创建或更新 DirectX11 纹理会导致访问冲突异常

Question

我正在尝试做一个简单的测试来更好地理解 DirectX11 以及如何使用 ID3D11Texture2D。

我愿意从unsigned char[] 创建一个ID3D11Texture2D，但由于某种原因它给了我以下错误：

Exception thrown at 0x00007FFBBCB9C21E (nvwgf2umx.dll) in TestDX.exe: 0xC0000005: Access violation reading location 0x0000024B1A7A4000.

我创建了带有调试标志的D3D11CreateDevice，但它没有显示更多有用的信息。

在网上查了一下，this topic 建议我的D3D11_TEXTURE2D_DESC Format 属性与输入数据格式不匹配。

为了重现，这是我的代码：

const int width = 1920;
const int height = 1080;

unsigned char* pixels = new unsigned char[width * height * 4];

int numPixels = (int)(width * height);

// Setting up pixels
for (int i = 0; i < numPixels; i++) 
{
    *(pixels) = 255;
    *(pixels + 1) = 255;
    *(pixels + 2) = 255;
    *(pixels + 3) = 255;
    pixels += 4; // move the pointer along to the next rgba pixel
}

// Creating DirectX11 Device
UINT creationFlags = D3D11_CREATE_DEVICE_BGRA_SUPPORT | D3D11_CREATE_DEVICE_DEBUG;

D3D_FEATURE_LEVEL featureLevels[] =
{
    D3D_FEATURE_LEVEL_11_1,
    D3D_FEATURE_LEVEL_11_0,
    D3D_FEATURE_LEVEL_10_1,
    D3D_FEATURE_LEVEL_10_0,
    D3D_FEATURE_LEVEL_9_3,
    D3D_FEATURE_LEVEL_9_1
};

ID3D11Texture2D* tex = nullptr;
ID3D11Device* device = nullptr;
ID3D11DeviceContext* context = nullptr; 

if (FAILED(D3D11CreateDevice(
    nullptr,                    // specify nullptr to use the default adapter
    D3D_DRIVER_TYPE_HARDWARE,
    nullptr,                    // specify nullptr because D3D_DRIVER_TYPE_HARDWARE 
                                // indicates that this function uses hardware
    creationFlags,              // optionally set debug and Direct2D compatibility flags
    featureLevels,
    ARRAYSIZE(featureLevels),
    D3D11_SDK_VERSION,          // always set this to D3D11_SDK_VERSION
    &device,
    nullptr,
    &context)))
{
    cout << "Failed creating device" << endl;
    return 0;
}
else
{
    cout << "Created device" << endl;
}

D3D11_SUBRESOURCE_DATA initData = { 0 };
initData.pSysMem = (const void*)pixels;
initData.SysMemPitch = width * 4 * sizeof(unsigned char);
initData.SysMemSlicePitch = height * width * 4;

D3D11_TEXTURE2D_DESC tex_desc = {};
tex_desc.Height = height;
tex_desc.Width = width;
tex_desc.MipLevels = 1;
tex_desc.ArraySize = 1;
tex_desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
tex_desc.SampleDesc.Count = 1;
tex_desc.SampleDesc.Quality = 0;
tex_desc.Usage = D3D11_USAGE_DEFAULT;
tex_desc.BindFlags = D3D11_BIND_SHADER_RESOURCE | D3D11_BIND_RENDER_TARGET;
tex_desc.CPUAccessFlags = 0;
tex_desc.MiscFlags = D3D11_RESOURCE_MISC_GENERATE_MIPS;

HRESULT hres = device->CreateTexture2D(&tex_desc, &initData, &tex); // Causes exception

if (FAILED(hres))
{
    cout << "Could not create texture" << endl;
    return 0;
}
else
{
    cout << "Created texture" << endl;
}

if (tex)
{
    tex->Release();
}

我还尝试创建一个空纹理并按照互联网上的建议使用 UpdateSubresource 并创建了这个场景：

const int width = 1920;
const int height = 1080;

unsigned char* pixels = new unsigned char[width * height * 4];

int numPixels = (int)(width * height);

