Code reformat and CLIENT SIDE PREDICTION!!

.clang-format

@@ -0,0 +1,4 @@
+BasedOnStyle: LLVM
+ColumnLimit: 0
+SpacesInParentheses: false
+BreakBeforeBraces: Allman

debugdraw.c

@@ -30,11 +30,6 @@ typedef struct Command
 // thread local variables so debug drawing in server thread
 // doesn't fuck up main thread
 
-#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
-#define THREADLOCAL __declspec(thread)
-#else
-#define THREADLOCAL __thread
-#endif
 
 static THREADLOCAL Command commands[MAX_COMMANDS] = {0};
 static THREADLOCAL int command_i = 0;

gamestate.c

@@ -1,7 +1,7 @@
 #include <chipmunk.h>
 #define QUEUE_IMPL
-#include "stdbool.h"
 #include "queue.h"
+#include "stdbool.h"
 #include "types.h"
 
 #include "ipsettings.h" // debug/developer settings
@@ -30,7 +30,6 @@ void __assert(bool cond, const char* file, int line, const char* cond_string)
   }
 }
 
-
 static V2 cp_to_v2(cpVect v)
 {
   return (V2){.x = (float)v.x, .y = (float)v.y};
@@ -55,8 +54,10 @@ Entity* get_entity_even_if_dead(GameState* gs, EntityID id)
   {
     return NULL;
   }
-	assert(id.index < gs->cur_next_entity || gs->cur_next_entity == 0);
-	assert(id.index < gs->max_entities);
+  if (!(id.index < gs->cur_next_entity || gs->cur_next_entity == 0))
+    return NULL;
+  if (!(id.index < gs->max_entities))
+    return NULL;
   Entity *to_return = &gs->entities[id.index];
   // don't validate the generation either
   return to_return;
@@ -386,17 +387,13 @@ static void grid_correct_for_holes(GameState* gs, struct Entity* grid)
           V2 cur_local_pos = entity_shape_pos(N);
           const V2 dirs[] = {
               (V2){
-							.x = -1.0f, .y = 0.0f
-},
+                  .x = -1.0f, .y = 0.0f},
               (V2){
-	.x = 1.0f, .y = 0.0f
-},
+                  .x = 1.0f, .y = 0.0f},
               (V2){
-	.x = 0.0f, .y = 1.0f
-},
+                  .x = 0.0f, .y = 1.0f},
               (V2){
-	.x = 0.0f, .y = -1.0f
-},
+                  .x = 0.0f, .y = -1.0f},
           };
           int num_dirs = sizeof(dirs) / sizeof(*dirs);
 
@@ -557,6 +554,7 @@ V2 grid_world_to_local(Entity* grid, V2 world)
 }
 V2 grid_local_to_world(Entity *grid, V2 local)
 {
+  assert(grid->is_grid);
   return cp_to_v2(cpBodyLocalToWorld(grid->body, v2_to_cp(local)));
 }
 // returned snapped position is in world coordinates
@@ -774,6 +772,8 @@ enum GameVersion
   VAddedLastUsedMedbay,
   VAddedSquads,
   VAddedSquadInvites,
+  VRemovedTimeFromDiskSave,       // did this to avoid wayy too big a time causing precision problems
+  VReallyRemovedTimeFromDiskSave, // apparently last one didn't work
   VMax,                           // this minus one will be the version used
 };
 
@@ -810,7 +810,6 @@ SerMaybeFailure ser_entityid(SerState* ser, EntityID* id)
 SerMaybeFailure ser_inputframe(SerState *ser, InputFrame *i)
 {
   SER_VAR(&i->tick);
-	SER_VAR(&i->id);
   SER_MAYBE_RETURN(ser_V2(ser, &i->movement));
   SER_VAR(&i->take_over_squad);
   SER_ASSERT(i->take_over_squad >= 0 || i->take_over_squad == -1);
@@ -823,9 +822,7 @@ SerMaybeFailure ser_inputframe(SerState* ser, InputFrame* i)
   }
 
   SER_VAR(&i->seat_action);
-	SER_MAYBE_RETURN(ser_entityid(ser, &i->seat_to_inhabit));
   SER_MAYBE_RETURN(ser_V2(ser, &i->hand_pos));
-	SER_MAYBE_RETURN(ser_entityid(ser, &i->grid_hand_pos_local_to));
 
   SER_VAR(&i->dobuild);
   SER_VAR(&i->build_type);
@@ -855,7 +852,7 @@ SerMaybeFailure ser_player(SerState* ser, Player* p)
 
 SerMaybeFailure ser_entity(SerState *ser, GameState *gs, Entity *e)
 {
-	SER_VAR(&e->no_save_to_disk); // this is always false when saving to disk?
+  SER_VAR(&e->no_save_to_disk); // @Robust this is always false when saving to disk?
   SER_VAR(&e->generation);
   SER_VAR(&e->damage);
 
