Multiple inputs per input packet

gamestate.c

@@ -268,6 +268,16 @@ void des_int(char **in, int *i)
     memread(in, i);
 }
 
+void ser_uint64(char **out, uint64_t i)
+{
+    memwrite(out, i);
+}
+
+void des_uint64(char **in, uint64_t *i)
+{
+    memread(in, i);
+}
+
 void ser_bool(char **out, bool b)
 {
     **out = (char)b;
@@ -403,6 +413,8 @@ void into_bytes(struct ServerToClient *msg, char *bytes, int *out_len, int max_l
     ser_int(&bytes, msg->your_player);
     LEN_CHECK();
 
+    ser_uint64(&bytes, gs->tick);
+
     ser_double(&bytes, gs->time);
     LEN_CHECK();
 
@@ -444,6 +456,9 @@ void from_bytes(struct ServerToClient *msg, char *bytes, int max_len)
     des_int(&bytes, &msg->your_player);
     LEN_CHECK();
 
+    des_uint64(&bytes, &gs->tick);
+    LEN_CHECK();
+
     des_double(&bytes, &gs->time);
     LEN_CHECK();
 
@@ -523,6 +538,7 @@ void process(struct GameState *gs, float dt)
 {
     assert(gs->space != NULL);
 
+    gs->tick += 1;
     gs->time += dt;
 
     // process input
@@ -578,7 +594,6 @@ void process(struct GameState *gs, float dt)
                         }
                     }
 
-
                     if (ship_to_inhabit == -1)
                     {
                         Log("Couldn't find ship to inhabit even though point collision returned something\n");

main.c

@@ -31,6 +31,7 @@ static bool mouse_pressed = false;
 static uint64_t mouse_pressed_frame = 0;
 static bool mouse_frozen = false;                    // @BeforeShip make this debug only thing
 static float funval = 0.0f;                          // easy to play with value controlled by left mouse button when held down @BeforeShip remove on release builds
+static struct ClientToServer client_to_server = {0}; // buffer of inputs
 static ENetHost *client;
 static ENetPeer *peer;
 
@@ -151,7 +152,7 @@ static void frame(void)
 {
     int width = sapp_width(), height = sapp_height();
     float ratio = width / (float)height;
-    float time = sapp_frame_count() * sapp_frame_duration();
+    double time = sapp_frame_count() * sapp_frame_duration();
     float dt = sapp_frame_duration();
 
     // pressed input management
@@ -287,32 +288,54 @@ static void frame(void)
         // Create and send input packet
         {
             // @Robust accumulate total time and send input at rate like 20 hz, not every frame
-            struct ClientToServer curmsg = {0};
+
+            struct InputFrame cur_input_frame = {0};
             V2 input = (V2){
                 .x = (float)keydown[SAPP_KEYCODE_D] - (float)keydown[SAPP_KEYCODE_A],
                 .y = (float)keydown[SAPP_KEYCODE_W] - (float)keydown[SAPP_KEYCODE_S],
             };
-            curmsg.movement = input;
-            curmsg.inhabit = keypressed[SAPP_KEYCODE_G].pressed;
-            curmsg.dobuild = mouse_pressed;
-            curmsg.grid_index = grid_index;
-            if (curmsg.dobuild)
+            cur_input_frame.movement = input;
+            cur_input_frame.inhabit = keypressed[SAPP_KEYCODE_G].pressed;
+            cur_input_frame.dobuild = mouse_pressed;
+            cur_input_frame.grid_index = grid_index;
+            if (cur_input_frame.dobuild)
             {
                 if (grid_index != -1)
                 {
-                    curmsg.build = grid_world_to_local(&gs.grids[curmsg.grid_index], build_preview.pos);
-                    V2 untransformed = grid_local_to_world(&gs.grids[curmsg.grid_index], curmsg.build);
+                    cur_input_frame.build = grid_world_to_local(&gs.grids[cur_input_frame.grid_index], build_preview.pos);
+                    V2 untransformed = grid_local_to_world(&gs.grids[cur_input_frame.grid_index], cur_input_frame.build);
                     untransformed.x += 5.0f;
                 }
                 else
                 {
-                    curmsg.build = build_preview.pos;
+                    cur_input_frame.build = build_preview.pos;
                 }
             }
 
-            // @BeforeShip figure out why tf the possess ship key is so unreliable
-            ENetPacket *packet = enet_packet_create((void *)&curmsg, sizeof(curmsg), ENET_PACKET_FLAG_UNRELIABLE_FRAGMENT);
+            struct InputFrame latest = client_to_server.inputs[0];
+            // if they're not the same
+            if (
+                !V2cmp(cur_input_frame.movement, latest.movement, 0.01f) ||
+                cur_input_frame.inhabit != latest.inhabit ||
+                cur_input_frame.dobuild != latest.dobuild ||
+                cur_input_frame.grid_index != latest.grid_index ||
+                !V2cmp(cur_input_frame.build, latest.build, 0.01f))
+            {
+                for (int i = 0; i < INPUT_BUFFER - 1; i++)
+                {
+                    client_to_server.inputs[i + 1] = client_to_server.inputs[i];
+                }
+                cur_input_frame.tick = gs.tick;
+                client_to_server.inputs[0] = cur_input_frame;
+            }
+
+            static double last_input_sent_time = 0.0;
+            if (fabs(last_input_sent_time - time) > TIME_BETWEEN_INPUT_PACKETS)
+            {
+                ENetPacket *packet = enet_packet_create((void *)&client_to_server, sizeof(client_to_server), ENET_PACKET_FLAG_UNRELIABLE_FRAGMENT);
                 enet_peer_send(peer, 0, packet);
+                last_input_sent_time = time;
+            }
         }
 
