ParticleGenerator::ParticleGenerator(Particle p, DirectX::XMFLOAT3 pos, float lt, float sr, float numRoots)
{
init = false;
lifeTime = lt;
spawnRate = sr;
position = pos;
// Get necessary resources
ResourceManager* rManager = ResourceManager::Instance();
ID3D11Device* device = rManager->GetDevice();
ID3D11DeviceContext* deviceContext = rManager->GetDeviceContext();
generatorVS = dynamic_cast<SimpleVertexShader*>(rManager->GetShader("ParticleGeneratorVS"));
generatorGS = dynamic_cast<SimpleGeometryShader*>(rManager->GetShader("ParticleGeneratorGS"));
// Create Stream Output variables
generatorGS->CreateCompatibleStreamOutBuffer(&readBuff, 1000000);
generatorGS->CreateCompatibleStreamOutBuffer(&writeBuff, 1000000);
// Create initial ROOT vertex buffer
UINT stride = sizeof(Particle);
UINT offset = 0;
Particle vertices[] = { p };
D3D11_BUFFER_DESC vbd;
vbd.Usage = D3D11_USAGE_IMMUTABLE;
vbd.ByteWidth = sizeof(Particle);
vbd.BindFlags = D3D11_BIND_VERTEX_BUFFER;
vbd.CPUAccessFlags = 0;
vbd.MiscFlags = 0;
vbd.StructureByteStride = 0;
D3D11_SUBRESOURCE_DATA initialVertexData;
initialVertexData.pSysMem = vertices;
device->CreateBuffer(&vbd, &initialVertexData, &particleBuff);
// Set constant variables
generatorGS->SetFloat("dt", 0.0f);
generatorGS->SetFloat("tt", 0.0f);
generatorGS->SetFloat("lifeTime", lifeTime);
generatorGS->SetFloat("spawnRate", spawnRate);
generatorGS->SetFloat3("generatorPos", position);
generatorGS->SetSamplerState("randomSampler", rManager->GetSamplerState("trilinear"));
generatorGS->SetShaderResourceView("randomTexture", rManager->GetTexture("randomTexture"));
// Activate shaders
generatorVS->SetShader(true);
generatorGS->SetShader(true);
deviceContext->PSSetShader(0, 0, 0);
deviceContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_POINTLIST);
// Unbind vertex buffers (incase)
ID3D11Buffer* unset = 0;
deviceContext->IASetVertexBuffers(0, 1, &unset, &stride, &offset);
deviceContext->IASetVertexBuffers(0, 1, &particleBuff, &stride, &offset);
deviceContext->SOSetTargets(1, &writeBuff, &offset);
deviceContext->Draw(1, 0);
SimpleGeometryShader::UnbindStreamOutStage(deviceContext);
deviceContext->GSSetShader(0, 0, 0);
SwapBuffers();
}
