Touhou/client/Assets/Plugins/FluidDynamics/Scripts/Main_Fluid_Simulation.cs

using UnityEngine;
namespace FluidDynamics
{
    [AddComponentMenu("Fluid Dynamics/Fluid Simulator")]
    public class Main_Fluid_Simulation : MonoBehaviour
    {

        #region Variables
        [HideInInspector]
        public ComputeShader m_simulationShader;
        [HideInInspector]
        public ComputeShader m_particleAreaShader;
        public bool m_simulate = true;
        [HideInInspector]
        public float m_speed = 500f;
        public float Speed { get { return m_speed; } set { m_speed = value; } }
        [HideInInspector]
        public int m_iterations = 50;
        public int Iterations { get { return m_iterations; } set { m_iterations = value; } }
        [HideInInspector]
        public float m_velocityDissipation = 1f;
        public float VelocityDissipation { get { return m_velocityDissipation; } set { m_velocityDissipation = value; } }
        [HideInInspector]
        public float m_vorticityScale = 0f;
        public float Vorticity { get { return m_vorticityScale; } set { m_vorticityScale = value; } }
        [HideInInspector]
        public float m_viscosity = 0f;
        public float Viscosity { get { return m_viscosity; } set { m_viscosity = value; } }
        [HideInInspector]
        public int m_nResolution = 512;
        [HideInInspector]
        public bool m_cacheVelocity = false;
        public int Resolution { get { return m_nResolution; } set { m_nResolution = value; } }
        public ComputeBuffer VelocityBuffer { get { return m_velocityBuffer[VELOCITY_READ]; } }
        public ComputeBuffer DivergenceBuffer { get { return m_divergenceBuffer; } }
        public ComputeBuffer PressureBuffer { get { return m_pressure[PRESSURE_READ]; } }
        public ComputeBuffer ObstaclesBuffer { get { return m_obstaclesBuffer; } }
        private ComputeBuffer m_obstaclesBuffer;
        private ComputeBuffer[] m_velocityBuffer;
        private ComputeBuffer m_divergenceBuffer;
        private ComputeBuffer[] m_pressure;
        private ComputeBuffer m_vorticityBuffer;
        private Vector2[] m_currentVelocity;
        private int m_nNumCells;
        private int m_nNumGroupsX;
        private int m_nNumGroupsY;
        private int m_nWidth = 512;
        private int m_nHeight = 512;
        private int m_addVelocityKernel = 0;
        private int m_initBoundariesKernel = 0;
        private int m_advectVelocityKernel = 0;
        private int m_divergenceKernel = 0;
        private int m_poissonKernel = 0;
        private int m_substractGradientKernel = 0;
        private int m_calcVorticityKernel = 0;
        private int m_applyVorticityKernel = 0;
        private int m_viscosityKernel = 0;
        private int m_addObstacleCircleKernel = 0;
        private int m_addObstacleTriangleKernel = 0;
        private int m_clearBufferKernel = 0;
        private int VELOCITY_READ = 0;
        private int VELOCITY_WRITE = 1;
        private int PRESSURE_READ = 0;
        private int PRESSURE_WRITE = 1;
        #endregion
        //
        #region Variables2
        [Tooltip("If m_ExposeParticles is true the value of the particles will be cached in memory for use by other systems")]
        public bool m_CacheParticles = false;
        public Gradient m_colourGradient;
        public bool m_updateGradient = false;
        [HideInInspector]
        public float m_densityDissipation = 1f;
        public float Dissipation { get { return m_densityDissipation; } set { m_densityDissipation = value; } }
        public ComputeBuffer ParticlesBuffer { get { return m_particlesBuffer[READ]; } }
        private ComputeBuffer m_colourRamp;
        private int m_addParticlesKernel = 0;
        private int m_advectKernel = 0;
        [HideInInspector]
        public int m_nParticlesResolution = 128;
        public int ParticlesResolution
        {
            get
            {
                return m_nParticlesResolution;
            }
            set
            {
                if (value != m_nParticlesResolution)
                {
                    m_nParticlesResolution = value;
                    if (Application.isPlaying && m_particlesBuffer[0] != null && m_particlesBuffer[1] != null)
                    {
                        int nOldHeight = m_nParticlesHeight;
                        int nOldWidth = m_nParticlesWidth;
                        float[] oldParticleData = new float[nOldWidth * nOldHeight];
                        m_particlesBuffer[READ].GetData(oldParticleData);
                        m_particlesBuffer[0].Dispose();
                        m_particlesBuffer[1].Dispose();