         // @BeforeShip client side prediction and rollback to previous server authoritative state, then replay inputs
@@ -434,9 +457,6 @@ static void frame(void)
             }
         }
 
-        set_color(RED);
-        sgp_draw_filled_rect(1.0f, 0.5f, 0.3f, 0.3f);
-
         // gold target
         set_color(GOLD);
         sgp_draw_filled_rect(gs.goldpos.x, gs.goldpos.y, 0.1f, 0.1f);
@@ -466,21 +486,28 @@ void event(const sapp_event *e)
     switch (e->type)
     {
     case SAPP_EVENTTYPE_KEY_DOWN:
-        keydown[e->key_code] = true;
         if (e->key_code == SAPP_KEYCODE_T)
         {
             mouse_frozen = !mouse_frozen;
         }
+        if (!mouse_frozen)
+        {
+            keydown[e->key_code] = true;
             if (keypressed[e->key_code].frame == 0)
             {
                 keypressed[e->key_code].pressed = true;
                 keypressed[e->key_code].frame = e->frame_count;
             }
+        }
         break;
     case SAPP_EVENTTYPE_KEY_UP:
+        if (!mouse_frozen)
+        {
             keydown[e->key_code] = false;
             keypressed[e->key_code].pressed = false;
+
             keypressed[e->key_code].frame = 0;
+        }
         break;
     case SAPP_EVENTTYPE_MOUSE_DOWN:
         if (e->mouse_button == SAPP_MOUSEBUTTON_LEFT)

server.c

@@ -78,6 +78,7 @@ void server(void *data)
     ENetEvent event;
     uint64_t last_processed_time = stm_now();
     float total_time = 0.0f;
+    uint64_t player_to_latest_tick_processed[MAX_PLAYERS] = {0};
     while (true)
     {
         // @Speed handle enet messages and simulate gamestate in parallel, then sync... must clone gamestate for this
@@ -140,34 +141,34 @@ void server(void *data)
                         struct ClientToServer received = {0};
                         memcpy(&received, event.packet->data, length);
                         int64_t player_slot = (int64_t)event.peer->data;
+                        uint64_t latest_tick = player_to_latest_tick_processed[player_slot];
 
-                        // dobuild logging
-                        if (false)
-                        {
-                            if (received.dobuild)
+                        if (received.inputs[0].tick > latest_tick)
                         {
-                                Log("Received build command\n");
-                            }
-                            if (gs.players[player_slot].dobuild && !received.dobuild)
+                            for (int i = INPUT_BUFFER - 1; i >= 0; i--)
                             {
-                                Log("Received end of build command\n");
-                            }
-                        }
-                        
-                        gs.players[player_slot].movement = received.movement;
-                        gs.players[player_slot].grid_index = received.grid_index;
+                                if (received.inputs[i].tick == 0) // empty input
+                                    continue;
+                                if(received.inputs[i].tick <= latest_tick)
+                                    continue; // don't reprocess inputs already processed
+                                struct InputFrame cur_input = received.inputs[i];
+                                gs.players[player_slot].movement = cur_input.movement;
+                                gs.players[player_slot].grid_index = cur_input.grid_index;
 
                                 // for these "event" inputs, only modify the game state 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 (received.inhabit)
+                                if (cur_input.inhabit)
                                 {
-                            gs.players[player_slot].inhabit = received.inhabit;
+                                    gs.players[player_slot].inhabit = cur_input.inhabit;
                                 }
-                        if (received.dobuild)
+                                if (cur_input.dobuild)
                                 {
-                            gs.players[player_slot].build = received.build;
-                            gs.players[player_slot].dobuild = received.dobuild;
+                                    gs.players[player_slot].build = cur_input.build;
+                                    gs.players[player_slot].dobuild = cur_input.dobuild;
+                                }
+                            }
+                            player_to_latest_tick_processed[player_slot] = received.inputs[0].tick;
                         }
                     }
 

types.h

@@ -8,7 +8,9 @@
 #define MAX_BOXES_PER_GRID 32
 #define BOX_MASS 1.0f
 #define TIMESTEP (1.0f / 60.0f) // not required to simulate at this, but this defines what tick the game is on
+#define TIME_BETWEEN_INPUT_PACKETS (1.0f / 20.0f)
 #define SERVER_PORT 2551
+#define INPUT_BUFFER 4
 
 // must make this header and set the target address, just #define SERVER_ADDRESS "127.0.0.1"
 #include "ipsettings.h" // don't leak IP!
@@ -61,6 +63,7 @@ struct GameState
 {
     cpSpace *space;
 
+    uint64_t tick;
     double time;
 
     V2 goldpos;
@@ -108,6 +111,9 @@ struct ServerToClient
 
 struct ClientToServer
 {
+    struct InputFrame
+    {
+        uint64_t tick;
         V2 movement;
         bool inhabit;
 
@@ -115,6 +121,7 @@ struct ClientToServer
         V2 build;
         bool dobuild;
         int grid_index;
+    } inputs[INPUT_BUFFER];
 };
 
 // server
@@ -224,6 +231,11 @@ static V2 V2sub(V2 a, V2 b)
     };
 }
 
+static bool V2cmp(V2 a, V2 b, float eps)
+{
+    return V2length(V2sub(a, b)) < eps;
+}
+
 static inline float clamp01(float f)
 {
     return fmax(0.0f, fmin(f, 1.0f));