add basic entity movement

src/server/state/GameState.cpp

@@ -25,8 +25,8 @@ void GameState::Update(float a_Delta) {
 	// TODO: don't make STEP_TIME constant
 	static const float stepTimeSecond = static_cast<float>(STEP_TIME) / 1000.0f;
 	m_Time += a_Delta;
-	if (m_Time > stepTimeSecond) {
+	while (m_Time > stepTimeSecond) {
-		m_Time = std::fmod(m_Time, stepTimeSecond);
+		m_Time -= stepTimeSecond;
 		auto lockStepPacket = m_Simulation.Update();
 		BroadcastPacket(lockStepPacket);
 	}

src/td/display/state/DebugWorldState.cpp

@@ -85,6 +85,7 @@ void DebugWorldState::OnAspectRatioChange(float a_Ratio) {
 
 void DebugWorldState::OnKeyDown(SDL_Keycode a_Key) {
 	// temporary tests
+	constexpr int SECONDS = 10;
 	switch (a_Key) {
 		case SDLK_A:
 			m_Client->SendPacket(td::protocol::packets::SpawnTroopPacket(td::EntityType::Zombie, 1));
@@ -94,6 +95,11 @@ void DebugWorldState::OnKeyDown(SDL_Keycode a_Key) {
 			m_Client->SendPacket(td::protocol::packets::PlaceTowerPacket(td::TowerType::Archer, td::TowerCoords(77, 13)));
 			break;
 
+		case SDLK_F:
+			m_Server->Update(SECONDS);
+			m_Client->Update(SECONDS);
+			break;
+
 		default:
 			break;
 	}

src/td/game/World.cpp

@@ -1,7 +1,10 @@
+#include <cassert>
+#include <td/Maths.h>
 #include <td/game/World.h>
+#include <td/game/WorldTypes.h>
 
-#include <td/simulation/WorldTicker.h>
 #include <td/protocol/packet/PacketSerialize.h>
+#include <td/simulation/WorldTicker.h>
 
 namespace td {
 namespace game {
@@ -89,5 +92,14 @@ void World::ResetSnapshots(std::shared_ptr<sim::WorldSnapshot>& a_Current, std::
 	m_NextState = a_Next;
 }
 
+TilePtr World::GetTile(std::int32_t x, std::int32_t y) const {
+	ChunkCoord coords{static_cast<std::int16_t>(x / Chunk::ChunkWidth), static_cast<std::int16_t>(y / Chunk::ChunkHeight)};
+	auto it = m_Chunks.find(coords);
+	assert(it != m_Chunks.end());
+	auto chunk = it->second;
+	Vec2i inchunkCoords{x % Chunk::ChunkWidth, y % Chunk::ChunkHeight};
+	return GetTilePtr(chunk->GetTileIndex(inchunkCoords.y * Chunk::ChunkWidth + inchunkCoords.x));
+}
+
 }  // namespace game
 }  // namespace td

src/td/render/renderer/EntityRenderer.cpp

@@ -22,7 +22,7 @@ void EntityRenderer::Render(float a_Lerp) {
 		float x = Lerp<game::Mob>(*mob, a_Lerp, [](const game::Mob& a_Mob) { return static_cast<float>(a_Mob.m_Position.x); });
 		float z = Lerp<game::Mob>(*mob, a_Lerp, [](const game::Mob& a_Mob) { return static_cast<float>(a_Mob.m_Position.y); });
 
