Nexen v1.4.36 -- SNES Performance Blitz & TAS Editor Optimization

22 commits | 13+ issues addressed | 4,313 tests passing (3,690 C++ + 623 .NET) | Zero warnings

Nexen v1.4.36 is a deep performance optimization release targeting the SNES emulation core and TAS editor. Four phases of SNES PPU optimizations deliver faster rendering through pointer hoisting, early exits, and attribute hints. The TAS editor receives major allocation reduction, frame ViewModel reuse, and a contiguous memory buffer for movie input data. A critical CDL recorder race condition fix rounds out the stability improvements.

Highlights

🚀 Performance

SNES PPU Phase 4 - #1381

• ApplyColorMath pointer hoist + [[likely]] attribute on fast path
• PrecomputeWindowMasks switch hoist to avoid redundant dispatch
• ConvertToHiRes pointer arithmetic optimization

SNES PPU Phase 3 - #1376

• PrecomputeWindowMasks skip memset when masks unchanged
• RenderBgColor computation hoist out of inner loop
• Sprite priority early-exit for empty priority slots

SNES Phase 2 - #1366

• Multiple hot-path SNES performance improvements across rendering pipeline

SNES Memory Dispatch + CPU Inlining - #1361

• Memory access dispatch optimization for faster read/write operations
• CPU method inlining for critical execution paths

TAS Editor Batch Updates - #1340

• RangeObservableCollection.AddRange for batch MarkerEntries insertion
• ViewModel allocation reduction: lazy strings, dirty-check, button reuse, stackalloc
• Remove unnecessary ToList() in CellsPainted
• Fix duplicate SyncFrameViewModels calls

TAS Frame ViewModel Reuse - #1360

• Reuse TasFrameViewModel objects in UpdateFrames via SyncFrameViewModels
• Eliminates per-update allocation churn in the piano roll

TAS ViewModel Caching - #1359

• Cache P1Input/P2Input/Background properties in TasFrameViewModel
• Avoid redundant property recalculation on every access

Movie Input Contiguous Buffer - #1358

• Replace vector<string> with contiguous buffer for movie input data
• Improved cache locality and reduced allocation pressure

Benchmark Suite - #1308

• New 60K and 300K frame benchmarks for Movie/TAS operations
• Enables regression tracking for future performance work

🔧 Fixed

Movie/TAS Pass 3 - #1312

• InputFrame buffer management improvements
• FDS roundtrip correctness fix
• HasInput accuracy fix
• Undo helper robustness
• NexenMovie parameter handling

CDL Recorder Use-After-Free Race - #1356

• Fixed race condition in CDL recorder Stop() and InitDebugger() that could cause use-after-free crashes

📋 Issues Addressed

Nexen v1.4.36 -- Pansy Jump Graph, OSD Improvements & SNES Performance

11 commits | 8 issues addressed | 4,313 tests passing (3,690 C++ + 623 .NET) | Zero warnings

Nexen v1.4.36 ships the Pansy Jump Graph export suite, bringing true one-source-many-target cross-reference serialization and conditional branch fallthrough edges to the .pansy metadata format. The UI gains Open ROM and Verified Games shortcut buttons on the game selection screen, and the OSD now scales its font with the HUD buffer and shows notifications for auto-save and recent-play saves. Two targeted performance improvements cover the TAS editor marker refresh and SNES Mode7 rendering.

Highlights

🌐 Pansy Jump Graph Export

Multi-Target XRef Export - #1399

• True one-source-many-target Pansy export contract implemented end-to-end
• A single source address can now serialize 2 or more outgoing targets without heuristic guessing
• Both the legacy CrossReference section and the grouped MultiTargetCrossReference section are written, maintaining full backward compatibility
• New tests pass in Nexen, Pansy, and Peony

Conditional Branch Fallthrough XRefs - #1396

• Explicit source-to-target jump graph entries written for indirect and multi-target control flows
• Conditional branch fallthrough edges included alongside taken-branch edges
• Deduplication ensures deterministic output

Pansy CDM Flag Fix - #1395

• CODE_DATA_MAP flag bits (JumpTarget, SubEntry, Opcode, Drawn, Read, Indirect) are now correctly preserved
• Platform-specific bits (SNES/GBA mode state) stored in SECTION_CPU_STATE only and no longer collide with standard CDM bits
• Roundtrip mapping tests verify all standard flags survive a full write-read cycle

🗂️ UI Improvements

Game Selection Screen Action Buttons - #1390

• Open ROM button added directly to the game selection screen for quick access
• Verified Games button added for browsing the curated verified game list
• Both buttons are positioned for easy access without navigating menus

OSD Font Scaling - #1388

• The bitmap OSD font now scales proportionally with the HUD buffer size
• Ensures readability across different output resolutions and window sizes

OSD Save Notifications - #1389

• Auto-save events now display an OSD notification message
• Recent-play save events also display an OSD notification
• Notifications use the scaled OSD font

🚀 Performance

RefreshMarkerEntries Cache-and-Filter - #1392

• Cache the current marker set and skip entries that have not changed
• Reduces redundant UI update work in the TAS editor piano roll on every marker refresh

SNES Mode7 LargeMap Templating - #1391

• Template the Mode7 LargeMap rendering path to eliminate branching in the inner loop
• Window mask computation hoisted out of per-pixel work
• [[likely]] attribute added to the Exec hot path for better branch prediction hints

📋 Issues Addressed

✅ Validation Summary

📥 Downloads

Windows

Linux

macOS (Apple Silicon)

Full Changelog: v1.4.35...v1.4.36