dawn-cmake/examples/ComputeBoids.cpp

333 lines
11 KiB
C++

// Copyright 2017 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "SampleUtils.h"
#include "utils/ComboRenderPipelineDescriptor.h"
#include "utils/ScopedAutoreleasePool.h"
#include "utils/SystemUtils.h"
#include "utils/WGPUHelpers.h"
#include <array>
#include <cstring>
#include <random>
wgpu::Device device;
wgpu::Queue queue;
wgpu::SwapChain swapchain;
wgpu::TextureView depthStencilView;
wgpu::Buffer modelBuffer;
std::array<wgpu::Buffer, 2> particleBuffers;
wgpu::RenderPipeline renderPipeline;
wgpu::Buffer updateParams;
wgpu::ComputePipeline updatePipeline;
std::array<wgpu::BindGroup, 2> updateBGs;
size_t pingpong = 0;
static const uint32_t kNumParticles = 1000;
struct Particle {
std::array<float, 2> pos;
std::array<float, 2> vel;
};
struct SimParams {
float deltaT;
float rule1Distance;
float rule2Distance;
float rule3Distance;
float rule1Scale;
float rule2Scale;
float rule3Scale;
int particleCount;
};
void initBuffers() {
std::array<std::array<float, 2>, 3> model = {{
{-0.01, -0.02},
{0.01, -0.02},
{0.00, 0.02},
}};
modelBuffer =
utils::CreateBufferFromData(device, &model, sizeof(model), wgpu::BufferUsage::Vertex);
SimParams params = {0.04f, 0.1f, 0.025f, 0.025f, 0.02f, 0.05f, 0.005f, kNumParticles};
updateParams =
utils::CreateBufferFromData(device, &params, sizeof(params), wgpu::BufferUsage::Uniform);
std::vector<Particle> initialParticles(kNumParticles);
{
std::mt19937 generator;
std::uniform_real_distribution<float> dist(-1.0f, 1.0f);
for (auto& p : initialParticles) {
p.pos = {dist(generator), dist(generator)};
p.vel = {dist(generator) * 0.1f, dist(generator) * 0.1f};
}
}
for (size_t i = 0; i < 2; i++) {
wgpu::BufferDescriptor descriptor;
descriptor.size = sizeof(Particle) * kNumParticles;
descriptor.usage =
wgpu::BufferUsage::CopyDst | wgpu::BufferUsage::Vertex | wgpu::BufferUsage::Storage;
particleBuffers[i] = device.CreateBuffer(&descriptor);
queue.WriteBuffer(particleBuffers[i], 0,
reinterpret_cast<uint8_t*>(initialParticles.data()),
sizeof(Particle) * kNumParticles);
}
}
void initRender() {
wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
struct VertexIn {
@location(0) a_particlePos : vec2<f32>;
@location(1) a_particleVel : vec2<f32>;
@location(2) a_pos : vec2<f32>;
};
@stage(vertex)
fn main(input : VertexIn) -> @builtin(position) vec4<f32> {
var angle : f32 = -atan2(input.a_particleVel.x, input.a_particleVel.y);
var pos : vec2<f32> = vec2<f32>(
(input.a_pos.x * cos(angle)) - (input.a_pos.y * sin(angle)),
(input.a_pos.x * sin(angle)) + (input.a_pos.y * cos(angle)));
return vec4<f32>(pos + input.a_particlePos, 0.0, 1.0);
}
)");
wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
@stage(fragment)
fn main() -> @location(0) vec4<f32> {
return vec4<f32>(1.0, 1.0, 1.0, 1.0);
}
)");
depthStencilView = CreateDefaultDepthStencilView(device);
utils::ComboRenderPipelineDescriptor descriptor;
descriptor.vertex.module = vsModule;
descriptor.vertex.bufferCount = 2;
descriptor.cBuffers[0].arrayStride = sizeof(Particle);
descriptor.cBuffers[0].stepMode = wgpu::VertexStepMode::Instance;
descriptor.cBuffers[0].attributeCount = 2;
descriptor.cAttributes[0].offset = offsetof(Particle, pos);
descriptor.cAttributes[0].format = wgpu::VertexFormat::Float32x2;
descriptor.cAttributes[1].shaderLocation = 1;
descriptor.cAttributes[1].offset = offsetof(Particle, vel);
descriptor.cAttributes[1].format = wgpu::VertexFormat::Float32x2;
descriptor.cBuffers[1].arrayStride = 2 * sizeof(float);
descriptor.cBuffers[1].attributeCount = 1;
descriptor.cBuffers[1].attributes = &descriptor.cAttributes[2];
descriptor.cAttributes[2].shaderLocation = 2;
descriptor.cAttributes[2].format = wgpu::VertexFormat::Float32x2;
descriptor.cFragment.module = fsModule;
descriptor.EnableDepthStencil(wgpu::TextureFormat::Depth24PlusStencil8);
descriptor.cTargets[0].format = GetPreferredSwapChainTextureFormat();
renderPipeline = device.CreateRenderPipeline(&descriptor);
}
void initSim() {
wgpu::ShaderModule module = utils::CreateShaderModule(device, R"(
struct Particle {
pos : vec2<f32>;
vel : vec2<f32>;
};
struct SimParams {
deltaT : f32;
rule1Distance : f32;
rule2Distance : f32;
rule3Distance : f32;
rule1Scale : f32;
rule2Scale : f32;
rule3Scale : f32;
particleCount : u32;
};
