unsigned int port_no)
+{
+    assert(cfg != NULL);
+    assert(ops != NULL);
+
+    if (!cfg->enable) {
+        return S_FALSE;
+    }
+
+    ffb_ops = ops;
+
+    uart_init(&ffb_uart, port_no);
+    ffb_uart.written.bytes = ffb_written;
+    ffb_uart.written.nbytes = sizeof(ffb_written);
+    ffb_uart.readable.bytes = ffb_readable;
+    ffb_uart.readable.nbytes = sizeof(ffb_readable);
+
+    dprintf("FFB: hook enabled.\n");
+
+    return iohook_push_handler(ffb_handle_irp);
+}
+
+static HRESULT ffb_handle_irp(struct irp *irp)
+{
+    HRESULT hr;
+
+    assert(irp != NULL);
+
+    if (!uart_match_irp(&ffb_uart, irp)) {
+        return iohook_invoke_next(irp);
+    }
+
+    hr = uart_handle_irp(&ffb_uart, irp);
+
+    if (FAILED(hr) || irp->op != IRP_OP_WRITE) {
+        return hr;
+    }
+
+    assert(&ffb_uart.written != NULL);
+    assert(ffb_uart.written.bytes != NULL || ffb_uart.written.nbytes == 0);
+    assert(ffb_uart.written.pos <= ffb_uart.written.nbytes);
+
+    // dprintf("FFB TX:\n");
+
+    hr = ffb_req_dispatch((const union ffb_req_any *) ffb_uart.written.bytes);
+
+    if (FAILED(hr)) {
+        dprintf("FFB: Processing error: %x\n", (int)hr);
+    }
+
+    // dump_iobuf(&ffb_uart.written);
+    ffb_uart.written.pos = 0;
+
+    return hr;
+}
+
+static HRESULT ffb_req_dispatch(const union ffb_req_any *req)
+{
+    switch (req->hdr.cmd) {
+    case FFB_CMD_TOGGLE:
+        return ffb_req_toggle(req->bytes);
+    case FFB_CMD_CONSTANT_FORCE:
+        return ffb_req_constant_force(req->bytes);
+    case FFB_CMD_RUMBLE:
+        return ffb_req_rumble(req->bytes);
+    case FFB_CMD_DAMPER:
+        return ffb_req_damper(req->bytes);
+    /* There are some test mode specfic commands which doesn't seem to be used in
+       game at all. The same is true for the initialization phase. */
+
+    default:
+        dprintf("FFB: Unhandled command %02x\n", req->hdr.cmd);
+
+        return S_OK;
+    }
+}
+
+static HRESULT ffb_req_toggle(const uint8_t *bytes)
+{
+    uint8_t activate = bytes[2];
+
+    if (activate == 0x01) {
+        dprintf("FFB: Activated\n");
+    } else {
+        dprintf("FFB: Deactivated\n");
+    }
+
+    if (ffb_ops->toggle != NULL) {
+        ffb_ops->toggle(activate == 0x01);
+    }
+
+    return S_OK;
+}
+
+static HRESULT ffb_req_constant_force(const uint8_t *bytes)
+{
+    // dprintf("FFB: Constant force\n");
+
+    uint8_t direction = bytes[1];
+    uint8_t force = bytes[2];
+
+    if (direction == 0x0) {
+        // Right
+        force = 128 - force;
+    }
+
+    // Update max strength if the current force is greater
+    if (force > max_constant_force) {
+        max_constant_force = force;
+    }
+
+    // dprintf("FFB: Constant Force Strength: %d (Max: %d)\n", force, max_constant_force);
+    if (ffb_ops->constant_force != NULL) {
+        ffb_ops->constant_force(direction, force);
+    }
+
+    return S_OK;
+}
+
+static HRESULT ffb_req_rumble(const uint8_t *bytes)
+{
+    // dprintf("FFB: Rumble\n");
+
+    uint8_t force = bytes[1];
+    uint8_t period = bytes[2];
+
+    // Update max strength if the current force is greater
+    if (force > max_rumble) {
+        max_rumble = force;
+    }
+
+    if (period > max_period) {
+        max_period = period;
+    }
+
+    // dprintf("FFB: Rumble Period: %d (Min %d, Max %d), Strength: %d (Max: %d)\n", period, min_period, max_period, force, max_rumble);
+    if (ffb_ops->rumble != NULL) {
+        ffb_ops->rumble(force, period);
+    }
+
+    return S_OK;
+}
+
+static HRESULT ffb_req_damper(const uint8_t *bytes)
+{
+    // dprintf("FFB: Damper\n");
+
+    uint8_t force = bytes[2];
+
+    // Update max strength if the current force is greater
+    if (force > max_damper) {
+        max_damper = force;
+    }
+
+    // dprintf("FFB: Damper Strength: %d (Max: %d)\n", force, max_damper);
+    if (ffb_ops->damper != NULL) {
+        ffb_ops->damper(force);
+    }
+
+    return S_OK;
+}

board/ffb.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <windows.h>
+#include <stdbool.h>
+
+struct ffb_config {
+    bool enable;
+};
+
+struct ffb_ops {
+    void (*toggle)(bool active);
+    void (*constant_force)(uint8_t direction, uint8_t force);
+    void (*rumble)(uint8_t force, uint8_t period);
+    void (*damper)(uint8_t force);
+};
+
+HRESULT ffb_hook_init(
+        const struct ffb_config *cfg,
+        const struct ffb_ops *ops,
+        unsigned int port_no);

board/meson.build

@@ -50,5 +50,7 @@ board_lib = static_library(
         'vfd-cmd.h',
         'vfd-frame.c',
         'vfd-frame.h',
+        'ffb.c',
+        'ffb.h'
     ],
 )

dist/idac/segatools.ini

@@ -75,6 +75,11 @@ dipsw3=0
 dipsw4=0
 dipsw5=0
 
+[ffb]
+; Enable force feedback (838-15069) board emulation. This is required for
+; both DirectInput and XInput steering wheel effects.
+enable=1
+
 ; -----------------------------------------------------------------------------
 ; LED settings
 ; -----------------------------------------------------------------------------
@@ -231,6 +236,21 @@ reverseAccelAxis=0
 reverseBrakeAxis=0
 
