diff --git a/app/meson.build b/app/meson.build index fc6b85e2..a4880420 100644 --- a/app/meson.build +++ b/app/meson.build @@ -32,6 +32,7 @@ src = [ 'src/screen.c', 'src/server.c', 'src/version.c', + 'src/hid/hid_gamepad.c', 'src/hid/hid_keyboard.c', 'src/hid/hid_mouse.c', 'src/trait/frame_source.c', diff --git a/app/src/hid/hid_event.h b/app/src/hid/hid_event.h index 9171004e..d6818e30 100644 --- a/app/src/hid/hid_event.h +++ b/app/src/hid/hid_event.h @@ -5,7 +5,7 @@ #include -#define SC_HID_MAX_SIZE 8 +#define SC_HID_MAX_SIZE 15 struct sc_hid_input { uint16_t hid_id; diff --git a/app/src/hid/hid_gamepad.c b/app/src/hid/hid_gamepad.c new file mode 100644 index 00000000..cd009d15 --- /dev/null +++ b/app/src/hid/hid_gamepad.c @@ -0,0 +1,451 @@ +#include "hid_gamepad.h" + +#include +#include + +#include "util/binary.h" +#include "util/log.h" + +// 2x2 bytes for left stick (X, Y) +// 2x2 bytes for right stick (Z, Rz) +// 2x2 bytes for L2/R2 triggers +// 2 bytes for buttons + padding, +// 1 byte for hat switch (dpad) + padding +#define SC_HID_GAMEPAD_EVENT_SIZE 15 + +// The ->buttons field stores the state for all buttons, but only some of them +// (the 16 LSB) must be transmitted "as is". The DPAD (hat switch) buttons are +// stored locally in the MSB of this field, but not transmitted as is: they are +// transformed to generate another specific byte. +#define SC_HID_BUTTONS_MASK 0xFFFF + +// outside SC_HID_BUTTONS_MASK +#define SC_GAMEPAD_BUTTONS_BIT_DPAD_UP UINT32_C(0x10000) +#define SC_GAMEPAD_BUTTONS_BIT_DPAD_DOWN UINT32_C(0x20000) +#define SC_GAMEPAD_BUTTONS_BIT_DPAD_LEFT UINT32_C(0x40000) +#define SC_GAMEPAD_BUTTONS_BIT_DPAD_RIGHT UINT32_C(0x80000) + +/** + * Gamepad descriptor manually crafted to transmit the input reports. + * + * The HID specification is available here: + * + * + * The HID Usage Tables is also useful: + * + */ +static const uint8_t SC_HID_GAMEPAD_REPORT_DESC[] = { + // Usage Page (Generic Desktop) + 0x05, 0x01, + // Usage (Gamepad) + 0x09, 0x05, + + // Collection (Application) + 0xA1, 0x01, + + // Collection (Physical) + 0xA1, 0x00, + + // Usage Page (Generic Desktop) + 0x05, 0x01, + // Usage (X) Left stick x + 0x09, 0x30, + // Usage (Y) Left stick y + 0x09, 0x31, + // Usage (Z) Right stick x + 0x09, 0x32, + // Usage (Rz) Right stick y + 0x09, 0x35, + // Logical Minimum (0) + 0x15, 0x00, + // Logical Maximum (65535) + // Cannot use 26 FF FF because 0xFFFF is interpreted as signed 16-bit + 0x27, 0xFF, 0xFF, 0x00, 0x00, // little-endian + // Report Size (16) + 0x75, 0x10, + // Report Count (4) + 0x95, 0x04, + // Input (Data, Variable, Absolute): 4 bytes (X, Y, Z, Rz) + 0x81, 0x02, + + // Usage Page (Simulation Controls) + 0x05, 0x02, + // Usage (Brake) + 0x09, 0xC5, + // Usage (Accelerator) + 0x09, 0xC4, + // Logical Minimum (0) + 0x15, 0x00, + // Logical