@@ -1023,16 +1020,11 @@ SerMaybeFailure ser_server_to_client(SerState* ser, ServerToClient* s)
   SER_ASSERT(ser->version < VMax);
 
   if (!ser->save_or_load_from_disk)
-		SER_MAYBE_RETURN(ser_opus_packets(ser, s->playback_buffer));
+    SER_MAYBE_RETURN(ser_opus_packets(ser, s->audio_playback_buffer));
 
   GameState *gs = s->cur_gs;
 
-	int cur_next_entity = 0;
-	if (ser->serializing)
-		cur_next_entity = gs->cur_next_entity;
-	SER_VAR(&cur_next_entity);
-	SER_ASSERT(cur_next_entity <= ser->max_entity_index);
-
+  // completely reset and destroy all gamestate data
   if (!ser->serializing)
   {
     // avoid a memset here very expensive. que rico!
@@ -1041,8 +1033,23 @@ SerMaybeFailure ser_server_to_client(SerState* ser, ServerToClient* s)
     gs->cur_next_entity = 0; // updated on deserialization
   }
 
+  int cur_next_entity = 0;
+  if (ser->serializing)
+    cur_next_entity = gs->cur_next_entity;
+  SER_VAR(&cur_next_entity);
+  SER_ASSERT(cur_next_entity <= ser->max_entity_index);
+
+  if (!ser->save_or_load_from_disk)
+    SER_MAYBE_RETURN(ser_entityid(ser, &gs->cur_spacestation));
+
   SER_VAR(&s->your_player);
+  if (ser->version >= VReallyRemovedTimeFromDiskSave && ser->save_or_load_from_disk)
+  {
+  }
+  else
+  {
     SER_VAR(&gs->time);
+  }
 
   SER_MAYBE_RETURN(ser_V2(ser, &gs->goldpos));
 
@@ -1228,13 +1235,47 @@ bool server_to_client_deserialize(struct ServerToClient* msg, char* bytes, size_
   }
 }
 
+// only serializes up to the maximum inputs the server holds
 SerMaybeFailure ser_client_to_server(SerState *ser, ClientToServer *msg)
 {
   SER_VAR(&ser->version);
   SER_MAYBE_RETURN(ser_opus_packets(ser, msg->mic_data));
-	for (int i = 0; i < INPUT_BUFFER; i++)
+
+  // serialize input packets
+  size_t num;
+  if (ser->serializing)
   {
-		SER_MAYBE_RETURN(ser_inputframe(ser, &msg->inputs[i]));
+    num = queue_num_elements(msg->input_data);
+    if (num > INPUT_QUEUE_MAX)
+      num = INPUT_QUEUE_MAX;
+  }
+  SER_VAR(&num);
+  SER_ASSERT(num <= INPUT_QUEUE_MAX);
+  if (ser->serializing)
+  {
+    size_t to_skip = queue_num_elements(msg->input_data) - num;
+    size_t i = 0;
+    QUEUE_ITER(msg->input_data, cur_header)
+    {
+      if (i < to_skip)
+      {
+        i++;
+      }
+      else
+      {
+        InputFrame *cur = (InputFrame *)cur_header->data;
+        SER_MAYBE_RETURN(ser_inputframe(ser, cur));
+      }
+    }
+  }
+  else
+  {
+    for (size_t i = 0; i < num; i++)
+    {
+      InputFrame *new_frame = (InputFrame *)queue_push_element(msg->input_data);
+      SER_ASSERT(new_frame != NULL);
+      SER_MAYBE_RETURN(ser_inputframe(ser, new_frame));
+    }
   }
   return ser_ok;
 }
@@ -1295,8 +1336,8 @@ bool client_to_server_deserialize(GameState* gs, struct ClientToServer* msg, cha
 }
 
 // has to be global var because can only get this information
-static cpShape* closest_to_point_in_radius_result = NULL;
-static float closest_to_point_in_radius_result_largest_dist = 0.0f;
+static THREADLOCAL cpShape *closest_to_point_in_radius_result = NULL;
+static THREADLOCAL float closest_to_point_in_radius_result_largest_dist = 0.0f;
 static void closest_point_callback_func(cpShape *shape, cpContactPointSet *points, void *data)
 {
   assert(points->count == 1);
@@ -1380,17 +1421,24 @@ uint64_t tick(GameState* gs)
   return (uint64_t)floor(gs->time / ((double)TIMESTEP));
 }
 
