webgpu-app/flat.js
2026-07-31 20:35:16 -05:00

343 lines
11 KiB
JavaScript

import { getPath } from "./common.js";
function test(position)
{
const x = position[0] * 4 * Math.PI;
const y = position[1] * 4 * Math.PI;
return Math.cos(y - 3 + Math.sin(x)) * 0.5 + 0.5;
}
function length(vector)
{
return Math.sqrt(vector[0] * vector[0] + vector[1] * vector[1]);
}
function sub(a, b)
{
return [
a[0] - b[0],
a[1] - b[1],
];
}
function smoothing(radius, distance)
{
const volume = Math.PI * Math.pow(radius, 8) / 4;
const value = Math.max(0, radius * radius - distance * distance);
return value * value * value / volume;
}
class FlatRenderer {
positionProperty(position, circleRadius, particleCount)
{
var property = 0.0;
for (var i = 0; i < particleCount; i++) {
const particlePosition = [this.particles[i * this.particleStride + 0],
this.particles[i * this.particleStride + 1]];
const particleProperty = this.particles[i * this.particleStride + 4];
const particleDensity = this.particles[i * this.particleStride + 5];
const distance = length(sub(position, particlePosition));
const influence = smoothing(circleRadius, distance);
property += particleProperty * influence / particleDensity;
}
return property;
}
particleDensity(aPosition, circleRadius, particleCount)
{
var density = 0.0;
for (var i = 0; i < particleCount; i++) {
const bPosition = [this.particles[i * this.particleStride + 0],
this.particles[i * this.particleStride + 1]];
const distance = length(sub(aPosition, bPosition));
const influence = smoothing(circleRadius, distance);
density += influence;
}
return density;
}
createParticles(device)
{
this.maxDim = 32;
this.maxParticles = this.maxDim * this.maxDim;
this.particleStride = 4 * 2; // in elements
this.particles = new Float32Array(this.maxParticles * this.particleStride);
this.maxGradientsDim = 32;
this.maxGradients = this.maxGradientsDim * this.maxGradientsDim;
this.gradientStride = 4 * 2;
this.gradients = new Float32Array(this.maxGradients * this.gradientStride);
this.particleBuffers = [];
this.gradientBuffers = [];
this.particleBindGroups = [];
this.particleConfiguration = new Float32Array(3 * 4);
this.particleConfigurationBuffers = [];
for (let i = 0; i < 2; i++) {
const particleBuffer = device.createBuffer({
label: `particle buffer ${i}`,
size: this.particles.byteLength,
usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST,
});
this.particleBuffers.push(particleBuffer);
const gradientBuffer = device.createBuffer({
label: `gradient buffer ${i}`,
size: this.gradients.byteLength,
usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST,
});
this.gradientBuffers.push(gradientBuffer);
const configBuffer = device.createBuffer({
label: `particle configuration buffer ${i}`,
size: this.particleConfiguration.byteLength,
usage: GPUBufferUsage.UNIFORM | GPUBufferUsage.COPY_DST,
});
this.particleConfigurationBuffers.push(configBuffer);
const bindGroup = device.createBindGroup({
label: `particle buffer bind group ${i}`,
layout: this.bindGroupLayout.particle,
entries: [{
binding: 0,
resource: { buffer: configBuffer },
}, {
binding: 1,
resource: { buffer: particleBuffer },
}, {
binding: 2,
resource: { buffer: gradientBuffer },
}],
});
this.particleBindGroups.push(bindGroup);
}
for (let i = 0; i < this.maxParticles; i++) {
// position
const position = [Math.random(), Math.random()];
this.particles[i * this.particleStride + 0] = position[0];
this.particles[i * this.particleStride + 1] = position[1];
this.particles[i * this.particleStride + 2] = 0.0;
this.particles[i * this.particleStride + 3] = 1.0;
// value.x
this.particles[i * this.particleStride + 4] = test(position);
}
}
constructor(device, canvasFormat, viewUniformBuffer, shaderModule)
{
const label = "flat";
//////////////////////////////////////////////////////////////////////
// buffer
//////////////////////////////////////////////////////////////////////
const array = new Uint16Array(6);
array[0] = 0;
array[1] = 1;
array[2] = 2;
array[3] = 0;
array[4] = 3;
array[5] = 1;
this.buffer = device.createBuffer({
label: `${label} renderer buffer`,
size: array.byteLength,
usage: GPUBufferUsage.INDEX | GPUBufferUsage.COPY_DST,
});
device.queue.writeBuffer(this.buffer, 0, array, 0, array.length);
//////////////////////////////////////////////////////////////////////
// pipeline
//////////////////////////////////////////////////////////////////////
this.bindGroupLayout = {
view: device.createBindGroupLayout({
label: `${label} bind group layout view`,
entries: [{
binding: 0,
visibility: GPUShaderStage.VERTEX,
buffer: { type: "uniform" }
}]
}),
particle: device.createBindGroupLayout({
label: `${label} bind group layout particle`,
entries: [{
binding: 0,
visibility: GPUShaderStage.FRAGMENT,
buffer: { type: "uniform" }