                        CalculateSize();

                        float[] newParticleData = new float[m_nParticlesWidth * m_nParticlesHeight];
                        for (int i = 0; i < m_nParticlesHeight; ++i)
                        {
                            for (int j = 0; j < m_nParticlesWidth; ++j)
                            {
                                float normX = (float)j / (float)m_nParticlesWidth;
                                float normY = (float)i / (float)m_nParticlesHeight;
                                int x = (int)(normX * (float)nOldWidth);
                                int y = (int)(normY * (float)nOldHeight);
                                newParticleData[i * m_nParticlesWidth + j] = oldParticleData[y * nOldWidth + x];
                            }
                        }

                        m_particlesBuffer = new ComputeBuffer[2];
                        for (int i = 0; i < 2; ++i)
                        {
                            m_particlesBuffer[i] = new ComputeBuffer(m_nParticlesWidth * m_nParticlesHeight, 4, ComputeBufferType.Default);
                        }
                        m_particlesBuffer[READ].SetData(newParticleData);

                    }
                }
            }
        }
        private int m_nColourRampSize = 256;
        private ComputeBuffer[] m_particlesBuffer;
        private int m_nParticlesNumGroupsX;
        private int m_nParticlesNumGroupsY;
        private int m_nParticlesWidth = 512;
        private int m_nParticlesHeight = 512;
        private int READ = 0;
        private int WRITE = 1;
        private float[] m_currentParticles;
        private Renderer m_tempRend;
        #endregion
        //
        #region Variables3
        static readonly int _Size = Shader.PropertyToID("_Size");
        static readonly int _VelocityIn = Shader.PropertyToID("_VelocityIn");
        static readonly int _VelocityOut = Shader.PropertyToID("_VelocityOut");
        static readonly int _Obstacles = Shader.PropertyToID("_Obstacles");
        static readonly int _Divergence = Shader.PropertyToID("_Divergence");
        static readonly int _PressureIn = Shader.PropertyToID("_PressureIn");
        static readonly int _PressureOut = Shader.PropertyToID("_PressureOut");
        static readonly int _Vorticity = Shader.PropertyToID("_Vorticity");

        static readonly int _ElapsedTime = Shader.PropertyToID("_ElapsedTime");
        static readonly int _Speed = Shader.PropertyToID("_Speed");
        static readonly int _Radius = Shader.PropertyToID("_Radius");
        static readonly int _Position = Shader.PropertyToID("_Position");
        static readonly int _Value = Shader.PropertyToID("_Value");
        static readonly int _VorticityScale = Shader.PropertyToID("_VorticityScale");
        static readonly int _Static = Shader.PropertyToID("_Static");
        static readonly int _P1 = Shader.PropertyToID("_P1");
        static readonly int _P2 = Shader.PropertyToID("_P2");
        static readonly int _P3 = Shader.PropertyToID("_P3");
        static readonly int _ParticlesIn = Shader.PropertyToID("_ParticlesIn");
        static readonly int _ParticlesOut = Shader.PropertyToID("_ParticlesOut");

        static readonly int _ParticleSize = Shader.PropertyToID("_ParticleSize");
        static readonly int _Velocity = Shader.PropertyToID("_Velocity");

        static readonly int _VelocitySize = Shader.PropertyToID("_VelocitySize");
        static readonly int _Dissipation = Shader.PropertyToID("_Dissipation");

