Files
INF6B/simulations/fluids/fluidsC#/FluidWindow3D_GPU.cs

844 lines
33 KiB
C#

using OpenTK.Graphics.OpenGL4;
using OpenTK.Windowing.Common;
using OpenTK.Windowing.Desktop;
using OpenTK.Mathematics;
using OpenTK.Windowing.GraphicsLibraryFramework;
namespace fluidsC_;
public class FluidWindow3D_GPU : GameWindow
{
private int _fluidSizeX = 64;
private int _fluidSizeY = 64;
private int _fluidSizeZ = 64;
// GPU buffers - double buffered
private int[] _densityTextures = new int[2];
private int[] _velocityTextures = new int[2];
private int[] _pressureTextures = new int[2];
private int _divergenceTexture;
private int _obstacleTexture;
// Shader programs
private int _advectionShader;
private int _forceShader;
private int _divergenceShader;
private int _pressureShader;
private int _gradientShader;
private int _renderShader;
private int _clearShader;
private int _obstacleShader;
private int _vertexArrayObject;
private int _pointCount;
private Camera _camera;
private bool _firstMove = true;
private Vector2 _lastPos;
private float _time = 0;
private int _currentDensity = 0;
private int _currentVelocity = 0;
private int _currentPressure = 0;
// Simulation parameters
private float _diffusion = 0.0001f;
private float _viscosity = 0.0001f;
public FluidWindow3D_GPU(GameWindowSettings gameWindowSettings, NativeWindowSettings nativeWindowSettings)
: base(gameWindowSettings, nativeWindowSettings)
{
_camera = new Camera(Vector3.UnitZ * 3, Size.X / (float)Size.Y);
}
protected override void OnLoad()
{
base.OnLoad();
Console.WriteLine($"OpenGL Version: {GL.GetString(StringName.Version)}");
Console.WriteLine($"GLSL Version: {GL.GetString(StringName.ShadingLanguageVersion)}");
GL.ClearColor(0.02f, 0.02f, 0.05f, 1.0f);
GL.Enable(EnableCap.DepthTest);
GL.Enable(EnableCap.Blend);
GL.BlendFunc(BlendingFactor.SrcAlpha, BlendingFactor.OneMinusSrcAlpha);
GL.Enable(EnableCap.ProgramPointSize);
CreateTextures();
SetupShaders();
SetupPointCloud();
InitializeObstacles();
// Add initial fluid
AddInitialFluid();
Console.WriteLine("🎯 WORKING GPU Fluid Simulation - CLICK AND DRAG!");
Console.WriteLine("Left Click: Add Fluid | Right Click: Add Force | R: Reset");
}
private void CreateTextures()
{
for (int i = 0; i < 2; i++)
{
_densityTextures[i] = Create3DTexture(_fluidSizeX, _fluidSizeY, _fluidSizeZ, false);
_velocityTextures[i] = Create3DTexture(_fluidSizeX, _fluidSizeY, _fluidSizeZ, true);
_pressureTextures[i] = Create3DTexture(_fluidSizeX, _fluidSizeY, _fluidSizeZ, false);
}
_divergenceTexture = Create3DTexture(_fluidSizeX, _fluidSizeY, _fluidSizeZ, false);
_obstacleTexture = Create3DTexture(_fluidSizeX, _fluidSizeY, _fluidSizeZ, false);
ClearAllTextures();
}
private int Create3DTexture(int width, int height, int depth, bool rgb)
{
int texture = GL.GenTexture();
GL.BindTexture(TextureTarget.Texture3D, texture);
GL.TexParameter(TextureTarget.Texture3D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear);
GL.TexParameter(TextureTarget.Texture3D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);
GL.TexParameter(TextureTarget.Texture3D, TextureParameterName.TextureWrapS, (int)TextureWrapMode.ClampToEdge);
GL.TexParameter(TextureTarget.Texture3D, TextureParameterName.TextureWrapT, (int)TextureWrapMode.ClampToEdge);