Maximum (32767) + 0x26, 0xFF, 0x7F, + // Report Size (16) + 0x75, 0x10, + // Report Count (2) + 0x95, 0x02, + // Input (Data, Variable, Absolute): 2 bytes (L2, R2) + 0x81, 0x02, + + // Usage Page (Buttons) + 0x05, 0x09, + // Usage Minimum (1) + 0x19, 0x01, + // Usage Maximum (16) + 0x29, 0x10, + // Logical Minimum (0) + 0x15, 0x00, + // Logical Maximum (1) + 0x25, 0x01, + // Report Count (16) + 0x95, 0x10, + // Report Size (1) + 0x75, 0x01, + // Input (Data, Variable, Absolute): 16 buttons bits + 0x81, 0x02, + + // Usage Page (Generic Desktop) + 0x05, 0x01, + // Usage (Hat switch) + 0x09, 0x39, + // Logical Minimum (1) + 0x15, 0x01, + // Logical Maximum (8) + 0x25, 0x08, + // Report Size (4) + 0x75, 0x04, + // Report Count (1) + 0x95, 0x01, + // Input (Data, Variable, Null State): 4-bit value + 0x81, 0x42, + + // End Collection + 0xC0, + + // End Collection + 0xC0, +}; + +/** + * A gamepad HID input report is 15 bytes long: + * - bytes 0-3: left stick state + * - bytes 4-7: right stick state + * - bytes 8-11: L2/R2 triggers state + * - bytes 12-13: buttons state + * - bytes 14: hat switch position (dpad) + * + * +---------------+ + * byte 0: |. . . . . . . .| + * | | left stick x (0-65535, little-endian) + * byte 1: |. . . . . . . .| + * +---------------+ + * byte 2: |. . . . . . . .| + * | | left stick y (0-65535, little-endian) + * byte 3: |. . . . . . . .| + * +---------------+ + * byte 4: |. . . . . . . .| + * | | right stick x (0-65535, little-endian) + * byte 5: |. . . . . . . .| + * +---------------+ + * byte 6: |. . . . . . . .| + * | | right stick y (0-65535, little-endian) + * byte 7: |. . . . . . . .| + * +---------------+ + * byte 8: |. . . . . . . .| + * | | L2 trigger (0-32767, little-endian) + * byte 9: |0 . . . . . . .| + * +---------------+ + * byte 10: |. . . . . . . .| + * | | R2 trigger (0-32767, little-endian) + * byte 11: |0 . . . . . . .| + * +---------------+ + * + * ,--------------- SC_GAMEPAD_BUTTON_RIGHT_SHOULDER + * | ,------------- SC_GAMEPAD_BUTTON_LEFT_SHOULDER + * | | + * | | ,--------- SC_GAMEPAD_BUTTON_NORTH + * | | | ,------- SC_GAMEPAD_BUTTON_WEST + * | | | | + * | | | | ,--- SC_GAMEPAD_BUTTON_EAST + * | | | | | ,- SC_GAMEPAD_BUTTON_SOUTH + * v v v v v v + * +---------------+ + * byte 12: |. . 0 . . 0 . .| + * | | Buttons (16-bit little-endian) + * byte 13: |0 . . . . . 0 0| + * +---------------+ + * ^ ^ ^ ^ ^ + * | | | | | + * | | | | | + * | | | | `----- SC_GAMEPAD_BUTTON_BACK + * | | | `------- SC_GAMEPAD_BUTTON_START + * | | `--------- SC_GAMEPAD_BUTTON_GUIDE + * | `----------- SC_GAMEPAD_BUTTON_LEFT_STICK + * `------------- SC_GAMEPAD_BUTTON_RIGHT_STICK + * + * +---------------+ + * byte 14: |0 0 0 . . . . .