 ; Force feedback settings.
-; Strength of the force feedback spring effect in percent. Possible values
-; are 0-100.
-centerSpringStrength=30
+; Only works when FFB board emulation is enabled!
+;
+; It is recommended to change the strength inside the Game Test Mode!
+;
+; These settings are only used when using DirectInput for the wheel.
+; The values are in the range 0%-100%, where 0 disables the effect and
+; 100 is the maximum.
+
+; Constant force strength, used for centering spring effect.
+constantForceStrength=100
+; Damper strength, used for steering wheel damper effect.
+damperStrength=100
+
+; Rumble strength, used for road surface effects.
+; WARNING: THIS WILL CRASH ON FANATEC (maybe even more) WHEELS!
+rumbleStrength=100
+; Rumble duration factor from ms to µs, used to scale the duration of the rumble effect.
+rumbleDuration=1000

hooklib/printer.c

@@ -82,7 +82,7 @@ int WINAPI fwdlusb_getErrorLog(uint16_t index, uint8_t *rData, uint16_t *rResult
 
 int WINAPI chcusb_MakeThread(uint16_t maxCount);
 int WINAPI chcusb_open(uint16_t *rResult);
-__stdcall void chcusb_close();
+void WINAPI chcusb_close();
 int WINAPI chcusb_ReleaseThread(uint16_t *rResult);
 int WINAPI chcusb_listupPrinter(uint8_t *rIdArray);
 int WINAPI chcusb_listupPrinterSN(uint64_t *rSerialArray);

idachook/config.c

@@ -89,6 +89,7 @@ void idac_hook_config_load(
     zinput_config_load(&cfg->zinput, filename);
     dvd_config_load(&cfg->dvd, filename);
     io4_config_load(&cfg->io4, filename);
+    ffb_config_load(&cfg->ffb, filename);
     led15070_config_load(&cfg->led15070, filename);
     indrun_config_load(&cfg->indrun, filename);
 }

idachook/config.h

@@ -19,6 +19,7 @@ struct idac_hook_config {
     struct aime_config aime;
     struct dvd_config dvd;
     struct io4_config io4;
+    struct ffb_config ffb;
     struct idac_dll_config dll;
     struct zinput_config zinput;
     struct led15070_config led15070;

idachook/dllmain.c

@@ -28,6 +28,7 @@
 #include "idachook/config.h"
 #include "idachook/idac-dll.h"
 #include "idachook/io4.h"
+#include "idachook/ffb.h"
 #include "idachook/zinput.h"
 
 #include "platform/platform.h"
@@ -84,6 +85,12 @@ static DWORD CALLBACK idac_pre_startup(void)
         goto fail;
     }
 
+    hr = idac_ffb_hook_init(&idac_hook_cfg.ffb, 1);
+
+    if (FAILED(hr)) {
+        goto fail;
+    }
+
     hr = led15070_hook_init(&idac_hook_cfg.led15070, idac_dll.led_init, 
         idac_dll.led_set_fet_output, NULL, idac_dll.led_gs_update, 2, 1);
 

idachook/ffb.c

@@ -0,0 +1,59 @@
+#include <windows.h>
+
+#include <xinput.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "board/ffb.h"
+
+#include "idachook/idac-dll.h"
+
+#include "util/dprintf.h"
+
+static void idac_ffb_toggle(bool active);
+static void idac_ffb_constant_force(uint8_t direction, uint8_t force);
+static void idac_ffb_rumble(uint8_t force, uint8_t period);
+static void idac_ffb_damper(uint8_t force);
+
+static const struct ffb_ops idac_ffb_ops = {
+    .toggle         = idac_ffb_toggle,
+    .constant_force = idac_ffb_constant_force,
+    .rumble         = idac_ffb_rumble,
+    .damper         = idac_ffb_damper
+};
+
+HRESULT idac_ffb_hook_init(const struct ffb_config *cfg, unsigned int port_no)
+{
+    HRESULT hr;
+
+    assert(idac_dll.init != NULL);
+
+    hr = ffb_hook_init(cfg, &idac_ffb_ops, port_no);
+
+    if (FAILED(hr)) {
+        return hr;
+    }
+
+    return idac_dll.ffb_init();
+}
+
+static void idac_ffb_toggle(bool active)
+{
+    idac_dll.ffb_toggle(active);
+}
+
+static void idac_ffb_constant_force(uint8_t direction, uint8_t force)
+{
+    idac_dll.ffb_constant_force(direction, force);
+}
+
+static void idac_ffb_rumble(uint8_t force, uint8_t period)
+{
+    idac_dll.ffb_rumble(force, period);
+}
+
+static void idac_ffb_damper(uint8_t force)
+{
+    idac_dll.ffb_damper(force);
+}

idachook/ffb.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <windows.h>
+
+#include "board/ffb.h"
+
+HRESULT idac_ffb_hook_init(const struct ffb_config *cfg, unsigned int port_no);

