Layer 3: System Layer

Responsibility

Game engine subsystems that implement high-level functionality. These systems provide the core capabilities that game code builds upon.

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Subsystem Overview

Subsystem	Document
Audio	Audio Subsystem
Physics	Physics Subsystem
Touch Input	Touch Input
Tile Animation	Tile Animation
Resolution Scaling	Resolution Scaling

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Architecture Diagrams

Rendering Pipeline (Game Code → Display)

Logical vs Physical Resolution

Indexed Color → RGB565

PC Keyboard/Mouse Mapping

UI Composition

System Architecture

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Data Flow

Game Loop Flow

Audio Pipeline

Game Code
    │
    ▼ (submitCommand)
AudioCommandQueue (Thread-Safe)
    │
    ▼ (processCommands)
AudioScheduler
    │
    ├──▶ Pulse Channel
    ├──▶ Triangle Channel
    ├──▶ Noise Channel
    └──▶ Music Sequencer
    │
    ▼ (generateSamples)
Mixer (with LUT)
    │
    ▼
AudioBackend
    ├──▶ ESP32_I2S_AudioBackend
    ├──▶ ESP32_DAC_AudioBackend
    └──▶ SDL2_AudioBackend

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Modular Compilation Flags

Subsystem	Flag	Default
Audio	PIXELROOT32_ENABLE_AUDIO	Enabled
Physics	PIXELROOT32_ENABLE_PHYSICS	Enabled
UI System	PIXELROOT32_ENABLE_UI_SYSTEM	Enabled
Particles	PIXELROOT32_ENABLE_PARTICLES	Enabled
Touch Input	PIXELROOT32_ENABLE_TOUCH	Disabled
Tile Animations	PIXELROOT32_ENABLE_TILE_ANIMATIONS	Enabled
Static tilemap framebuffer cache (4bpp)	PIXELROOT32_ENABLE_STATIC_TILEMAP_FB_CACHE	Enabled
Static layer snapshot (game-drawn layers)	PIXELROOT32_ENABLE_STATIC_LAYER_SNAPSHOT	Disabled
Dirty Regions (selective clear)	PIXELROOT32_ENABLE_DIRTY_REGIONS	Disabled

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Related Documentation

Subsystem	Document
Audio	Audio Subsystem
Physics	Physics Subsystem
Touch Input	Touch Input
Tile Animation	Tile Animation
Resolution Scaling	Resolution Scaling
Memory	Memory System
API Reference	API Index