        static readonly int _Buffer = Shader.PropertyToID("_Buffer");
        static readonly int _Particles = Shader.PropertyToID("_Particles");
        static readonly int _ColourRamp = Shader.PropertyToID("_ColourRamp");
        static readonly int _Alpha = Shader.PropertyToID("_Alpha");
        static readonly int _rBeta = Shader.PropertyToID("_rBeta");
        #endregion

        private void Start()
        {
            m_simulationShader = (ComputeShader)Instantiate(Resources.Load("FLUID_DYNAMICS_SIMULATION"));
            m_particleAreaShader = (ComputeShader)Instantiate(Resources.Load("FLUID_DYNAMICS_PARTICLES"));
            m_tempRend = GetComponent<Renderer>();
            if (SystemInfo.supportsComputeShaders)
            {
                m_nNumCells = m_nWidth * m_nHeight;
                m_addVelocityKernel = m_simulationShader.FindKernel("AddVelocity");
                m_initBoundariesKernel = m_simulationShader.FindKernel("InitBoundaries");
                m_advectVelocityKernel = m_simulationShader.FindKernel("AdvectVelocity");
                m_divergenceKernel = m_simulationShader.FindKernel("Divergence");
                m_clearBufferKernel = m_simulationShader.FindKernel("ClearBuffer");
                m_poissonKernel = m_simulationShader.FindKernel("Poisson");
                m_substractGradientKernel = m_simulationShader.FindKernel("SubstractGradient");
                m_calcVorticityKernel = m_simulationShader.FindKernel("CalcVorticity");
                m_applyVorticityKernel = m_simulationShader.FindKernel("ApplyVorticity");
                m_viscosityKernel = m_simulationShader.FindKernel("Viscosity");
                m_addObstacleCircleKernel = m_simulationShader.FindKernel("AddCircleObstacle");
                m_addObstacleTriangleKernel = m_simulationShader.FindKernel("AddTriangleObstacle");
                CalculateSize();
                LinkToFluidSimulation();
                m_advectKernel = m_particleAreaShader.FindKernel("Advect");
                m_addParticlesKernel = m_particleAreaShader.FindKernel("AddParticles");
            }
            else
            {
                m_simulate = false;
                Debug.LogError("Seems like your target Hardware does not support Compute Shaders. 'Fluid Dynamics' needs support for Compute Shaders to work.");
            }
        }
        private void Update()
        {
            if (m_simulate)
            {
                UpdateParameters();
                CreateBuffersIfNeeded();
                m_simulationShader.SetBuffer(m_initBoundariesKernel, _VelocityIn, m_velocityBuffer[VELOCITY_READ]);
                m_simulationShader.Dispatch(m_initBoundariesKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                m_simulationShader.SetBuffer(m_advectVelocityKernel, _Obstacles, m_obstaclesBuffer);
                m_simulationShader.SetBuffer(m_advectVelocityKernel, _VelocityIn, m_velocityBuffer[VELOCITY_READ]);
                m_simulationShader.SetBuffer(m_advectVelocityKernel, _VelocityOut, m_velocityBuffer[VELOCITY_WRITE]);
                m_simulationShader.Dispatch(m_advectVelocityKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                FlipVelocityBuffers();
                m_simulationShader.SetBuffer(m_calcVorticityKernel, _VelocityIn, m_velocityBuffer[VELOCITY_READ]);
                m_simulationShader.SetBuffer(m_calcVorticityKernel, _Vorticity, m_vorticityBuffer);
                m_simulationShader.Dispatch(m_calcVorticityKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                m_simulationShader.SetBuffer(m_applyVorticityKernel, _VelocityIn, m_velocityBuffer[VELOCITY_READ]);
                m_simulationShader.SetBuffer(m_applyVorticityKernel, _Vorticity, m_vorticityBuffer);
                m_simulationShader.SetBuffer(m_applyVorticityKernel, _VelocityOut, m_velocityBuffer[VELOCITY_WRITE]);
                m_simulationShader.Dispatch(m_applyVorticityKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                FlipVelocityBuffers();
                if (m_viscosity > 0.0f)
                {
                    for (int i = 0; i < m_iterations; ++i)
                    {
                        m_simulationShader.SetBuffer(m_viscosityKernel, _VelocityIn, m_velocityBuffer[VELOCITY_READ]);
                        m_simulationShader.SetBuffer(m_viscosityKernel, _VelocityOut, m_velocityBuffer[VELOCITY_WRITE]);
                        m_simulationShader.Dispatch(m_viscosityKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                        FlipVelocityBuffers();
                    }
                }
                m_simulationShader.SetBuffer(m_divergenceKernel, _VelocityIn, m_velocityBuffer[VELOCITY_READ]);
                m_simulationShader.SetBuffer(m_divergenceKernel, _Obstacles, m_obstaclesBuffer);
                m_simulationShader.SetBuffer(m_divergenceKernel, _Divergence, m_divergenceBuffer);
                m_simulationShader.Dispatch(m_divergenceKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                m_simulationShader.SetBuffer(m_clearBufferKernel, _Buffer, m_pressure[PRESSURE_READ]);
