EngineMap.txt

# Apus Game Engine Class Map
# Created: January 28, 2026
# Engine version: unknown

## Engine Structure Overview

Apus Game Engine is a modular system built on interfaces and abstract classes.
Main components:

1. **Engine Core (TGame, TGameBase)** - main loop management, scenes, input
2. **Graphics Subsystem (IGraphicsSystem)** - abstraction over OpenGL/DirectX
3. **Resource System (IResourceManager)** - texture and buffer management
4. **Scene System (TGameScene, TUIScene)** - game logic organization
5. **User Interface (TUIElement and descendants)** - widget system
6. **Auxiliary Systems** - sound, network, physics, etc.

## Classes and Interfaces

### Module: Apus.Engine.API.pas

#### Graphics Subsystem Interfaces:

**ISystemPlatform** - interface to native OS or base library
- Purpose: Abstraction of platform-dependent functions (windows, cursors, input)
- Dependencies: Types, THandle
- Interface: CreateWindow, DestroyWindow, SetupWindow, GetWindowHandle, ProcessSystemMessages, GetSystemCursor, SetCursor, CreateOpenGLContext, etc.

**IRenderTarget** - render target management
- Purpose: Control of render target (clear, viewport, blending)
- Dependencies: TTexture, TDepthBufferTest, TBlendingMode
- Interface: Clear, Viewport, UseDepthBuffer, BlendMode, Mask, UnMask, Backbuffer, Texture, Push, Pop

**IClipping** - clipping management
- Purpose: Setting and restoring clipping regions
- Dependencies: TRect
- Interface: Rect, Nothing, Restore, Reject, Get, Prepare

**ITransformation** - transformation and projection management
- Purpose: Setting projection, view, and model matrices
- Dependencies: T3DMatrix, TPoint3, TVector3
- Interface: DefaultView, Perspective, Orthographic, SetProjection, SetView, SetCamera, SetObj, ResetObj, MVPMatrix, Transform, etc.

**IShader** - shader management
- Purpose: Compilation and use of shaders, texture mode configuration
- Dependencies: TShader, TTexBlendingMode, TTexFilter, TShadowMapMode
- Interface: Build, Load, UseCustom, UseCustomized, Reset, SetUniform, TexMode, DefaultTexMode, UseTexture, AmbientLight, DirectLight, PointLight, LightOff, Material, Shadow, Apply

**IGraphicsSystemConfig** - graphics system configuration
- Purpose: Pixel format selection, vertical sync configuration
- Dependencies: TImagePixelFormat
- Interface: ChoosePixelFormats, SetVSyncDivider, QueryMaxRTSize, ShouldUseTextureAsDefaultRT

**IResourceManager** - resource manager (textures, buffers)
- Purpose: Creation and management of textures, vertex and index buffers
- Dependencies: TTexture, TVertexBuffer, TIndexBuffer, TImagePixelFormat, TBufferUsage
- Interface: AllocImage, QueryParams, FreeImage, ResizeImage, Clone, Copy, AttachDepthBuffer, MakeOnline, AllocVertexBuffer, AllocIndexBuffer, FreeBuffer, UseVertexBuffer, UseIndexBuffer, GetStatus, Dump

**ITextDrawer** - text output
- Purpose: Font loading, text output and measurement
- Dependencies: TFontHandle, TTextAlignment, TBuffer
- Interface: LoadFont, SetScale, GetFont, ScaleFont, SetFontOption, Write, WriteW, Width, WidthW, Height, MeasuredCnt, MeasuredRect, ClearLink, Link, LinkRect, BeginBlock, EndBlock, SetTarget

**IDrawer** - primitive drawing
- Purpose: Drawing lines, rectangles, textures, particles, meshes
- Dependencies: TTexture, TParticle, TVertex, TVertexBuffer, TIndexBuffer, TColorGradient
- Interface: Line, Polyline, Polygon, Rect, FillRect, Image, TexturedRect, Scaled, RotScaled, WithGradient, NoGradient, Billboard, TrgList, IndexedMesh, DoubleTex, Particles, Band, EnableSoftParticles, DisableSoftParticles, SetZ

