Bugfixes and compatibility enhancements.

  - Fix non-aligned nkro bit array parsing.
  - Small refactoring of multiple report ID parsing

Author: Hrvoje Cavrak

src/hid_parser.c

@@ -69,7 +69,7 @@ void store_element(parser_state_t *parser, report_val_t *val, int i, uint32_t da
 
 void handle_global_item(parser_state_t *parser, item_t *item) {
     if (item->hdr.tag == RI_GLOBAL_REPORT_ID) {
-        // reset offset for a new page
+        /* Reset offset for a new page */
         parser->offset_in_bits = 0;
         parser->report_id = item->val;
     }

src/hid_report.c

@@ -28,7 +28,7 @@ int32_t get_report_value(uint8_t *report, int len, report_val_t *val) {
 
     /* Calculate the byte offset in the array */
     uint16_t byte_offset = val->offset >> 3;
-    
+
     if (byte_offset >= len)
         return 0;
 
@@ -216,10 +216,11 @@ void extract_data(hid_interface_t *iface, report_val_t *val) {
     }
 }
 
-int32_t extract_bit_variable(uint32_t min_val, uint32_t max_val, uint8_t *raw_report, int len, uint8_t *dst) {
+int32_t extract_bit_variable(report_val_t *kbd, uint8_t *raw_report, int len, uint8_t *dst) {
     int key_count = 0;
+    int bit_offset = kbd->offset & 0b111;
 
-    for (int i = min_val, j = 0; i <= max_val && key_count < len; i++, j++) {
+    for (int i = kbd->usage_min, j = bit_offset; i <= kbd->usage_max && key_count < len; i++, j++) {
         int byte_index = j >> 3;
         int bit_index  = j & 0b111;
 
@@ -279,8 +280,7 @@ int32_t _extract_kbd_nkro(uint8_t *raw_report, int len, hid_interface_t *iface,
     /* Move the pointer to the nkro offset's byte index */
     ptr = &ptr[kb->nkro.offset_idx];
 
-    return extract_bit_variable(
-        kb->nkro.usage_min, kb->nkro.usage_max, ptr, KEYS_IN_USB_REPORT, report->keycode);
+    return extract_bit_variable(&kb->nkro, ptr, KEYS_IN_USB_REPORT, report->keycode);
 }
 
 int32_t extract_kbd_data(

src/include/hid_parser.h

@@ -71,7 +71,7 @@ typedef struct {
     int32_t move_y;
     int32_t wheel;
     int32_t pan;
-    uint32_t buttons;
+    int32_t buttons;
 } mouse_values_t;
 
 /* Describes where can we find a value in a HID report */
@@ -99,7 +99,6 @@ typedef struct {
     report_val_t move_y;
     report_val_t wheel;
     report_val_t pan;
-
     uint8_t report_id;
 
     bool is_found;

src/include/main.h

@@ -463,7 +463,7 @@ void queue_system_packet(uint8_t *, device_t *);
 void send_key(hid_keyboard_report_t *, device_t *);
 void send_consumer_control(uint8_t *, device_t *);
 bool key_in_report(uint8_t, const hid_keyboard_report_t *);
-int32_t extract_bit_variable(uint32_t, uint32_t, uint8_t *, int, uint8_t *);
+int32_t extract_bit_variable(report_val_t *, uint8_t *, int, uint8_t *);
 int32_t extract_kbd_data(uint8_t *, int, uint8_t, hid_interface_t *, hid_keyboard_report_t *);
 
 /*********  Mouse  **********/

src/mouse.c

@@ -225,6 +225,14 @@ void do_screen_switch(device_t *state, int direction) {
         switch_virtual_desktop(state, output, output->screen_index + 1, direction);
 }
 
+inline void extract_value(bool uses_id, int32_t *dst, report_val_t *src, uint8_t *raw_report, int len) {
+    /* If HID Report ID is used, the report is prefixed by the report ID so we have to move by 1 byte */
+    if (uses_id && (*raw_report++ != src->report_id))
+        return;
+
+    *dst = get_report_value(raw_report, len, src);
+}
+
 void extract_report_values(uint8_t *raw_report, int len, device_t *state, mouse_values_t *values, hid_interface_t *iface) {
     /* Interpret values depending on the current protocol used. */
     if (iface->protocol == HID_PROTOCOL_BOOT) {
@@ -237,34 +245,14 @@ void extract_report_values(uint8_t *raw_report, int len, device_t *state, mouse_
         values->buttons = mouse_report->buttons;
         return;
     }
-
-    /* If HID Report ID is used, the report is prefixed by the report ID so we have to move by 1 byte */
-    if (iface->uses_report_id) {
-        uint8_t report_id = raw_report[0];
-        raw_report++;
-        if (report_id == iface->mouse.move_x.report_id)
-            values->move_x = get_report_value(raw_report, len, &iface->mouse.move_x);
-
-        if (report_id == iface->mouse.move_y.report_id)
-            values->move_y = get_report_value(raw_report, len, &iface->mouse.move_y);
-
-        if (report_id == iface->mouse.wheel.report_id)
-            values->wheel = get_report_value(raw_report, len, &iface->mouse.wheel);
-
-        if (report_id == iface->mouse.pan.report_id)
-            values->pan = get_report_value(raw_report, len, &iface->mouse.pan);
-
-        if (report_id == iface->mouse.buttons.report_id)
-            values->buttons = get_report_value(raw_report, len, &iface->mouse.buttons);
-        else
-            values->buttons = state->mouse_buttons;
-    } else {
-        values->move_x = get_report_value(raw_report, len, &iface->mouse.move_x);
-        values->move_y = get_report_value(raw_report, len, &iface->mouse.move_y);
-        values->wheel = get_report_value(raw_report, len, &iface->mouse.wheel);
-        values->pan = get_report_value(raw_report, len, &iface->mouse.pan);
-        values->buttons = get_report_value(raw_report, len, &iface->mouse.buttons);
-    }
+    mouse_t *mouse = &iface->mouse;
+    bool uses_id = iface->uses_report_id;
+
+    extract_value(uses_id, &values->move_x, &mouse->move_x, raw_report, len);
+    extract_value(uses_id, &values->move_y, &mouse->move_y, raw_report, len);
+    extract_value(uses_id, &values->wheel, &mouse->wheel, raw_report, len);
+    extract_value(uses_id, &values->pan, &mouse->pan, raw_report, len);
+    extract_value(uses_id, &values->buttons, &mouse->buttons, raw_report, len);
 }
 
 mouse_report_t create_mouse_report(device_t *state, mouse_values_t *values) {