Introduce protocol-neutral controller state

2026-09-02 14:53:56 -06:00 · 2026-09-02 14:53:56 -06:00 · b11ae076a8
commit b11ae076a8
parent df515934ab
28 changed files with 833 additions and 501 deletions
--- a/controller_state.h
+++ b/controller_state.h
@ -0,0 +1,92 @@
+#pragma once
+
+#include <stdint.h>
+
+constexpr uint8_t CONTROLLER_MOTION_SAMPLE_CAPACITY = 3;
+constexpr uint16_t CONTROLLER_AXIS_UNSIGNED_MIN = 0;
+constexpr uint16_t CONTROLLER_AXIS_UNSIGNED_CENTER =
+    static_cast<uint16_t>(UINT16_MAX / 2u + 1u);
+constexpr uint16_t CONTROLLER_AXIS_UNSIGNED_MAX = UINT16_MAX;
+constexpr uint16_t CONTROLLER_TRIGGER_MIN = 0;
+constexpr uint16_t CONTROLLER_TRIGGER_MAX = UINT16_MAX;
+constexpr uint8_t CONTROLLER_TRIGGER_TO_U8_SHIFT = 8;
+
+
+// Motion uses the existing fixed-point units carried by the UART protocol and
+// consumed by the Switch serializer. Axis names are controller-relative.
+struct ControllerMotionSample {
+    int16_t accel_x;
+    int16_t accel_y;
+    int16_t accel_z;
+    int16_t gyro_x;
+    int16_t gyro_y;
+    int16_t gyro_z;
+};
+
+// Protocol-neutral controller state. Face buttons are positional, sticks are
+// signed with zero at rest, and triggers retain their full analog range.
+struct ControllerState {
+    bool dpad_up;
+    bool dpad_down;
+    bool dpad_left;
+    bool dpad_right;
+
+    bool button_south;
+    bool button_east;
+    bool button_west;
+    bool button_north;
+    bool button_left_shoulder;
+    bool button_right_shoulder;
+    bool button_select;
+    bool button_start;
+    bool button_system;
+    bool button_capture;
+    bool button_left_stick;
+    bool button_right_stick;
+
+    uint16_t left_trigger;
+    uint16_t right_trigger;
+
+    int16_t left_stick_x;
+    int16_t left_stick_y;
+    int16_t right_stick_x;
+    int16_t right_stick_y;
+
+    uint8_t motion_sample_count;
+    ControllerMotionSample
+        motion_samples[CONTROLLER_MOTION_SAMPLE_CAPACITY];
+};
+constexpr uint16_t controller_axis_to_unsigned(int16_t value) {
+    return static_cast<uint16_t>(
+        static_cast<int32_t>(value) - INT16_MIN);
+}
+
+constexpr int16_t controller_axis_from_unsigned(uint16_t value) {
+    return static_cast<int16_t>(
+        static_cast<int32_t>(value) + INT16_MIN);
+}
+
+constexpr uint8_t controller_trigger_to_u8(uint16_t value) {
+    return static_cast<uint8_t>(
+        value >> CONTROLLER_TRIGGER_TO_U8_SHIFT);
+}
+
+constexpr ControllerState controller_neutral_state() {
+    return {};
+}
+
+static_assert(controller_axis_to_unsigned(INT16_MIN) ==
+              CONTROLLER_AXIS_UNSIGNED_MIN);
+static_assert(controller_axis_to_unsigned(0) ==
+              CONTROLLER_AXIS_UNSIGNED_CENTER);
+static_assert(controller_axis_to_unsigned(INT16_MAX) ==
+              CONTROLLER_AXIS_UNSIGNED_MAX);
+static_assert(controller_axis_from_unsigned(
+                  CONTROLLER_AXIS_UNSIGNED_MIN) == INT16_MIN);
+static_assert(controller_axis_from_unsigned(
+                  CONTROLLER_AXIS_UNSIGNED_CENTER) == 0);
+static_assert(controller_axis_from_unsigned(
+                  CONTROLLER_AXIS_UNSIGNED_MAX) == INT16_MAX);
+static_assert(controller_trigger_to_u8(0x7fff) == 0x7f);
+static_assert(controller_trigger_to_u8(0x8000) == 0x80);
+static_assert(controller_trigger_to_u8(CONTROLLER_TRIGGER_MAX) == UINT8_MAX);