chore(renderer): refactor renderer and add post-process + spell visuals systems

- Updated core render pipeline and renderer integration in CMakeLists.txt, renderer.cpp, renderer.hpp
- Added post-process pipeline module:
  - post_process_pipeline.hpp
  - post_process_pipeline.cpp
- Added spell visual system module:
  - spell_visual_system.hpp
  - spell_visual_system.cpp
- Adjusted application/audio integration:
  - application.cpp
  - audio_coordinator.cpp

src/rendering/spell_visual_system.cpp

@@ -0,0 +1,231 @@
+#include "rendering/spell_visual_system.hpp"
+#include "rendering/m2_renderer.hpp"
+#include "pipeline/asset_manager.hpp"
+#include "pipeline/dbc_loader.hpp"
+#include "pipeline/dbc_layout.hpp"
+#include "pipeline/m2_loader.hpp"
+#include "core/application.hpp"
+#include "core/logger.hpp"
+#include <algorithm>
+
+namespace wowee {
+namespace rendering {
+
+void SpellVisualSystem::initialize(M2Renderer* m2Renderer) {
+    m2Renderer_ = m2Renderer;
+}
+
+void SpellVisualSystem::shutdown() {
+    reset();
+    m2Renderer_ = nullptr;
+    cachedAssetManager_ = nullptr;
+}
+
+// Load SpellVisual DBC chain: SpellVisualEffectName → SpellVisualKit → SpellVisual
+// to build cast/impact M2 path lookup maps.
+void SpellVisualSystem::loadSpellVisualDbc() {
+    if (spellVisualDbcLoaded_) return;
+    spellVisualDbcLoaded_ = true; // Set early to prevent re-entry on failure
+
+    if (!cachedAssetManager_) {
+        cachedAssetManager_ = core::Application::getInstance().getAssetManager();
+    }
+    if (!cachedAssetManager_) return;
+
+    auto* layout = pipeline::getActiveDBCLayout();
+    const pipeline::DBCFieldMap* svLayout  = layout ? layout->getLayout("SpellVisual")           : nullptr;
+    const pipeline::DBCFieldMap* kitLayout = layout ? layout->getLayout("SpellVisualKit")        : nullptr;
+    const pipeline::DBCFieldMap* fxLayout  = layout ? layout->getLayout("SpellVisualEffectName") : nullptr;
+
+    uint32_t svCastKitField   = svLayout  ? (*svLayout)["CastKit"]       : 2;
+    uint32_t svImpactKitField = svLayout  ? (*svLayout)["ImpactKit"]     : 3;
+    uint32_t svMissileField   = svLayout  ? (*svLayout)["MissileModel"]  : 8;
+    uint32_t kitSpecial0Field = kitLayout ? (*kitLayout)["SpecialEffect0"] : 11;
+    uint32_t kitBaseField     = kitLayout ? (*kitLayout)["BaseEffect"]     : 5;
+    uint32_t fxFilePathField  = fxLayout  ? (*fxLayout)["FilePath"]       : 2;
+
+    // Helper to look up effectName path from a kit ID
+    // Load SpellVisualEffectName.dbc — ID → M2 path
+    auto fxDbc = cachedAssetManager_->loadDBC("SpellVisualEffectName.dbc");
+    if (!fxDbc || !fxDbc->isLoaded() || fxDbc->getFieldCount() <= fxFilePathField) {
+        LOG_DEBUG("SpellVisual: SpellVisualEffectName.dbc unavailable (fc=",
+                  fxDbc ? fxDbc->getFieldCount() : 0, ")");
+        return;
+    }
+    std::unordered_map<uint32_t, std::string> effectPaths; // effectNameId → path
+    for (uint32_t i = 0; i < fxDbc->getRecordCount(); ++i) {
+        uint32_t id   = fxDbc->getUInt32(i, 0);
+        std::string p = fxDbc->getString(i, fxFilePathField);
+        if (id && !p.empty()) effectPaths[id] = p;
+    }
+
+    // Load SpellVisualKit.dbc — kitId → best SpellVisualEffectName ID
+    auto kitDbc = cachedAssetManager_->loadDBC("SpellVisualKit.dbc");
+    std::unordered_map<uint32_t, uint32_t> kitToEffectName; // kitId → effectNameId
+    if (kitDbc && kitDbc->isLoaded()) {
+        uint32_t fc = kitDbc->getFieldCount();
+        for (uint32_t i = 0; i < kitDbc->getRecordCount(); ++i) {