idachook/idac-dll.c

@@ -36,7 +36,22 @@ const struct dll_bind_sym idac_dll_syms[] = {
     }, {
         .sym = "idac_io_led_set_leds",
         .off = offsetof(struct idac_dll, led_set_leds),
-    }
+    }, {
+        .sym = "idac_io_ffb_init",
+        .off = offsetof(struct idac_dll, ffb_init),
+    }, {
+        .sym = "idac_io_ffb_toggle",
+        .off = offsetof(struct idac_dll, ffb_toggle),
+    }, {
+        .sym = "idac_io_ffb_constant_force",
+        .off = offsetof(struct idac_dll, ffb_constant_force),
+    }, {
+        .sym = "idac_io_ffb_rumble",
+        .off = offsetof(struct idac_dll, ffb_rumble),
+    }, {
+        .sym = "idac_io_ffb_damper",
+        .off = offsetof(struct idac_dll, ffb_damper),
+    },
 };
 
 struct idac_dll idac_dll;

idachook/idac-dll.h

@@ -15,6 +15,11 @@ struct idac_dll {
     void (*led_set_fet_output)(const uint8_t *rgb);
     void (*led_gs_update)(const uint8_t *rgb);
     void (*led_set_leds)(const uint8_t *rgb);
+    HRESULT (*ffb_init)(void);
+    void (*ffb_toggle)(bool active);
+    void (*ffb_constant_force)(uint8_t direction, uint8_t force);
+    void (*ffb_rumble)(uint8_t period, uint8_t force);
+    void (*ffb_damper)(uint8_t force);
 };
 
 struct idac_dll_config {

idachook/idachook.def

@@ -21,3 +21,8 @@ EXPORTS
     idac_io_led_set_fet_output
     idac_io_led_gs_update
     idac_io_led_set_leds
+    idac_io_ffb_init
+    idac_io_ffb_toggle
+    idac_io_ffb_constant_force
+    idac_io_ffb_rumble
+    idac_io_ffb_damper

idachook/meson.build

@@ -30,5 +30,7 @@ shared_library(
         'zinput.h',
         'indrun.c',
         'indrun.h',
+        'ffb.c',
+        'ffb.h',
     ],
 )

idacio/backend.h

@@ -9,4 +9,9 @@ struct idac_io_backend {
     void (*get_gamebtns)(uint8_t *gamebtn);
     void (*get_shifter)(uint8_t *gear);
     void (*get_analogs)(struct idac_io_analog_state *state);
+    HRESULT (*ffb_init)(void);
+    void (*ffb_toggle)(bool active);
+    void (*ffb_constant_force)(uint8_t direction, uint8_t force);
+    void (*ffb_rumble)(uint8_t period, uint8_t force);
+    void (*ffb_damper)(uint8_t force);
 };

idacio/config.c

@@ -80,13 +80,29 @@ void idac_di_config_load(struct idac_di_config *cfg, const wchar_t *filename)
     }
 
     // FFB configuration
+    cfg->ffb_constant_force_strength = GetPrivateProfileIntW(
+            L"dinput",
+            L"constantForceStrength",
+            100,
+            filename);
 
-    cfg->center_spring_strength = GetPrivateProfileIntW(
-                            L"dinput",
-                            L"centerSpringStrength",
-                            30,
-                            filename);
+    cfg->ffb_rumble_strength = GetPrivateProfileIntW(
+            L"dinput",
+            L"rumbleStrength",
+            100,
+            filename);
 
+    cfg->ffb_damper_strength = GetPrivateProfileIntW(
+            L"dinput",
+            L"damperStrength",
+            100,
+            filename);
+
+    cfg->ffb_rumble_duration = GetPrivateProfileIntW(
+            L"dinput",
+            L"rumbleDuration",
+            1000,
+            filename);
 }
 
 void idac_xi_config_load(struct idac_xi_config *cfg, const wchar_t *filename)

idacio/config.h

@@ -25,7 +25,11 @@ struct idac_di_config {
     bool reverse_accel_axis;
 
     // FFB configuration
-    uint16_t center_spring_strength;
+    uint8_t ffb_constant_force_strength;
+    uint8_t ffb_rumble_strength;
+    uint8_t ffb_damper_strength;
+
+    uint32_t ffb_rumble_duration;
 };
 
 struct idac_xi_config {

idacio/di-dev.c

@@ -1,134 +1,39 @@
 #include <windows.h>
 #include <dinput.h>
-
+#include <stdbool.h>
 #include <assert.h>
 
 #include "idacio/di-dev.h"
 
 #include "util/dprintf.h"
 
-HRESULT idac_di_dev_start(IDirectInputDevice8W *dev, HWND wnd)
+const struct idac_di_config *idac_di_cfg;
+static HWND idac_di_wnd;
+static IDirectInputDevice8W *idac_di_dev;
+
+/* Individual DI Effects */
+static IDirectInputEffect *idac_di_fx;
+static IDirectInputEffect *idac_di_fx_rumble;
+static IDirectInputEffect *idac_di_fx_damper;
+
+/* Max FFB Board value is 127 */
+static const double idac_di_ffb_scale = 127.0;
+
+HRESULT idac_di_dev_init(
+    const struct idac_di_config *cfg,
+    IDirectInputDevice8W *dev,
+    HWND wnd)
 {
     HRESULT hr;
 
     assert(dev != NULL);
     assert(wnd != NULL);
 
-    hr = IDirectInputDevice8_SetCooperativeLevel(
-            dev,
-            wnd,
-            DISCL_BACKGROUND | DISCL_EXCLUSIVE);
+    idac_di_cfg = cfg;
+    idac_di_dev = dev;
+    idac_di_wnd = wnd;
 