-		m_Shader->SetModelPos({x, 1, z});
+		m_Shader->SetModelPos({x, .001, z});
 		Renderer::Render(*m_EntityVao);
 	}
 }

src/td/render/renderer/TowerRenderer.cpp

@@ -18,7 +18,7 @@ TowerRenderer::~TowerRenderer() {}
 void TowerRenderer::Render(float a_Lerp) {
 	m_Shader->Start();
 	for (const auto& tower : m_World->GetTowers()) {
-		m_Shader->SetModelPos({tower->GetCenterX(), 1, tower->GetCenterY()});
+		m_Shader->SetModelPos({tower->GetCenterX(), .001, tower->GetCenterY()});
 		Renderer::Render(*m_EntityVao);
 	}
 }

src/td/simulation/ClientSimulation.cpp

@@ -51,8 +51,8 @@ float ClientSimulation::Update(float a_Delta) {
 	// TODO: handle freezes (m_CurrentTime > 2 * m_StepTime)
 	static const float stepTimeSecond = static_cast<float>(m_StepTime) / 1000.0f;
 	m_CurrentTime += a_Delta;
-	if (m_CurrentTime > stepTimeSecond) {
+	while (m_CurrentTime > stepTimeSecond) {
-		m_CurrentTime = std::fmod(m_CurrentTime, stepTimeSecond);
+		m_CurrentTime -= stepTimeSecond;
 		Step();
 	}
 	return (float)m_CurrentTime / stepTimeSecond;

src/td/simulation/CommandApply.cpp

@@ -1,3 +1,4 @@
+#include <td/Types.h>
 #include <td/simulation/CommandApply.h>
 
 namespace td {
@@ -24,6 +25,10 @@ void CommandApply::Handle(const protocol::commands::PlayerJoinCommand& a_PlayerJ
 void CommandApply::Handle(const protocol::commands::SpawnTroopCommand& a_SpawnTroop) {
 	auto zombie = std::make_shared<game::Zombie>();
 	zombie->m_Position = a_SpawnTroop->m_Position;
+
+	// TODO: make it spawn dependant
+	zombie->m_Direction = Direction::PositiveY;
+
 	m_Snapshot.m_Mobs.push_back(zombie);
 }
 

src/td/simulation/system/EntityMove.cpp

@@ -1,11 +1,61 @@
+#include <td/Maths.h>
+#include <td/Types.h>
+#include <td/game/WorldTypes.h>
 #include <td/simulation/system/EntityMove.h>
 
+#include <td/game/World.h>
+
 namespace td {
 namespace sim {
 
+static Vec2i GetUnitDirection(Direction a_Direction) {
+	switch (a_Direction) {
+		case Direction::PositiveX:
+			return {1, 0};
+		case Direction::NegativeX:
+			return {-1, 0};
+		case Direction::PositiveY:
+			return {0, 1};
+		case Direction::NegativeY:
+			return {0, -1};
+	}
+	return {0, 0};
+}
+
+class DirectionTileVisitor : public game::TileHandler {
+  private:
+	Direction m_Direction;
+
+  public:
+	DirectionTileVisitor() {}
+
+	virtual void Handle(const game::EmptyTile& a_Tile) override {}
+
+	virtual void Handle(const game::TowerTile& a_Tile) override {}
+
+	virtual void Handle(const game::DecorationTile& a_Tile) override {}
+
+	virtual void Handle(const game::WalkableTile& a_Tile) override {
+		m_Direction = a_Tile->m_Direction;
+	}
+
+	const Direction GetDirection() {
+		return m_Direction;
+	}
+};
+
 void EntityMove::Tick(const game::World& a_World, WorldSnapshot& a_State, FpFloat a_Delta) {
 	for (auto& mob : a_State.m_Mobs) {
-		mob->m_Position.x += a_Delta;
+		auto tile = a_World.GetTile(static_cast<std::int32_t>(mob->m_Position.x), static_cast<std::int32_t>(mob->m_Position.y));
+		Direction direction = mob->m_Direction;
+		if (tile) {
+			DirectionTileVisitor visitor;
+			tile->Dispatch(visitor);
+			direction = visitor.GetDirection();
+		}
+		auto directVector = GetUnitDirection(direction);
+		mob->m_Position.x += directVector.x * a_Delta;
+		mob->m_Position.y += directVector.y * a_Delta;
 	}
 }