GL.TexParameter(TextureTarget.Texture3D, TextureParameterName.TextureWrapR, (int)TextureWrapMode.ClampToEdge);
var format = rgb ? PixelInternalFormat.Rgb32f : PixelInternalFormat.R32f;
var pixelFormat = rgb ? PixelFormat.Rgb : PixelFormat.Red;
GL.TexImage3D(TextureTarget.Texture3D, 0, format, width, height, depth, 0, pixelFormat, PixelType.Float, IntPtr.Zero);
return texture;
}
private void SetupShaders()
{
// PROPER FLUID SIMULATION SHADERS
_advectionShader = CreateComputeShader(@"
#version 430
layout(local_size_x = 4, local_size_y = 4, local_size_z = 4) in;
layout(r32f, binding = 0) uniform image3D densityIn;
layout(rgba32f, binding = 1) uniform image3D velocityIn;
layout(r32f, binding = 2) uniform image3D densityOut;
layout(rgba32f, binding = 3) uniform image3D velocityOut;
layout(r32f, binding = 4) uniform image3D obstacles;
uniform float dt;
uniform float dissipation;
vec3 sampleVelocity(vec3 pos) {
ivec3 coord = ivec3(clamp(pos, vec3(0), vec3(imageSize(velocityIn)) - vec3(1)));
return imageLoad(velocityIn, coord).rgb;
}
float sampleDensity(vec3 pos) {
ivec3 coord = ivec3(clamp(pos, vec3(0), vec3(imageSize(densityIn)) - vec3(1)));
return imageLoad(densityIn, coord).r;
}
void main() {
ivec3 coord = ivec3(gl_GlobalInvocationID.xyz);
ivec3 size = imageSize(densityIn);
if(coord.x >= size.x || coord.y >= size.y || coord.z >= size.z)
return;
if(imageLoad(obstacles, coord).r > 0.5) {
imageStore(densityOut, coord, vec4(0.0));
imageStore(velocityOut, coord, vec4(0.0));
return;
}
// Semi-Lagrangian advection
vec3 vel = sampleVelocity(vec3(coord));
vec3 prevPos = vec3(coord) - vel * dt * 10.0;
// Advect density
float density = sampleDensity(prevPos);
imageStore(densityOut, coord, vec4(density * dissipation, 0.0, 0.0, 1.0));
// Advect velocity (self-advection)
vec3 prevVel = sampleVelocity(prevPos);
imageStore(velocityOut, coord, vec4(prevVel, 1.0));
}");
_forceShader = CreateComputeShader(@"
#version 430
layout(local_size_x = 4, local_size_y = 4, local_size_z = 4) in;
layout(rgba32f, binding = 0) uniform image3D velocity;
layout(r32f, binding = 1) uniform image3D density;
layout(r32f, binding = 2) uniform image3D obstacles;
uniform vec3 force;
uniform vec3 position;
uniform float radius;
uniform float densityAmount;
void main() {
ivec3 coord = ivec3(gl_GlobalInvocationID.xyz);
if(imageLoad(obstacles, coord).r > 0.5)
return;
vec3 cellPos = vec3(coord);
vec3 diff = cellPos - position;
float dist = length(diff);
if(dist < radius) {
float influence = (1.0 - dist/radius) * (1.0 - dist/radius);
// Add force to velocity
vec3 currentVel = imageLoad(velocity, coord).rgb;
vec3 newVel = currentVel + force * influence * 0.5;
imageStore(velocity, coord, vec4(newVel, 1.0));
// Add density
if(densityAmount > 0.0) {
float currentDensity = imageLoad(density, coord).r;
float newDensity = currentDensity + densityAmount * influence;
imageStore(density, coord, vec4(newDensity, 0.0, 0.0, 1.0));
}
}
}");
_divergenceShader = CreateComputeShader(@"
#version 430
layout(local_size_x = 4, local_size_y = 4, local_size_z = 4) in;
layout(rgba32f, binding = 0) uniform image3D velocity;
layout(r32f, binding = 1) uniform image3D divergence;
