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Visera Engine

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Visera is a cross-platform engine for modern games and real-time applications. It uses C++23 with C++ modules (.ixx) and provides a full runtime stack from platform abstraction to rendering, audio, input, scripting, and asset pipelines.

Introduction

Visera uses a layered architecture:

  • Core — Foundation: math, containers, type system, concurrency, OS abstraction (file, memory, thread, time), logging, compression, and more.
  • Platform — Window, path, file system, and dynamic library loading: Windows and macOS native backends, plus GLFW and Null implementations compiled alongside them. The CMake configuration for this tree targets Windows and Apple hosts only.
  • Runtime — RHI (Vulkan), graphics (scene, material, render graph), AssetHub, audio, input, UI (ImGui), window, and JavaScript scripting (V8).
  • Forge (optional) — Separate Visera-Forge toolchain executable for shaders and batch utilities, controlled by VISERA_BUILD_FORGE.

The Engine section in the sidebar matches the source layout: Architecture, Repository layout, Forge, Core, Platform, and Runtime, with pages keyed by module names.

Section Description
Engine → Architecture Layer diagram, Visera module, FViseraEngine, Standard vs Forge mode, service dependencies
Engine → Repository layout Core, Platform, Runtime, Forge, APIs, Schemas, Shaders directories
Engine → Forge Optional Visera-Forge executable and Visera.Forge modules
Engine → Core Core library: algorithm, compression, concurrency, containers, delegate, font, image, log, math, meta, OS, traits, types
Engine → Platform Platform: interface, GLFW, Null, Windows, MacOS
Engine → Runtime Runtime: AssetHub, Audio, Graphics, Input, Scripting, RHI, UI, Window

Recent changes

Summary of recent modifications (engine, game, and tooling):

  • Runtime.Graphics — Immediate-mode draw API: FScene removed. Game submits per-frame via SetCamera(FCamera), SubmitLight(FLight), Draw(const IRenderable&) or Draw(const FRenderableMeta&). Data is captured at submit time (FRenderableMeta: InstanceData + Material + Mesh); no TSharedPtr<IRenderable> crosses the thread boundary. Engine calls Render(FWindow*) after OnPreRender to build FRenderTask from accumulated draws/camera/lights and send to the Graphics thread. Engine loop order: OnTick → OnPreRender → Graphics->Render(Window) → OnPostRender. FRenderData holds DrawCommands (TArray<FRenderableMeta>) and Lights; BatchAndSort iterates draw commands. Channel, RegisterPass, PipelineCache, RenderGraph unchanged. See Framework, RenderGraph, Scene.Renderable.
  • Runtime.Graphics.Scene.Camera — Docs: FCamera API, left-handed, lazy matrices, Euler Yaw–Pitch–Roll. See Camera.
  • Core.Types.Path — FPath::NormalizeString now preserves a leading slash for absolute paths (fixes shader/material loading from app bundle on macOS).
  • Runtime.Input — Mouse cursor position is in framebuffer (pixel) space: on macOS/Retina the GLFW window multiplies cursor coordinates by content scale before notifying Input. Keyboard key storage uses a dense array Keys[FirstKey..LastKey] with offset in GetKey, avoiding unused slots for low key codes.
  • Platform.GLFW.Window — Cursor position callback scales by GetScaleX()/GetScaleY(); SetContentScale updates scale when the window content-scale callback fires (e.g. moving to another monitor).
  • Game / Scripting — Scripting bindings keep a list of created applications (State->Apps); CreateApplication returns TSharedPtr<FViseraApp>. Mouse position exposed to scripts via GetCursor().Position. Engine terminate clears Apps before resetting the engine.
  • Game (Verdandi) — Demo uses background material and sky texture, R8G8B8A8_UNorm scene color, black clear; sprite push constants include GlowRadius (from left-button hold duration); hit test uses cursor AABB and glow radius; window size read each frame for resize.