}, {
binding: 1,
visibility: GPUShaderStage.FRAGMENT,
buffer: { type: "read-only-storage" }
}, {
binding: 2,
visibility: GPUShaderStage.FRAGMENT,
buffer: { type: "read-only-storage" }
}]
}),
};
const pipelineLayout = device.createPipelineLayout({
label: `${label} pipeline layout`,
bindGroupLayouts: [
this.bindGroupLayout.view,
this.bindGroupLayout.particle
],
});
this.renderPipeline = device.createRenderPipeline({
label: `${label} pipeline`,
layout: pipelineLayout,
vertex: {
module: shaderModule,
entryPoint: "vertexMain",
},
fragment: {
module: shaderModule,
entryPoint: "fragmentMain",
targets: [{
format: canvasFormat,
}]
},
primitive: {
topology: "triangle-list",
},
depthStencil: {
depthWriteEnabled: true,
depthCompare: "less",
format: "depth24plus",
},
});
//////////////////////////////////////////////////////////////////////
// particles
//////////////////////////////////////////////////////////////////////
this.createParticles(device);
//////////////////////////////////////////////////////////////////////
// bind group
//////////////////////////////////////////////////////////////////////
this.bindGroups = [
device.createBindGroup({
label: `${label} bind group`,
layout: this.bindGroupLayout.view,
entries: [{
binding: 0,
resource: { buffer: viewUniformBuffer },
}],
}),
];
}
updateGradients(device, frameNumber, configuration)
{
const radius = configuration.circleRadius;
const count = configuration.particleCount;
// calculate particle gradients
for (let y = 0; y < this.maxGradientsDim; y++) {
for (let x = 0; x < this.maxGradientsDim; x++) {
const i = y * this.maxGradientsDim + x;
const position = [(x / this.maxGradientsDim) + 0.5 / this.maxGradientsDim,
(y / this.maxGradientsDim) + 0.5 / this.maxGradientsDim];
const stepSize = 0.001;
const px = [position[0] + stepSize, position[1]];
const py = [position[0], position[1] + stepSize];
const property = this.positionProperty(position, radius, count);
const dx = this.positionProperty(px, radius, count) - property;
const dy = this.positionProperty(py, radius, count) - property;
this.gradients[i * this.gradientStride + 0] = position[0];
this.gradients[i * this.gradientStride + 1] = position[1];
this.gradients[i * this.gradientStride + 4] = dx / stepSize;
this.gradients[i * this.gradientStride + 5] = dy / stepSize;
}
}
device.queue.writeBuffer(this.gradientBuffers[frameNumber], 0,
this.gradients, 0, this.gradients.length);
}
updateParticles(device, frameNumber, configuration)
{
for (var i = 0; i < configuration.particleCount; i++) {
const position = [this.particles[i * this.particleStride + 0],
this.particles[i * this.particleStride + 1]];
const density = this.particleDensity(position,
configuration.circleRadius,
configuration.particleCount);
// value.y
this.particles[i * this.particleStride + 5] = density;
}
device.queue.writeBuffer(this.particleBuffers[frameNumber], 0,
this.particles, 0, this.particles.length);
}
updateConfiguration(device, frameNumber, configuration)
{
const PARTICLE = 0;
const CIRCLE = 1;
const MOUSE = 2;
const config = this.particleConfiguration;
config[PARTICLE * 4 + 0] = configuration.particleCount;
config[PARTICLE * 4 + 1] = configuration.particleSize;
config[PARTICLE * 4 + 2] = configuration.particleMass1;
config[PARTICLE * 4 + 3] = configuration.particleMass2;
config[CIRCLE * 4 + 0] = configuration.circleRadius;
config[CIRCLE * 4 + 1] = configuration.circleThickness;
config[CIRCLE * 4 + 2] = configuration.testIntensity;
config[CIRCLE * 4 + 3] = configuration.mass12Mix;
config[MOUSE * 4 + 0] = configuration.mousePosition[0];
config[MOUSE * 4 + 1] = configuration.mousePosition[1];
config[MOUSE * 4 + 2] = configuration.lineThickness;
config[MOUSE * 4 + 3] = configuration.lineLength;
device.queue.writeBuffer(this.particleConfigurationBuffers[frameNumber], 0,
this.particleConfiguration, 0, this.particleConfiguration.length)
}
render(device, renderPass, frameNumber, configuration)
{
// particle update must be before gradient update
this.updateParticles(device, frameNumber, configuration);
this.updateGradients(device, frameNumber, configuration);
this.updateConfiguration(device, frameNumber, configuration);
renderPass.setPipeline(this.renderPipeline);
renderPass.setIndexBuffer(this.buffer, "uint16");
renderPass.setBindGroup(0, this.bindGroups[0]);
renderPass.setBindGroup(1, this.particleBindGroups[frameNumber]);
renderPass.drawIndexed(6);
}
}
async function loadFlat(device, canvasFormat, viewUniformBuffer)
{
const flatWgsl = await getPath("flat.wgsl");
const shaderModule = device.createShaderModule({
label: "flag shader",
code: flatWgsl,
});
const renderer = new FlatRenderer(device, canvasFormat, viewUniformBuffer, shaderModule);
return renderer;
}
export { loadFlat };