layout(r32f, binding = 2) uniform image3D obstacles;
void main() {
ivec3 coord = ivec3(gl_GlobalInvocationID.xyz);
ivec3 size = imageSize(velocity);
if(coord.x < 1 || coord.x >= size.x-1 ||
coord.y < 1 || coord.y >= size.y-1 ||
coord.z < 1 || coord.z >= size.z-1)
return;
if(imageLoad(obstacles, coord).r > 0.5) {
imageStore(divergence, coord, vec4(0.0));
return;
}
// Calculate divergence
float left = imageLoad(velocity, coord - ivec3(1,0,0)).r;
float right = imageLoad(velocity, coord + ivec3(1,0,0)).r;
float down = imageLoad(velocity, coord - ivec3(0,1,0)).g;
float up = imageLoad(velocity, coord + ivec3(0,1,0)).g;
float back = imageLoad(velocity, coord - ivec3(0,0,1)).b;
float front = imageLoad(velocity, coord + ivec3(0,0,1)).b;
float div = (right - left + up - down + front - back) * 0.5;
imageStore(divergence, coord, vec4(div, 0.0, 0.0, 1.0));
}");
_pressureShader = CreateComputeShader(@"
#version 430
layout(local_size_x = 4, local_size_y = 4, local_size_z = 4) in;
layout(r32f, binding = 0) uniform image3D pressureIn;
layout(r32f, binding = 1) uniform image3D pressureOut;
layout(r32f, binding = 2) uniform image3D divergence;
layout(r32f, binding = 3) uniform image3D obstacles;
void main() {
ivec3 coord = ivec3(gl_GlobalInvocationID.xyz);
ivec3 size = imageSize(pressureIn);
if(coord.x < 1 || coord.x >= size.x-1 ||
coord.y < 1 || coord.y >= size.y-1 ||
coord.z < 1 || coord.z >= size.z-1)
return;
if(imageLoad(obstacles, coord).r > 0.5) {
imageStore(pressureOut, coord, vec4(0.0));
return;
}
// Jacobi iteration for pressure
float left = imageLoad(pressureIn, coord - ivec3(1,0,0)).r;
float right = imageLoad(pressureIn, coord + ivec3(1,0,0)).r;
float down = imageLoad(pressureIn, coord - ivec3(0,1,0)).r;
float up = imageLoad(pressureIn, coord + ivec3(0,1,0)).r;
float back = imageLoad(pressureIn, coord - ivec3(0,0,1)).r;
float front = imageLoad(pressureIn, coord + ivec3(0,0,1)).r;
float div = imageLoad(divergence, coord).r;
float pressure = (left + right + down + up + back + front - div) / 6.0;
imageStore(pressureOut, coord, vec4(pressure, 0.0, 0.0, 1.0));
}");
_gradientShader = CreateComputeShader(@"
#version 430
layout(local_size_x = 4, local_size_y = 4, local_size_z = 4) in;
layout(rgba32f, binding = 0) uniform image3D velocity;
layout(r32f, binding = 1) uniform image3D pressure;
layout(r32f, binding = 2) uniform image3D obstacles;
void main() {
ivec3 coord = ivec3(gl_GlobalInvocationID.xyz);
ivec3 size = imageSize(velocity);
if(coord.x < 1 || coord.x >= size.x-1 ||
coord.y < 1 || coord.y >= size.y-1 ||
coord.z < 1 || coord.z >= size.z-1)
return;
if(imageLoad(obstacles, coord).r > 0.5) {
imageStore(velocity, coord, vec4(0.0));
return;
}
// Subtract pressure gradient
float pressureLeft = imageLoad(pressure, coord - ivec3(1,0,0)).r;
float pressureRight = imageLoad(pressure, coord + ivec3(1,0,0)).r;
float pressureDown = imageLoad(pressure, coord - ivec3(0,1,0)).r;
float pressureUp = imageLoad(pressure, coord + ivec3(0,1,0)).r;
float pressureBack = imageLoad(pressure, coord - ivec3(0,0,1)).r;
float pressureFront = imageLoad(pressure, coord + ivec3(0,0,1)).r;
vec3 grad = vec3(
pressureRight - pressureLeft,
pressureUp - pressureDown,
pressureFront - pressureBack
) * 0.5;