-    if (FAILED(hr)) {
-        dprintf("DirectInput: SetCooperativeLevel failed: %08x\n", (int) hr);
-
-        return hr;
-    }
-
-    hr = IDirectInputDevice8_SetDataFormat(dev, &c_dfDIJoystick);
-
-    if (FAILED(hr)) {
-        dprintf("DirectInput: SetDataFormat failed: %08x\n", (int) hr);
-
-        return hr;
-    }
-
-    hr = IDirectInputDevice8_Acquire(dev);
-
-    if (FAILED(hr)) {
-        dprintf("DirectInput: Acquire failed: %08x\n", (int) hr);
-
-        return hr;
-    }
-
-    return hr;
-}
-
-void idac_di_dev_start_fx(
-    IDirectInputDevice8W *dev, IDirectInputEffect **out, uint16_t strength)
-{
-    /* Set up force-feedback on devices that support it. This is just a stub
-       for the time being, since we don't yet know how the serial port force
-       feedback protocol works.
-
-       I'm currently developing with an Xbox One Thrustmaster TMX wheel, if
-       we don't perform at least some perfunctory FFB initialization of this
-       nature (or indeed if no DirectInput application is running) then the
-       wheel exhibits considerable resistance, similar to that of a stationary
-       car. Changing cf.lMagnitude to a nonzero value does cause the wheel to
-       continuously turn in the given direction with the given force as one
-       would expect (max magnitude per DirectInput docs is +/- 10000).
-
-       Failure here is non-fatal, we log any errors and move on.
-
-       https://docs.microsoft.com/en-us/previous-versions/windows/desktop/ee416353(v=vs.85)
-    */
-
-    IDirectInputEffect *obj;
-    DWORD axis;
-    LONG direction;
-    DIEFFECT fx;
-    DICONDITION cond;
-    HRESULT hr;
-
-    assert(dev != NULL);
-    assert(out != NULL);
-
-    *out = NULL;
-
-    dprintf("DirectInput: Starting force feedback (may take a sec)\n");
-
-    // Auto-centering effect
-    axis = DIJOFS_X;
-    direction = 0;
-
-    memset(&cond, 0, sizeof(cond));
-    cond.lOffset = 0;
-    cond.lPositiveCoefficient = strength;
-    cond.lNegativeCoefficient = strength;
-    cond.dwPositiveSaturation = strength; // For FG920?
-    cond.dwNegativeSaturation = strength; // For FG920?
-    cond.lDeadBand = 0;
-
-    memset(&fx, 0, sizeof(fx));
-    fx.dwSize = sizeof(fx);
-    fx.dwFlags = DIEFF_CARTESIAN | DIEFF_OBJECTOFFSETS;
-    fx.dwDuration = INFINITE;
-    fx.dwGain = DI_FFNOMINALMAX;
-    fx.dwTriggerButton = DIEB_NOTRIGGER;
-    fx.dwTriggerRepeatInterval = INFINITE;
-    fx.cAxes = 1;
-    fx.rgdwAxes = &axis;
-    fx.rglDirection = &direction;
-    fx.cbTypeSpecificParams = sizeof(cond);
-    fx.lpvTypeSpecificParams = &cond;
-
-    hr = IDirectInputDevice8_CreateEffect(
-            dev,
-            &GUID_Spring,
-            &fx,
-            &obj,
-            NULL);
-
-    if (FAILED(hr)) {
-        dprintf("DirectInput: Centering spring force feedback unavailable: %08x\n",
-                (int) hr);
-        return;
-    }
-
-    hr = IDirectInputEffect_Start(obj, INFINITE, 0);
-
-    if (FAILED(hr)) {
-        IDirectInputEffect_Release(obj);
-        dprintf("DirectInput: Centering spring force feedback start failed: %08x\n",
-                (int) hr);
-        return;
-    }
-
-    *out = obj;
-
-    dprintf("DirectInput: Centering spring effects initialized with strength %d%%\n", 
-            strength / 100);
+    return S_OK;
 }
 