                m_simulationShader.Dispatch(m_clearBufferKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                m_simulationShader.SetBuffer(m_poissonKernel, _Divergence, m_divergenceBuffer);
                m_simulationShader.SetBuffer(m_poissonKernel, _Obstacles, m_obstaclesBuffer);
                for (int i = 0; i < m_iterations; ++i)
                {
                    m_simulationShader.SetBuffer(m_poissonKernel, _PressureIn, m_pressure[PRESSURE_READ]);
                    m_simulationShader.SetBuffer(m_poissonKernel, _PressureOut, m_pressure[PRESSURE_WRITE]);
                    m_simulationShader.Dispatch(m_poissonKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                    FlipPressureBuffers();
                }
                m_simulationShader.SetBuffer(m_substractGradientKernel, _PressureIn, m_pressure[PRESSURE_READ]);
                m_simulationShader.SetBuffer(m_substractGradientKernel, _VelocityIn, m_velocityBuffer[VELOCITY_READ]);
                m_simulationShader.SetBuffer(m_substractGradientKernel, _VelocityOut, m_velocityBuffer[VELOCITY_WRITE]);
                m_simulationShader.SetBuffer(m_substractGradientKernel, _Obstacles, m_obstaclesBuffer);
                m_simulationShader.Dispatch(m_substractGradientKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                FlipVelocityBuffers();
                m_simulationShader.SetBuffer(m_clearBufferKernel, _Buffer, m_obstaclesBuffer);
                m_simulationShader.Dispatch(m_clearBufferKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                if (m_cacheVelocity)
                {
                    m_velocityBuffer[VELOCITY_READ].GetData(m_currentVelocity);
                }
            }
            if (m_particlesBuffer == null)
            {
                //Debug.Log( null );
                m_particlesBuffer = new ComputeBuffer[2];
                for (int i = 0; i < 2; ++i)
                {
                    m_particlesBuffer[i] = new ComputeBuffer(m_nParticlesWidth * m_nParticlesHeight, 4, ComputeBufferType.Default);
                }
            }
            m_particleAreaShader.SetFloat(_Dissipation, m_densityDissipation);
            m_particleAreaShader.SetFloat(_ElapsedTime, Time.deltaTime);
            m_particleAreaShader.SetFloat(_Speed, GetSimulationSpeed());
            m_particleAreaShader.SetBuffer(m_advectKernel, _Obstacles, ObstaclesBuffer);
            m_particleAreaShader.SetBuffer(m_advectKernel, _Velocity, VelocityBuffer);
            m_particleAreaShader.SetBuffer(m_advectKernel, _ParticlesIn, m_particlesBuffer[READ]);
            m_particleAreaShader.SetBuffer(m_advectKernel, _ParticlesOut, m_particlesBuffer[WRITE]);
            m_particleAreaShader.Dispatch(m_advectKernel, m_nParticlesNumGroupsX, m_nParticlesNumGroupsY, 1);
            FlipBuffers();
            if (m_colourRamp == null)
            {
                m_colourRamp = new ComputeBuffer(m_nColourRampSize, 16, ComputeBufferType.Default);
                UpdateGradient();
            }
            if (m_updateGradient)
            {
                UpdateGradient();
            }
            m_tempRend.material.SetBuffer(_Particles, m_particlesBuffer[READ]);
            m_tempRend.material.SetBuffer(_ColourRamp, m_colourRamp);
            m_tempRend.material.SetVector(_Size, new Vector2(m_nParticlesWidth, m_nParticlesHeight));
            if (m_CacheParticles)
            {
                m_particlesBuffer[READ].GetData(m_currentParticles);
            }
        }
        private void OnDisable()
        {
            if (m_velocityBuffer != null && m_velocityBuffer.Length == 2)
            {
                if (m_velocityBuffer[0] != null)
                {
                    m_velocityBuffer[0].Dispose();
                }
                if (m_velocityBuffer[1] != null)
                {
                    m_velocityBuffer[1].Dispose();
                }
            }
            if (m_divergenceBuffer != null)
            {
                m_divergenceBuffer.Dispose();
            }
            if (m_pressure != null && m_pressure.Length == 2)
            {
                if (m_pressure[0] != null)
                {
                    m_pressure[0].Dispose();
                }
                if (m_pressure[1] != null)
                {
                    m_pressure[1].Dispose();
                }
            }
            if (m_obstaclesBuffer != null)
            {
                m_obstaclesBuffer.Dispose();
            }
            if (m_vorticityBuffer != null)
            {
                m_vorticityBuffer.Dispose();
            }
            if (m_colourRamp != null)
            {
                m_colourRamp.Dispose();
            }
            if (m_particlesBuffer != null && m_particlesBuffer.Length == 2)
            {
                if (m_particlesBuffer[0] != null)
                {
                    m_particlesBuffer[0].Dispose();
                }
                if (m_particlesBuffer[1] != null)
                {
                    m_particlesBuffer[1].Dispose();
                }
            }
        }

