Add shadow toggle (F4) and distance-based WMO group culling

Shadow toggle allows disabling shadow pass for performance testing.
Distance culling skips WMO groups beyond 200 units. Occlusion queries
disabled by default as overhead outweighs benefits in dense scenes.

include/rendering/renderer.hpp

@@ -184,7 +184,13 @@ private:
     glm::mat4 lightSpaceMatrix = glm::mat4(1.0f);
     glm::vec3 shadowCenter = glm::vec3(0.0f);
     bool shadowCenterInitialized = false;
+    bool shadowsEnabled = true;
 
+public:
+    void setShadowsEnabled(bool enabled) { shadowsEnabled = enabled; }
+    bool areShadowsEnabled() const { return shadowsEnabled; }
+
+private:
     void initShadowMap();
     void renderShadowPass();
     uint32_t compileShadowShader();

include/rendering/wmo_renderer.hpp

@@ -428,7 +428,7 @@ private:
     bool frustumCulling = true;
     bool portalCulling = false;  // Disabled by default - needs debugging
     bool distanceCulling = false;  // Disabled - causes ground to disappear
-    bool occlusionCulling = true;  // GPU occlusion queries
+    bool occlusionCulling = false;  // GPU occlusion queries - disabled, adds overhead
     float maxGroupDistance = 500.0f;
     float maxGroupDistanceSq = 250000.0f;  // maxGroupDistance^2
     uint32_t lastDrawCalls = 0;

src/core/application.cpp

@@ -255,6 +255,14 @@ void Application::run() {
                         LOG_INFO("Performance HUD: ", enabled ? "ON" : "OFF");
                     }
                 }
+                // F4: Toggle shadows
+                else if (event.key.keysym.scancode == SDL_SCANCODE_F4) {
+                    if (renderer) {
+                        bool enabled = !renderer->areShadowsEnabled();
+                        renderer->setShadowsEnabled(enabled);
+                        LOG_INFO("Shadows: ", enabled ? "ON" : "OFF");
+                    }
+                }
                 // T: Toggle teleporter panel
                 else if (event.key.keysym.scancode == SDL_SCANCODE_T) {
                     if (state == AppState::IN_GAME && uiManager) {

src/rendering/renderer.cpp

@@ -1039,8 +1039,14 @@ void Renderer::renderWorld(game::World* world) {
     lastM2RenderMs = 0.0;
 
     // Shadow pass (before main scene)
-    if (shadowFBO && shadowShaderProgram && terrainLoaded) {
+    if (shadowsEnabled && shadowFBO && shadowShaderProgram && terrainLoaded) {
         renderShadowPass();
+    } else {
+        // Clear shadow maps when disabled
+        if (terrainRenderer) terrainRenderer->clearShadowMap();
+        if (wmoRenderer) wmoRenderer->clearShadowMap();
+        if (m2Renderer) m2Renderer->clearShadowMap();
+        if (characterRenderer) characterRenderer->clearShadowMap();
     }
 
     // Bind HDR scene framebuffer for world rendering

src/rendering/wmo_renderer.cpp

@@ -645,7 +645,7 @@ void WMORenderer::render(const Camera& camera, const glm::mat4& view, const glm:
                 continue;
             }
 
-            // Occlusion culling check (uses previous frame results)
+            // Occlusion culling check first (uses previous frame results)
             if (occlusionCulling && isGroupOccluded(instance.id, static_cast<uint32_t>(gi))) {
                 lastOcclusionCulledGroups++;
                 continue;
@@ -654,14 +654,12 @@ void WMORenderer::render(const Camera& camera, const glm::mat4& view, const glm:
             if (gi < instance.worldGroupBounds.size()) {
                 const auto& [gMin, gMax] = instance.worldGroupBounds[gi];
 
-                // Distance culling: skip groups whose center is too far
-                if (distanceCulling) {
-                    glm::vec3 groupCenter = (gMin + gMax) * 0.5f;
-                    float distSq = glm::dot(groupCenter - camPos, groupCenter - camPos);
-                    if (distSq > maxGroupDistanceSq) {
-                        lastDistanceCulledGroups++;
-                        continue;
-                    }
+                // Hard distance cutoff - skip groups entirely if closest point is too far
+                glm::vec3 closestPoint = glm::clamp(camPos, gMin, gMax);
+                float distSq = glm::dot(closestPoint - camPos, closestPoint - camPos);
+                if (distSq > 40000.0f) {  // Beyond 200 units - hard skip
+                    lastDistanceCulledGroups++;
+                    continue;
                 }
 
                 // Frustum culling