 HRESULT idac_di_dev_poll(
@@ -167,3 +72,312 @@ HRESULT idac_di_dev_poll(
 
     return hr;
 }
+
+HRESULT idac_di_dev_start(IDirectInputDevice8W *dev, HWND wnd) {
+    HRESULT hr;
+
+    assert(dev != NULL);
+    assert(wnd != NULL);
+
+    hr = IDirectInputDevice8_SetCooperativeLevel(
+            dev,
+            wnd,
+            DISCL_BACKGROUND | DISCL_EXCLUSIVE);
+
+    if (FAILED(hr)) {
+        dprintf("DirectInput: SetCooperativeLevel failed: %08x\n", (int) hr);
+
+        return hr;
+    }
+
+    hr = IDirectInputDevice8_SetDataFormat(dev, &c_dfDIJoystick);
+
+    if (FAILED(hr)) {
+        dprintf("DirectInput: SetDataFormat failed: %08x\n", (int) hr);
+
+        return hr;
+    }
+
+    hr = IDirectInputDevice8_Acquire(dev);
+
+    if (FAILED(hr)) {
+        dprintf("DirectInput: Acquire failed: %08x\n", (int) hr);
+
+        return hr;
+    }
+
+    return hr;
+}
+
+HRESULT idac_di_ffb_init(void)
+{
+    HRESULT hr;
+
+    hr = idac_di_dev_start(idac_di_dev, idac_di_wnd);
+
+    if (FAILED(hr)) {
+        return hr;
+    }
+
+    return S_OK;
+}
+
+void idac_di_ffb_toggle(bool active)
+{
+    if (active) {
+        return;
+    }
+
+    /* Stop and release all effects */
+    /* I never programmed DirectInput Effects, so this might be bad practice. */
+    if (idac_di_fx != NULL) {
+        IDirectInputEffect_Stop(idac_di_fx);
+        IDirectInputEffect_Release(idac_di_fx);
+        idac_di_fx = NULL;
+    }
+
+    if (idac_di_fx_rumble != NULL) {
+        IDirectInputEffect_Stop(idac_di_fx_rumble);
+        IDirectInputEffect_Release(idac_di_fx_rumble);
+        idac_di_fx_rumble = NULL;
+    }
+
+    if (idac_di_fx_damper != NULL) {
+        IDirectInputEffect_Stop(idac_di_fx_damper);
+        IDirectInputEffect_Release(idac_di_fx_damper);
+        idac_di_fx_damper = NULL;
+    }
+}
+
+void idac_di_ffb_constant_force(uint8_t direction_ffb, uint8_t force)
+{
+    /* DI expects a magnitude in the range of -10.000 to 10.000 */
+    uint16_t ffb_strength = idac_di_cfg->ffb_constant_force_strength * 100;
+    if (ffb_strength == 0) {
+        return;
+    }
+
+    DWORD axis;
+    LONG direction;
+    DIEFFECT fx;
+    DICONSTANTFORCE cf;
+    HRESULT hr;
+
+    /* Direction 0: move to the right, 1: move to the left */
+    LONG magnitude = (LONG)(((double)force / idac_di_ffb_scale) * ffb_strength);
+    cf.lMagnitude = (direction_ffb == 0) ? -magnitude : magnitude;
+
+    axis = DIJOFS_X;
+    /* Irrelevant as magnitude descripbes the direction */
+    direction = 0;
+
+    memset(&fx, 0, sizeof(fx));
+    fx.dwSize = sizeof(fx);
+    fx.dwFlags = DIEFF_CARTESIAN | DIEFF_OBJECTOFFSETS;
+    fx.dwDuration = INFINITE;
+    fx.dwGain = DI_FFNOMINALMAX;
+    fx.dwTriggerButton = DIEB_NOTRIGGER;
+    fx.dwTriggerRepeatInterval = INFINITE;
+    fx.cAxes = 1;
+    fx.rgdwAxes = &axis;
+    fx.rglDirection = &direction;
+    fx.cbTypeSpecificParams = sizeof(cf);
+    fx.lpvTypeSpecificParams = &cf;
+
+    if (idac_di_fx != NULL) {
+        // Try to update the existing effect
+        hr = IDirectInputEffect_SetParameters(idac_di_fx, &fx, DIEP_TYPESPECIFICPARAMS);
+        
+        if (SUCCEEDED(hr)) {
+            return;
+        } else {
+            dprintf("DirectInput: Failed to update constant force feedback, recreating effect: %08x\n", (int)hr);
+            // Stop and release the current effect if updating fails
+            IDirectInputEffect_Stop(idac_di_fx);
+            IDirectInputEffect_Release(idac_di_fx);
+            idac_di_fx = NULL;
+        }
+    }
+
+    // Create a new constant force effect
+    IDirectInputEffect *obj;
+    hr = IDirectInputDevice8_CreateEffect(
+            idac_di_dev,
+            &GUID_ConstantForce,
+            &fx,
+            &obj,
+            NULL);
+
+    if (FAILED(hr)) {
+        dprintf("DirectInput: Constant force feedback creation failed: %08x\n", (int) hr);
+        return;
+    }
+
+    hr = IDirectInputEffect_Start(obj, INFINITE, 0);
+    if (FAILED(hr)) {
+        dprintf("DirectInput: Constant force feedback start failed: %08x\n", (int) hr);
+        IDirectInputEffect_Release(obj);
+        return;
+    }
+
+    idac_di_fx = obj;
+}
+
+void idac_di_ffb_rumble(uint8_t force, uint8_t period)
+{
+    /* DI expects a magnitude in the range of -10.000 to 10.000 */
+    uint16_t ffb_strength = idac_di_cfg->ffb_rumble_strength * 100;
+    if (ffb_strength == 0) {
+        return;
+    }
+
+    uint32_t ffb_duration = idac_di_cfg->ffb_rumble_duration;
+
+    DWORD axis;
+    LONG direction;
+    DIEFFECT fx;
+    DIPERIODIC pe;
+    HRESULT hr;
+