        public void SetSize(int nWidth, int nHeight)
        {
            uint groupSizeX = 8;
            uint groupSizeY = 8;
            uint groupSizeZ = 8;
            m_simulationShader.GetKernelThreadGroupSizes(0, out groupSizeX, out groupSizeY, out groupSizeZ);
            m_nWidth = nWidth;
            m_nHeight = nHeight;
            m_nNumCells = m_nWidth * m_nHeight;
            m_nNumGroupsX = Mathf.CeilToInt((float)m_nWidth / (float)groupSizeX);
            m_nNumGroupsY = Mathf.CeilToInt((float)m_nHeight / (float)groupSizeX);
        }
        public int GetWidth()
        {
            return m_nWidth;
        }
        public int GetHeight()
        {
            return m_nHeight;
        }
        public void AddVelocity(Vector2 position, Vector2 velocity, float fRadius)
        {
            if (m_simulationShader != null && m_velocityBuffer != null && m_velocityBuffer.Length >= 2)
            {
                float[] pos = { position.x, position.y };
                m_simulationShader.SetFloats(_Position, pos);
                float[] val = { velocity.x, velocity.y };
                m_simulationShader.SetFloats(_Value, val);
                m_simulationShader.SetFloat(_Radius, fRadius);
                m_simulationShader.SetInts(_Size, new int[] { m_nWidth, m_nHeight });
                m_simulationShader.SetBuffer(m_addVelocityKernel, _VelocityIn, m_velocityBuffer[VELOCITY_READ]);
                m_simulationShader.SetBuffer(m_addVelocityKernel, _VelocityOut, m_velocityBuffer[VELOCITY_WRITE]);
                m_simulationShader.Dispatch(m_addVelocityKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
                FlipVelocityBuffers();
            }
        }
        public void AddObstacleCircle(Vector2 position, float fRadius, bool bStatic)
        {
            float[] pos = { position.x, position.y };
            m_simulationShader.SetFloats(_Position, pos);
            m_simulationShader.SetFloat(_Radius, fRadius);
            m_simulationShader.SetInt(_Static, bStatic ? 1 : 0);
            m_simulationShader.SetBuffer(m_addObstacleCircleKernel, _Obstacles, m_obstaclesBuffer);
            m_simulationShader.Dispatch(m_addObstacleCircleKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
        }
        public void AddObstacleTriangle(Vector2 p1, Vector2 p2, Vector2 p3, bool bStatic = false)
        {
            float[] pos1 = { p1.x, p1.y };
            float[] pos2 = { p2.x, p2.y };
            float[] pos3 = { p3.x, p3.y };
            m_simulationShader.SetFloats(_P1, pos1);
            m_simulationShader.SetFloats(_P2, pos2);
            m_simulationShader.SetFloats(_P3, pos3);
            m_simulationShader.SetInt(_Static, bStatic ? 1 : 0);
            m_simulationShader.SetBuffer(m_addObstacleTriangleKernel, _Obstacles, m_obstaclesBuffer);
            m_simulationShader.Dispatch(m_addObstacleTriangleKernel, m_nNumGroupsX, m_nNumGroupsY, 1);
        }
        public Vector2 GetVelocity(int x, int y)
        {
            return m_currentVelocity[y * m_nWidth + x] * m_speed;
        }
        public void InitShaders()
        {
            CreateBuffersIfNeeded();
            UpdateParameters();
            int[] size = new int[] { m_nWidth, m_nHeight };
            m_simulationShader.SetInts(_Size, size);
            m_currentVelocity = new Vector2[m_nNumCells];
        }
        public float GetSimulationSpeed()
        {
            return m_speed;
        }
        private void CreateBuffersIfNeeded()
        {
            if (m_velocityBuffer == null)
            {
                m_velocityBuffer = new ComputeBuffer[2];
                for (int i = 0; i < 2; ++i)
                {
                    m_velocityBuffer[i] = new ComputeBuffer(m_nNumCells, 8, ComputeBufferType.Default);
                }
            }
            if (m_divergenceBuffer == null)
            {
                m_divergenceBuffer = new ComputeBuffer(m_nNumCells, 4, ComputeBufferType.Default);
            }
            if (m_pressure == null)
            {
                m_pressure = new ComputeBuffer[2];
                for (int i = 0; i < 2; ++i)
                {
                    m_pressure[i] = new ComputeBuffer(m_nNumCells, 4, ComputeBufferType.Default);
                }
            }
            if (m_obstaclesBuffer == null)
            {
                m_obstaclesBuffer = new ComputeBuffer(m_nNumCells, 8, ComputeBufferType.Default);
            }
            if (m_vorticityBuffer == null)
            {
                m_vorticityBuffer = new ComputeBuffer(m_nNumCells, 4, ComputeBufferType.Default);
            }
        }
        private void UpdateParameters()
        {
            m_simulationShader.SetFloat(_Dissipation, m_velocityDissipation);
            m_simulationShader.SetFloat(_ElapsedTime, Time.deltaTime);
            m_simulationShader.SetFloat(_Speed, m_speed);
            m_simulationShader.SetFloat(_VorticityScale, m_vorticityScale);

