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/* 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();
}