+    /* Duration in microseconds,
+       Might be totally wrong as especially on FANATEC wheels as this code will
+       crash the game. TODO: Figure out why this effect will crash on FANATEC! */
+    DWORD duration = (DWORD)((double)force * ffb_duration);
+
+    memset(&pe, 0, sizeof(pe));
+    pe.dwMagnitude = (DWORD)(((double)force / idac_di_ffb_scale) * ffb_strength);
+    pe.lOffset = 0;
+    pe.dwPhase = 0;
+    pe.dwPeriod = duration;
+
+    axis = DIJOFS_X;
+    direction = 0;
+
+    memset(&fx, 0, sizeof(fx));
+    fx.dwSize = sizeof(fx);
+    fx.dwFlags = DIEFF_CARTESIAN | DIEFF_OBJECTOFFSETS;
+    fx.dwDuration = duration;
+    fx.dwGain = DI_FFNOMINALMAX;
+    fx.dwTriggerButton = DIEB_NOTRIGGER;
+    fx.dwTriggerRepeatInterval = INFINITE;
+    fx.cAxes = 1;
+    fx.rgdwAxes = &axis;
+    fx.rglDirection = &direction;
+    fx.cbTypeSpecificParams = sizeof(pe);
+    fx.lpvTypeSpecificParams = &pe;
+
+    if (idac_di_fx_rumble != NULL) {
+        // Try to update the existing effect
+        hr = IDirectInputEffect_SetParameters(idac_di_fx_rumble, &fx, DIEP_TYPESPECIFICPARAMS);
+        
+        if (SUCCEEDED(hr)) {
+            return;
+        } else {
+            dprintf("DirectInput: Failed to update periodic force feedback, recreating effect: %08x\n", (int)hr);
+            // Stop and release the current effect if updating fails
+            IDirectInputEffect_Stop(idac_di_fx_rumble);
+            IDirectInputEffect_Release(idac_di_fx_rumble);
+            idac_di_fx_rumble = NULL;
+        }
+    }
+
+    IDirectInputEffect *obj;
+    hr = IDirectInputDevice8_CreateEffect(
+            idac_di_dev,
+            &GUID_Sine,
+            &fx,
+            &obj,
+            NULL);
+
+    if (FAILED(hr)) {
+        dprintf("DirectInput: Periodic force feedback creation failed: %08x\n", (int) hr);
+        return;
+    }
+
+    hr = IDirectInputEffect_Start(obj, INFINITE, 0);
+    if (FAILED(hr)) {
+        dprintf("DirectInput: Periodic force feedback start failed: %08x\n", (int) hr);
+        IDirectInputEffect_Release(obj);
+        return;
+    }
+
+    idac_di_fx_rumble = obj;
+}
+
+void idac_di_ffb_damper(uint8_t force)
+{
+    /* DI expects a coefficient in the range of -10.000 to 10.000 */
+    uint16_t ffb_strength = idac_di_cfg->ffb_damper_strength * 100;
+    if (ffb_strength == 0) {
+        return;
+    }
+
+    DWORD axis;
+    LONG direction;
+    DIEFFECT fx;
+    DICONDITION cond;
+    HRESULT hr;
+
+    memset(&cond, 0, sizeof(cond));
+    cond.lOffset = 0;
+    cond.lPositiveCoefficient = (LONG)(((double)force / idac_di_ffb_scale) * ffb_strength);
+    cond.lNegativeCoefficient = (LONG)(((double)force / idac_di_ffb_scale) * ffb_strength);
+    /* Not sure on this one */
+    cond.dwPositiveSaturation = DI_FFNOMINALMAX;
+    cond.dwNegativeSaturation = DI_FFNOMINALMAX;
+    cond.lDeadBand = 0;
+
+    axis = DIJOFS_X;
+    direction = 0;
+
+    memset(&fx, 0, sizeof(fx));
+    fx.dwSize = sizeof(fx);
+    fx.dwFlags = DIEFF_CARTESIAN | DIEFF_OBJECTOFFSETS;
+    fx.dwDuration = INFINITE;
+    fx.dwGain = DI_FFNOMINALMAX;
+    fx.dwTriggerButton = DIEB_NOTRIGGER;
+    fx.dwTriggerRepeatInterval = INFINITE;
+    fx.cAxes = 1;
+    fx.rgdwAxes = &axis;
+    fx.rglDirection = &direction;
+    fx.cbTypeSpecificParams = sizeof(cond);
+    fx.lpvTypeSpecificParams = &cond;
+
+    if (idac_di_fx_damper != NULL) {
+        // Try to update the existing effect
+        hr = IDirectInputEffect_SetParameters(idac_di_fx_damper, &fx, DIEP_TYPESPECIFICPARAMS);
+        
+        if (SUCCEEDED(hr)) {
+            return;
+        } else {
+            dprintf("DirectInput: Failed to update damper force feedback, recreating effect: %08x\n", (int)hr);
+            // Stop and release the current effect if updating fails
+            IDirectInputEffect_Stop(idac_di_fx_damper);
+            IDirectInputEffect_Release(idac_di_fx_damper);
+            idac_di_fx_damper = NULL;
+        }
+    }
+
+    // Create a new damper force effect
+    IDirectInputEffect *obj;
+    hr = IDirectInputDevice8_CreateEffect(
+            idac_di_dev,
+            &GUID_Damper,
+            &fx,
+            &obj,
+            NULL);
+
+    if (FAILED(hr)) {
+        dprintf("DirectInput: Damper force feedback creation failed: %08x\n", (int) hr);
+        return;
+    }
+
+    hr = IDirectInputEffect_Start(obj, INFINITE, 0);
+    if (FAILED(hr)) {
+        dprintf("DirectInput: Damper force feedback start failed: %08x\n", (int) hr);
+        IDirectInputEffect_Release(obj);
+        return;
+    }
+
+    idac_di_fx_damper = obj;
+}

