#pragma once

#include "CoreMinimal.h"
#include "ProceduralMeshComponent.h"
#include "World/TerrainChunk.h"

namespace Descent::World
{
	class FDescentWorldDef;

	struct FSurfaceNetsInput
	{
		const float* Data = nullptr;       // P^3 densities
		const uint8* Cut = nullptr;        // P^3 cut amounts
		FIntVector Key = FIntVector::ZeroValue;
		const FDescentWorldDef* Def = nullptr;
		TConstArrayView<int32> Deposits;   // deposits that may touch the chunk
		TConstArrayView<uint8> Exhausted;  // parallel: 1 = mined out (its vein no longer shows)
	};

	/**
	 * The mesher (DESIGN_UE.md section 2.4; port of 04_terrain.js meshChunk): surface nets with the gradient normal
	 * blended trilinearly from the eight corners. Static and thread-safe. The 2-sample padding makes neighbouring
	 * chunks produce identical border vertices, so there are no seams. Vertex positions are chunk-local centimetres.
	 */
	struct THEDESCENT_API FSurfaceNets
	{
		/** Returns false (and an empty section) when the chunk has no surface. */
		static bool Mesh(const FSurfaceNetsInput& In, FProcMeshSection& OutSection, int32& OutTriangles);
		/** Palette colour of the rock at a point (section 2.4), sRGB-encoded. N is the unit normal. */
		static FColor RockColor(const FDescentWorldDef& Def, const FVector& Pm, const FVector& N);
	};
}