ProjektMWS/Projekt MWS/Assets/Scripts/GrassController.cs

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

struct DifferentialEquationData {
    public float water;
    public float vegetation;
}


public class GrassController : MonoBehaviour {
    int _structSize() {
        return sizeof(float) + sizeof(float);
    }
    private GameObject cube;

    public float updateInterval;
    float timePassed;
    Terrain terrain;
    public ComputeShader computeShader;

    [Header("equation coeffs")]
    public float DWater = 1.0f;
    public float DVegetation = 0.5f;
    public float feedRate = 0.055f;
    public float killRate = 0.0462f;
    public float dT = 0.10f;
    public int stepsNumber = 1;


    int sizeX;
    int sizeY;
    ComputeBuffer vegetation;
    ComputeBuffer oldVegetation;
    ComputeBuffer water;
    ComputeBuffer oldWater;

    ComputeBuffer feedModifier;
    ComputeBuffer killModifier;
    // Start is called before the first frame update
    void Start() {
        terrain = gameObject.GetComponent<Terrain>();

        sizeX = terrain.terrainData.detailWidth;
        sizeY = terrain.terrainData.detailWidth;

        initComputeShader();
    }


    bool doUpdate() {
        timePassed += Time.deltaTime;
        if (timePassed < updateInterval) {
            return false;
        }
        else {
            timePassed = 0;
            return true;
        }

    }

    void initKillFeedBuffers() {
        //tutaj stworz
    }
    public void initBufferValues() {
        // tutaj uzupelnij wartosci buforow

        float[] initValues = new float[sizeX * sizeY];

        for(int i=0; i < sizeX*sizeY; i++)
        {
            initValues[i] = Random.Range(0.0f, 1.0f);
        }


        vegetation.SetData(initValues);
        oldVegetation.SetData(initValues);

         initValues = new float[sizeX * sizeY];

        for (int i = 0; i < sizeX * sizeY; i++)
        {
            initValues[i] = Random.Range(0.0f, 1.0f);
        }
        water.SetData(initValues);
        oldWater.SetData(initValues);
    }

    public void resetGrass() {
        initBufferValues();

        terrain = gameObject.GetComponent<Terrain>();
        
        sizeX = terrain.terrainData.detailWidth;
        sizeY = terrain.terrainData.detailHeight;
        
        
        var layer = new int[sizeX, sizeY];
        
        for(int i =0; i<sizeX; i++)
        {
            layer[i, i] = 16;
        }
        terrain.terrainData.SetDetailLayer(0, 0, 1, layer);

    }
    void initParameters() {
        //tutaj zainicjalizuj parametry
        computeShader.SetInt("sizeX",sizeX);
        computeShader.SetInt("sizeY", sizeY);
     

        computeShader.SetFloat("DWater", DWater     );
        computeShader.SetFloat("DVegetation", DVegetation);
        computeShader.SetFloat("feedRate", feedRate   );
        computeShader.SetFloat("killRate", killRate   );
        computeShader.SetFloat("dT", dT         );
        computeShader.SetFloat("stepsNumber", stepsNumber);

    }
    void initComputeShader() {
        //tutaj zainicjalizuj compute shader
        vegetation = new ComputeBuffer(sizeX * sizeY, sizeof(float));
        oldVegetation = new ComputeBuffer(sizeX * sizeY, sizeof(float));

        computeShader.SetBuffer(0, "vegetation", vegetation);
        computeShader.SetBuffer(0, "oldVegetation", oldVegetation);
        computeShader.SetBuffer(0, "water", water);
        computeShader.SetBuffer(0, "oldWater", oldWater);
         

        initKillFeedBuffers();
        initBufferValues();
        initParameters();
    }


    void swapBuffers() {
        //tutaj zamien bufory ze soba

        var temp = vegetation;
        vegetation = oldVegetation;
        oldVegetation = temp;

        temp = water;
        water = oldWater;
        oldWater = water;

        computeShader.SetBuffer(0, "vegetation", vegetation);
        computeShader.SetBuffer(0, "oldVegetation", oldVegetation);
        
        computeShader.SetBuffer(0, "water", water);
        computeShader.SetBuffer(0, "oldWater", oldWater);
    }
    void doSimulationSteps(int steps) {
        //tutaj wykonaj kroki symulacji
        for (int i = 0; i < steps; i++)
        {
            swapBuffers();
            computeShader.Dispatch(0, sizeX, sizeY, 1);
        }
    }

    void recoverData() {
        //tutaj odczytaj bufor i przeslij wynik jako mapa detali
        var result = new float[sizeX * sizeY];

        vegetation.GetData(result);

        var detailLayer = new int[sizeX, sizeY];
        for (int i = 0; i < sizeX; i++)
            for (int j = 0; j < sizeY; j++)
                detailLayer[i, j] = Mathf.FloorToInt(result[i + j * sizeX]*10);
            

        terrain.terrainData.SetDetailLayer(0, 0, 1, detailLayer);
    }
    // Update is called once per frame
    void Update() {
        if (doUpdate()) {
            initParameters();
            doSimulationSteps(stepsNumber);
            recoverData();
        }
    }
}