MappedRelation / MappedRelationComponent

Overview

MappedRelation and MappedRelationComponent are data classes that hold the correspondence between recipe coordinates and the actual input slot coordinates.

For shaped recipes (SHAPED), a match is found regardless of where on the grid the player places the items as long as the shape matches. MappedRelation records the mapping between those “coordinates in the recipe definition” and “the coordinates where items are actually placed.”

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Class Definition

data class MappedRelation(
    val components: Set<MappedRelationComponent>
)

data class MappedRelationComponent(
    val recipe: CoordinateComponent,
    val input: CoordinateComponent
)

Field	Type	Description
MappedRelation.components	Set<MappedRelationComponent>	Set of correspondence components
MappedRelationComponent.recipe	CoordinateComponent	Coordinate in the recipe definition
MappedRelationComponent.input	CoordinateComponent	Coordinate of the actually placed slot

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Where It Is Used

MappedRelation is passed in the following contexts:

Context	Field Name
ResultSupplier.Context	relation
CRecipePredicate.Context	relations
SearchResult	relation (via getter method)

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Usage Example

An example of checking which slot contains which item inside a ResultSupplier:

val supplier = ResultSupplier { ctx ->
    // Get the input coordinate that corresponds to recipe coordinate (0,0)
    val recipeCoord = CoordinateComponent(0, 0)
    val inputCoord: CoordinateComponent? = ctx.relation.components
        .firstOrNull { it.recipe == recipeCoord }
        ?.input

    val inputItem: ItemStack = inputCoord?.let { ctx.mapped[it] } ?: ItemStack.empty()

    listOf(ItemStack.of(Material.DIAMOND, inputItem.amount))
}