vec3 currentVel = imageLoad(velocity, coord).rgb;
vec3 newVel = currentVel - grad;
imageStore(velocity, coord, vec4(newVel, 1.0));
}");
_clearShader = CreateComputeShader(@"
#version 430
layout(local_size_x = 8, local_size_y = 8, local_size_z = 8) in;
layout(r32f, binding = 0) uniform image3D textureToClear;
uniform float value;
void main() {
ivec3 coord = ivec3(gl_GlobalInvocationID.xyz);
ivec3 size = imageSize(textureToClear);
if(coord.x >= size.x || coord.y >= size.y || coord.z >= size.z)
return;
imageStore(textureToClear, coord, vec4(value, 0.0, 0.0, 1.0));
}");
_obstacleShader = CreateComputeShader(@"
#version 430
layout(local_size_x = 8, local_size_y = 8, local_size_z = 8) in;
layout(r32f, binding = 0) uniform image3D obstacles;
uniform vec3 position;
uniform float radius;
uniform float setValue;
void main() {
ivec3 coord = ivec3(gl_GlobalInvocationID.xyz);
ivec3 size = imageSize(obstacles);
if(coord.x >= size.x || coord.y >= size.y || coord.z >= size.z)
return;
vec3 cellPos = vec3(coord);
float dist = length(cellPos - position);
if(dist <= radius) {
imageStore(obstacles, coord, vec4(setValue, 0.0, 0.0, 1.0));
}
}");
// RENDER SHADER
_renderShader = CreateRenderShader();
}
private int CreateComputeShader(string source)
{
var shader = GL.CreateShader(ShaderType.ComputeShader);
GL.ShaderSource(shader, source);
GL.CompileShader(shader);
GL.GetShader(shader, ShaderParameter.CompileStatus, out int success);
if (success == 0)
{
var infoLog = GL.GetShaderInfoLog(shader);
Console.WriteLine($"Compute Shader Compilation Failed:\n{infoLog}");
}
var program = GL.CreateProgram();
GL.AttachShader(program, shader);
GL.LinkProgram(program);
GL.DeleteShader(shader);
return program;
}
private int CreateRenderShader()
{
const string vertexShaderSource = @"
#version 330 core
layout (location = 0) in vec3 aPosition;
out vec3 fragTexCoord;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main()
{
gl_Position = projection * view * model * vec4(aPosition, 1.0);
fragTexCoord = (aPosition + 1.0) * 0.5;
gl_PointSize = 4.0;
}";
const string fragmentShaderSource = @"
#version 330 core
in vec3 fragTexCoord;
out vec4 fragColor;
uniform sampler3D densityTexture;
uniform sampler3D obstacleTexture;
uniform float time;
void main()
{
vec3 texCoord = fragTexCoord;
if(texCoord.x < 0.0 || texCoord.x > 1.0 ||
texCoord.y < 0.0 || texCoord.y > 1.0 ||
texCoord.z < 0.0 || texCoord.z > 1.0)
discard;
float density = texture(densityTexture, texCoord).r;
float obstacle = texture(obstacleTexture, texCoord).r;
if(obstacle > 0.5) {
fragColor = vec4(0.3, 0.3, 0.3, 1.0);
} else if(density > 0.01) {
vec3 color = mix(vec3(0.1, 0.3, 0.8), vec3(0.0, 0.8, 1.0), density * 2.0);
color += 0.1 * sin(time + fragTexCoord.y * 10.0);
fragColor = vec4(color, density * 0.9);
} else {
discard;
}
}";
var vertexShader = GL.CreateShader(ShaderType.VertexShader);
GL.ShaderSource(vertexShader, vertexShaderSource);
GL.CompileShader(vertexShader);
var fragmentShader = GL.CreateShader(ShaderType.FragmentShader);
GL.ShaderSource(fragmentShader, fragmentShaderSource);
GL.CompileShader(fragmentShader);
var program = GL.CreateProgram();
GL.AttachShader(program, vertexShader);
GL.AttachShader(program, fragmentShader);
GL.LinkProgram(program);
