(untested) small changes and few typos

hid.c

@@ -70,16 +70,18 @@ void setup_device(PhysicalDevice *dev) {
     ioctl(dev->event, EVIOCGBIT(0, EV_MAX), type_bits);
     // Loop over all event types
     for (int type = 0; type < EV_MAX; type++) {
-        // Ignore if the the device doesn't have this even type
+        // Ignore if the the device doesn't have any of this event type
         if (!bit_set(type_bits, type)) {
             continue;
         }
-
+        // Clear feat_bits to only have the features of the current type
         memset(feat_bits, 0, sizeof(feat_bits));
         ioctl(dev->event, EVIOCGBIT(type, KEY_MAX), feat_bits);
 
         // Loop over "instances" of type (i.e Each axis of a controller for EV_ABS)
         for (int i = 0; i < KEY_MAX; i++) {
+            // "instances" don't have to be consecutive (this is why we do all this instead of just worrying
+            // about the count)
             if (!bit_set(feat_bits, i)) {
                 continue;
             }
@@ -90,12 +92,14 @@ void setup_device(PhysicalDevice *dev) {
 
                 uint16_t index = dev->device_info.abs_count++;
 
-                dev->device_info.abs_id[index]   = i;
                 dev->device_info.abs_min[index]  = abs.minimum;
                 dev->device_info.abs_max[index]  = abs.maximum;
                 dev->device_info.abs_fuzz[index] = abs.fuzz;
                 dev->device_info.abs_flat[index] = abs.flat;
                 dev->device_info.abs_res[index]  = abs.resolution;
+                // Bidirectional mapping id <-> index
+                // We need this to avoid wasting space in packets because ids are sparse
+                dev->device_info.abs_id[index] = i;
                 dev->mapping.abs_indices[i]    = index;
             } else if (type == EV_REL) {
                 uint16_t index = dev->device_info.rel_count++;
@@ -240,14 +244,16 @@ void poll_devices() {
         // Try to get the name, default to DEFAULT_NAME if impossible
         char        name_buf[256] = {};
         const char *name;
-        if (ioctl(dev.event, EVIOCGNAME(256), name_buf) >= 0)
+        if (ioctl(dev.event, EVIOCGNAME(256), name_buf) >= 0) {
             name = name_buf;
-        else
+        } else {
             name = DEVICE_DEFAULT_NAME;
+        }
 
         // Filter events we don't care about
-        if (!filter_event(dev.event, input->d_name))
+        if (!filter_event(dev.event, input->d_name)) {
             goto skip;
+        }
 
         // Try to get uniq, drop device if we can't
         uniq_t uniq;
@@ -258,9 +264,10 @@ void poll_devices() {
             uniq = parse_uniq(uniq_str);
 
             // If we couldn't parse the uniq (this assumes uniq can't be zero, which is probably alright)
-            if (uniq == 0)
+            if (uniq == 0) {
                 goto skip;
             }
+        }
 
         // Check if we already know of this device
         bool found = false;
@@ -349,9 +356,9 @@ void poll_devices() {
     }
 }
 
-// "Execute" a MessageControllerState: set the led color and such using the hidraw interface
+// "Execute" a MessageControllerState: set the led color, rumble and flash using the hidraw interface
 void apply_controller_state(PhysicalDevice *dev, MessageControllerState *state) {
-    printf("HID:     (%012lx) Controller state: #%02x%02x%02x (%d, %d) rumble: (%d, %d)\n", dev->uniq,
+    printf("HID:     (%012lx) Controller state: #%02x%02x%02x flash: (%d, %d) rumble: (%d, %d)\n", dev->uniq,
            state->led[0], state->led[1], state->led[2], state->flash_on, state->flash_off,
            state->small_rumble, state->big_rumble);
 
@@ -369,7 +376,7 @@ void apply_controller_state(PhysicalDevice *dev, MessageControllerState *state)
     if (state->flash_on == 0 && state->flash_off == 0) {
         // May not be necessary
         fsync(dev->hidraw);
-        // Send a second time, for some reason the flash doesn't stop otherwise
+        // Send a second time, to reenable the led
         write(dev->hidraw, buf, 32);
     };
 }

main.c

@@ -13,6 +13,7 @@ const char *USAGE[] = {
     "jsfw server [port]\n",
 };
 
+// Start the server
 void server(uint16_t port) {
     printf("[Server (0.0.0.0:%u)]\n\n", port);
 
@@ -22,6 +23,7 @@ void server(uint16_t port) {
     server_run(port);
 }
 
+// Start the client
 void client(char *address, uint16_t port) {
     printf("[Client (%s:%d)]\n\n", address, port);
     client_run(address, port);
@@ -37,17 +39,17 @@ int main(int argc, char *argv[]) {
     char *mode = argv[1];
 
     if (strcmp(mode, "server") == 0) {
-
-        if (argc < 3)
+        if (argc < 3) {
             panicf("Usage: %s", USAGE[1]);
+        }
 
         uint16_t port = parse_port(argv[2]);
         server(port);
 
     } else if (strcmp(mode, "client") == 0) {
-
-        if (argc < 4)
+        if (argc < 4) {
             panicf("Usage: %s", USAGE[0]);
+        }
 
         char    *address = argv[2];
         uint16_t port    = parse_port(argv[3]);

server.c

@@ -16,7 +16,7 @@
 #include <sys/socket.h>
 #include <unistd.h>
 
-// Arguments for a connecion thread
+// Arguments for a connection thread
 struct Connection {
     int      socket;
     uint32_t id;

vec.c

@@ -22,6 +22,7 @@ Vec vec_cap(size_t data_size, size_t initial_capacity) {
     return v;
 }
 
+// Ensure the vector can store at least cap elements
 static inline void vec_grow(Vec *v, size_t cap) {
     if (v->cap >= cap) {
         return;
@@ -96,6 +97,7 @@ void vec_remove(Vec *v, size_t index, void *data) {
 
 void vec_clear(Vec *v) { v->len = 0; }
 
+// Add the content of a buffer of len elements to the end of the vector
 void vec_extend(Vec *v, void *data, size_t len) {
     if (len == 0) {
         return;