+            uint32_t kitId = kitDbc->getUInt32(i, 0);
+            if (!kitId) continue;
+            // Prefer SpecialEffect0, fall back to BaseEffect
+            uint32_t eff = 0;
+            if (kitSpecial0Field < fc) eff = kitDbc->getUInt32(i, kitSpecial0Field);
+            if (!eff && kitBaseField < fc) eff = kitDbc->getUInt32(i, kitBaseField);
+            if (eff) kitToEffectName[kitId] = eff;
+        }
+    }
+
+    // Helper: resolve path for a given kit ID
+    auto kitPath = [&](uint32_t kitId) -> std::string {
+        if (!kitId) return {};
+        auto kitIt = kitToEffectName.find(kitId);
+        if (kitIt == kitToEffectName.end()) return {};
+        auto fxIt = effectPaths.find(kitIt->second);
+        return (fxIt != effectPaths.end()) ? fxIt->second : std::string{};
+    };
+    auto missilePath = [&](uint32_t effId) -> std::string {
+        if (!effId) return {};
+        auto fxIt = effectPaths.find(effId);
+        return (fxIt != effectPaths.end()) ? fxIt->second : std::string{};
+    };
+
+    // Load SpellVisual.dbc — visualId → cast/impact M2 paths via kit chain
+    auto svDbc = cachedAssetManager_->loadDBC("SpellVisual.dbc");
+    if (!svDbc || !svDbc->isLoaded()) {
+        LOG_DEBUG("SpellVisual: SpellVisual.dbc unavailable");
+        return;
+    }
+    uint32_t svFc = svDbc->getFieldCount();
+    uint32_t loadedCast = 0, loadedImpact = 0;
+    for (uint32_t i = 0; i < svDbc->getRecordCount(); ++i) {
+        uint32_t vid = svDbc->getUInt32(i, 0);
+        if (!vid) continue;
+
+        // Cast path: CastKit → SpecialEffect0/BaseEffect, fallback to MissileModel
+        {
+            std::string path;
+            if (svCastKitField < svFc)
+                path = kitPath(svDbc->getUInt32(i, svCastKitField));
+            if (path.empty() && svMissileField < svFc)
+                path = missilePath(svDbc->getUInt32(i, svMissileField));
+            if (!path.empty()) { spellVisualCastPath_[vid] = path; ++loadedCast; }
+        }
+        // Impact path: ImpactKit → SpecialEffect0/BaseEffect, fallback to MissileModel
+        {
+            std::string path;
+            if (svImpactKitField < svFc)
+                path = kitPath(svDbc->getUInt32(i, svImpactKitField));
+            if (path.empty() && svMissileField < svFc)
+                path = missilePath(svDbc->getUInt32(i, svMissileField));
+            if (!path.empty()) { spellVisualImpactPath_[vid] = path; ++loadedImpact; }
+        }
+    }
+    LOG_INFO("SpellVisual: loaded cast=", loadedCast, " impact=", loadedImpact,
+             " visual→M2 mappings (of ", svDbc->getRecordCount(), " records)");
+}
+
+void SpellVisualSystem::playSpellVisual(uint32_t visualId, const glm::vec3& worldPosition,
+                                         bool useImpactKit) {
+    if (!m2Renderer_ || visualId == 0) return;
+
+    if (!cachedAssetManager_)
+        cachedAssetManager_ = core::Application::getInstance().getAssetManager();
+    if (!cachedAssetManager_) return;
+
+    if (!spellVisualDbcLoaded_) loadSpellVisualDbc();
+
+    // Select cast or impact path map
+    auto& pathMap = useImpactKit ? spellVisualImpactPath_ : spellVisualCastPath_;
+    auto pathIt = pathMap.find(visualId);
+    if (pathIt == pathMap.end()) return; // No model for this visual
+
+    const std::string& modelPath = pathIt->second;
+
+    // Get or assign a model ID for this path
+    auto midIt = spellVisualModelIds_.find(modelPath);
+    uint32_t modelId = 0;
+    if (midIt != spellVisualModelIds_.end()) {
+        modelId = midIt->second;