**IGraphicsSystem** - main graphics subsystem interface
- Purpose: Combines all graphics interfaces, rendering management
- Dependencies: All above interfaces
- Interface: Init, Done, GetVersion, GetName, config, resman, target, shader, clip, transform, draw, txt, BeginPaint, EndPaint, SetCullMode, CopyFromBackbuffer, GetPixelValue, PresentFrame, Restore, DrawDebugOverlay, Breakpoint

#### Abstract Classes:

**TGameBase** - base game class (abstract)
- Purpose: Defines common interface for game management
- Dependencies: ISystemPlatform, IGraphicsSystem, TGameSettings, TGameScene, TAnimatedValue
- Interface: SetSettings, GetSettings, Run, Stop, SwitchToAltSettings, OnFrame, RenderFrame, AddScene, RemoveScene, TopmostVisibleScene, GetScene, SwitchToScene, ShowWindowScene, HideWindowScene, RegisterCursor, GetCursorForID, ToggleCursor, HideAllCursors, ClientToGame, GameToClient, RunAsync, GetThreadResult, FLog, GetStatus, FireMessage, DebugFeature, EnterCritSect, LeaveCritSect, RequestScreenshot, RequestFrameCapture, StartVideoCap, FinishVideoCap, MouseInRect, MouseIsNear, WaitFor, SuppressKbdEvent, GetDepthBufferTex, Minimize, MoveWindowTo, SetWindowCaption, DPadCustomPoint

**TNinePatch** - nine-patch image (stretchable)
- Purpose: Creation of stretchable images for UI
- Dependencies: TNamedObject
- Interface: minWidth, minHeight, baseWidth, baseHeight, scaleFactor, Draw (abstract), ClassHash

### Module: Apus.Engine.Game.pas

**TGame** - concrete game engine implementation
- Purpose: Main class implementing game loop, scene management, input
- Inherits: TGameBase
- Dependencies: ISystemPlatform, IGraphicsSystem, TGameScene, TGameSettings, TGameCursor, TCustomThread
- Interface: All TGameBase methods + internal: ApplyNewSettings, SetVSync, InitGraph, InitDefaultResources, AfterInitGraph, SetupRenderArea, InitDefaultRenderTarget, InitMainLoop, FrameLoop, RenderAndPresentFrame, PresentFrame, DoneGraph, CaptureFrame, DrawCursor, DrawOverlays, NotifyScenesAboutMouseMove, NotifyScenesAboutMouseBtn, TopmostSceneForKbd, onEngineEvent, onCmdEvent, onKbdEvent, onMouseEvent, onJoystickEvent, onGamepadEvent, MouseMovedTo, CharEntered, KeyPressed, MouseButtonPressed, MouseWheelMoved, SizeChanged, Activate, CreateDebugLogs, DrawMagnifier, HandleInternalHotkeys, HandleGamepadNavigation

**TMainThread** - main game thread
- Purpose: Execution of main game loop in separate thread
- Inherits: TThread
- Dependencies: TGame
- Interface: Execute (overridden)

**TCustomThread** - custom thread for asynchronous tasks
- Purpose: Execution of user functions in separate thread
- Inherits: TThread
- Dependencies: TAsyncProc
- Interface: Execute (overridden), id, TimeToKill, running, func, FinishTime, param, name

**TGameCursor** - cursor representation
- Purpose: Storage of cursor information (ID, priority, handle, visibility)
- Dependencies: THandle
- Interface: ID, priority, handle, visible

### Module: Apus.Engine.Scene.pas

**TSceneEffect** - base scene effect
- Purpose: Abstract class for scene transition effects
- Dependencies: TGameScene
- Interface: timer, duration, done, target, name, Create, DrawScene (abstract), Destroy