-V2 get_world_hand_pos(GameState* gs, InputFrame* input, Entity* player)
+Entity *grid_to_build_on(GameState *gs, V2 world_hand_pos)
 {
-	Entity* potential_grid = get_entity(gs, input->grid_hand_pos_local_to);
+  return closest_to_point_in_radius(gs, world_hand_pos, BUILD_BOX_SNAP_DIST_TO_SHIP);
+}
+
+V2 potentially_snap_hand_pos(GameState *gs, V2 world_hand_pos)
+{
+  Entity *potential_grid = grid_to_build_on(gs, world_hand_pos);
   if (potential_grid != NULL)
   {
-		return grid_local_to_world(potential_grid, input->hand_pos);
+    world_hand_pos = grid_snapped_box_pos(potential_grid, world_hand_pos);
   }
-	else
-	{
-		return V2add(entity_pos(player), input->hand_pos);
+  return world_hand_pos;
 }
+
+V2 get_world_hand_pos(GameState *gs, InputFrame *input, Entity *player)
+{
+  return potentially_snap_hand_pos(gs, V2add(entity_pos(player), input->hand_pos));
 }
 
 // return true if used the energy
@@ -1439,7 +1487,7 @@ EntityID create_spacestation(GameState* gs)
   Entity *grid = new_entity(gs);
   grid_create(gs, grid);
   grid->no_save_to_disk = true;
-	entity_set_pos(grid, (V2) { -150.0f, 0.0f });
+  entity_set_pos(grid, (V2){-15.0f, 0.0f});
   entity_ensure_in_orbit(grid);
   Entity *explosion_box = new_entity(gs);
   box_create(gs, explosion_box, grid, (V2){0});
@@ -1478,11 +1526,15 @@ void exit_seat(GameState* gs, Entity* seat_in, Entity* player)
   cpBodySetVelocity(player->body, v2_to_cp(player_vel(gs, player)));
 }
 
+void process_fixed_timestep(GameState *gs)
+{
+  process(gs, TIMESTEP);
+}
+
 void process(GameState *gs, float dt)
 {
   assert(gs->space != NULL);
 
-	assert(dt == TIMESTEP); // @TODO fix tick being incremented every time
   gs->time += dt;
 
   // process input
@@ -1494,7 +1546,8 @@ void process(GameState* gs, float dt)
       {
         player->squad = SquadNone;
       }
-			else {
+      else
+      {
         bool squad_taken = false;
         PLAYERS_ITER(gs->players, other_player)
         {
@@ -1601,18 +1654,19 @@ void process(GameState* gs, float dt)
     // process movement
     {
       // no cheating by making movement bigger than length 1
-			float movement_strength = V2length(player->input.movement);
-			if (movement_strength != 0.0f)
+      V2 movement_this_tick = (V2){0};
+      if (V2length(player->input.movement) > 0.0f)
       {
-				player->input.movement = V2scale(V2normalize(player->input.movement), clamp(V2length(player->input.movement), 0.0f, 1.0f));
+        movement_this_tick = V2scale(V2normalize(player->input.movement), clamp(V2length(player->input.movement), 0.0f, 1.0f));
+        player->input.movement = (V2){0};
       }
       Entity *seat_inside_of = get_entity(gs, p->currently_inside_of_box);
 
       if (seat_inside_of == NULL)
       {
         cpShapeSetFilter(p->shape, PLAYER_SHAPE_FILTER);
-				cpBodyApplyForceAtWorldPoint(p->body, v2_to_cp(V2scale(player->input.movement, PLAYER_JETPACK_FORCE)), cpBodyGetPosition(p->body));
-				p->damage += movement_strength * dt * PLAYER_JETPACK_SPICE_PER_SECOND;
+        cpBodyApplyForceAtWorldPoint(p->body, v2_to_cp(V2scale(movement_this_tick, PLAYER_JETPACK_FORCE)), cpBodyGetPosition(p->body));
+        p->damage += V2length(movement_this_tick) * dt * PLAYER_JETPACK_SPICE_PER_SECOND;
       }
       else
       {
@@ -1627,9 +1681,9 @@ void process(GameState* gs, float dt)
           Entity *g = get_entity(gs, seat_inside_of->shape_parent_entity);
 
           V2 target_direction = {0};
-					if (V2length(player->input.movement) > 0.0f)
+          if (V2length(movement_this_tick) > 0.0f)
           {
-						target_direction = V2normalize(player->input.movement);
+            target_direction = V2normalize(movement_this_tick);
           }
           BOXES_ITER(gs, cur, g)
           {
@@ -1652,7 +1706,7 @@ void process(GameState* gs, float dt)
       V2 world_build = world_hand_pos;
 