struct Particles {
particles : array<Particle>;
};
@binding(0) @group(0) var<uniform> params : SimParams;
@binding(1) @group(0) var<storage, read> particlesA : Particles;
@binding(2) @group(0) var<storage, read_write> particlesB : Particles;
// https://github.com/austinEng/Project6-Vulkan-Flocking/blob/master/data/shaders/computeparticles/particle.comp
@stage(compute) @workgroup_size(1)
fn main(@builtin(global_invocation_id) GlobalInvocationID : vec3<u32>) {
var index : u32 = GlobalInvocationID.x;
if (index >= params.particleCount) {
return;
}
var vPos : vec2<f32> = particlesA.particles[index].pos;
var vVel : vec2<f32> = particlesA.particles[index].vel;
var cMass : vec2<f32> = vec2<f32>(0.0, 0.0);
var cVel : vec2<f32> = vec2<f32>(0.0, 0.0);
var colVel : vec2<f32> = vec2<f32>(0.0, 0.0);
var cMassCount : u32 = 0u;
var cVelCount : u32 = 0u;
var pos : vec2<f32>;
var vel : vec2<f32>;
for (var i : u32 = 0u; i < params.particleCount; i = i + 1u) {
if (i == index) {
continue;
}
pos = particlesA.particles[i].pos.xy;
vel = particlesA.particles[i].vel.xy;
if (distance(pos, vPos) < params.rule1Distance) {
cMass = cMass + pos;
cMassCount = cMassCount + 1u;
}
if (distance(pos, vPos) < params.rule2Distance) {
colVel = colVel - (pos - vPos);
}
if (distance(pos, vPos) < params.rule3Distance) {
cVel = cVel + vel;
cVelCount = cVelCount + 1u;
}
}
if (cMassCount > 0u) {
cMass = (cMass / vec2<f32>(f32(cMassCount), f32(cMassCount))) - vPos;
}
if (cVelCount > 0u) {
cVel = cVel / vec2<f32>(f32(cVelCount), f32(cVelCount));
}
vVel = vVel + (cMass * params.rule1Scale) + (colVel * params.rule2Scale) +
(cVel * params.rule3Scale);
// clamp velocity for a more pleasing simulation
vVel = normalize(vVel) * clamp(length(vVel), 0.0, 0.1);
// kinematic update
vPos = vPos + (vVel * params.deltaT);
// Wrap around boundary
if (vPos.x < -1.0) {
vPos.x = 1.0;
}
if (vPos.x > 1.0) {
vPos.x = -1.0;
}
if (vPos.y < -1.0) {
vPos.y = 1.0;
}
if (vPos.y > 1.0) {
vPos.y = -1.0;
}
// Write back
particlesB.particles[index].pos = vPos;
particlesB.particles[index].vel = vVel;
return;
}
)");
auto bgl = utils::MakeBindGroupLayout(
device, {
{0, wgpu::ShaderStage::Compute, wgpu::BufferBindingType::Uniform},
{1, wgpu::ShaderStage::Compute, wgpu::BufferBindingType::Storage},
{2, wgpu::ShaderStage::Compute, wgpu::BufferBindingType::Storage},
});
wgpu::PipelineLayout pl = utils::MakeBasicPipelineLayout(device, &bgl);
wgpu::ComputePipelineDescriptor csDesc;
csDesc.layout = pl;
csDesc.compute.module = module;
csDesc.compute.entryPoint = "main";
updatePipeline = device.CreateComputePipeline(&csDesc);
for (uint32_t i = 0; i < 2; ++i) {
updateBGs[i] = utils::MakeBindGroup(
device, bgl,
{
{0, updateParams, 0, sizeof(SimParams)},
{1, particleBuffers[i], 0, kNumParticles * sizeof(Particle)},
{2, particleBuffers[(i + 1) % 2], 0, kNumParticles * sizeof(Particle)},
});
}
}
wgpu::CommandBuffer createCommandBuffer(const wgpu::TextureView backbufferView, size_t i) {
auto& bufferDst = particleBuffers[(i + 1) % 2];
wgpu::CommandEncoder encoder = device.CreateCommandEncoder();
{
wgpu::ComputePassEncoder pass = encoder.BeginComputePass();
pass.SetPipeline(updatePipeline);
pass.SetBindGroup(0, updateBGs[i]);
pass.Dispatch(kNumParticles);
pass.EndPass();
}
{
utils::ComboRenderPassDescriptor renderPass({backbufferView}, depthStencilView);
wgpu::RenderPassEncoder pass = encoder.BeginRenderPass(&renderPass);
pass.SetPipeline(renderPipeline);
pass.SetVertexBuffer(0, bufferDst);
pass.SetVertexBuffer(1, modelBuffer);
pass.Draw(3, kNumParticles);
pass.EndPass();
}
return encoder.Finish();
}
void init() {
device = CreateCppDawnDevice();
queue = device.GetQueue();
swapchain = GetSwapChain(device);
swapchain.Configure(GetPreferredSwapChainTextureFormat(), wgpu::TextureUsage::RenderAttachment,
640, 480);
initBuffers();
initRender();
initSim();
}
void frame() {
wgpu::TextureView backbufferView = swapchain.GetCurrentTextureView();
wgpu::CommandBuffer commandBuffer = createCommandBuffer(backbufferView, pingpong);
queue.Submit(1, &commandBuffer);
swapchain.Present();
DoFlush();
pingpong = (pingpong + 1) % 2;
}
int main(int argc, const char* argv[]) {
if (!InitSample(argc, argv)) {
return 1;
}
init();
while (!ShouldQuit()) {
utils::ScopedAutoreleasePool pool;
frame();
utils::USleep(16000);
}
// TODO release stuff
}