**TSceneSwitcher** - scene switcher (abstract)
- Purpose: Interface for switching between scenes
- Dependencies: none
- Interface: SwitchToScene, ShowWindowScene, HideWindowScene (all abstract)

**TGameScene** - base game scene
- Purpose: Abstract class for all game scenes
- Inherits: TNamedObject
- Dependencies: TSceneStatus, TSceneEffect, TQueue
- Interface: status, fullscreen, frequency, effect, zOrder, activated, shadowColor, ignoreKeyboardEvents, initialized, loaded, accumTime, Create, Destroy, onCreate, SetStatus, IsActive, Load, Initialize, Process, Render, KeyPressed, ReadKey, WriteKey, ClearKeyBuf, ModeChanged, onResize, onMouseMove, onMouseBtn, onMouseWheel, onShow, onHide, onEvent, GetArea (abstract), LoadAllScenes, ClassHash

### Module: Apus.Engine.UIScene.pas

**TUIScene** - scene with user interface
- Purpose: Scene containing UI layer, base for most game scenes
- Inherits: TGameScene
- Dependencies: TUIElement
- Interface: UI, frameTime, Create, SetStatus, Process, Render, onResize, GetArea, WriteKey, onMouseMove, onMouseBtn, onMouseWheel, BackgroundRenderBegin, BackgroundRenderEnd

### Module: Apus.Engine.Resources.pas

**TTexture** - base texture class
- Purpose: Texture abstraction in graphics subsystem
- Inherits: TNamedObject
- Dependencies: TImagePixelFormat, TLockMode, TRawImage
- Interface: CloneFrom, Clone, ClonePart, Clear, ClearPart, Upload, UploadPart, Lock, LockLayer, GetLayer, GetRawImage, IsLocked, Unlock, AddDirtyRect, HasFlag, SetFilter, Size, Dump, FindByFile, src (property)

**TShader** - base shader class
- Purpose: Shader program abstraction
- Inherits: TNamedObject
- Dependencies: TVector2s, TVector3s, TVector4s, T3DMatrix, T3DMatrixS
- Interface: SetUniform (overloaded methods), VectorFromColor, VectorFromColor3

**TEngineBuffer** - base buffer class
- Purpose: Base class for vertex and index buffers
- Inherits: TObjectEx
- Dependencies: none
- Interface: sizeInBytes

**TVertexBuffer** - vertex buffer
- Purpose: Storage of vertices for rendering
- Inherits: TEngineBuffer
- Dependencies: TVertexLayout
- Interface: count, layout, Create, Upload, Resize

**TIndexBuffer** - index buffer
- Purpose: Storage of indices for rendering
- Inherits: TEngineBuffer
- Dependencies: none
- Interface: count, bytesPerIndex, Create, Upload, Resize

### Module: Apus.Engine.UITypes.pas

**TLayouter** - base layouter class
- Purpose: Abstract class for child element placement
- Dependencies: TUIElement
- Interface: Layout (abstract), GetItems

**IScroller** - scroller interface
- Purpose: Interface for external scrollbars
- Dependencies: TUIElement
- Interface: GetElement, SetRange, SetValue, SetStep, SetPageSize, MoveRel, GetValue, GetStep, GetPageSize

