fluid: incomplete webassembly rewrite

flat.js

@@ -135,43 +135,43 @@ class FlatRenderer {
     return density;
   }
 
-  createParticles(device)
+  createBuffers(device)
   {
     this.maxDim = 32;
     this.maxParticles = this.maxDim * this.maxDim;
-    this.particleStride = 4 * 3; // in elements
+    this.particleStride = this.module.instance.exports.particle__stride(); // bytes
-    this.particles = new Float32Array(this.maxParticles * this.particleStride);
+    this.particlesSize = this.maxParticles * this.particleStride; // bytes
 
     this.maxGradientsDim = 32;
     this.maxGradients = this.maxGradientsDim * this.maxGradientsDim;
     this.gradientStride = 4 * 2;
-    this.gradients = new Float32Array(this.maxGradients * this.gradientStride);
+
+    this.particleConfigurationStride = this.module.instance.exports.particle_configuration__stride();
 
     this.particleBuffers = [];
     this.gradientBuffers = [];
-    this.particleBindGroups = [];
-
-    this.particleConfiguration = new Float32Array(4 * 4);
     this.particleConfigurationBuffers = [];
 
+    this.particleBindGroups = [];
+
     for (let i = 0; i < 2; i++) {
       const particleBuffer = device.createBuffer({
         label: `particle buffer ${i}`,
-        size: this.particles.byteLength,
+        size: this.particlesSize,
         usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST,
       });
       this.particleBuffers.push(particleBuffer);
 
       const gradientBuffer = device.createBuffer({
         label: `gradient buffer ${i}`,
-        size: this.gradients.byteLength,
+        size: 4 * 4 * 2,
         usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST,
       });
       this.gradientBuffers.push(gradientBuffer);
 
       const configBuffer = device.createBuffer({
         label: `particle configuration buffer ${i}`,
-        size: this.particleConfiguration.byteLength,
+        size: this.particleConfigurationStride,
         usage: GPUBufferUsage.UNIFORM | GPUBufferUsage.COPY_DST,
       });
       this.particleConfigurationBuffers.push(configBuffer);
@@ -192,21 +192,16 @@ class FlatRenderer {
       });
       this.particleBindGroups.push(bindGroup);
     }
-
-    for (let i = 0; i < this.maxParticles; i++) {
-      // position
-      const position = [Math.random(), Math.random()];
-      this.particles[i * this.particleStride + 0] = position[0];
-      this.particles[i * this.particleStride + 1] = position[1];
-      this.particles[i * this.particleStride + 2] = 0.0;
-      this.particles[i * this.particleStride + 3] = 1.0;
-      // value.x
-      this.particles[i * this.particleStride + 4] = test(position);
-    }
   }
 
-  constructor(device, canvasFormat, viewUniformBuffer, shaderModule)
+  initializeState()
   {
+
+  }
+
+  constructor(device, canvasFormat, viewUniformBuffer, shaderModule, module)
+  {
+    this.module = module;
     const label = "flat";
 
     //////////////////////////////////////////////////////////////////////
@@ -296,7 +291,7 @@ class FlatRenderer {
     // particles
     //////////////////////////////////////////////////////////////////////
 
-    this.createParticles(device);
+    this.createBuffers(device);
 
     //////////////////////////////////////////////////////////////////////
     // bind group
@@ -434,10 +429,10 @@ class FlatRenderer {
   render(device, renderPass, frameNumber, configuration)
   {
     // particle update must be before gradient update
-    this.updateParticles(device, frameNumber, configuration);
+    //this.updateParticles(device, frameNumber, configuration);
-    this.updateGradients(device, frameNumber, configuration);
+    //this.updateGradients(device, frameNumber, configuration);
-    this.updateSimulation(device, frameNumber, configuration);
+    //this.updateSimulation(device, frameNumber, configuration);
-    this.updateConfiguration(device, frameNumber, configuration);
+    //this.updateConfiguration(device, frameNumber, configuration);
 
     renderPass.setPipeline(this.renderPipeline);
     renderPass.setIndexBuffer(this.buffer, "uint16");
@@ -447,7 +442,7 @@ class FlatRenderer {
   }
 }
 
-async function loadFlat(device, canvasFormat, viewUniformBuffer)
+async function loadFlat(device, canvasFormat, viewUniformBuffer, module)
 {
   const flatWgsl = await getPath("flat.wgsl");
   const shaderModule = device.createShaderModule({
@@ -455,7 +450,7 @@ async function loadFlat(device, canvasFormat, viewUniformBuffer)
     code: flatWgsl,
   });
 