       // @Robust sanitize this input so player can't build on any grid in the world
-			Entity* target_grid = get_entity(gs, player->input.grid_hand_pos_local_to);
+      Entity *target_grid = grid_to_build_on(gs, world_hand_pos);
       cpShape *nearest = cpSpacePointQueryNearest(gs->space, v2_to_cp(world_build), 0.01f, cpShapeFilterNew(CP_NO_GROUP, CP_ALL_CATEGORIES, BOXES), &info);
       if (nearest != NULL)
       {

queue.h

@@ -1,17 +1,21 @@
 #pragma once
 
+#include <stdbool.h>
+
 #ifndef QUEUE_ASSERT
 void __assert(bool cond, const char *file, int line, const char *cond_string);
 #define QUEUE_ASSERT(condition) __assert(condition, __FILE__, __LINE__, #condition)
 #endif
 
-typedef struct QueueElementHeader {
+typedef struct QueueElementHeader
+{
   bool exists;
   struct QueueElementHeader *next;
   char data[];
 } QueueElementHeader;
 
-typedef struct Queue {
+typedef struct Queue
+{
   char *data;
   size_t data_length; // must be a multiple of sizeof(QueueElementHeader) + element_size
   size_t element_size;
@@ -20,11 +24,14 @@ typedef struct Queue {
 
 #define QUEUE_SIZE_FOR_ELEMENTS(element_size, max_elements) ((sizeof(QueueElementHeader) + element_size) * max_elements)
 
+// oldest to newest
+#define QUEUE_ITER(q_ptr, cur_header) for (QueueElementHeader *cur_header = (q_ptr)->next; cur_header != NULL; cur_header = cur_header->next)
 void queue_init(Queue *q, size_t element_size, char *data, size_t data_length);
 void queue_clear(Queue *q);
 void *queue_push_element(Queue *q);
 size_t queue_num_elements(Queue *q);
 void *queue_pop_element(Queue *q);
+void *queue_most_recent_element(Queue *q);
 
 #ifdef QUEUE_IMPL
 
@@ -68,7 +75,8 @@ void* queue_push_element(Queue* q)
   {
     return NULL;
   }
-	else {
+  else
+  {
     to_return->exists = true;
     to_return->next = NULL; // very important.
     for (size_t i = 0; i < q->element_size; i++)
@@ -78,10 +86,12 @@ void* queue_push_element(Queue* q)
     if (q->next != NULL)
     {
       QueueElementHeader *cur = q->next;
-			while (cur->next != NULL) cur = cur->next;
+      while (cur->next != NULL)
+        cur = cur->next;
       cur->next = to_return;
     }
-		else {
+    else
+    {
       q->next = to_return;
     }
 
@@ -94,7 +104,8 @@ size_t queue_num_elements(Queue* q)
   QUEUE_ASSERT(q->data != NULL);
   size_t to_return = 0;
   QUEUE_ELEM_ITER(cur)
-		if (cur->exists) to_return++;
+  if (cur->exists)
+    to_return++;
   return to_return;
 }
 
@@ -103,10 +114,24 @@ void* queue_pop_element(Queue* q)
 {
   QUEUE_ASSERT(q->data != NULL);
   QueueElementHeader *to_return = q->next;
-	if (q->next != NULL) q->next = q->next->next;
-	if (to_return != NULL) to_return->exists = false; // jank!
+  if (q->next != NULL)
+    q->next = q->next->next;
+  if (to_return != NULL)
+    to_return->exists = false; // jank!
   return to_return == NULL ? NULL : (void *)to_return->data;
 }
 
+void *queue_most_recent_element(Queue *q)
+{
+  if (q->next == NULL)
+    return NULL;
+  else
+  {
+    QueueElementHeader *cur = q->next;
+    while (cur->next != NULL)
+      cur = cur->next;
+    return (void *)cur->data;
+  }
+}
 #undef QUEUE_ELEM_ITER
 #endif

server.c

@@ -1,12 +1,12 @@
+#include "sokol_time.h"
 #include <chipmunk.h> // initializing bodies
 #include "types.h"
-#include "sokol_time.h"
 #include <enet/enet.h>
-#include <stdio.h>
+#include <errno.h>
 #include <inttypes.h> // int64 printing
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h> // error string
-#include <errno.h>
 
 #include "minilzo.h"
 
@@ -31,9 +31,11 @@
 #define NOMINMAX
 #include <Windows.h>
 // This is slow, if you can use RDTSC and set the multiplier in SpallInit, you'll have far better timing accuracy
-double get_time_in_micros() {
+double get_time_in_micros()
+{
   static double invfreq;
-	if (!invfreq) {
+  if (!invfreq)
+  {
     LARGE_INTEGER frequency;
     QueryPerformanceFrequency(&frequency);
     invfreq = 1000000.0 / frequency.QuadPart;
@@ -70,16 +72,23 @@ void server(void* info_raw)
 
 #endif
 
-
   struct GameState gs = {0};
   size_t entities_size = (sizeof(Entity) * MAX_ENTITIES);
   Entity *entity_data = malloc(entities_size);
   initialize(&gs, entity_data, entities_size);
   Log("Allocated %zu bytes for entities\n", entities_size);
 