| hat switch (dpad) position (0-8) + * +---------------+ + * 9 possible positions and their values: + * 8 1 2 + * 7 0 3 + * 6 5 4 + * (8 is top-left, 1 is top, 2 is top-right, etc.) + */ + +static void +sc_hid_gamepad_slot_init(struct sc_hid_gamepad_slot *slot, + uint32_t gamepad_id) { + assert(gamepad_id != SC_GAMEPAD_ID_INVALID); + slot->gamepad_id = gamepad_id; + slot->buttons = 0; + slot->axis_left_x = 0; + slot->axis_left_y = 0; + slot->axis_right_x = 0; + slot->axis_right_y = 0; + slot->axis_left_trigger = 0; + slot->axis_right_trigger = 0; +} + +static ssize_t +sc_hid_gamepad_slot_find(struct sc_hid_gamepad *hid, uint32_t gamepad_id) { + for (size_t i = 0; i < SC_MAX_GAMEPADS; ++i) { + if (gamepad_id == hid->slots[i].gamepad_id) { + // found + return i; + } + } + + return -1; +} + +void +sc_hid_gamepad_init(struct sc_hid_gamepad *hid) { + for (size_t i = 0; i < SC_MAX_GAMEPADS; ++i) { + hid->slots[i].gamepad_id = SC_GAMEPAD_ID_INVALID; + } +} + +static inline uint16_t +sc_hid_gamepad_slot_get_id(size_t slot_idx) { + assert(slot_idx < SC_MAX_GAMEPADS); + return SC_HID_ID_GAMEPAD_FIRST + slot_idx; +} + +bool +sc_hid_gamepad_generate_open(struct sc_hid_gamepad *hid, + struct sc_hid_open *hid_open, + uint32_t gamepad_id) { + assert(gamepad_id != SC_GAMEPAD_ID_INVALID); + ssize_t slot_idx = sc_hid_gamepad_slot_find(hid, SC_GAMEPAD_ID_INVALID); + if (slot_idx == -1) { + LOGW("No gamepad slot available for new gamepad %" PRIu32, gamepad_id); + return false; + } + + sc_hid_gamepad_slot_init(&hid->slots[slot_idx], gamepad_id); + + uint16_t hid_id = sc_hid_gamepad_slot_get_id(slot_idx); + hid_open->hid_id = hid_id; + hid_open->report_desc = SC_HID_GAMEPAD_REPORT_DESC; + hid_open->report_desc_size = sizeof(SC_HID_GAMEPAD_REPORT_DESC); + + return true; +} + +bool +sc_hid_gamepad_generate_close(struct sc_hid_gamepad *hid, + struct sc_hid_close *hid_close, + uint32_t gamepad_id) { + assert(gamepad_id != SC_GAMEPAD_ID_INVALID); + ssize_t slot_idx = sc_hid_gamepad_slot_find(hid, gamepad_id); + if (slot_idx == -1) { + LOGW("Unknown gamepad removed %" PRIu32, gamepad_id); + return false; + } + + hid->slots[slot_idx].gamepad_id = SC_GAMEPAD_ID_INVALID; + + uint16_t hid_id = sc_hid_gamepad_slot_get_id(slot_idx); + hid_close->hid_id = hid_id; + + return true; +} + +static uint8_t +sc_hid_gamepad_get_dpad_value(uint32_t buttons) { + // Value depending on direction: + // 8 1 2 + // 7 0 3 + // 6 5 4 + if (buttons & SC_GAMEPAD_BUTTONS_BIT_DPAD_UP) { + if (buttons & SC_GAMEPAD_BUTTONS_BIT_DPAD_LEFT) { + return 8; + } + if (buttons & SC_GAMEPAD_BUTTONS_BIT_DPAD_RIGHT) { + return 2; + } + return 1; + } + if (buttons & SC_GAMEPAD_BUTTONS_BIT_DPAD_DOWN) { + if (buttons & SC_GAMEPAD_BUTTONS_BIT_DPAD_LEFT) { + return 6; + } + if (buttons & SC_GAMEPAD_BUTTONS_BIT_DPAD_RIGHT) { + return 4; + } + return 5; + } + if (buttons & SC_GAMEPAD_BUTTONS_BIT_DPAD_LEFT) { + return 7; + } + if (buttons & SC_GAMEPAD_BUTTONS_BIT_DPAD_RIGHT) { + return 3; + } + + return 0; +} + +static void +sc_hid_gamepad_event_from_slot(uint16_t hid_id, + const struct sc_hid_gamepad_slot *slot, + struct sc_hid_input *hid_input) { + hid_input->hid_id = hid_id; + hid_input->size = SC_HID_GAMEPAD_EVENT_SIZE; + + uint8_t *data = hid_input->data; + // Values must be written in little-endian + sc_write16le(data, slot->axis_left_x); + sc_write16le(data + 2, slot->axis_left_y); + sc_write16le(data + 4, slot->axis_right_x); + sc_write16le(data + 6, slot->axis_right_y); + sc_write16le(data + 8, slot->axis_left_trigger); + sc_write16le(data + 10, slot->axis_right_trigger); + sc_write16le(data + 12, slot->buttons & SC_HID_BUTTONS_MASK); + data[14] = sc_hid_gamepad_get_dpad_value(slot->buttons); +} + +static uint32_t +sc_hid_gamepad_get_button_id(enum sc_gamepad_button button) { + switch (button) { + case SC_GAMEPAD_BUTTON_SOUTH: + return 0x0001; + case SC_GAMEPAD_BUTTON_EAST: + return 0x0002; + case SC_GAMEPAD_BUTTON_WEST: + return 0x0008; + case SC_GAMEPAD_BUTTON_NORTH: + return 0x0010; + case SC_GAMEPAD_BUTTON_BACK: + return 0x0400; + case SC_GAMEPAD_BUTTON_GUIDE: + return 0x1000; + case SC_GAMEPAD_BUTTON_START: + return 0x0800; + case SC_GAMEPAD_BUTTON_LEFT_STICK: + return 0x2000; + case SC_GAMEPAD_BUTTON_RIGHT_STICK: + return 0x4000; + case SC_GAMEPAD_BUTTON_LEFT_SHOULDER: + return 0x0040; + case SC_GAMEPAD_BUTTON_RIGHT_SHOULDER: + return 0x0080; + case SC_GAMEPAD_BUTTON_DPAD_UP: + return SC_GAMEPAD_BUTTONS_BIT_DPAD_UP; + case SC_GAMEPAD_BUTTON_DPAD_DOWN: + return SC_GAMEPAD_BUTTONS_BIT_DPAD_DOWN; + case SC_GAMEPAD_BUTTON_DPAD_LEFT: + return SC_GAMEPAD_BUTTONS_BIT_DPAD_LEFT; + case SC_GAMEPAD_BUTTON_DPAD_RIGHT: + return SC_GAMEPAD_BUTTONS_BIT_DPAD_RIGHT; + default: + // unknown button, ignore + return 0; + } +} + +bool +sc_hid_gamepad_generate_input_from_button(struct sc_hid_gamepad *hid, + struct sc_hid_input *hid_input, + const struct sc_gamepad_button_event *event) { + if ((event->button < 0) || (event->button > 15)) { + return false; + } + + uint32_t gamepad_id = event->gamepad_id; + + ssize_t slot_idx = sc_hid_gamepad_slot_find(hid, gamepad_id); + if (slot_idx == -1) { + LOGW("Axis event for unknown gamepad %" PRIu32, gamepad_id); + return false; + } + + assert(slot_idx < SC_MAX_GAMEPADS); + + struct sc_hid_gamepad_slot *slot = &hid->slots[slot_idx]; + + uint32_t button = sc_hid_gamepad_get_button_id(event->button); + if (!button) { + // unknown button, ignore + return false; + } + + if (event->action == SC_ACTION_DOWN) { + slot->buttons |= button; + } else { + assert(event->action == SC_ACTION_UP); + slot->buttons &= ~button; + } + + uint16_t hid_id = sc_hid_gamepad_slot_get_id(slot_idx); + sc_hid_gamepad_event_from_slot(hid_id, slot, hid_input); + + return true; +} + +bool +sc_hid_gamepad_generate_input_from_axis(struct