using UnityEngine;
using System.Collections;

public class ParticleSea : MonoBehaviour {

    public ParticleSystem particleSystem;
    private ParticleSystem.Particle[] particlesArray;

    public Gradient colorGradient;

    public int seaResolution = 50;
    public float spacing = 0.5f;
    public float noiseScale = 0.1f;
    public float heightScale = 1f;

    private float perlinNoiseAnimX = 0.01f;
    private float perlinNoiseAnimY = 0.01f;

    void Start() {
        particlesArray = new ParticleSystem.Particle[seaResolution * seaResolution];
        particleSystem.maxParticles = seaResolution * seaResolution;
        particleSystem.Emit(seaResolution * seaResolution);
        particleSystem.GetParticles(particlesArray);
    }

    void Update() {
        for(int i = 0; i < seaResolution; i++) {
            for(int j = 0; j < seaResolution; j++) {
                float zPos = Mathf.PerlinNoise(i * noiseScale + perlinNoiseAnimX, j * noiseScale + perlinNoiseAnimY);
                particlesArray[i * seaResolution + j].color = colorGradient.Evaluate(zPos);
                particlesArray[i * seaResolution + j].position = new Vector3(i * spacing, zPos  * heightScale, j * spacing);
            }
        }

        perlinNoiseAnimX += 0.01f;
        perlinNoiseAnimY += 0.01f;

        particleSystem.SetParticles(particlesArray, particlesArray.Length);
    }

}