- /* Copyright 2022
- *
- * 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, see <http://www.gnu.org/licenses/>.
- */
-
- #include "joystick.h"
- #include "wait.h"
-
- #if defined(JOYSTICK_ANALOG)
- # include "analog.h"
- #endif
-
- joystick_t joystick_state = {
- .buttons = {0},
- .axes =
- {
- #if JOYSTICK_AXIS_COUNT > 0
- 0
- #endif
- },
- .dirty = false,
- };
-
- // array defining the reading of analog values for each axis
- __attribute__((weak)) joystick_config_t joystick_axes[JOYSTICK_AXIS_COUNT] = {
- #if JOYSTICK_AXIS_COUNT > 0
- [0 ...(JOYSTICK_AXIS_COUNT - 1)] = JOYSTICK_AXIS_VIRTUAL
- #endif
- };
-
- __attribute__((weak)) void joystick_axis_init(uint8_t axis) {
- if (axis >= JOYSTICK_AXIS_COUNT) return;
-
- #if defined(JOYSTICK_ANALOG)
- gpio_set_pin_input(joystick_axes[axis].input_pin);
- #endif
- }
-
- __attribute__((weak)) uint16_t joystick_axis_sample(uint8_t axis) {
- if (axis >= JOYSTICK_AXIS_COUNT) return 0;
-
- #if defined(JOYSTICK_ANALOG)
- return analogReadPin(joystick_axes[axis].input_pin);
- #else
- // default to resting position
- return joystick_axes[axis].mid_digit;
- #endif
- }
-
- static inline bool is_virtual_axis(uint8_t axis) {
- return joystick_axes[axis].input_pin == NO_PIN;
- }
-
- void joystick_flush(void) {
- if (!joystick_state.dirty) return;
-
- // TODO: host.h?
- void host_joystick_send(joystick_t * joystick);
- host_joystick_send(&joystick_state);
- joystick_state.dirty = false;
- }
-
- void register_joystick_button(uint8_t button) {
- if (button >= JOYSTICK_BUTTON_COUNT) return;
-
- joystick_state.buttons[button / 8] |= 1 << (button % 8);
- joystick_state.dirty = true;
- joystick_flush();
- }
-
- void unregister_joystick_button(uint8_t button) {
- if (button >= JOYSTICK_BUTTON_COUNT) return;
-
- joystick_state.buttons[button / 8] &= ~(1 << (button % 8));
- joystick_state.dirty = true;
- joystick_flush();
- }
-
- int16_t joystick_read_axis(uint8_t axis) {
- if (axis >= JOYSTICK_AXIS_COUNT) return 0;
-
- int16_t axis_val = joystick_axis_sample(axis);
-
- // test the converted value against the lower range
- int32_t ref = joystick_axes[axis].mid_digit;
- int32_t range = joystick_axes[axis].min_digit;
- int32_t ranged_val = ((axis_val - ref) * -JOYSTICK_MAX_VALUE) / (range - ref);
-
- if (ranged_val > 0) {
- // the value is in the higher range
- range = joystick_axes[axis].max_digit;
- ranged_val = ((axis_val - ref) * JOYSTICK_MAX_VALUE) / (range - ref);
- }
-
- // clamp the result in the valid range
- ranged_val = ranged_val < -JOYSTICK_MAX_VALUE ? -JOYSTICK_MAX_VALUE : ranged_val;
- ranged_val = ranged_val > JOYSTICK_MAX_VALUE ? JOYSTICK_MAX_VALUE : ranged_val;
-
- return ranged_val;
- }
-
- void joystick_init_axes(void) {
- #if JOYSTICK_AXIS_COUNT > 0
- for (int i = 0; i < JOYSTICK_AXIS_COUNT; ++i) {
- if (is_virtual_axis(i)) {
- continue;
- }
-
- joystick_axis_init(i);
- }
- #endif
- }
-
- void joystick_read_axes(void) {
- #if JOYSTICK_AXIS_COUNT > 0
- for (int i = 0; i < JOYSTICK_AXIS_COUNT; ++i) {
- if (is_virtual_axis(i)) {
- continue;
- }
-
- joystick_set_axis(i, joystick_read_axis(i));
- }
-
- joystick_flush();
- #endif
- }
-
- void joystick_set_axis(uint8_t axis, int16_t value) {
- if (axis >= JOYSTICK_AXIS_COUNT) return;
-
- if (value != joystick_state.axes[axis]) {
- joystick_state.axes[axis] = value;
- joystick_state.dirty = true;
- }
- }
-
- void joystick_init(void) {
- joystick_init_axes();
- }
-
- void joystick_task(void) {
- joystick_read_axes();
- }
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