MVI Editor UI Overhaul & Virtualized GPU-Driven Shadow Architecture

[TamasPetii]

Overview

This massive PR introduces two major architectural leaps for the Synapse Engine: a complete ground-up rewrite of the Editor UI utilizing an MVI architecture, and a fully unified, virtualized shadow mapping system for Directional, Spot, and Point lights.

Furthermore, this update brings core engine improvements including Jolt Physics and Taskflow integration, SSAO, Xmake cross-platform builds.

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Editor UI Overhaul

The editor has been completely transformed to provide a professional, highly functional workspace. Built around the MVI pattern, the UI is now modular, state-driven, and significantly easier to extend.

Key UI Additions:

• Scene Hierarchy: Searchable entity tree with visibility toggles and data-oriented parent-child grouping.
• Performance Profiler: Real-time CPU/GPU metrics, frametime graphs, and granular task timing breakdowns.
• Interactive Viewport: Main 3D view with simulation controls, transform gizmos, and depth-aware selection outlines.
• Content Browser & Log: Tabbed dual-pane asset explorer and real-time engine output log.
• Dynamic Inspector: Edits entity components and exposes real-time global rendering and culling configurations.
• Integration: Native ImGui Node Editor and FileDialog support for advanced workflows.

*The new Synapse Engine Editor featuring the Content Browser, Hierarchy, Inspector, and Workspaces.*

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Virtualized Shadow Map Architecture

This PR completely overhauls how shadows are calculated and rendered. We now utilize a fully virtualized, dynamic shadow atlas. Distant lights are dynamically assigned smaller footprint sizes within the atlas, maximizing texture memory efficiency.

Core Shadow Features:

• Hybrid Execution: Fully supports both CPU-driven and GPU-driven shadow pipelines. This can be toggled in real-time.
• Compute Shader Culling: Dedicated compute culling for all light types:
  • Directional Lights: Cascade-based frustum culling.
  • Spot Lights: Cone-based culling.
  • Point Lights: Sphere-based culling.
• Hierarchical Pipeline: Fully supports the Chunk (Static/Morton) -> Model -> Mesh culling hierarchy, seamlessly integrating with both the Meshlet and Traditional rendering pipelines.
• Ultimate Batching: The entire system is purely GPU-driven using one large command buffer. All models across all visible lights are rendered simultaneously in a single indirect draw call (opaque only).

Directional Light Shadows

Utilizes a cascaded approach mapped directly into the virtual atlas. Culling efficiently discards geometry outside the cascades before rendering.

Spot & Point Light Shadows

Because Spot and Point lights typically affect a significantly smaller subset of the scene geometry, these pipelines utilize a highly optimized Gather and Radix Sort workflow. Instance data is gathered and sorted before the final draw, ensuring maximum GPU occupancy.

Spot Lights:

Point Lights:
Point lights allocate 3x2 chunks for the cubemap faces, flattened directly into the 2D virtual atlas to avoid cubemap overhead.

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Core Engine & Rendering Enhancements

Beyond UI and Shadows, several critical rendering and system features have been implemented:

• Screen Space Ambient Occlusion (SSAO): Added a dedicated SSAO render pass with configurable settings.
• Depth-Aware Outline Shader: Implemented robust outline systems for entity selection/highlighting.
• Physics & Concurrency: Integrated Jolt Physics for robust collision handling and Taskflow for modern task-based multithreading.
• Visual Debugging: Added comprehensive wireframe visualization for Morton Chunks, AABBs, Spheres, Capsules, and Meshlet colliders.
• Colliders: Implemented Mesh/Convex colliders along with a StaticMesh schema and serialization system.
• Work Graphs: Refactored geometry culling render passes to utilize Vulkan Work Graphs.

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Build System & CI/CD

• Xmake Integration: Transitioned the build system to xmake supporting Visual Studio 2026, Linux, and VSCode environments.
• Linux Readiness: Resolved missing syslinks, include errors (VMA), and fixed character input callbacks specifically for Linux builds.
• CI Actions: Updated GitHub Actions for robust Windows and Linux engine build validation.