GL.DeleteShader(vertexShader);
GL.DeleteShader(fragmentShader);
return program;
}
private void SetupPointCloud()
{
var vertices = new List<Vector3>();
// Reduced point count for performance but still good coverage
for (int x = 0; x < _fluidSizeX; x += 1)
{
for (int y = 0; y < _fluidSizeY; y += 1)
{
for (int z = 0; z < _fluidSizeZ; z += 1)
{
float px = (x / (float)_fluidSizeX) * 2.0f - 1.0f;
float py = (y / (float)_fluidSizeY) * 2.0f - 1.0f;
float pz = (z / (float)_fluidSizeZ) * 2.0f - 1.0f;
vertices.Add(new Vector3(px, py, pz));
}
}
}
_pointCount = vertices.Count;
Console.WriteLine($"Rendering {_pointCount} points");
_vertexArrayObject = GL.GenVertexArray();
int vbo = GL.GenBuffer();
GL.BindVertexArray(_vertexArrayObject);
GL.BindBuffer(BufferTarget.ArrayBuffer, vbo);
GL.BufferData(BufferTarget.ArrayBuffer, vertices.Count * 3 * sizeof(float), vertices.ToArray(), BufferUsageHint.StaticDraw);
GL.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, 3 * sizeof(float), 0);
GL.EnableVertexAttribArray(0);
}
private void InitializeObstacles()
{
// Simple box boundaries
AddBoxObstacle(new Vector3(0, 0, 0), new Vector3(_fluidSizeX, 2, _fluidSizeZ)); // Floor
AddBoxObstacle(new Vector3(0, 0, 0), new Vector3(2, _fluidSizeY, _fluidSizeZ)); // Left
AddBoxObstacle(new Vector3(_fluidSizeX - 2, 0, 0), new Vector3(2, _fluidSizeY, _fluidSizeZ)); // Right
AddBoxObstacle(new Vector3(0, 0, 0), new Vector3(_fluidSizeX, _fluidSizeY, 2)); // Back
AddBoxObstacle(new Vector3(0, 0, _fluidSizeZ - 2), new Vector3(_fluidSizeX, _fluidSizeY, 2)); // Front
// Central obstacle
AddSphereObstacle(new Vector3(_fluidSizeX / 2, _fluidSizeY / 4, _fluidSizeZ / 2), 6.0f);
}
private void AddInitialFluid()
{
// Add initial falling fluid
Vector3 sourcePos = new Vector3(_fluidSizeX / 2, _fluidSizeY - 10, _fluidSizeZ / 2);
AddForce(sourcePos, new Vector3(0.0f, -2.0f, 0.0f), 8.0f, 10.0f);
// Add some random fluid blobs
Random rand = new Random();
for (int i = 0; i < 5; i++)
{
Vector3 randomPos = new Vector3(
rand.Next(10, _fluidSizeX - 10),
rand.Next(10, _fluidSizeY - 10),
rand.Next(10, _fluidSizeZ - 10)
);
AddForce(randomPos, Vector3.Zero, 4.0f, 3.0f);
}
}
private void AddSphereObstacle(Vector3 center, float radius)
{
GL.UseProgram(_obstacleShader);
BindImageTexture(0, _obstacleTexture, TextureAccess.WriteOnly);
GL.Uniform3(GL.GetUniformLocation(_obstacleShader, "position"), center);
GL.Uniform1(GL.GetUniformLocation(_obstacleShader, "radius"), radius);
GL.Uniform1(GL.GetUniformLocation(_obstacleShader, "setValue"), 1.0f);
DispatchCompute(_fluidSizeX, _fluidSizeY, _fluidSizeZ, 8, 8, 8);
GL.MemoryBarrier(MemoryBarrierFlags.ShaderImageAccessBarrierBit);
}
private void AddBoxObstacle(Vector3 min, Vector3 max)
{
Vector3 center = (min + max) * 0.5f;
Vector3 size = max - min;
AddSphereObstacle(center, Math.Max(size.X, Math.Max(size.Y, size.Z)) * 0.5f);
}
protected override void OnRenderFrame(FrameEventArgs e)
{
base.OnRenderFrame(e);
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
StepSimulation((float)e.Time);
RenderFluid();
SwapBuffers();
}
private void StepSimulation(float dt)
{
dt = Math.Min(dt, 0.016f); // Cap at ~60fps
// Full fluid simulation steps
Advect(dt, 0.99f);
AddExternalForces(dt);
