Resource Management - DirectX Textures

Overview

Resource management in DirectX textures involves allocating GPU memory, controlling resource states, and synchronizing CPU‑GPU access. Proper handling ensures optimal performance and prevents leaks or undefined behavior.

Creating Resources

Use ID3D11Device::CreateTexture2D (or corresponding DX12 functions) with a D3D11_TEXTURE2D_DESC that describes format, size, usage, and bind flags.

#include <d3d11.h>
ID3D11Texture2D* tex = nullptr;
D3D11_TEXTURE2D_DESC desc = {};
desc.Width = 1024;
desc.Height = 1024;
desc.MipLevels = 0; // generate mipmaps
desc.ArraySize = 1;
desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
desc.SampleDesc.Count = 1;
desc.Usage = D3D11_USAGE_DEFAULT;
desc.BindFlags = D3D11_BIND_SHADER_RESOURCE | D3D11_BIND_RENDER_TARGET;
desc.CPUAccessFlags = 0;
desc.MiscFlags = D3D11_RESOURCE_MISC_GENERATE_MIPS;

HRESULT hr = device->CreateTexture2D(&desc, nullptr, &tex);
if (FAILED(hr)) { /* handle error */ }

Managing Resource Lifetime

Resources are reference‑counted COM objects. Release them when no longer needed. Prefer ComPtr<T> to automate lifetime management.

Microsoft::WRL::ComPtr<ID3D11Texture2D> texture;
device->CreateTexture2D(&desc, nullptr, &texture);
// texture automatically releases when it goes out of scope

Updating Resources

For dynamic data, create textures with D3D11_USAGE_DYNAMIC and update via Map/Unmap or UpdateSubresource.

D3D11_MAPPED_SUBRESOURCE mapped;
deviceContext->Map(texture.Get(), 0, D3D11_MAP_WRITE_DISCARD, 0, &mapped);
memcpy(mapped.pData, sourceData, rowPitch * height);
deviceContext->Unmap(texture.Get(), 0);

Mapping & Unmapping

When mapping, respect the CPU access flags and avoid writing outside the mapped region. Always unmap before using the resource in the GPU pipeline.

// Example of read‑only mapping
D3D11_MAPPED_SUBRESOURCE ms;
deviceContext->Map(texture.Get(), 0, D3D11_MAP_READ, 0, &ms);
// Read data...
deviceContext->Unmap(texture.Get(), 0);

Best Practices

Prefer immutable resources for static textures.
Use staging resources only for CPU‑GPU transfers.
Generate mipmaps after initial data upload with GenerateMips.
Avoid frequent state changes; batch draws with the same texture.
Release resources promptly to free GPU memory.

Microsoft Docs