-  const renderer = new FlatRenderer(device, canvasFormat, viewUniformBuffer, shaderModule);
+  const renderer = new FlatRenderer(device, canvasFormat, viewUniformBuffer, shaderModule, module);
   return renderer;
 }
 

index.js

@@ -47,6 +47,7 @@ const module = await WebAssembly.instantiateStreaming(fetch("src/module.wasm"),
     log: console.log,
   }
 });
+module.memory = memory;
 
 function createDepthTexture() {
   return device.createTexture({
@@ -98,7 +99,7 @@ module.instance.exports.camera_init(cameraStateAddress);
 
 //const gltfRenderer = await loadGltf(device, canvasFormat, viewUniformBuffer, memory, module);
 //const lightRenderer = await loadLight(device, canvasFormat, viewUniformBuffer);
-const flatRenderer = await loadFlat(device, canvasFormat, viewUniformBuffer);
+const flatRenderer = await loadFlat(device, canvasFormat, viewUniformBuffer, module);
 
 
 const KEY = {

src/Makefile

@@ -32,6 +32,10 @@ LDFLAGS = \
 	-Wl,--export=camera_move \
 	-Wl,--export=camera_init \
 	-Wl,--export=camera_view_projection \
+	-Wl,--export=particle_system__create \
+	-Wl,--export=particle_system__update \
+	-Wl,--export=particle__stride \
+	-Wl,--export=particle_configuration__stride \
 	-Wl,--import-undefined \
 	-Wl,--print-map \
 	-Wl,--import-memory \
@@ -49,7 +53,10 @@ PNG_OBJ = \
 	$(MINIZ)/miniz_tinfl.o \
 	memory.o \
 	node.o \
-	camera.o
+	camera.o \
+	fluid/particle.o \
+	fluid/particle_system.o \
+	fluid/api.o
 
 module.wasm: $(PNG_OBJ)
 	clang++ $(CFLAGS) $(LDFLAGS) -o $@ $^

src/builtin_math.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#define acosf(x) __builtin_acosf(x)
+#define asinf(x) __builtin_asinf(x)
+#define atan2f(x, y) __builtin_atan2f(x, y)
+#define atanf(x) __builtin_atanf(x)
+#define ceilf(x) __builtin_ceilf(x)
+#define cosf(x) __builtin_cosf(x)
+#define coshf(x) __builtin_coshf(x)
+#define exp2f(x) __builtin_exp2f(x)
+#define expf(x) __builtin_expf(x)
+#define fabsf(x) __builtin_fabsf(x)
+#define floorf(x) __builtin_floorf(x)
+#define isinf(x) (false)
+#define isnan(x) (false)
+#define log10f(x) __builtin_log10f(x)
+#define log2f(x) __builtin_log2f(x)
+#define logf(x) __builtin_logf(x)
+#define modff(x, y) __builtin_modff(x, y)
+#define powf(x, y) __builtin_powf(x, y)
+#define sinf(x) __builtin_sinf(x)
+#define sinhf(x) __builtin_sinhf(x)
+#define sqrtf(x) __builtin_sqrtf(x)
+#define tanf(x) __builtin_tanf(x)
+#define tanhf(x) __builtin_tanhf(x)
+#define sign(x) ((x > 0) - (x < 0))

src/directxmath/DirectXMath.h

@@ -154,32 +154,9 @@
 #endif // !_XM_NO_INTRINSICS_
 
 #include "sal.h"
-//#include <assert.h>
 #define assert(x)
-#define isnan(x) (false)
-#define floorf(x) __builtin_floorf(x)
-#define sqrtf(x) __builtin_sqrtf(x)
-#define expf(x) __builtin_expf(x)
-#define exp2f(x) __builtin_exp2f(x)
-#define logf(x) __builtin_logf(x)
-#define log2f(x) __builtin_log2f(x)
-#define log10f(x) __builtin_log10f(x)
-#define powf(x, y) __builtin_powf(x, y)
-#define fabsf(x) __builtin_fabsf(x)
-#define sinf(x) __builtin_sinf(x)
-#define sinhf(x) __builtin_sinhf(x)
-#define tanf(x) __builtin_tanf(x)
-#define tanhf(x) __builtin_tanhf(x)
-#define cosf(x) __builtin_cosf(x)
-#define asinf(x) __builtin_asinf(x)
-#define acosf(x) __builtin_acosf(x)
-#define coshf(x) __builtin_coshf(x)
-#define atanf(x) __builtin_atanf(x)
-#define atan2f(x, y) __builtin_atan2f(x, y)
-#define isinf(x) (false)
-#define ceilf(x) __builtin_ceilf(x)
-#define modff(x, y) __builtin_modff(x, y)
 #include <stddef.h>
+#include "builtin_math.h"
 
