feat: add horizontal scrolling

src/hid_report.c

@@ -166,6 +166,14 @@ void extract_data(hid_interface_t *iface, report_val_t *val) {
          .dst          = &iface->mouse.wheel,
          .id           = &iface->mouse.report_id},
 
+        {.usage_page   = HID_USAGE_PAGE_CONSUMER,
+         .global_usage = HID_USAGE_DESKTOP_MOUSE,
+         .usage        = HID_USAGE_CONSUMER_AC_PAN,
+         .handler      = _store,
+         .receiver     = process_mouse_report,
+         .dst          = &iface->mouse.pan,
+         .id           = &iface->mouse.report_id},
+
         {.usage_page   = HID_USAGE_PAGE_KEYBOARD,
          .global_usage = HID_USAGE_DESKTOP_KEYBOARD,
          .handler      = handle_keyboard_descriptor_values,

src/include/hid_parser.h

@@ -98,6 +98,7 @@ typedef struct {
     report_val_t move_x;
     report_val_t move_y;
     report_val_t wheel;
+    report_val_t pan;
 
     uint8_t report_id;
 

src/include/main.h

@@ -177,7 +177,7 @@ typedef struct {
 #define KEYARRAY_BIT_OFFSET     16
 #define KEYS_IN_USB_REPORT      6
 #define KBD_REPORT_LENGTH       8
-#define MOUSE_REPORT_LENGTH     7
+#define MOUSE_REPORT_LENGTH     8
 #define CONSUMER_CONTROL_LENGTH 4
 #define SYSTEM_CONTROL_LENGTH   1
 #define MODIFIER_BIT_LENGTH     8
@@ -345,6 +345,7 @@ typedef struct TU_ATTR_PACKED {
     int16_t x;
     int16_t y;
     int8_t wheel;
+    int8_t pan;
     uint8_t mode;
 } mouse_report_t;
 
@@ -460,7 +461,7 @@ int32_t extract_bit_variable(uint32_t, uint32_t, uint8_t *, int, uint8_t *);
 int32_t extract_kbd_data(uint8_t *, int, uint8_t, hid_interface_t *, hid_keyboard_report_t *);
 
 /*********  Mouse  **********/
-bool tud_mouse_report(uint8_t mode, uint8_t buttons, int16_t x, int16_t y, int8_t wheel);
+bool tud_mouse_report(uint8_t mode, uint8_t buttons, int16_t x, int16_t y, int8_t wheel, int8_t pan);
 
 void process_mouse_report(uint8_t *, int, uint8_t, hid_interface_t *);
 void parse_report_descriptor(hid_interface_t *, uint8_t const *, int);

src/include/usb_descriptors.h

@@ -98,6 +98,15 @@ HID_COLLECTION ( HID_COLLECTION_APPLICATION  )                   ,\
       HID_REPORT_SIZE ( 8                                      )  ,\
       HID_INPUT       ( HID_DATA | HID_VARIABLE | HID_RELATIVE )  ,\
       \
+      /* Horizontal wheel (AC Pan) */ \
+      HID_USAGE_PAGE  ( HID_USAGE_PAGE_CONSUMER               )   ,\
+      HID_LOGICAL_MIN ( 0x81                                   )   ,\
+      HID_LOGICAL_MAX ( 0x7f                                   )   ,\
+      HID_REPORT_COUNT( 1                                      )   ,\
+      HID_REPORT_SIZE ( 8                                      )   ,\
+      HID_USAGE_N     ( HID_USAGE_CONSUMER_AC_PAN, 2          )   ,\
+      HID_INPUT       ( HID_DATA | HID_VARIABLE | HID_RELATIVE )  ,\
+      \
       /* Mouse mode (0 = absolute, 1 = relative) */ \
       HID_REPORT_COUNT( 1                                      ), \
       HID_REPORT_SIZE ( 8                                      ), \

src/mouse.c

@@ -219,6 +219,7 @@ void extract_report_values(uint8_t *raw_report, device_t *state, mouse_values_t
         values->move_x  = mouse_report->x;
         values->move_y  = mouse_report->y;
         values->wheel   = mouse_report->wheel;
+        values->pan     = mouse_report->pan;
         values->buttons = mouse_report->buttons;
         return;
     }
@@ -230,6 +231,7 @@ void extract_report_values(uint8_t *raw_report, device_t *state, mouse_values_t
     values->move_x  = get_report_value(raw_report, &iface->mouse.move_x);
     values->move_y  = get_report_value(raw_report, &iface->mouse.move_y);
     values->wheel   = get_report_value(raw_report, &iface->mouse.wheel);
+    values->pan     = get_report_value(raw_report, &iface->mouse.pan);
     values->buttons = get_report_value(raw_report, &iface->mouse.buttons);
 }
 
@@ -239,6 +241,7 @@ mouse_report_t create_mouse_report(device_t *state, mouse_values_t *values) {
         .x       = state->pointer_x,
         .y       = state->pointer_y,
         .wheel   = values->wheel,
+        .pan     = values->pan,
         .mode    = ABSOLUTE,
     };
 
@@ -296,7 +299,8 @@ void process_mouse_queue_task(device_t *state) {
         return;
 
     /* Try sending it to the host, if it's successful */
-    bool succeeded = tud_mouse_report(report.mode, report.buttons, report.x, report.y, report.wheel);
+    bool succeeded
+        = tud_mouse_report(report.mode, report.buttons, report.x, report.y, report.wheel, report.pan);
 
     /* ... then we can remove it from the queue */
     if (succeeded)

src/usb_descriptors.c

@@ -81,10 +81,10 @@ uint8_t const *tud_hid_descriptor_report_cb(uint8_t instance) {
     }
 }
 
-bool tud_mouse_report(uint8_t mode, uint8_t buttons, int16_t x, int16_t y, int8_t wheel) {
-    mouse_report_t report = {.buttons = buttons, .wheel = wheel, .x = x, .y = y, .mode = mode};
     uint8_t instance = ITF_NUM_HID;
     uint8_t report_id = REPORT_ID_MOUSE;
+bool tud_mouse_report(uint8_t mode, uint8_t buttons, int16_t x, int16_t y, int8_t wheel, int8_t pan) {
+    mouse_report_t report = {.buttons = buttons, .wheel = wheel, .x = x, .y = y, .mode = mode, .pan = pan};
 
     if (mode == RELATIVE) {
         instance = ITF_NUM_HID_REL_M;