+  // inputs
+  Queue player_input_queues[MAX_PLAYERS] = {0};
+  size_t input_queue_data_size = QUEUE_SIZE_FOR_ELEMENTS(sizeof(InputFrame), INPUT_QUEUE_MAX);
+  for (int i = 0; i < MAX_PLAYERS; i++)
+    queue_init(&player_input_queues[i], sizeof(InputFrame), calloc(1, input_queue_data_size), input_queue_data_size);
+
+  // voip
   Queue player_voip_buffers[MAX_PLAYERS] = {0};
   size_t player_voip_buffer_size = QUEUE_SIZE_FOR_ELEMENTS(sizeof(OpusPacket), VOIP_PACKET_BUFFER_SIZE);
-	for (int i = 0; i < MAX_PLAYERS; i++) queue_init(&player_voip_buffers[i], sizeof(OpusPacket), calloc(1, player_voip_buffer_size), player_voip_buffer_size);
+  for (int i = 0; i < MAX_PLAYERS; i++)
+    queue_init(&player_voip_buffers[i], sizeof(OpusPacket), calloc(1, player_voip_buffer_size), player_voip_buffer_size);
   OpusEncoder *player_encoders[MAX_PLAYERS] = {0};
   OpusDecoder *player_decoders[MAX_PLAYERS] = {0};
 
@@ -189,14 +198,15 @@ void server(void* info_raw)
   uint64_t last_processed_time = stm_now();
   uint64_t last_saved_world_time = stm_now();
   uint64_t last_sent_audio_time = stm_now();
+  uint64_t last_sent_gamestate_time = stm_now();
   float audio_time_to_send = 0.0f;
   float total_time = 0.0f;
-	size_t player_to_latest_id_processed[MAX_PLAYERS] = { 0 };
   char *world_save_buffer = malloc(entities_size);
   while (true)
   {
     ma_mutex_lock(&info->info_mutex);
-		if (info->should_quit) {
+    if (info->should_quit)
+    {
       ma_mutex_unlock(&info->info_mutex);
       break;
     }
@@ -241,7 +251,6 @@ void server(void* info_raw)
             event.peer->data = (void *)player_slot;
             gs.players[player_slot] = (struct Player){0};
             gs.players[player_slot].connected = true;
-						player_to_latest_id_processed[player_slot] = 0;
 
             int error;
             player_encoders[player_slot] = opus_encoder_create(VOIP_SAMPLE_RATE, 1, OPUS_APPLICATION_VOIP, &error);
@@ -268,62 +277,37 @@ void server(void* info_raw)
           {
             Log("Wtf an empty packet from enet?\n");
           }
-					else {
+          else
+          {
             int64_t player_slot = (int64_t)event.peer->data;
             size_t length = event.packet->dataLength;
-#define VOIP_QUEUE_DECL(queue_name, queue_data_name) Queue queue_name = {0}; char queue_data_name[QUEUE_SIZE_FOR_ELEMENTS(sizeof(OpusPacket), VOIP_PACKET_BUFFER_SIZE)] = {0}; queue_init(&queue_name, sizeof(OpusPacket), queue_data_name, QUEUE_SIZE_FOR_ELEMENTS(sizeof(OpusPacket), VOIP_PACKET_BUFFER_SIZE))
+#define VOIP_QUEUE_DECL(queue_name, queue_data_name)                                                \
+  Queue queue_name = {0};                                                                           \
+  char queue_data_name[QUEUE_SIZE_FOR_ELEMENTS(sizeof(OpusPacket), VOIP_PACKET_BUFFER_SIZE)] = {0}; \
+  queue_init(&queue_name, sizeof(OpusPacket), queue_data_name, QUEUE_SIZE_FOR_ELEMENTS(sizeof(OpusPacket), VOIP_PACKET_BUFFER_SIZE))
             VOIP_QUEUE_DECL(throwaway_buffer, throwaway_buffer_data);
             Queue *buffer_to_fill = &player_voip_buffers[player_slot];
-						if (get_entity(&gs, gs.players[player_slot].entity) == NULL) buffer_to_fill = &throwaway_buffer;
-						struct ClientToServer received = { .mic_data = buffer_to_fill };
-						if (!client_to_server_deserialize(&gs, &received, event.packet->data, event.packet->dataLength))
-						{
-							Log("Bad packet from client %d\n", (int)player_slot);
-						}
-						else
-						{
-							size_t latest_id = player_to_latest_id_processed[player_slot];
+            if (get_entity(&gs, gs.players[player_slot].entity) == NULL)
+              buffer_to_fill = &throwaway_buffer;
 