**TUIElement** - base user interface element
- Purpose: Main class for all UI elements, manages positioning, size, events
- Inherits: TNamedObject
- Dependencies: TElementShape, TAnchorMode, TSnapMode, TSendSignals, TClipMouse, TUIPlacementMode, TRegion, TLayouter, IScroller
- Interface: position, size, pivot, anchors, shape, scale, padding, scroll, enabled, visible, cursor, order, styleClass, canHaveFocus, hint, parent, children, layout, Create, Destroy, SafeDestroy, GetNext, GetPrev, GetRoot, IsVisible, IsEnabled, IsChild, HasParent, HasChild, DeleteChildren, ChildIndex, AttachTo, Detach, InsertAfter, InsertBefore, TransformTo, TransformToScreen, TransformFromScreen, GetRect, GetClientRect, GetPosOnScreen, GetClientPosOnScreen, onMouseMove, onMouseScroll, onMouseButtons, onKey, onChar, onUniChar, onHotKey, onTimer, onLostFocus, SetFocus, HasFocus, SetFocusToNext, SetFocusToPrev, SetPos, MoveBy, SetAnchors, SetPadding, SetScale, Resize, ResizeClient, Center, Snap, ScrollTo, SetupScrollers, CheckAndSetFocus, FindElementAt, FindAnyElementAt, FindChildByName, SetHotKey, RemoveHotKey, IsOpaque, IsOutOfOrder, Show, Hide, Toggle, Enable, Disable, ToggleEnabled, IsWindow, IsActiveWindow, SetDefault, SetStyle

### Module: Apus.Engine.UIWidgets.pas

**TUIFlexControl** - element with size constraints
- Purpose: Base class for elements with minimum/maximum sizes
- Inherits: TUIElement
- Dependencies: TUIElement
- Interface: minWidth, minHeight, maxWidth, maxHeight

**TUISplitter** - splitter
- Purpose: Visual separator between elements, can be horizontal or vertical
- Inherits: TUIElement
- Dependencies: TUIElement
- Interface: canResize, CreateH, CreateV (overloaded constructors)

**TUIImage** - static image
- Purpose: Display of images from files, events, or rendering procedures
- Inherits: TUIElement
- Dependencies: TUIElement
- Interface: src, Create, SetRenderProc

**TUIScrollArea** - scroll area for touchscreen
- Purpose: Independent area for content scrolling, captures drag events
- Inherits: TUIElement
- Dependencies: TUIElement, TUIScrollDirection
- Interface: fullWidth, fullHeight, direction, Create, onMouseMove, onMouseButtons, onTimer

**TUIHint** - tooltip
- Purpose: Popup window with text hint, automatically hides
- Inherits: TUIImage
- Dependencies: TUIImage
- Interface: simpleText, active, created, adjusted, hiding, Create, Destroy, Hide, onMouseButtons, onTimer

**TUILabel** - text label
- Purpose: Text display with alignment and auto-size support
- Inherits: TUIElement
- Dependencies: TUIElement, TTextAlignment
- Interface: align, autoSize, verticalOffset, Create (overloaded constructors), CreateCentered, CreateRight, CaptionWidthIs

**TUIButton** - button
- Purpose: Interactive button with support for various styles (normal, switch, checkbox)
- Inherits: TUIElement
- Dependencies: TUIElement, TButtonStyle, TProcedure
- Interface: default, pressed, pending, autoPendingTime, btnStyle, group, onClick, onClickEvent, Create (overloaded constructors), CreateSwitch, CreateGroupSwitch, Destroy, onMouseButtons, onMouseMove, onKey, onHotKey, onTimer, SetPressed, MakeSwitches, Click, GetSwitchIndex, Sender

**TUICheckBox** - checkbox
- Purpose: Element for option selection (checkbox)
- Inherits: TUIButton
- Dependencies: TUIButton
- Interface: checked, Create, SetPressed

**TUIRadioButton** - radio button
- Purpose: Element for single option selection from group
- Inherits: TUICheckbox
- Dependencies: TUICheckbox
- Interface: Create

**TUIFrame** - frame
- Purpose: Visual frame around elements
- Inherits: TUIElement
- Dependencies: TUIElement
- Interface: borderWidth, Create, SetBorderWidth

**TUIWindow** - base window
- Purpose: Window with title, move and resize support
- Inherits: TUIImage
- Dependencies: TUIImage
- Interface: header, autoBringToFront, moveable, resizeable, minW, minH, maxW, maxH, Create, GetAreaType, onMouseMove, onMouseButtons, onLostFocus, Resize, IsWindow

