Surface Benchmarker

benchmarks/Hex1b.Benchmarks/
├── Hex1b.Benchmarks.csproj    # Console app with BenchmarkDotNet
├── Program.cs                  # Entry point
└── SurfaceBenchmarks.cs        # Surface API benchmarks

┌─────────────────────────────────────────────────────────────────┐
│ 1. GlobalSetup                                                  │
│    - Runs once before all benchmarks                            │
│    - Creates pre-allocated surfaces, diffs, etc.                │
│    - Sets up shared test data                                   │
└─────────────────────────────────────────────────────────────────┘
                              ▼
┌─────────────────────────────────────────────────────────────────┐
│ 2. For each [Benchmark] method:                                 │
│    a. Warmup phase (JIT compilation, cache warming)             │
│    b. Pilot phase (determine optimal iteration count)           │
│    c. Actual measurements (multiple iterations)                 │
│    d. Results aggregation                                       │
└─────────────────────────────────────────────────────────────────┘
                              ▼
┌─────────────────────────────────────────────────────────────────┐
│ 3. Report Generation                                            │
│    - Console output with statistics                             │
│    - Optional: HTML, CSV, JSON exports                          │
└─────────────────────────────────────────────────────────────────┘

[Benchmark]
public Surface CreateSurface_Small() => new Surface(80, 24);    // Standard terminal
public Surface CreateSurface_Medium() => new Surface(160, 48);  // Large terminal
public Surface CreateSurface_Large() => new Surface(320, 96);   // Very large
public Surface CreateSurface_4K() => new Surface(480, 135);     // 4K equivalent

[Benchmark]
public void WriteText_Short();      // "Hello"
public void WriteText_Medium();     // Standard sentence
public void WriteText_Long();       // Long paragraph
public void WriteText_WideChars();  // Chinese characters (2 cells each)
public void WriteText_FillScreen(); // 24 lines of text

[Benchmark]
public void Fill_SmallRect();   // 20x10 region
public void Fill_FullScreen();  // 80x24
public void Fill_LargeScreen(); // 320x96

[Benchmark]
public void Composite_SmallOntoSmall();         // 20x10 onto 80x24
public void Composite_MediumOntoLarge();        // 80x24 onto 320x96
public Surface CompositeSurface_Flatten_3Layers();  // Resolve 3 layers
public SurfaceCell CompositeSurface_GetCell_Resolved();  // Single cell lookup
public void CompositeSurface_GetAllCells();     // 80x24 = 1920 lookups

[Benchmark]
public SurfaceDiff Compare_FullDiff();    // 100% of cells changed
public SurfaceDiff Compare_SparseDiff();  // ~10% of cells changed
public SurfaceDiff Compare_NoDiff();      // 0% changed
public SurfaceDiff CompareToEmpty();      // Initial render

[Benchmark]
public IReadOnlyList<AnsiToken> ToTokens_FullDiff();  // Generate tokens
public string ToAnsiString_FullDiff();                // Tokens → string
public string ToAnsiString_SparseDiff();              // Fewer changes

cd /home/midenn/Code/hex1b
dotnet run -c Release --project benchmarks/Hex1b.Benchmarks -- --filter "Surface*"

dotnet run -c Release --project benchmarks/Hex1b.Benchmarks -- --filter "Surface*" --job dry

# Only WriteText benchmarks
dotnet run -c Release --project benchmarks/Hex1b.Benchmarks -- --filter "*WriteText*"

# Only Diff/Token generation
dotnet run -c Release --project benchmarks/Hex1b.Benchmarks -- --filter "*Compare*|*Token*|*Ansi*"

# Single benchmark
dotnet run -c Release --project benchmarks/Hex1b.Benchmarks -- --filter "*Fill_FullScreen*"

| Method                | Mean       | Error    | StdDev   | Gen0   | Allocated |
|-----------------------|------------|----------|----------|--------|-----------|
| CreateSurface_Small   | 12.34 μs   | 0.15 μs  | 0.14 μs  | 1.2345 | 15.36 KB  |
| CreateSurface_Large   | 98.76 μs   | 1.23 μs  | 1.15 μs  | 9.8765 | 122.88 KB |