sc_hid_gamepad *hid, + struct sc_hid_input *hid_input, + const struct sc_gamepad_axis_event *event) { + uint32_t gamepad_id = event->gamepad_id; + + ssize_t slot_idx = sc_hid_gamepad_slot_find(hid, gamepad_id); + if (slot_idx == -1) { + LOGW("Button event for unknown gamepad %" PRIu32, gamepad_id); + return false; + } + + assert(slot_idx < SC_MAX_GAMEPADS); + + struct sc_hid_gamepad_slot *slot = &hid->slots[slot_idx]; + +// [-32768 to 32767] -> [0 to 65535] +#define AXIS_RESCALE(V) (uint16_t) (((int32_t) V) + 0x8000) + switch (event->axis) { + case SC_GAMEPAD_AXIS_LEFTX: + slot->axis_left_x = AXIS_RESCALE(event->value); + break; + case SC_GAMEPAD_AXIS_LEFTY: + slot->axis_left_y = AXIS_RESCALE(event->value); + break; + case SC_GAMEPAD_AXIS_RIGHTX: + slot->axis_right_x = AXIS_RESCALE(event->value); + break; + case SC_GAMEPAD_AXIS_RIGHTY: + slot->axis_right_y = AXIS_RESCALE(event->value); + break; + case SC_GAMEPAD_AXIS_LEFT_TRIGGER: + // Trigger is always positive between 0 and 32767 + slot->axis_left_trigger = MAX(0, event->value); + break; + case SC_GAMEPAD_AXIS_RIGHT_TRIGGER: + // Trigger is always positive between 0 and 32767 + slot->axis_right_trigger = MAX(0, event->value); + break; + default: + return false; + } + + uint16_t hid_id = sc_hid_gamepad_slot_get_id(slot_idx); + sc_hid_gamepad_event_from_slot(hid_id, slot, hid_input); + + return true; +} diff --git a/app/src/hid/hid_gamepad.h b/app/src/hid/hid_gamepad.h new file mode 100644 index 00000000..b532a703 --- /dev/null +++ b/app/src/hid/hid_gamepad.h @@ -0,0 +1,53 @@ +#ifndef SC_HID_GAMEPAD_H +#define SC_HID_GAMEPAD_H + +#include "common.h" + +#include + +#include "hid/hid_event.h" +#include "input_events.h" + +#define SC_MAX_GAMEPADS 8 +#define SC_HID_ID_GAMEPAD_FIRST 3 +#define SC_HID_ID_GAMEPAD_LAST (SC_HID_ID_GAMEPAD_FIRST + SC_MAX_GAMEPADS - 1) + +struct sc_hid_gamepad_slot { + uint32_t gamepad_id; + uint32_t buttons; + uint16_t axis_left_x; + uint16_t axis_left_y; + uint16_t axis_right_x; + uint16_t axis_right_y; + uint16_t axis_left_trigger; + uint16_t axis_right_trigger; +}; + +struct sc_hid_gamepad { + struct sc_hid_gamepad_slot slots[SC_MAX_GAMEPADS]; +}; + +void +sc_hid_gamepad_init(struct sc_hid_gamepad *hid); + +bool +sc_hid_gamepad_generate_open(struct sc_hid_gamepad *hid, + struct sc_hid_open *hid_open, + uint32_t gamepad_id); + +bool +sc_hid_gamepad_generate_close(struct sc_hid_gamepad *hid, + struct sc_hid_close *hid_close, + uint32_t gamepad_id); + +bool +sc_hid_gamepad_generate_input_from_button(struct sc_hid_gamepad *hid, + struct sc_hid_input *hid_input, + const struct sc_gamepad_button_event *event); + +bool +sc_hid_gamepad_generate_input_from_axis(struct sc_hid_gamepad *hid, + struct sc_hid_input *hid_input, + const struct sc_gamepad_axis_event *event); + +#endif