-							if (received.inputs[0].id > latest_id)
-							{
-								for (int i = INPUT_BUFFER - 1; i >= 0; i--)
-								{
-									if (received.inputs[i].tick == 0) // empty input
-										continue;
-									if (received.inputs[i].id <= latest_id)
-										continue; // don't reprocess inputs already processed
-									InputFrame cur_input = received.inputs[i];
-									gs.players[player_slot].input.movement = cur_input.movement;
-									gs.players[player_slot].input.hand_pos = cur_input.hand_pos;
+            queue_clear(&player_input_queues[player_slot]);
+            struct ClientToServer received = {.mic_data = buffer_to_fill, .input_data = &player_input_queues[player_slot]};
+            char decompressed[MAX_CLIENT_TO_SERVER] = {0};
+            size_t decompressed_max_len = MAX_CLIENT_TO_SERVER;
+            assert(LZO1X_MEM_DECOMPRESS == 0);
 
-									// for these "event" inputs, only modify the current input if the event is true.
-									// while processing the gamestate, will mark it as false once processed. This
-									// prevents setting the event input to false before it's been processed.
-									if (cur_input.take_over_squad >= 0)
-										gs.players[player_slot].input.take_over_squad = cur_input.take_over_squad;
-									if (cur_input.accept_cur_squad_invite)
-										gs.players[player_slot].input.accept_cur_squad_invite = cur_input.accept_cur_squad_invite;
-									if (cur_input.reject_cur_squad_invite)
-										gs.players[player_slot].input.reject_cur_squad_invite = cur_input.reject_cur_squad_invite;
-									if (cur_input.invite_this_player.generation > 0)
-									{
-										gs.players[player_slot].input.invite_this_player = cur_input.invite_this_player;
-									}
-									if (cur_input.seat_action)
+            int return_value = lzo1x_decompress_safe(event.packet->data, event.packet->dataLength, decompressed, &decompressed_max_len, NULL);
+
+            if (return_value == LZO_E_OK)
             {
-										gs.players[player_slot].input.seat_action = cur_input.seat_action;
-										gs.players[player_slot].input.grid_hand_pos_local_to = cur_input.grid_hand_pos_local_to;
-									}
-									if (cur_input.dobuild)
+              if (!client_to_server_deserialize(&gs, &received, decompressed, decompressed_max_len))
               {
-										gs.players[player_slot].input.grid_hand_pos_local_to = cur_input.grid_hand_pos_local_to;
-										gs.players[player_slot].input.dobuild = cur_input.dobuild;
-										gs.players[player_slot].input.build_type = cur_input.build_type;
-										gs.players[player_slot].input.build_rotation = cur_input.build_rotation;
-									}
+                Log("Bad packet from client %d\n", (int)player_slot);
               }
-								player_to_latest_id_processed[player_slot] = received.inputs[0].id;
             }
+            else
+            {
+              Log("Couldn't decompress player packet, error code %d from lzo\n", return_value);
             }
           }
           /* Clean up the packet now that we're done using it. */
@@ -356,7 +340,6 @@ void server(void* info_raw)
         break;
         }
       }
-
     }
     total_time += (float)stm_sec(stm_diff(stm_now(), last_processed_time));
     last_processed_time = stm_now();
@@ -368,12 +351,24 @@ void server(void* info_raw)
       total_time = max_time;
     }
 
-		bool processed = false;
     PROFILE_SCOPE("World Processing")
     {
       while (total_time > TIMESTEP)
       {
-				processed = true;
+        CONNECTED_PEERS(enet_host, cur)
+        {
+          int this_player_index = (int)(int64_t)cur->data;
+          QUEUE_ITER(&player_input_queues[this_player_index], cur_header)
+          {
+            InputFrame *cur = (InputFrame *)cur_header->data;
+            if (cur->tick == tick(&gs))
+            {
+              gs.players[this_player_index].input = *cur;
+              break;
+            }
+          }
+        }
+
         process(&gs, TIMESTEP);
         total_time -= TIMESTEP;
       }
@@ -381,7 +376,8 @@ void server(void* info_raw)
 
     if (world_save_name != NULL && (stm_sec(stm_diff(stm_now(), last_saved_world_time))) > TIME_BETWEEN_WORLD_SAVE)
     {
-			PROFILE_SCOPE("Save World") {
+      PROFILE_SCOPE("Save World")
+      {
         last_saved_world_time = stm_now();
         ServerToClient msg = (ServerToClient){
             .cur_gs = &gs,
@@ -416,9 +412,11 @@ void server(void* info_raw)
       }
     }
 