idacio/di-dev.h

@@ -5,15 +5,26 @@
 
 #include <stdint.h>
 
+#include "idacio/config.h"
+
 union idac_di_state {
     DIJOYSTATE st;
     uint8_t bytes[sizeof(DIJOYSTATE)];
 };
 
+HRESULT idac_di_dev_init(
+    const struct idac_di_config *cfg,
+    IDirectInputDevice8W *dev,
+    HWND wnd);
+
 HRESULT idac_di_dev_start(IDirectInputDevice8W *dev, HWND wnd);
-void idac_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out, uint16_t strength);
 HRESULT idac_di_dev_poll(
         IDirectInputDevice8W *dev,
         HWND wnd,
         union idac_di_state *out);
 
+HRESULT idac_di_ffb_init(void);
+void idac_di_ffb_toggle(bool active);
+void idac_di_ffb_constant_force(uint8_t direction, uint8_t force);
+void idac_di_ffb_rumble(uint8_t force, uint8_t period);
+void idac_di_ffb_damper(uint8_t force);

idacio/di.c

@@ -52,9 +52,14 @@ static const struct idac_di_axis idac_di_axes[] = {
 };
 
 static const struct idac_io_backend idac_di_backend = {
-    .get_gamebtns   = idac_di_get_buttons,
-    .get_shifter   = idac_di_get_shifter,
-    .get_analogs   = idac_di_get_analogs,
+    .get_gamebtns       = idac_di_get_buttons,
+    .get_shifter        = idac_di_get_shifter,
+    .get_analogs        = idac_di_get_analogs,
+    .ffb_init           = idac_di_ffb_init,
+    .ffb_toggle         = idac_di_ffb_toggle,
+    .ffb_constant_force = idac_di_ffb_constant_force,
+    .ffb_rumble         = idac_di_ffb_rumble,
+    .ffb_damper         = idac_di_ffb_damper
 };
 
 static HWND idac_di_wnd;
@@ -62,7 +67,6 @@ static IDirectInput8W *idac_di_api;
 static IDirectInputDevice8W *idac_di_dev;
 static IDirectInputDevice8W *idac_di_pedals;
 static IDirectInputDevice8W *idac_di_shifter;
-static IDirectInputEffect *idac_di_fx;
 static size_t idac_di_off_brake;
 static size_t idac_di_off_accel;
 static uint8_t idac_di_shift_dn;
@@ -105,7 +109,7 @@ HRESULT idac_di_init(
         return hr;
     }
 
-    /* Initial D Zero has some built-in DirectInput support that is not
+    /* Initial D THE ARCADE has some built-in DirectInput support that is not
        particularly useful. idachook shorts this out by redirecting dinput8.dll
        to a no-op implementation of DirectInput. However, idacio does need to
        talk to the real operating system implementation of DirectInput without
@@ -168,16 +172,12 @@ HRESULT idac_di_init(
         return HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND);
     }
 
-    hr = idac_di_dev_start(idac_di_dev, idac_di_wnd);
+    hr = idac_di_dev_init(cfg, idac_di_dev, idac_di_wnd);
 
     if (FAILED(hr)) {
         return hr;
     }
 
-    // Convert the strength from 0-100 to 0-10000 for DirectInput
-    idac_di_dev_start_fx(idac_di_dev, &idac_di_fx, 
-                         idac_di_center_spring_strength * 100);
-
     if (cfg->pedals_name[0] != L'\0') {
         hr = IDirectInput8_EnumDevices(
                 idac_di_api,
@@ -367,15 +367,24 @@ static HRESULT idac_di_config_apply(const struct idac_di_config *cfg)
         idac_di_gear[i] = cfg->gear[i];
     }
 
-    // FFB configuration
+    /* FFB configuration */
+    if (cfg->ffb_constant_force_strength < 0 || cfg->ffb_constant_force_strength > 100) {
+        dprintf("Wheel: Invalid constant force strength: %i\n", cfg->ffb_constant_force_strength);
 
-    if (cfg->center_spring_strength < 0 || cfg->center_spring_strength > 100) {
-        dprintf("Wheel: Invalid center spring strength: %i\n", cfg->center_spring_strength);
+        return E_INVALIDARG;
+    }
+    
+    if (cfg->ffb_rumble_strength < 0 || cfg->ffb_rumble_strength > 100) {
+        dprintf("Wheel: Invalid rumble strength: %i\n", cfg->ffb_rumble_strength);
 
         return E_INVALIDARG;
     }
 
-    idac_di_center_spring_strength = cfg->center_spring_strength;
+    if (cfg->ffb_damper_strength < 0 || cfg->ffb_damper_strength > 100) {
+        dprintf("Wheel: Invalid damper strength: %i\n", cfg->ffb_damper_strength);
+
+        return E_INVALIDARG;
+    }
 
     return S_OK;
 }

idacio/dllmain.c

@@ -19,7 +19,7 @@ static bool idac_io_coin;
 
 uint16_t idac_io_get_api_version(void)
 {
-    return 0x0101;
+    return 0x0102;
 }
 
 HRESULT idac_io_init(void)
@@ -62,6 +62,8 @@ void idac_io_get_opbtns(uint8_t *opbtn_out)
 
     opbtn = 0;
 
+    /* Common operator buttons, not backend-specific */
+
     if (GetAsyncKeyState(idac_io_cfg.vk_test) & 0x8000) {
         opbtn |= IDAC_IO_OPBTN_TEST;
     }
@@ -159,3 +161,38 @@ void idac_io_led_set_leds(const uint8_t *rgb)
 
     return;
 }
+
+HRESULT idac_io_ffb_init(void)
+{
+    assert(idac_io_backend != NULL);
+
+    return idac_io_backend->ffb_init();
+}
+
+void idac_io_ffb_toggle(bool active)
+{
+    assert(idac_io_backend != NULL);
+    
+    idac_io_backend->ffb_toggle(active);
+}
+
+void idac_io_ffb_constant_force(uint8_t direction, uint8_t force)
+{
+    assert(idac_io_backend != NULL);
+    
+    idac_io_backend->ffb_constant_force(direction, force);
+}
+
+void idac_io_ffb_rumble(uint8_t period, uint8_t force)
+{
+    assert(idac_io_backend != NULL);
+    
+    idac_io_backend->ffb_rumble(period, force);
+}
+
+void idac_io_ffb_damper(uint8_t force)
+{
+    assert(idac_io_backend != NULL);
+    
+    idac_io_backend->ffb_damper(force);
+}

idacio/idacio.def

@@ -10,3 +10,8 @@ EXPORTS
     idac_io_led_set_fet_output
     idac_io_led_gs_update
     idac_io_led_set_leds
+    idac_io_ffb_init
+    idac_io_ffb_toggle
+    idac_io_ffb_constant_force
+    idac_io_ffb_rumble
+    idac_io_ffb_damper

