What OreGen does (in one sentence)
OreGen replaces the single cobblestone that vanilla would form with a configured ore only when it detects a strict, vanilla-looking setup. Otherwise, it leaves everything 100% vanilla.



The strict layout rule (core mechanic)
OreGen will only trigger when the target block sits in this exact straight-line pattern (no diagonals):

• Water Source: a true source block (level 0)
• Flowing Water: non-source water moving toward the target
• [TARGET BLOCK]: the spot vanilla would fill with cobblestone/stone
• Lava Source: a true lava source block (level 0)
• Exactly one lava source may touch the target block; otherwise OreGen won’t trigger

If (and only if) this pattern is met, OreGen:

1. Cancels the normal block-forming event for that one target block
2. Selects an ore from the player/world generator config
3. Places that ore at the target position (optionally with sounds/particles if enabled and supported)

Event paths (modern and legacy)

• Modern (1.12+) — BlockFormEvent: When Minecraft is about to form cobblestone/stone at the target, OreGen checks the strict pattern.
  
  Match → cancel vanilla and place the ore. • No match → do nothing; vanilla forms.​
• Legacy/flow — BlockFromToEvent: When fluids move, OreGen first requires that water is the moving fluid, then applies the same strict pattern to the would-be target block before acting.

How OreGen preserves vanilla behavior (safety net)
OreGen falls back to vanilla (does nothing) in all of these cases:

• Flowing water touches flowing lava (no lava source on the lava side)
• Multiple lava sources adjacent to the target
• No water source behind the flowing water
• Lava is the moving fluid (instead of water)
• Target isn’t valid for vanilla formation (not air/water)
• Downward flow when [tt]enable-stone-generator[/tt] is false
• World disabled (via plugin config)
• Particles/Sounds unsupported: visuals/audio are skipped; block logic remains vanilla-safe

Where the ore choice comes from
When the rule matches, OreGen asks the per-player/per-world GeneratorConfig for a random item:
GeneratorConfig → GeneratorItem → Material (+ optional damage/meta)
That material is placed at the target block (the same spot vanilla would have placed cobble/stone).



Demo: OreGen in action


What to show

• Lay out: Water Source → Flowing Water → Air → Lava Source
• When vanilla would create cobblestone, OreGen replaces that one target block with a configured ore
• Repeat in all four cardinal directions to show it only works in straight lines (no diagonals)

Demo: Vanilla safety net


Show these cases

• Flowing vs. Flowing: Flowing water meeting flowing lava → vanilla cobblestone/stone (no ore)
• Multiple lava sources near the target → vanilla forms (no ore)
• No water source behind the flow → vanilla forms (no ore)
• Lava-moving scenario: Lava is the moving fluid → vanilla forms (no ore)

Quick test checklist

• ✔ Exact pattern triggers ore
• ✔ Any deviation (extra lava source, missing water source, diagonals, flow↔flow) → vanilla only
• ✔ Only the one target block is ever replaced; nearby blocks remain vanilla
• ✔ Disabled worlds and downward-flow rules respect your config