-		if (processed)
+    if (stm_sec(stm_diff(stm_now(), last_sent_gamestate_time)) > TIME_BETWEEN_SEND_GAMESTATE)
+    {
+      last_sent_gamestate_time = stm_now();
+      PROFILE_SCOPE("send_data")
       {
-			PROFILE_SCOPE("send_data") {
         static char lzo_working_mem[LZO1X_1_MEM_COMPRESS] = {0};
 
         audio_time_to_send += (float)stm_sec(stm_diff(stm_now(), last_sent_audio_time));
@@ -494,7 +492,8 @@ void server(void* info_raw)
               {
                 Log("Failed to encode audio packet for player %d: opus error code %d\n", this_player_index, ret);
               }
-							else {
+              else
+              {
                 this_packet->length = ret;
               }
             }
@@ -502,7 +501,7 @@ void server(void* info_raw)
           ServerToClient to_send = (ServerToClient){
               .cur_gs = &gs,
               .your_player = this_player_index,
-						.playback_buffer = &buffer_to_play,
+              .audio_playback_buffer = &buffer_to_play,
           };
 
           size_t len = 0;
@@ -536,7 +535,6 @@ void server(void* info_raw)
           free(compressed_buffer);
         }
       }
-
     }
   }
   for (int i = 0; i < MAX_PLAYERS; i++)
@@ -546,7 +544,10 @@ void server(void* info_raw)
     if (player_decoders[i] != NULL)
       opus_decoder_destroy(player_decoders[i]);
   }
-	for (int i = 0; i < MAX_PLAYERS; i++) free(player_voip_buffers[i].data);
+  for (int i = 0; i < MAX_PLAYERS; i++)
+    free(player_voip_buffers[i].data);
+  for (int i = 0; i < MAX_PLAYERS; i++)
+    free(player_input_queues[i].data);
   free(world_save_buffer);
   destroy(&gs);
   free(entity_data);

types.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "ipsettings.h"
+
 #define MAX_PLAYERS 16
 #define MAX_ENTITIES 1024 * 25
 #define BOX_SIZE 0.25f
@@ -21,7 +23,11 @@
 #define SUN_RADIUS 10.0f
 #define INSTANT_DEATH_DISTANCE_FROM_SUN 2000.0f
 #define SUN_POS ((V2){50.0f, 0.0f})
+#ifdef NO_GRAVITY
+#define SUN_GRAVITY_STRENGTH 0.1f
+#else
 #define SUN_GRAVITY_STRENGTH (9.0e2f)
+#endif
 #define SOLAR_ENERGY_PER_SECOND 0.02f
 #define DAMAGE_TO_PLAYER_PER_BLOCK 0.1f
 #define BATTERY_CAPACITY DAMAGE_TO_PLAYER_PER_BLOCK * 0.7f
@@ -38,15 +44,24 @@
 #define VOIP_PACKET_BUFFER_SIZE 15 // audio. Must be bigger than 2
 #define VOIP_EXPECTED_FRAME_COUNT 480
 #define VOIP_SAMPLE_RATE 48000
-#define VOIP_TIME_PER_PACKET 1.0f / ((float)(VOIP_SAMPLE_RATE/VOIP_EXPECTED_FRAME_COUNT)) // in seconds
+#define VOIP_TIME_PER_PACKET (1.0f / ((float)(VOIP_SAMPLE_RATE / VOIP_EXPECTED_FRAME_COUNT))) // in seconds
 #define VOIP_PACKET_MAX_SIZE 4000
 #define VOIP_DISTANCE_WHEN_CANT_HEAR (VISION_RADIUS * 0.8f)
 
+#define MAX_REPREDICTION_TIME (TIMESTEP * 50.0f)
 #define TIME_BETWEEN_SEND_GAMESTATE (1.0f / 20.0f)
 #define TIME_BETWEEN_INPUT_PACKETS (1.0f / 20.0f)
 #define TIMESTEP (1.0f / 60.0f) // server required to simulate at this, defines what tick the game is on
 #define SERVER_PORT 2551
-#define INPUT_BUFFER 6
+#define LOCAL_INPUT_QUEUE_MAX 90 // please god let you not have more than 90 frames of game latency
+#define INPUT_QUEUE_MAX 15
+
+// cross platform threadlocal variables
+#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
+#define THREADLOCAL __declspec(thread)
+#else
+#define THREADLOCAL __thread
+#endif
 
 // must make this header and set the target address, just #define SERVER_ADDRESS "127.0.0.1"
 #include "ipsettings.h" // don't leak IP!
@@ -85,8 +100,8 @@ typedef void cpBody;
 typedef void cpShape;
 #endif
 
-#include <stdbool.h>
 #include "queue.h"
+#include <stdbool.h>
 
 #ifndef OPUS_TYPES_H
 typedef int opus_int32;
@@ -103,9 +118,11 @@ typedef int opus_int32;
 typedef sgp_vec2 V2;
 typedef sgp_point P2;
 