**TUISkinnedWindow** - skinned window
- Purpose: Window with custom skin and non-rectangular shape
- Inherits: TUIWindow
- Dependencies: TUIWindow, TRegion
- Interface: dragRegion, background, Create, Destroy, GetAreaType

**TUIEditBox** - text input field
- Purpose: Single-line text input field with selection, copy/paste support
- Inherits: TUIElement
- Dependencies: TUIElement
- Interface: realText, completion, defaultText, cursorPos, maxLength, password, noBorder, selStart, selCount, cursorTimer, needPos, msSelect, protection, offset, Create, onChar, onUniChar, onKey, onMouseButtons, onMouseMove, SetFocus, onLostFocus, SelectAll, text (property)

**TUIScrollBar** - scroll bar
- Purpose: Vertical or horizontal scroll bar with animation
- Inherits: TUIElement
- Dependencies: TUIElement, TAnimatedValue, IScroller
- Interface: horizontal, isInteger, min, max, pagesize, step, sliderUnder, sliderStart, sliderEnd, autoHide, Create, GetValue, SetValue, GetAnimating, SetPageSize, GetStep, GetScroller, SetRange, MoveTo, MoveRel, Link, UseButtons, CalcSliderPos, onTimer, onMouseMove, onMouseButtons, onMouseScroll, onLostFocus

**TUIListBox** - list box
- Purpose: Scrollable list of elements with selection support
- Inherits: TUIElement
- Dependencies: TUIElement, TUIScrollBar
- Interface: lines, tags, hints, lineHeight, selectedLine, hoverLine, autoSelectMode, bgColor, bgHoverColor, bgSelColor, textColor, hoverTextColor, selTextColor, Create, Destroy, AddLine, SetLine, ClearLines, SetLines, SelectLine, onMouseMove, onMouseButtons, UpdateScroller

**TUIComboBox** - combo box
- Purpose: Combined field with dropdown list for value selection
- Inherits: TUIButton
- Dependencies: TUIButton, TUIFrame, TUIListBox
- Interface: items, hints, tags, defaultText, fCurItem, fCurTag, frame, popup, maxlines, Create, AddItem, SetItem, ClearItems, onDropDown, onMouseButtons, onTimer, SetCurItem, SetCurItemByText, SetCurItemByTag, text (property)

### Module: Apus.Engine.OpenGL.pas

**TOpenGL** - OpenGL graphics system implementation
- Purpose: Concrete implementation of IGraphicsSystem and IGraphicsSystemConfig interfaces for OpenGL
- Inherits: TInterfacedObject
- Implements: IGraphicsSystem, IGraphicsSystemConfig
- Dependencies: ISystemPlatform, IResourceManager, IRenderTarget, IShader, IClipping, ITransformation, IDrawer, ITextDrawer
- Interface: Init, Done, GetVersion, GetName, ChoosePixelFormats, ShouldUseTextureAsDefaultRT, SetVSyncDivider, QueryMaxRTSize, config, resman, target, shader, clip, transform, draw, txt, PresentFrame, CopyFromBackbuffer, GetPixelValue, BeginPaint, EndPaint, SetCullMode, Restore, DrawDebugOverlay, PostDebugMsg, Breakpoint

**TRenderDevice** - OpenGL rendering device
- Purpose: Low-level abstraction for drawing primitives through OpenGL
- Inherits: TInterfacedObject
- Implements: IRenderDevice
- Dependencies: TVertexLayout, TPrimitiveType
- Interface: Create, Destroy, Reset, Draw, DrawIndexed (overloaded), DrawInstanced (overloaded), UseExtraVertexData, SetVertexDataDivisors, SetupAttributes