Project(dt);
AddDemoSources();
// Swap buffers
_currentDensity = 1 - _currentDensity;
_currentVelocity = 1 - _currentVelocity;
_currentPressure = 1 - _currentPressure;
}
private void Advect(float dt, float dissipation)
{
GL.UseProgram(_advectionShader);
BindImageTexture(0, _densityTextures[_currentDensity], TextureAccess.ReadOnly);
BindImageTexture(1, _velocityTextures[_currentVelocity], TextureAccess.ReadOnly);
BindImageTexture(2, _densityTextures[1 - _currentDensity], TextureAccess.WriteOnly);
BindImageTexture(3, _velocityTextures[1 - _currentVelocity], TextureAccess.WriteOnly);
BindImageTexture(4, _obstacleTexture, TextureAccess.ReadOnly);
GL.Uniform1(GL.GetUniformLocation(_advectionShader, "dt"), dt);
GL.Uniform1(GL.GetUniformLocation(_advectionShader, "dissipation"), dissipation);
DispatchCompute(_fluidSizeX, _fluidSizeY, _fluidSizeZ, 4, 4, 4);
GL.MemoryBarrier(MemoryBarrierFlags.ShaderImageAccessBarrierBit);
}
private void AddExternalForces(float dt)
{
// Gravity
Vector3 gravity = new Vector3(0.0f, -9.8f, 0.0f) * dt;
GL.UseProgram(_forceShader);
BindImageTexture(0, _velocityTextures[_currentVelocity], TextureAccess.ReadWrite);
BindImageTexture(1, _densityTextures[_currentDensity], TextureAccess.ReadWrite);
BindImageTexture(2, _obstacleTexture, TextureAccess.ReadOnly);
GL.Uniform3(GL.GetUniformLocation(_forceShader, "force"), gravity);
GL.Uniform3(GL.GetUniformLocation(_forceShader, "position"), new Vector3(_fluidSizeX / 2, _fluidSizeY / 2, _fluidSizeZ / 2));
GL.Uniform1(GL.GetUniformLocation(_forceShader, "radius"), _fluidSizeX * 2.0f); // Affect entire field
GL.Uniform1(GL.GetUniformLocation(_forceShader, "densityAmount"), 0.0f);
DispatchCompute(_fluidSizeX, _fluidSizeY, _fluidSizeZ, 4, 4, 4);
GL.MemoryBarrier(MemoryBarrierFlags.ShaderImageAccessBarrierBit);
}
private void Project(float dt)
{
// Calculate divergence
GL.UseProgram(_divergenceShader);
BindImageTexture(0, _velocityTextures[_currentVelocity], TextureAccess.ReadOnly);
BindImageTexture(1, _divergenceTexture, TextureAccess.WriteOnly);
BindImageTexture(2, _obstacleTexture, TextureAccess.ReadOnly);
DispatchCompute(_fluidSizeX, _fluidSizeY, _fluidSizeZ, 4, 4, 4);
GL.MemoryBarrier(MemoryBarrierFlags.ShaderImageAccessBarrierBit);
// Solve pressure (Jacobi iterations)
for (int i = 0; i < 10; i++)
{
GL.UseProgram(_pressureShader);
BindImageTexture(0, _pressureTextures[_currentPressure], TextureAccess.ReadOnly);
BindImageTexture(1, _pressureTextures[1 - _currentPressure], TextureAccess.WriteOnly);
BindImageTexture(2, _divergenceTexture, TextureAccess.ReadOnly);
BindImageTexture(3, _obstacleTexture, TextureAccess.ReadOnly);
DispatchCompute(_fluidSizeX, _fluidSizeY, _fluidSizeZ, 4, 4, 4);
GL.MemoryBarrier(MemoryBarrierFlags.ShaderImageAccessBarrierBit);
_currentPressure = 1 - _currentPressure;
}
// Subtract pressure gradient
GL.UseProgram(_gradientShader);
BindImageTexture(0, _velocityTextures[_currentVelocity], TextureAccess.ReadWrite);
BindImageTexture(1, _pressureTextures[_currentPressure], TextureAccess.ReadOnly);
BindImageTexture(2, _obstacleTexture, TextureAccess.ReadOnly);
DispatchCompute(_fluidSizeX, _fluidSizeY, _fluidSizeZ, 4, 4, 4);
GL.MemoryBarrier(MemoryBarrierFlags.ShaderImageAccessBarrierBit);