+    } else {
+        if (nextSpellVisualModelId_ >= 999800) {
+            LOG_WARNING("SpellVisual: model ID pool exhausted");
+            return;
+        }
+        modelId = nextSpellVisualModelId_++;
+        spellVisualModelIds_[modelPath] = modelId;
+    }
+
+    // Skip models that have previously failed to load (avoid repeated I/O)
+    if (spellVisualFailedModels_.count(modelId)) return;
+
+    // Load the M2 model if not already loaded
+    if (!m2Renderer_->hasModel(modelId)) {
+        auto m2Data = cachedAssetManager_->readFile(modelPath);
+        if (m2Data.empty()) {
+            LOG_DEBUG("SpellVisual: could not read model: ", modelPath);
+            spellVisualFailedModels_.insert(modelId);
+            return;
+        }
+        pipeline::M2Model model = pipeline::M2Loader::load(m2Data);
+        if (model.vertices.empty() && model.particleEmitters.empty()) {
+            LOG_DEBUG("SpellVisual: empty model: ", modelPath);
+            spellVisualFailedModels_.insert(modelId);
+            return;
+        }
+        // Load skin file for WotLK-format M2s
+        if (model.version >= 264) {
+            std::string skinPath = modelPath.substr(0, modelPath.rfind('.')) + "00.skin";
+            auto skinData = cachedAssetManager_->readFile(skinPath);
+            if (!skinData.empty()) pipeline::M2Loader::loadSkin(skinData, model);
+        }
+        if (!m2Renderer_->loadModel(model, modelId)) {
+            LOG_WARNING("SpellVisual: failed to load model to GPU: ", modelPath);
+            spellVisualFailedModels_.insert(modelId);
+            return;
+        }
+        LOG_DEBUG("SpellVisual: loaded model id=", modelId, " path=", modelPath);
+    }
+
+    // Spawn instance at world position
+    uint32_t instanceId = m2Renderer_->createInstance(modelId, worldPosition,
+                                                       glm::vec3(0.0f), 1.0f);
+    if (instanceId == 0) {
+        LOG_WARNING("SpellVisual: failed to create instance for visualId=", visualId);
+        return;
+    }
+    // Determine lifetime from M2 animation duration (clamp to reasonable range)
+    float animDurMs = m2Renderer_->getInstanceAnimDuration(instanceId);
+    float duration = (animDurMs > 100.0f)
+        ? std::clamp(animDurMs / 1000.0f, 0.5f, SPELL_VISUAL_MAX_DURATION)
+        : SPELL_VISUAL_DEFAULT_DURATION;
+    activeSpellVisuals_.push_back({instanceId, 0.0f, duration});
+    LOG_DEBUG("SpellVisual: spawned visualId=", visualId, " instanceId=", instanceId,
+              " duration=", duration, "s model=", modelPath);
+}
+
+void SpellVisualSystem::update(float deltaTime) {
+    if (activeSpellVisuals_.empty() || !m2Renderer_) return;
+    for (auto it = activeSpellVisuals_.begin(); it != activeSpellVisuals_.end(); ) {
+        it->elapsed += deltaTime;
+        if (it->elapsed >= it->duration) {
+            m2Renderer_->removeInstance(it->instanceId);
+            it = activeSpellVisuals_.erase(it);
+        } else {
+            ++it;
+        }
+    }
+}
+
+void SpellVisualSystem::reset() {
+    // Clear lingering spell visual instances from the previous map/combat session.
+    // Without this, old effects could remain visible after teleport or map change.
+    for (auto& sv : activeSpellVisuals_) {
+        if (m2Renderer_) m2Renderer_->removeInstance(sv.instanceId);
+    }
+    activeSpellVisuals_.clear();
+    // Reset the negative cache so models that failed during asset loading can retry.
+    spellVisualFailedModels_.clear();
+}
+
+} // namespace rendering
+} // namespace wowee