some experiements with state sync

[blank.git] / src / client / client.cpp

diff --git a/src/client/client.cpp b/src/client/client.cpp
index 4a48b45afc91eb5179f9a6d038c88b19244f213d..dbdaa73641c5f52c58949d82d2f7b09bb0038bed 100644 (file)
--- a/src/client/client.cpp
+++ b/src/client/client.cpp
@@ -56,6 +56,7 @@ InteractiveState::InteractiveState(MasterState &master, uint32_t player_id)
 )
 , chunk_renderer(*interface.GetPlayer().chunks)
 , skeletons()
+, loop_timer(16)
 , update_timer(16)
 , player_hist() {
        TextureIndex tex_index;
@@ -65,6 +66,7 @@ InteractiveState::InteractiveState(MasterState &master, uint32_t player_id)
        skeletons.Load();
        // TODO: better solution for initializing HUD
        interface.SelectNext();
+       loop_timer.Start();
        update_timer.Start();
 }
 
@@ -101,14 +103,17 @@ void InteractiveState::Handle(const SDL_Event &event) {
 }
 
 void InteractiveState::Update(int dt) {
+       loop_timer.Update(dt);
+       update_timer.Update(dt);
        master.Update(dt);
 
        interface.Update(dt);
-       world.Update(dt);
+       while (loop_timer.HitOnce()) {
+               world.Update(loop_timer.Interval());
+               loop_timer.PopIteration();
+       }
        chunk_renderer.Update(dt);
 
-       update_timer.Update(dt);
-
        Entity &player = *interface.GetPlayer().entity;
 
        if (update_timer.Hit()) {
@@ -126,11 +131,10 @@ void InteractiveState::Update(int dt) {
 void InteractiveState::PushPlayerUpdate(const Entity &player) {
        std::uint16_t packet = master.GetClient().SendPlayerUpdate(player);
        if (player_hist.size() < 16) {
-               player_hist.emplace_back(player.GetState(), update_timer.Elapsed(), packet);
+               player_hist.emplace_back(player.GetState(), packet);
        } else {
                auto entry = player_hist.begin();
                entry->state = player.GetState();
-               entry->timestamp = update_timer.Elapsed();
                entry->packet = packet;
                player_hist.splice(player_hist.end(), player_hist, entry);
        }
@@ -145,13 +149,49 @@ void InteractiveState::MergePlayerCorrection(uint16_t seq, const EntityState &co
        // drop anything older than the fix
        while (entry != end) {
                int pack_diff = int16_t(seq) - int16_t(entry->packet);
-               if (pack_diff < 0) {
+               if (pack_diff > 0) {
                        entry = player_hist.erase(entry);
                } else {
                        break;
                }
        }
-       if (entry == end) return;
+
+       EntityState replay_state(corrected_state);
+       EntityState &player_state = interface.GetPlayer().entity->GetState();
+
+       if (entry != end) {
+               entry->state.chunk_pos = replay_state.chunk_pos;
+               entry->state.block_pos = replay_state.block_pos;
+               ++entry;
+       }
+
+       while (entry != end) {
+               replay_state.velocity = entry->state.velocity;
+               replay_state.Update(16);
+               entry->state.chunk_pos = replay_state.chunk_pos;
+               entry->state.block_pos = replay_state.block_pos;
+               ++entry;
+       }
+
+       glm::vec3 displacement(replay_state.Diff(player_state));
+       const float disp_squared = dot(displacement, displacement);
+
+       if (disp_squared < 16.0f * numeric_limits<float>::epsilon()) {
+               return;
+       }
+
+       constexpr float warp_thresh = 1.0f;
+       constexpr float max_disp = 0.0001f; // (1/100)^2
+
+       if (disp_squared > warp_thresh) {
+               player_state.chunk_pos = replay_state.chunk_pos;
+               player_state.block_pos = replay_state.block_pos;
+       } else if (disp_squared < max_disp) {
+               player_state.block_pos += displacement;
+       } else {
+               displacement *= 0.01f / sqrt(disp_squared);
+               player_state.block_pos += displacement;
+       }
 }
 
 void InteractiveState::Render(Viewport &viewport) {