**TGLRenderTargetAPI** - OpenGL render target implementation
- Purpose: Management of render targets in OpenGL (backbuffer, textures)
- Inherits: TRendertargetAPI
- Dependencies: TTexture, TDepthBufferTest, TBlendingMode
- Interface: Create, Backbuffer, Texture, Clear, ClearDepth, Viewport, UseDepthBuffer, BlendMode, Clip, ApplyMask, Resized, ClearBuffers

### Module: Apus.Engine.ResManGL.pas (assumed)

**TGLResourceManager** - OpenGL resource manager
- Purpose: Concrete implementation of IResourceManager for OpenGL
- Dependencies: TTexture, TVertexBuffer, TIndexBuffer
- Interface: (implements IResourceManager)

**TGLTexture** - OpenGL texture
- Purpose: Concrete implementation of TTexture for OpenGL
- Inherits: TTexture
- Dependencies: TTexture
- Interface: SetAsRenderTarget and other OpenGL-specific methods

### Module: Apus.Engine.ShadersGL.pas (assumed)

**TGLShadersAPI** - OpenGL shaders API
- Purpose: Concrete implementation of IShader for OpenGL
- Dependencies: TShader
- Interface: (implements IShader)

### Module: Apus.Engine.Mesh.pas

**TMesh** - 3D mesh
- Purpose: Representation of 3D model with geometry
- Dependencies: (assumed TVertex, TIndices)
- Interface: (defined in API.pas as type)

## Other Important Modules (briefly):

### Module: Apus.Engine.Sound.pas
- **TSoundSystem** - abstract sound system
- **TSoundSample** - sound sample
- **TSoundStream** - sound stream

### Module: Apus.Engine.Networking2.pas / Networking3.pas
- **TNetworking** - networking subsystem
- **TConnection** - network connection

### Module: Apus.Engine.Model3D.pas
- **TModel3D** - 3D model with bone hierarchy and animations

### Module: Apus.Engine.Console.pas
- **TConsole** - in-game console

### Module: Apus.Engine.CmdProc.pas
- **TCommandProcessor** - command processor

## Dependencies Between Main Components

```
TGame (core)
  ├── IGraphicsSystem (graphics)
  │     ├── IResourceManager (resources) → TGLResourceManager (OpenGL)
  │     ├── IDrawer (drawing)
  │     ├── ITextDrawer (text)
  │     ├── IShader (shaders) → TGLShadersAPI (OpenGL)
  │     ├── ITransformation (transformations)
  │     ├── IClipping (clipping)
  │     └── IRenderTarget (render target) → TGLRenderTargetAPI (OpenGL)
  ├── ISystemPlatform (platform)
  ├── TSoundSystem (sound)
  ├── TNetworking (network)
  └── TGameScene and descendants (scenes)
        └── TUIScene (UI scenes)
              └── TUIElement and descendants (UI elements)
```

## Architectural Features

1. **Interface-Oriented Design**: All major subsystems are represented by interfaces (IGraphicsSystem, IResourceManager, etc.), allowing easy replacement of implementations.

2. **Modularity**: The engine is divided into clear modules:
   - Core (Game, Scene)
   - Graphics (OpenGL/DirectX implementations)
   - Resources (textures, buffers)
   - User Interface
   - Sound, network, physics

3. **Scene Hierarchy**: Game logic is organized through scenes (TGameScene), which can be nested and have transition effects.

4. **UI System**: Full-featured widget system with support for layouts, events, input focus.

5. **Cross-Platform**: Platform abstraction through ISystemPlatform allows working on Windows, Linux, mobile platforms.

6. **Multithreading**: Support for asynchronous tasks through TCustomThread.

## Key Abstractions

1. **TGame** - central class managing the entire lifecycle
2. **TGameScene** - unit of game logic
3. **TUIElement** - base UI element
4. **TTexture** - graphics resource abstraction
5. **ISystemPlatform** - operating system abstraction

This class map represents the main architecture of Apus Game Engine and can be expanded with more detailed analysis of specific modules.