}
private void AddDemoSources()
{
// Continuous falling source
Vector3 sourcePos = new Vector3(_fluidSizeX / 2, _fluidSizeY - 8, _fluidSizeZ / 2);
AddForce(sourcePos, new Vector3(0.0f, -3.0f, 0.0f), 6.0f, 2.0f);
// Random turbulence
if ((int)(_time * 2) % 4 == 0)
{
Vector3 randomPos = new Vector3(
_fluidSizeX * 0.3f + MathF.Sin(_time) * 5.0f,
_fluidSizeY - 5,
_fluidSizeZ * 0.7f + MathF.Cos(_time) * 5.0f
);
AddForce(randomPos, new Vector3(0.0f, -2.0f, 0.0f), 4.0f, 1.5f);
}
}
private void AddForce(Vector3 position, Vector3 force, float radius, float densityAmount)
{
GL.UseProgram(_forceShader);
BindImageTexture(0, _velocityTextures[_currentVelocity], TextureAccess.ReadWrite);
BindImageTexture(1, _densityTextures[_currentDensity], TextureAccess.ReadWrite);
BindImageTexture(2, _obstacleTexture, TextureAccess.ReadOnly);
GL.Uniform3(GL.GetUniformLocation(_forceShader, "force"), force);
GL.Uniform3(GL.GetUniformLocation(_forceShader, "position"), position);
GL.Uniform1(GL.GetUniformLocation(_forceShader, "radius"), radius);
GL.Uniform1(GL.GetUniformLocation(_forceShader, "densityAmount"), densityAmount);
DispatchCompute(_fluidSizeX, _fluidSizeY, _fluidSizeZ, 4, 4, 4);
GL.MemoryBarrier(MemoryBarrierFlags.ShaderImageAccessBarrierBit);
}
private void RenderFluid()
{
GL.UseProgram(_renderShader);
var model = Matrix4.Identity;
var view = _camera.GetViewMatrix();
var projection = _camera.GetProjectionMatrix();
GL.UniformMatrix4(GL.GetUniformLocation(_renderShader, "model"), false, ref model);
GL.UniformMatrix4(GL.GetUniformLocation(_renderShader, "view"), false, ref view);
GL.UniformMatrix4(GL.GetUniformLocation(_renderShader, "projection"), false, ref projection);
GL.Uniform1(GL.GetUniformLocation(_renderShader, "time"), _time);
GL.ActiveTexture(TextureUnit.Texture0);
GL.BindTexture(TextureTarget.Texture3D, _densityTextures[_currentDensity]);
GL.Uniform1(GL.GetUniformLocation(_renderShader, "densityTexture"), 0);
GL.ActiveTexture(TextureUnit.Texture1);
GL.BindTexture(TextureTarget.Texture3D, _obstacleTexture);
GL.Uniform1(GL.GetUniformLocation(_renderShader, "obstacleTexture"), 1);
GL.BindVertexArray(_vertexArrayObject);
GL.DrawArrays(PrimitiveType.Points, 0, _pointCount);
}
private void BindImageTexture(int unit, int texture, TextureAccess access)
{
GL.BindImageTexture(unit, texture, 0, false, 0, access, SizedInternalFormat.R32f);
}
private void DispatchCompute(int sizeX, int sizeY, int sizeZ, int localSizeX, int localSizeY, int localSizeZ)
{
int groupsX = (sizeX + localSizeX - 1) / localSizeX;
int groupsY = (sizeY + localSizeY - 1) / localSizeY;
int groupsZ = (sizeZ + localSizeZ - 1) / localSizeZ;
GL.DispatchCompute(groupsX, groupsY, groupsZ);
}
private void ClearAllTextures()
{
GL.UseProgram(_clearShader);
foreach (var texture in _densityTextures)
{
BindImageTexture(0, texture, TextureAccess.WriteOnly);
GL.Uniform1(GL.GetUniformLocation(_clearShader, "value"), 0.0f);
DispatchCompute(_fluidSizeX, _fluidSizeY, _fluidSizeZ, 8, 8, 8);
}
foreach (var texture in _velocityTextures)
{
BindImageTexture(0, texture, TextureAccess.WriteOnly);
GL.Uniform1(GL.GetUniformLocation(_clearShader, "value"), 0.0f);
DispatchCompute(_fluidSizeX, _fluidSizeY, _fluidSizeZ, 8, 8, 8);