idacio/idacio.h

@@ -2,6 +2,7 @@
 
 #include <windows.h>
 
+#include <stdbool.h>
 #include <stdint.h>
 
 enum {
@@ -160,3 +161,51 @@ void idac_io_led_gs_update(const uint8_t *rgb);
    Minimum API version: 0x0101 */
 
 void idac_io_led_set_leds(const uint8_t *rgb);
+
+/* Initialize FFB emulation. This function will be called before any
+   other idac_io_ffb_*() function calls.
+
+   This will always be called even if FFB board emulation is disabled to allow
+   the IO DLL to initialize any necessary resources.
+
+   Minimum API version: 0x0102 */
+
+HRESULT idac_io_ffb_init(void);
+
+/* Toggle FFB emulation. If active is true, FFB emulation should be enabled.
+   If active is false, FFB emulation should be disabled and all FFB effects
+   should be stopped and released.
+
+   Minimum API version: 0x0102 */
+
+void idac_io_ffb_toggle(bool active);
+
+/* Set a constant force FFB effect.
+   
+   Direction is 0 for right and 1 for left.
+   Force is the magnitude of the force, where 0 is no force and 127 is the
+   maximum force in a given direction.
+
+   Minimum API version: 0x0102 */
+
+void idac_io_ffb_constant_force(uint8_t direction, uint8_t force);
+
+/* Set a (sine) periodic force FFB effect.
+   
+   Period is the period of the effect in milliseconds (not sure).
+   Force is the magnitude of the force, where 0 is no force and 127 is the
+   maximum force.
+
+   Minimum API version: 0x0102 */
+
+void idac_io_ffb_rumble(uint8_t period, uint8_t force);
+
+/* Set a damper FFB effect.
+   
+   Force is the magnitude of the force, where 0 is no force and 40 is the
+   maximum force. Theoretically the maximum force is 127, but the game only
+   uses a maximum of 40.
+
+   Minimum API version: 0x0102 */
+
+void idac_io_ffb_damper(uint8_t force);

idacio/xi.c

@@ -1,5 +1,3 @@
-#include "idacio/xi.h"
-
 #include <assert.h>
 #include <math.h>
 #include <stdbool.h>
@@ -7,22 +5,35 @@
 #include <windows.h>
 #include <xinput.h>
 
+#include "idacio/xi.h"
 #include "idacio/backend.h"
 #include "idacio/config.h"
 #include "idacio/idacio.h"
 #include "idacio/shifter.h"
+
 #include "util/dprintf.h"
 
 static void idac_xi_get_gamebtns(uint8_t *gamebtn_out);
 static void idac_xi_get_shifter(uint8_t *gear);
 static void idac_xi_get_analogs(struct idac_io_analog_state *out);
 
+static HRESULT idac_xi_ffb_init(void);
+static void idac_xi_ffb_toggle(bool active);
+static void idac_xi_ffb_constant_force(uint8_t direction, uint8_t force);
+static void idac_xi_ffb_rumble(uint8_t force, uint8_t period);
+static void idac_xi_ffb_damper(uint8_t force);
+
 static HRESULT idac_xi_config_apply(const struct idac_xi_config *cfg);
 
 static const struct idac_io_backend idac_xi_backend = {
-    .get_gamebtns = idac_xi_get_gamebtns,
-    .get_shifter = idac_xi_get_shifter,
-    .get_analogs = idac_xi_get_analogs,
+    .get_gamebtns       = idac_xi_get_gamebtns,
+    .get_shifter        = idac_xi_get_shifter,
+    .get_analogs        = idac_xi_get_analogs,
+    .ffb_init           = idac_xi_ffb_init,
+    .ffb_toggle         = idac_xi_ffb_toggle,
+    .ffb_constant_force = idac_xi_ffb_constant_force,
+    .ffb_rumble         = idac_xi_ffb_rumble,
+    .ffb_damper         = idac_xi_ffb_damper
 };
 
 static bool idac_xi_single_stick_steering;
@@ -46,7 +57,7 @@ HRESULT idac_xi_init(const struct idac_xi_config *cfg, const struct idac_io_back
         return hr;
     }
 
-    dprintf("XInput: Using XInput controller\n");
+    dprintf("IDACIO: Using XInput controller\n");
     *backend = &idac_xi_backend;
 
     return S_OK;
@@ -205,3 +216,35 @@ static void idac_xi_get_analogs(struct idac_io_analog_state *out) {
     out->accel = xi.Gamepad.bRightTrigger << 8;
     out->brake = xi.Gamepad.bLeftTrigger << 8;
 }
+
+static HRESULT idac_xi_ffb_init(void) {
+    return S_OK;
+}
+
+static void idac_xi_ffb_toggle(bool active) {
+    XINPUT_VIBRATION vibration;
+
+    memset(&vibration, 0, sizeof(vibration));
+
+    XInputSetState(0, &vibration);
+}
+
+static void idac_xi_ffb_constant_force(uint8_t direction, uint8_t force) {
+    return;
+}
+
+static void idac_xi_ffb_rumble(uint8_t force, uint8_t period) {
+    XINPUT_VIBRATION vibration;
+    /* XInput max strength is 65.535, so multiply the 127.0 by 516. */
+    uint16_t strength = force * 516;
+
+    memset(&vibration, 0, sizeof(vibration));
+    vibration.wLeftMotorSpeed = strength;
+    vibration.wRightMotorSpeed = strength;
+
+    XInputSetState(0, &vibration);
+}
+
+static void idac_xi_ffb_damper(uint8_t force) {
+    return;
+}