 #ifdef _MSC_VER
 #pragma warning(push)

src/fluid/api.cpp

@@ -0,0 +1,29 @@
+#include "particle_system.h"
+#include "new.h"
+
+using namespace fluid;
+
+extern "C" {
+  ParticleSystem * particle_system__create(int maxParticles)
+  {
+    auto particleSystem = New<ParticleSystem>();
+    particleSystem->init(maxParticles);
+    return particleSystem;
+  }
+
+  void particle_system__update(ParticleSystem * particleSystem)
+  {
+    particleSystem->update();
+  }
+
+  int particle__stride()
+  {
+    return (sizeof (Particle));
+  }
+
+  int particle_configuration__stride()
+  {
+    return (sizeof (ParticleConfiguration));
+  }
+
+};

src/fluid/particle.cpp

@@ -0,0 +1,32 @@
+#include "particle.h"
+
+namespace fluid
+{
+  void Particle::update(ParticleConfiguration * configuration)
+  {
+    XMVECTOR nextPosition = XMLoadFloat4(&position);
+    XMVECTOR nextVelocity = XMLoadFloat4(&velocity);
+
+    nextVelocity += XMVectorSet(0, 1, 0, 0) * configuration->gravity;
+    nextPosition += nextVelocity;
+
+    resolveCollision(configuration);
+
+    XMStoreFloat4(&position, nextPosition);
+    XMStoreFloat4(&velocity, nextVelocity);
+  }
+
+  void Particle::resolveCollision(ParticleConfiguration * configuration)
+  {
+    XMVECTOR halfExtents = XMLoadFloat2(&configuration->halfExtents) - XMVectorReplicate(configuration->particleRadius);
+    if (fabsf(position.x) > XMVectorGetX(halfExtents)) {
+      position.x = XMVectorGetX(halfExtents) * sign(position.x);
+      velocity.x *= -1;
+    }
+    if (fabsf(position.y) > XMVectorGetX(halfExtents)) {
+      position.y = XMVectorGetX(halfExtents) * sign(position.y);
+      velocity.y *= -1;
+    }
+  }
+
+}

src/fluid/particle.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "directxmath/DirectXMath.h"
+#include "particle_configuration.h"
+
+namespace fluid {
+
+  struct Particle {
+    XMFLOAT4 position;
+    XMFLOAT4 velocity;
+    XMFLOAT4 value;
+
+    void update(ParticleConfiguration * configuration);
+    void resolveCollision(ParticleConfiguration * configuration);
+  };
+
+}

src/fluid/particle_configuration.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include "directxmath/DirectXMath.h"
+
+namespace fluid {
+
+  struct ParticleConfiguration {
+    float particleCount;
+    float particleRadius;
+    float particleMass1;
+    float particleMass2;
+
+    float smoothingRadius;
+    float lineThickness;
+    float lineLength;
+    float _padding1;
+
+    float targetDensity;
+    float pressure;
+    float gravity;
+    float _padding2;
+
+    XMFLOAT2 testSamplePosition;
+    XMFLOAT2 halfExtents;
+  };
+
+}

src/fluid/particle_system.cpp

@@ -0,0 +1,25 @@
+#include "particle_system.h"
+#include "new.h"
+
+namespace fluid {
+
+  void ParticleSystem::init(int maxParticles)
+  {
+    this->maxParticles = maxParticles;
+    configuration = New<ParticleConfiguration>();
+    particles = New<Particle>(maxParticles);
+
+    for (int i = 0; i < maxParticles; i++) {
+      XMStoreFloat4(&particles[i].position, XMVectorZero());
+      XMStoreFloat4(&particles[i].velocity, XMVectorZero());
+      XMStoreFloat4(&particles[i].value, XMVectorZero());
+    }
+  }
+
+  void ParticleSystem::update()
+  {
+    for (int i = 0; i < configuration->particleCount; i++) {
+      particles[i].update(configuration);
+    }
+  }
+}

src/fluid/particle_system.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include "particle.h"
+
+namespace fluid {
+
+  struct ParticleSystem {
+    ParticleConfiguration * configuration;
+    Particle * particles;
+    int maxParticles;
+
+    void init(int maxParticles);
+    void update();
+  };
+};

src/new.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include "memory.h"
+
+template <typename T>
+T * New(int count = 1)
+{
+  size_t size = size_t(count) * (sizeof (T));
+  T * ptr = reinterpret_cast<T *>(mem_alloc(size));
+  return ptr;
+}