yaze/docs/analysis/dungeon_editor_bottleneck_analysis.md

DungeonEditor Bottleneck Analysis

🚨 Critical Performance Issue Identified

Problem Summary

The DungeonEditor::Load() is taking 18,113ms (18.1 seconds), making it the primary bottleneck in YAZE's ROM loading process.

Performance Breakdown

Component	Time	Percentage
DungeonEditor::Load	18,113ms	97.3%
OverworldEditor::Load	527ms	2.8%
All Other Editors	<6ms	<0.1%
Total Loading Time	18.6 seconds	100%

🔍 Root Cause Analysis

The DungeonEditor is 36x slower than the entire overworld loading process, which suggests:

1. Massive Data Processing: Likely loading all dungeon rooms, graphics, and metadata
2. Inefficient Algorithms: Possibly O(n²) or worse complexity
3. No Lazy Loading: Loading everything upfront instead of on-demand
4. Memory-Intensive Operations: Large data structures being processed

🎯 Detailed Timing Added

Added granular timing to identify the exact bottleneck:

// DungeonEditor::Load() now includes:
{
  core::ScopedTimer rooms_timer("DungeonEditor::LoadAllRooms");
  RETURN_IF_ERROR(room_loader_.LoadAllRooms(rooms_));
}

{
  core::ScopedTimer entrances_timer("DungeonEditor::LoadRoomEntrances");
  RETURN_IF_ERROR(room_loader_.LoadRoomEntrances(entrances_));
}

{
  core::ScopedTimer palette_timer("DungeonEditor::LoadPalettes");
  // Palette loading operations
}

{
  core::ScopedTimer usage_timer("DungeonEditor::CalculateUsageStats");
  usage_tracker_.CalculateUsageStats(rooms_);
}

{
  core::ScopedTimer init_timer("DungeonEditor::InitializeSystem");
  // System initialization
}

📊 Expected Detailed Results

The next performance run will show:

DungeonEditor::LoadAllRooms       1           XXXXms        XXXXms
DungeonEditor::LoadRoomEntrances  1           XXXXms        XXXXms  
DungeonEditor::LoadPalettes       1           XXXXms        XXXXms
DungeonEditor::CalculateUsageStats1           XXXXms        XXXXms
DungeonEditor::InitializeSystem   1           XXXXms        XXXXms

🚀 Optimization Strategy

Phase 1: Identify Specific Bottleneck

• Run performance test to see which operation takes the most time
• Likely candidates: LoadAllRooms or CalculateUsageStats

Phase 2: Apply Targeted Optimizations

If LoadAllRooms is the bottleneck:

• Implement lazy loading for dungeon rooms
• Only load rooms that are actually accessed
• Use progressive loading for room graphics

If CalculateUsageStats is the bottleneck:

• Defer usage calculation until needed
• Cache usage statistics
• Optimize the calculation algorithm

If LoadRoomEntrances is the bottleneck:

• Load entrances on-demand
• Cache entrance data
• Optimize data structures

Phase 3: Advanced Optimizations

• Parallel Processing: Load rooms concurrently
• Memory Optimization: Reduce memory allocations
• Caching: Cache frequently accessed room data
• Progressive Loading: Load rooms in background threads

🎯 Expected Impact

Current State

• Total Loading Time: 18.6 seconds
• User Experience: 18-second freeze when opening ROMs
• Primary Bottleneck: DungeonEditor (97.3% of loading time)

After Optimization (Target)

• Total Loading Time: <2 seconds (90%+ improvement)
• User Experience: Near-instant ROM opening
• Bottleneck Eliminated: DungeonEditor optimized to <1 second

📈 Success Metrics

• DungeonEditor::Load: <1000ms (down from 18,113ms)
• Total ROM Loading: <2000ms (down from 18,600ms)
• User Perceived Performance: Near-instant startup
• Memory Usage: Reduced initial memory footprint

🔄 Next Steps

1. Run Performance Test: Load ROM and collect detailed timing
2. Identify Specific Bottleneck: Find which operation takes 18+ seconds
3. Implement Optimization: Apply targeted fix for the bottleneck
4. Measure Results: Verify 90%+ improvement in loading time

The DungeonEditor optimization will be the final piece to make YAZE lightning-fast!