Architecture and Mixins

Architecture & Mixins

This technical reference details the package hierarchy, source layout, and Mixin injection target breakdown for Speedometer.

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📊 Package Architecture Diagram

net.vanillaoutsider.speedometer
├── SpeedometerMod.java               <-- Constants & Identifier definitions
├── client
│   ├── SpeedometerClient.java        <-- ClientModInitializer entrypoint
│   ├── DebugEntrySpeedometer.java     <-- Custom DebugScreenEntry implementation
│   └── DebugEntryPlayerSpeedWrapper.java <-- Interceptor spy-wrapper for player_speed
└── mixin
    ├── DebugScreenEntriesMixin.java   <-- Hooks into DebugScreenEntries static init
    └── DebugScreenEntryListMixin.java <-- Enforces default IN_OVERLAY status

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🧩 Mixin Target Breakdown Table

Mixin Class	Target Minecraft Class	Target Method / Point	Injection Type	Purpose
DebugScreenEntriesMixin	net.minecraft.client.gui.components.debug.DebugScreenEntries	<clinit> @At("TAIL")	@Inject	Registers speedometer entry ID and wraps native player_speed entry if present.
DebugScreenEntriesMixin	net.minecraft.client.gui.components.debug.DebugScreenEntries	register	@Invoker	Invokes private vanilla register(Identifier, DebugScreenEntry) method.
DebugScreenEntryListMixin	net.minecraft.client.gui.components.debug.DebugScreenEntryList	rebuildCurrentList @At("HEAD")	@Inject	Ensures speedometer status defaults to DebugScreenEntryStatus.IN_OVERLAY.

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🔒 Thread Safety & Looper Rules

• Render Thread Isolation: All Mixin injections execute exclusively on Minecraft's Client Render Thread during static initialization or UI list rebuilding.
• Non-Blocking Guarantee: Zero blocking latches, thread synchronization locks, or futures are used in DebugEntrySpeedometer.display(), guaranteeing zero frame drops ($<0.001\text{ ms}$ cost).

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🔗 Related Pages

• Developer Setup & Building
• API & Addon Integration
• Zero-Dependency Design