dawn-cmake/examples/ComputeBoids.cpp

326 lines
10 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/SystemUtils.h"
#include "utils/WGPUHelpers.h"
#include <array>
#include <cstring>
#include <random>
#include <glm/glm.hpp>
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 {
glm::vec2 pos;
glm::vec2 vel;
};
struct SimParams {
float deltaT;
float rule1Distance;
float rule2Distance;
float rule3Distance;
float rule1Scale;
float rule2Scale;
float rule3Scale;
int particleCount;
};
void initBuffers() {
glm::vec2 model[3] = {
{-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 = glm::vec2(dist(generator), dist(generator));
p.vel = glm::vec2(dist(generator), 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);
particleBuffers[i].SetSubData(0,
sizeof(Particle) * kNumParticles,
reinterpret_cast<uint8_t*>(initialParticles.data()));
}
}
void initRender() {
wgpu::ShaderModule vsModule =
utils::CreateShaderModule(device, utils::SingleShaderStage::Vertex, R"(
#version 450
layout(location = 0) in vec2 a_particlePos;
layout(location = 1) in vec2 a_particleVel;
layout(location = 2) in vec2 a_pos;
void main() {
float angle = -atan(a_particleVel.x, a_particleVel.y);
vec2 pos = vec2(a_pos.x * cos(angle) - a_pos.y * sin(angle),
a_pos.x * sin(angle) + a_pos.y * cos(angle));
gl_Position = vec4(pos + a_particlePos, 0, 1);
}
)");
wgpu::ShaderModule fsModule =
utils::CreateShaderModule(device, utils::SingleShaderStage::Fragment, R"(
#version 450
layout(location = 0) out vec4 fragColor;
void main() {
fragColor = vec4(1.0);
}
)");
depthStencilView = CreateDefaultDepthStencilView(device);
utils::ComboRenderPipelineDescriptor descriptor(device);
descriptor.vertexStage.module = vsModule;
descriptor.cFragmentStage.module = fsModule;
descriptor.cVertexState.vertexBufferCount = 2;
descriptor.cVertexState.cVertexBuffers[0].arrayStride = sizeof(Particle);
descriptor.cVertexState.cVertexBuffers[0].stepMode = wgpu::InputStepMode::Instance;
descriptor.cVertexState.cVertexBuffers[0].attributeCount = 2;
descriptor.cVertexState.cAttributes[0].offset = offsetof(Particle, pos);
descriptor.cVertexState.cAttributes[0].format = wgpu::VertexFormat::Float2;
descriptor.cVertexState.cAttributes[1].shaderLocation = 1;
descriptor.cVertexState.cAttributes[1].offset = offsetof(Particle, vel);
descriptor.cVertexState.cAttributes[1].format = wgpu::VertexFormat::Float2;
descriptor.cVertexState.cVertexBuffers[1].arrayStride = sizeof(glm::vec2);
descriptor.cVertexState.cVertexBuffers[1].attributeCount = 1;
descriptor.cVertexState.cVertexBuffers[1].attributes = &descriptor.cVertexState.cAttributes[2];
descriptor.cVertexState.cAttributes[2].shaderLocation = 2;
descriptor.cVertexState.cAttributes[2].format = wgpu::VertexFormat::Float2;
descriptor.depthStencilState = &descriptor.cDepthStencilState;
descriptor.cDepthStencilState.format = wgpu::TextureFormat::Depth24PlusStencil8;
descriptor.cColorStates[0].format = GetPreferredSwapChainTextureFormat();
renderPipeline = device.CreateRenderPipeline(&descriptor);
}
void initSim() {
wgpu::ShaderModule module =
utils::CreateShaderModule(device, utils::SingleShaderStage::Compute, R"(
#version 450
struct Particle {
vec2 pos;
vec2 vel;
};
layout(std140, set = 0, binding = 0) uniform SimParams {
float deltaT;
float rule1Distance;
float rule2Distance;
float rule3Distance;
float rule1Scale;
float rule2Scale;
float rule3Scale;
int particleCount;
} params;
layout(std140, set = 0, binding = 1) buffer ParticlesA {
Particle particles[1000];
} particlesA;
layout(std140, set = 0, binding = 2) buffer ParticlesB {
Particle particles[1000];
} particlesB;
void main() {
// https://github.com/austinEng/Project6-Vulkan-Flocking/blob/master/data/shaders/computeparticles/particle.comp
uint index = gl_GlobalInvocationID.x;
if (index >= params.particleCount) { return; }
vec2 vPos = particlesA.particles[index].pos;
vec2 vVel = particlesA.particles[index].vel;
vec2 cMass = vec2(0.0, 0.0);
vec2 cVel = vec2(0.0, 0.0);
vec2 colVel = vec2(0.0, 0.0);
int cMassCount = 0;
int cVelCount = 0;
vec2 pos;
vec2 vel;
for (int i = 0; i < params.particleCount; ++i) {
if (i == index) { continue; }
pos = particlesA.particles[i].pos.xy;
vel = particlesA.particles[i].vel.xy;
if (distance(pos, vPos) < params.rule1Distance) {
cMass += pos;
cMassCount++;
}
if (distance(pos, vPos) < params.rule2Distance) {
colVel -= (pos - vPos);
}
if (distance(pos, vPos) < params.rule3Distance) {
cVel += vel;
cVelCount++;
}
}
if (cMassCount > 0) {
cMass = cMass / cMassCount - vPos;
}
if (cVelCount > 0) {
cVel = cVel / cVelCount;
}
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 += 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;
particlesB.particles[index].pos = vPos;
// Write back
particlesB.particles[index].vel = vVel;
}
)");
auto bgl = utils::MakeBindGroupLayout(
device, {
{0, wgpu::ShaderStage::Compute, wgpu::BindingType::UniformBuffer},
{1, wgpu::ShaderStage::Compute, wgpu::BindingType::StorageBuffer},
{2, wgpu::ShaderStage::Compute, wgpu::BindingType::StorageBuffer},
});
wgpu::PipelineLayout pl = utils::MakeBasicPipelineLayout(device, &bgl);
wgpu::ComputePipelineDescriptor csDesc;
csDesc.layout = pl;
csDesc.computeStage.module = module;
csDesc.computeStage.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.CreateQueue();
swapchain = GetSwapChain(device);
swapchain.Configure(GetPreferredSwapChainTextureFormat(), wgpu::TextureUsage::OutputAttachment,
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()) {
frame();
utils::USleep(16000);
}
// TODO release stuff
}