dawn-cmake/examples/ComputeBoids.cpp

321 lines
10 KiB
C++

// Copyright 2017 The NXT 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/NXTHelpers.h"
#include "utils/SystemUtils.h"
#include <array>
#include <cstring>
#include <random>
#include <glm/glm.hpp>
nxt::Device device;
nxt::Queue queue;
nxt::Buffer modelBuffer;
std::array<nxt::Buffer, 2> particleBuffers;
nxt::RenderPipeline renderPipeline;
nxt::RenderPass renderpass;
nxt::Framebuffer framebuffer;
nxt::Buffer updateParams;
nxt::ComputePipeline updatePipeline;
std::array<nxt::BindGroup, 2> updateBGs;
std::array<nxt::CommandBuffer, 2> commandBuffers;
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::CreateFrozenBufferFromData(device, model, sizeof(model), nxt::BufferUsageBit::Vertex);
SimParams params = { 0.04f, 0.1f, 0.025f, 0.025f, 0.02f, 0.05f, 0.005f, kNumParticles };
updateParams = utils::CreateFrozenBufferFromData(device, &params, sizeof(params), nxt::BufferUsageBit::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++) {
particleBuffers[i] = device.CreateBufferBuilder()
.SetAllowedUsage(nxt::BufferUsageBit::TransferDst | nxt::BufferUsageBit::Vertex | nxt::BufferUsageBit::Storage)
.SetInitialUsage(nxt::BufferUsageBit::TransferDst)
.SetSize(sizeof(Particle) * kNumParticles)
.GetResult();
particleBuffers[i].SetSubData(0,
sizeof(Particle) * kNumParticles / sizeof(uint32_t),
reinterpret_cast<uint32_t*>(initialParticles.data()));
}
}
void initRender() {
nxt::ShaderModule vsModule = utils::CreateShaderModule(device, nxt::ShaderStage::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);
}
)");
nxt::ShaderModule fsModule = utils::CreateShaderModule(device, nxt::ShaderStage::Fragment, R"(
#version 450
out vec4 fragColor;
void main() {
fragColor = vec4(1.0);
}
)");
nxt::InputState inputState = device.CreateInputStateBuilder()
.SetAttribute(0, 0, nxt::VertexFormat::FloatR32G32, offsetof(Particle, pos))
.SetAttribute(1, 0, nxt::VertexFormat::FloatR32G32, offsetof(Particle, vel))
.SetInput(0, sizeof(Particle), nxt::InputStepMode::Instance)
.SetAttribute(2, 1, nxt::VertexFormat::FloatR32G32, 0)
.SetInput(1, sizeof(glm::vec2), nxt::InputStepMode::Vertex)
.GetResult();
utils::CreateDefaultRenderPass(device, &renderpass, &framebuffer);
renderPipeline = device.CreateRenderPipelineBuilder()
.SetSubpass(renderpass, 0)
.SetStage(nxt::ShaderStage::Vertex, vsModule, "main")
.SetStage(nxt::ShaderStage::Fragment, fsModule, "main")
.SetInputState(inputState)
.GetResult();
}
void initSim() {
nxt::ShaderModule module = utils::CreateShaderModule(device, nxt::ShaderStage::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 particlesA[1000];
};
layout(std140, set = 0, binding = 2) buffer ParticlesB {
Particle particlesB[1000];
};
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[index].pos;
vec2 vVel = particlesA[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[i].pos.xy;
vel = particlesA[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[index].pos = vPos;
// Write back
particlesB[index].vel = vVel;
}
)");
nxt::BindGroupLayout bgl = device.CreateBindGroupLayoutBuilder()
.SetBindingsType(nxt::ShaderStageBit::Compute, nxt::BindingType::UniformBuffer, 0, 1)
.SetBindingsType(nxt::ShaderStageBit::Compute, nxt::BindingType::StorageBuffer, 1, 2)
.GetResult();
nxt::PipelineLayout pl = device.CreatePipelineLayoutBuilder()
.SetBindGroupLayout(0, bgl)
.GetResult();
updatePipeline = device.CreateComputePipelineBuilder()
.SetLayout(pl)
.SetStage(nxt::ShaderStage::Compute, module, "main")
.GetResult();
nxt::BufferView updateParamsView = updateParams.CreateBufferViewBuilder()
.SetExtent(0, sizeof(SimParams))
.GetResult();
std::array<nxt::BufferView, 2> views;
for (uint32_t i = 0; i < 2; ++i) {
views[i] = particleBuffers[i].CreateBufferViewBuilder()
.SetExtent(0, kNumParticles * sizeof(Particle))
.GetResult();
}
for (uint32_t i = 0; i < 2; ++i) {
updateBGs[i] = device.CreateBindGroupBuilder()
.SetLayout(bgl)
.SetUsage(nxt::BindGroupUsage::Frozen)
.SetBufferViews(0, 1, &updateParamsView)
.SetBufferViews(1, 1, &views[i])
.SetBufferViews(2, 1, &views[(i + 1) % 2])
.GetResult();
}
}
void initCommandBuffers() {
static const uint32_t zeroOffsets[1] = {0};
for (size_t i = 0; i < 2; ++i) {
auto& bufferSrc = particleBuffers[i];
auto& bufferDst = particleBuffers[(i + 1) % 2];
commandBuffers[i] = device.CreateCommandBufferBuilder()
.BeginComputePass()
.SetComputePipeline(updatePipeline)
.TransitionBufferUsage(bufferSrc, nxt::BufferUsageBit::Storage)
.TransitionBufferUsage(bufferDst, nxt::BufferUsageBit::Storage)
.SetBindGroup(0, updateBGs[i])
.Dispatch(kNumParticles, 1, 1)
.EndComputePass()
.BeginRenderPass(renderpass, framebuffer)
.BeginRenderSubpass()
.SetRenderPipeline(renderPipeline)
.TransitionBufferUsage(bufferDst, nxt::BufferUsageBit::Vertex)
.SetVertexBuffers(0, 1, &bufferDst, zeroOffsets)
.SetVertexBuffers(1, 1, &modelBuffer, zeroOffsets)
.DrawArrays(3, kNumParticles, 0, 0)
.EndRenderSubpass()
.EndRenderPass()
.GetResult();
}
}
void init() {
device = CreateCppNXTDevice();
queue = device.CreateQueueBuilder().GetResult();
initBuffers();
initRender();
initSim();
initCommandBuffers();
}
void frame() {
queue.Submit(1, &commandBuffers[pingpong]);
DoSwapBuffers();
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
}