            float centreFactor = 1.0f / (m_viscosity);
            float stencilFactor = 1.0f / (4.0f + centreFactor);
            m_simulationShader.SetFloat(_Alpha, centreFactor);
            m_simulationShader.SetFloat(_rBeta, stencilFactor);
        }
        private void FlipVelocityBuffers()
        {
            int aux = VELOCITY_READ;
            VELOCITY_READ = VELOCITY_WRITE;
            VELOCITY_WRITE = aux;
        }
        private void FlipPressureBuffers()
        {
            int aux = PRESSURE_READ;
            PRESSURE_READ = PRESSURE_WRITE;
            PRESSURE_WRITE = aux;
        }
        public float GetParticles(int x, int y)
        {
            return m_currentParticles[y * m_nParticlesWidth + x];
        }
        private void CalculateSize()
        {
            float x = gameObject.transform.lossyScale.x;
            float y = gameObject.transform.lossyScale.z;
            if (x > y)
            {
                float fHeight = (y / x) * m_nParticlesResolution;
                m_nParticlesWidth = m_nParticlesResolution;
                m_nParticlesHeight = (int)fHeight;
            }
            else
            {
                float fWidth = (x / y) * m_nParticlesResolution;
                m_nParticlesWidth = (int)fWidth;
                m_nParticlesHeight = m_nParticlesResolution;
            }
            SetSizeInShaders();
            uint groupSizeX = 8;
            uint groupSizeY = 8;
            uint groupSizeZ = 8;
            m_particleAreaShader.GetKernelThreadGroupSizes(0, out groupSizeX, out groupSizeY, out groupSizeZ);
            m_nParticlesNumGroupsX = Mathf.CeilToInt((float)m_nParticlesWidth / (float)groupSizeX);
            m_nParticlesNumGroupsY = Mathf.CeilToInt((float)m_nParticlesHeight / (float)groupSizeX);
            m_currentParticles = new float[m_nParticlesWidth * m_nParticlesHeight];
        }
        private void LinkToFluidSimulation()
        {
            float fResolutionRatio = Resolution / (float)m_nParticlesResolution;
            SetSize((int)(m_nParticlesWidth * fResolutionRatio), (int)(m_nParticlesHeight * fResolutionRatio));

