using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class GetTerrainTextureIndice : MonoBehaviour {

	public Terrain myActiveTerrain;
	public List<int> terrainTextureIndices = new List<int>();
	public int dominantTerrainIndex;
	//
	TerrainData terrainData;
	float[] terrainCompositionArray;
	float[,,] splatmapData;
	float[] cellMix;

	void Update(){
		myActiveTerrain = Terrain.activeTerrain;
		dominantTerrainIndex = GetDominantTerrainTexture(transform.position);
		if(dominantTerrainIndex != -1){
			if (terrainTextureIndices.Count > 0 && terrainTextureIndices.Contains(dominantTerrainIndex)){

			}
		}
	}

	float[] TerrainComposition(Vector3 worldPos){
		try{
			terrainData = myActiveTerrain.terrainData;
			int mapX = (int)(((worldPos.x - myActiveTerrain.transform.position.x) / terrainData.size.x) * terrainData.alphamapWidth);
			int mapZ = (int)(((worldPos.z - myActiveTerrain.transform.position.z) / terrainData.size.z) * terrainData.alphamapHeight);
			splatmapData = terrainData.GetAlphamaps(mapX, mapZ, 1, 1);
			cellMix = new float[splatmapData.GetUpperBound(2) + 1];
			for (int x = 0; x < cellMix.Length; ++x){
				cellMix[x] = splatmapData[0, 0, x];
			}
			return cellMix;
		}
		catch{
			return null;
		}
	}

	int GetDominantTerrainTexture(Vector3 worldPos){
		terrainCompositionArray = TerrainComposition(worldPos);
		if(terrainCompositionArray != null){
			float maxMix = 0;
			int maxIndex = 0;
			for (int x = 0; x < terrainCompositionArray.Length; ++x){
				if (terrainCompositionArray[x] > maxMix){
					maxIndex = x;
					maxMix = terrainCompositionArray[x];
				}
			}
			return maxIndex;
		}
		else{
			return -1;
		}
	}
}