-#define Log(...){                                     \
+#define Log(...)                                     \
+  {                                                  \
     fprintf(stdout, "%s:%d | ", __FILE__, __LINE__); \
-    fprintf(stdout, __VA_ARGS__);}
+    fprintf(stdout, __VA_ARGS__);                    \
+  }
 
 enum BoxType
 {
@@ -155,7 +172,6 @@ static bool entityids_same(EntityID a, EntityID b)
 typedef struct InputFrame
 {
   uint64_t tick;
-	size_t id; // each input has unique, incrementing, I.D, so server doesn't double process inputs. Inputs to server should be ordered from 0-max like biggest id-smallest. This is done so if packet loss server still processes input
   V2 movement;
 
   int take_over_squad; // -1 means not taking over any squad
@@ -164,10 +180,8 @@ typedef struct InputFrame
   EntityID invite_this_player; // null means inviting nobody! @Robust make it so just sends interact pos input, and server processes who to invite. This depends on client side prediction + proper input processing at the right tick.
 
   bool seat_action;
-	EntityID seat_to_inhabit;
-	V2 hand_pos; // local to player transationally but not rotationally unless field below is not null, then it's local to that grid
+  V2 hand_pos; // local to player transationally but not rotationally
   // @BeforeShip bounds check on the hand_pos so that players can't reach across the entire map
-	EntityID grid_hand_pos_local_to; // when not null, hand_pos is local to this grid. this prevents bug where at high speeds the built block is in the wrong place on the selected grid
 
   bool dobuild;
   enum BoxType build_type;
@@ -240,7 +254,7 @@ typedef struct GameState
 {
   cpSpace *space;
 
-	double time;
+  double time; // @Robust separate tick integer not prone to precision issues
 
   V2 goldpos;
 
@@ -258,7 +272,9 @@ typedef struct GameState
   EntityID free_list;
 } GameState;
 
-#define PLAYERS_ITER(players, cur) for(Player * cur = players; cur < players+MAX_PLAYERS; cur++) if(cur->connected)
+#define PLAYERS_ITER(players, cur)                                \
+  for (Player *cur = players; cur < players + MAX_PLAYERS; cur++) \
+    if (cur->connected)
 
 #define PI 3.14159f
 #define TAU (PI * 2.0f)
@@ -287,7 +303,8 @@ static float rotangle(enum CompassRotation rot)
   }
 }
 
-typedef struct OpusPacket {
+typedef struct OpusPacket
+{
   opus_int32 length;
   char data[VOIP_PACKET_MAX_SIZE];
 } OpusPacket;
@@ -295,14 +312,14 @@ typedef struct OpusPacket {
 typedef struct ServerToClient
 {
   struct GameState *cur_gs;
-	Queue* playback_buffer;
+  Queue *audio_playback_buffer;
   int your_player;
 } ServerToClient;
 
 typedef struct ClientToServer
 {
   Queue *mic_data;   // on serialize, flushes this of packets. On deserialize, fills it
-	InputFrame inputs[INPUT_BUFFER];
+  Queue *input_data; // does not flush on serialize! must be in order of tick
 } ClientToServer;
 
 #define DeferLoop(start, end) \
@@ -315,6 +332,7 @@ void server(void* info); // data parameter required from thread api...
 EntityID create_spacestation(GameState *gs);
 void initialize(struct GameState *gs, void *entity_arena, size_t entity_arena_size);
 void destroy(struct GameState *gs);
+void process_fixed_timestep(GameState *gs);
 void process(struct GameState *gs, float dt); // does in place
 Entity *closest_to_point_in_radius(struct GameState *gs, V2 point, float radius);
 uint64_t tick(struct GameState *gs);
@@ -360,7 +378,8 @@ void dbg_drawall();
 void dbg_line(V2 from, V2 to);
 void dbg_rect(V2 center);
 
-typedef struct ServerThreadInfo {
+typedef struct ServerThreadInfo
+{
   ma_mutex info_mutex;
   const char *world_save;
   bool should_quit;
@@ -374,8 +393,7 @@ typedef struct AABB
 
 static AABB centered_at(V2 point, V2 size)
 {
-	return (AABB)
-	{
+  return (AABB){
       .x = point.x - size.x / 2.0f,
       .y = point.y - size.y / 2.0f,
       .width = size.x,
@@ -419,7 +437,6 @@ static V2 V2normalize(V2 v)
   return V2scale(v, 1.0f / V2length(v));
 }
 
-
 static float V2dot(V2 a, V2 b)
 {
   return a.x * b.x + a.y * b.y;
@@ -497,7 +514,8 @@ static float lerp(float a, float b, float f)
   return a * (1.0f - f) + (b * f);
 }
 
-static float lerp_angle(float p_from, float p_to, float p_weight) {
+static float lerp_angle(float p_from, float p_to, float p_weight)
+{
   float difference = fmodf(p_to - p_from, (float)TAU);
   float distance = fmodf(2.0f * difference, (float)TAU) - difference;
   return p_from + distance * p_weight;