}
foreach (var texture in _pressureTextures)
{
BindImageTexture(0, texture, TextureAccess.WriteOnly);
GL.Uniform1(GL.GetUniformLocation(_clearShader, "value"), 0.0f);
DispatchCompute(_fluidSizeX, _fluidSizeY, _fluidSizeZ, 8, 8, 8);
}
GL.MemoryBarrier(MemoryBarrierFlags.AllBarrierBits);
// Re-add initial fluid
AddInitialFluid();
}
protected override void OnUpdateFrame(FrameEventArgs e)
{
base.OnUpdateFrame(e);
_time += (float)e.Time;
_camera.UpdateVectors();
var input = KeyboardState;
float cameraSpeed = _camera.Speed * (float)e.Time;
if (input.IsKeyDown(Keys.W))
_camera.Position += _camera.Front * cameraSpeed;
if (input.IsKeyDown(Keys.S))
_camera.Position -= _camera.Front * cameraSpeed;
if (input.IsKeyDown(Keys.A))
_camera.Position -= _camera.Right * cameraSpeed;
if (input.IsKeyDown(Keys.D))
_camera.Position += _camera.Right * cameraSpeed;
if (input.IsKeyDown(Keys.Space))
_camera.Position += _camera.Up * cameraSpeed;
if (input.IsKeyDown(Keys.LeftShift))
_camera.Position -= _camera.Up * cameraSpeed;
Title = $"🎯 WORKING Fluid Simulation - FPS: {1.0 / e.Time:0} - CLICK TO INTERACT!";
}
protected override void OnMouseMove(MouseMoveEventArgs e)
{
base.OnMouseMove(e);
if (IsFocused)
{
if (_firstMove)
{
_lastPos = new Vector2(e.X, e.Y);
_firstMove = false;
}
else
{
var deltaX = e.X - _lastPos.X;
var deltaY = e.Y - _lastPos.Y;
_lastPos = new Vector2(e.X, e.Y);
_camera.Yaw += deltaX * _camera.Sensitivity;
_camera.Pitch -= deltaY * _camera.Sensitivity;
_camera.Pitch = Math.Clamp(_camera.Pitch, -MathHelper.PiOver2 + 0.1f, MathHelper.PiOver2 - 0.1f);
}
}
}
protected override void OnMouseDown(MouseButtonEventArgs e)
{
base.OnMouseDown(e);
var mousePos = new Vector2(MouseState.X, MouseState.Y);
// Simple direct mapping
Vector3 fluidPos = new Vector3(
(mousePos.X / Size.X) * _fluidSizeX,
(1.0f - mousePos.Y / Size.Y) * _fluidSizeY,
_fluidSizeZ / 2
);
// Clamp to reasonable bounds
fluidPos.X = Math.Clamp(fluidPos.X, 5, _fluidSizeX - 5);
fluidPos.Y = Math.Clamp(fluidPos.Y, 5, _fluidSizeY - 5);
fluidPos.Z = Math.Clamp(fluidPos.Z, 5, _fluidSizeZ - 5);
if (e.Button == MouseButton.Left)
{
AddForce(fluidPos, Vector3.Zero, 8.0f, 15.0f);
Console.WriteLine($"💧 Added DENSITY at: {fluidPos}");
}
else if (e.Button == MouseButton.Right)
{
// Add velocity away from center for explosion effect
Vector3 center = new Vector3(_fluidSizeX / 2, _fluidSizeY / 2, _fluidSizeZ / 2);
Vector3 dir = Vector3.Normalize(fluidPos - center);
AddForce(fluidPos, dir * 20.0f, 6.0f, 0.0f);
Console.WriteLine($"💨 Added VELOCITY at: {fluidPos}");
}
}
protected override void OnKeyDown(KeyboardKeyEventArgs e)
{
base.OnKeyDown(e);
if (e.Key == Keys.Escape)
Close();
else if (e.Key == Keys.R)
{
ClearAllTextures();
Console.WriteLine("🔄 Simulation RESET!");
}
else if (e.Key == Keys.O)
{
var mousePos = new Vector2(MouseState.X, MouseState.Y);
Vector3 fluidPos = new Vector3(
(mousePos.X / Size.X) * _fluidSizeX,
(1.0f - mousePos.Y / Size.Y) * _fluidSizeY,
_fluidSizeZ / 2
);
AddSphereObstacle(fluidPos, 5.0f);
Console.WriteLine($"🧱 Added OBSTACLE at: {fluidPos}");
}
}
protected override void OnResize(ResizeEventArgs e)
{
base.OnResize(e);
GL.Viewport(0, 0, Size.X, Size.Y);
_camera.AspectRatio = Size.X / (float)Size.Y;
}
}