Much better physics but still no rotation

gamestate.c

@@ -39,11 +39,12 @@ static void integrate_acceleration(struct Body *body, float dt)
 
 static void modify_interval(struct Body *from, float *from_interval, V2 center, V2 axis)
 {
+    float halfbox = BOX_SIZE/2.0f;
     V2 points[4] = {
-        V2add(from->position, V2rotate((V2){.x = 0.5f, .y = -0.5f}, from->rotation)),  // upper right
+        V2add(from->position, V2rotate((V2){.x = halfbox, .y = -halfbox}, from->rotation)),  // upper right
-        V2add(from->position, V2rotate((V2){.x = 0.5f, .y = 0.5f}, from->rotation)),   // bottom right
+        V2add(from->position, V2rotate((V2){.x = halfbox, .y = halfbox}, from->rotation)),   // bottom right
-        V2add(from->position, V2rotate((V2){.x = -0.5f, .y = 0.5f}, from->rotation)),  // lower left
+        V2add(from->position, V2rotate((V2){.x = -halfbox, .y = halfbox}, from->rotation)),  // lower left
-        V2add(from->position, V2rotate((V2){.x = -0.5f, .y = -0.5f}, from->rotation)), // upper left
+        V2add(from->position, V2rotate((V2){.x = -halfbox, .y = -halfbox}, from->rotation)), // upper left
     };
     for (int point_i = 0; point_i < 4; point_i++)
     {
@@ -119,10 +120,11 @@ void process(struct GameState *gs, float dt)
             assert(from_interval[0] < from_interval[1]);
             assert(to_interval[0] < to_interval[1]);
 
-            if (to_interval[0] < from_interval[1]) // intersecting
+            if (from_interval[1] > to_interval[0]) // intersecting
             {
-                from->position = V2add(from->position, V2scale(axis, -0.5f));
+                float intersection_depth = from_interval[1] - to_interval[0];
-                to->position = V2add(from->position, V2scale(axis, 0.5f));
+                from->position = V2add(from->position, V2scale(axis, intersection_depth*-0.5f));
+                to->position = V2add(to->position, V2scale(axis, intersection_depth*0.5f));
             }
         }
     }

main.c

@@ -113,6 +113,10 @@ static void frame(void)
                         Log("New client from host %x\n", event.peer->address.host);
                         break;
                     case ENET_EVENT_TYPE_RECEIVE:
+                        // @Robust @BeforeShip use some kind of serialization strategy that checks for out of bounds
+                        // and other validation instead of just casting to a struct
+                        // "Alignment of structure members can be different even among different compilers on the same platform, let alone different platforms."
+                        // ^^ need serialization strategy that accounts for this if multiple platforms is happening https://stackoverflow.com/questions/28455163/how-can-i-portably-send-a-c-struct-through-a-network-socket
                         struct ServerToClient msg;
                         if(event.packet->dataLength != sizeof(msg))
                         {
@@ -151,7 +155,7 @@ static void frame(void)
         ENetPacket * packet = enet_packet_create((void*)&curmsg, sizeof(curmsg), ENET_PACKET_FLAG_UNRELIABLE_FRAGMENT);
         enet_peer_send(peer, 0, packet);
 
-        process(&gs, (float)sapp_frame_duration());
+        // process(&gs, (float)sapp_frame_duration());
     }
 
     // drawing

server.c

@@ -15,6 +15,9 @@ void server(void *data)
 
     struct GameState gs = {0};
 
+    // two boxes stacked on top
+    if (false)
+    {
         gs.boxes[0] = (struct Box){
             .body = (struct Body){
                 .position = (P2){.x = 0.75f, .y = 0.0}},
@@ -26,6 +29,18 @@ void server(void *data)
         };
         gs.boxes[1].body.old_position = gs.boxes[1].body.position;
         gs.num_boxes = 2;
+    }
+
+    // one box
+    if (true)
+    {
+        gs.boxes[0] = (struct Box){
+            .body = (struct Body){
+                .position = (P2){.x = 0.75f, .y = 0.0}},
+        };
+        gs.boxes[0].body.old_position = gs.boxes[0].body.position;
+        gs.num_boxes = 1;
+    }
 
     if (enet_initialize() != 0)
     {
@@ -92,9 +107,9 @@ void server(void *data)
                     else
                     {
                         event.peer->data = (void *)player_slot;
-                        gs.players[player_slot] = (struct Player){ .body.position = (V2){
+                        gs.players[player_slot] = (struct Player){.body.position = (V2){
                                                                       .x = 0.0f,
-                            .y = 1.0f*(float)player_slot,
+                                                                      .y = 1.0f * (float)player_slot,
                                                                   }};
                         gs.players[player_slot].body.old_position = gs.players[player_slot].body.position;
                         gs.players[player_slot].connected = true;