            InitShaders();
            m_particleAreaShader.SetInts(_VelocitySize, new int[] { GetWidth(), GetHeight() });
        }
        private void FlipBuffers()
        {
            int aux = READ;
            READ = WRITE;
            WRITE = aux;
        }
        public Vector2 GetRenderScale()
        {
            return transform.lossyScale;
        }
        public Vector2 GetRenderSize()
        {
            return m_tempRend.bounds.size;
        }
        public int GetParticlesWidth()
        {
            return m_nParticlesWidth;
        }
        public int GetParticlesHeight()
        {
            return m_nParticlesHeight;
        }
        private void UpdateGradient()
        {
            Vector4[] colourData = new Vector4[m_nColourRampSize];
            for (int i = 0; i < m_nColourRampSize; ++i)
            {
                colourData[i] = m_colourGradient.Evaluate(i / 255.0f);
            }
            m_colourRamp.SetData(colourData);
        }
        void SetSizeInShaders()
        {
            m_particleAreaShader.SetInts(_ParticleSize, new int[] { m_nParticlesWidth, m_nParticlesHeight });
            m_tempRend.material.SetVector(_Size, new Vector2(m_nParticlesWidth, m_nParticlesHeight));
        }
        public void AddParticles(Vector2 position, float fRadius, float fStrength)
        {
            if (m_particleAreaShader != null && m_particlesBuffer != null && m_particlesBuffer.Length >= 2)
            {
                float[] pos = { position.x, position.y };
                m_particleAreaShader.SetFloats(_Position, pos);
                m_particleAreaShader.SetFloat(_Value, fStrength);
                m_particleAreaShader.SetFloat(_Radius, fRadius);
                m_particleAreaShader.SetInts(_Size, new int[] { m_nParticlesWidth, m_nParticlesHeight });
                m_particleAreaShader.SetBuffer(m_addParticlesKernel, _ParticlesIn, m_particlesBuffer[READ]);
                m_particleAreaShader.SetBuffer(m_addParticlesKernel, _ParticlesOut, m_particlesBuffer[WRITE]);
                m_particleAreaShader.Dispatch(m_addParticlesKernel, m_nParticlesNumGroupsX, m_nParticlesNumGroupsY, 1);
                FlipBuffers();
                m_tempRend.material.SetBuffer("_Particles", m_particlesBuffer[READ]);
            }
        }
    }
}