// Setting up pixels
for (int i = 0; i < numPixels; i++)
{
    *(pixels) = 255;
    *(pixels + 1) = 255;
    *(pixels + 2) = 255;
    *(pixels + 3) = 255;
    pixels += 4; // move the pointer along to the next rgba pixel
}

// Creating DirectX11 Device
UINT creationFlags = D3D11_CREATE_DEVICE_BGRA_SUPPORT | D3D11_CREATE_DEVICE_DEBUG;

D3D_FEATURE_LEVEL featureLevels[] =
{
    D3D_FEATURE_LEVEL_11_1,
    D3D_FEATURE_LEVEL_11_0,
    D3D_FEATURE_LEVEL_10_1,
    D3D_FEATURE_LEVEL_10_0,
    D3D_FEATURE_LEVEL_9_3,
    D3D_FEATURE_LEVEL_9_1
};

ID3D11Texture2D* tex = nullptr;
ID3D11Device* device = nullptr;
ID3D11DeviceContext* context = nullptr;

if (FAILED(D3D11CreateDevice(
    nullptr,                    // specify nullptr to use the default adapter
    D3D_DRIVER_TYPE_HARDWARE,
    nullptr,                    // specify nullptr because D3D_DRIVER_TYPE_HARDWARE 
                                // indicates that this function uses hardware
    creationFlags,              // optionally set debug and Direct2D compatibility flags
    featureLevels,
    ARRAYSIZE(featureLevels),
    D3D11_SDK_VERSION,          // always set this to D3D11_SDK_VERSION
    &device,
    nullptr,
    &context)))
{
    cout << "Failed creating device" << endl;
    return 0;
}
else
{
    cout << "Created device" << endl;
}

D3D11_TEXTURE2D_DESC tex_desc = {};
tex_desc.Height = height;
tex_desc.Width = width;
tex_desc.MipLevels = 1;
tex_desc.ArraySize = 1;
tex_desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
tex_desc.SampleDesc.Count = 1;
tex_desc.SampleDesc.Quality = 0;
tex_desc.Usage = D3D11_USAGE_DEFAULT;
tex_desc.BindFlags = D3D11_BIND_SHADER_RESOURCE | D3D11_BIND_RENDER_TARGET;
tex_desc.CPUAccessFlags = 0;
tex_desc.MiscFlags = D3D11_RESOURCE_MISC_GENERATE_MIPS;

HRESULT hres = device->CreateTexture2D(&tex_desc, NULL, &tex);

if (FAILED(hres))
{
    cout << "Could not create texture" << endl;
    return 0;
}
else
{
    cout << "Created texture" << endl;
}

int row_pitch = (width * 4) * sizeof(unsigned char);

context->UpdateSubresource(tex, 0, NULL, pixels, row_pitch, 0); // Causes exception

if (tex)
{
    tex->Release();
}

但是，这两种情况都会导致相同的异常，我认为这表明我的输入数据实际上是错误的，但我不明白为什么它是错误的。我的 pixels 确实代表 RGBA 图像，我设置了 tex_desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM，这对我来说看起来是正确的，但我对此完全没有经验，所以我无法真正判断。

我将不胜感激。

Answer 1

这与 DirectX 无关，您的代码修改了原始的 pixels 指针（pixels++ 等），因此它传递垃圾（并最终指向锁定/未分配的操作系统内存页面，因为它是一个大缓冲区) 作为初始数据，因此崩溃。

所以，例如，改变这个：

unsigned char* pixels = new unsigned char[width * height * 4];

到这里：

unsigned char* pixels = new unsigned char[width * height * 4];
unsigned char* mem = pixels;

并改变这个：

initData.pSysMem = (const void*)pixels;

到这里：

initData.pSysMem = (const void*)mem;