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• By cozzie
Hi all,
As a part of the debug drawing system in my engine,  I want to add support for rendering simple text on screen  (aka HUD/ HUD style). From what I've read there are a few options, in short:
1. Write your own font sprite renderer
2. Using Direct2D/Directwrite, combine with DX11 rendertarget/ backbuffer
3. Use an external library, like the directx toolkit etc.
I want to go for number 2, but articles/ documentation confused me a bit. Some say you need to create a DX10 device, to be able to do this, because it doesn't directly work with the DX11 device.  But other articles tell that this was 'patched' later on and should work now.
Can someone shed some light on this and ideally provide me an example or article on  how to set this up?
All input is appreciated.
• By stale
I've just started learning about tessellation from Frank Luna's DX11 book. I'm getting some very weird behavior when I try to render a tessellated quad patch if I also render a mesh in the same frame. The tessellated quad patch renders just fine if it's the only thing I'm rendering. This is pictured below:
'
However, when I attempt to render the same tessellated quad patch along with the other entities in the scene (which are simple triangle-lists), I get the following error:

I have no idea why this is happening, and google searches have given me no leads at all. I use the following code to render the tessellated quad patch:
for (unsigned int i = 0; i < scene->GetEntityList()->size(); i++) { Entity* entity = scene->GetEntityList()->at(i); if (entity->m_VisualComponent->m_visualType == VisualType::MESH) DrawMeshEntity(entity, cam, sun, point); else if (entity->m_VisualComponent->m_visualType == VisualType::BILLBOARD) DrawBillboardEntity(entity, cam, sun, point); else if (entity->m_VisualComponent->m_visualType == VisualType::TERRAIN) DrawTerrainEntity(entity, cam); } HR(m_swapChain->Present(0, 0)); Any help/advice would be much appreciated!

Direct2D fails when drawing a single-channel bitmap

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I'm an experienced programmer specialized in Computer Graphics, mainly using Direct3D 9.0c, OpenGL and general algorithms. Currently, I am evaluating Direct2D as rendering technology for a professional application dealing with medical image data. As for rendering, it is a x64 desktop application in windowed mode (not fullscreen).

Already with my very initial steps I struggle with a task I thought would be a no-brainer: Rendering a single-channel bitmap on screen.

Running on a Windows 8.1 machine, I create an ID2D1DeviceContext with a Direct3D swap chain buffer surface as render target. The swap chain is created from a HWND and buffer format DXGI_FORMAT_B8G8R8A8_UNORM. Note: See also the code snippets at the end.

Afterwards, I create a bitmap with pixel format DXGI_FORMAT_R8_UNORM and alpha mode D2d1_ALPHA_MODE_IGNORE. When calling DrawBitmap(...) on the device context, a debug break point is triggered with the debug message "D2d DEBUG ERROR - This operation is not compatible with the pixel format of the bitmap".

I know that this output is quite clear. Also, when changing the pixel format to DXGI_FORMAT_R8G8B8A8_UNORM with DXGI_ALPHA_MODE_IGNORE everything works well and I see the bitmap rendered. However, I simply cannot believe that! Graphics cards support single-channel textures ever since - every 3D graphics application can use them without thinking twice. This goes without speaking.

I tried to find anything here and at Google, without success. The only hint I could find was the MSDN Direct2D page with the (supported pixel formats). The documentation suggests - by not mentioning it - that DXGI_FORMAT_R8_UNORM is indeed not supported as bitmap format. I also find posts talking about alpha masks (using DXGI_FORMAT_A8_UNORM), but that's not what I'm after.

What am I missing that I can't convince Direct2D to create and draw a grayscale bitmap? Or is it really true that Direct2D doesn't support drawing of R8 or R16 bitmaps??

Any help is really appreciated as I don't know how to solve this. If I can't get this trivial basics to work, I think I'd have to stop digging deeper into Direct2D :-(.

And here is the code snippets of relevance. Please note that they might not compile since I ported this on the fly from my C++/CLI code to plain C++. Also, I threw away all error checking and other noise:

Device, Device Context and Swap Chain Creation (D3D and Direct2D):

// Direct2D factory creation
D2D1_FACTORY_OPTIONS options = {};
options.debugLevel = D2D1_DEBUG_LEVEL_INFORMATION;
ID2D1Factory1* d2dFactory;

// Direct3D device creation
const auto type = D3D_DRIVER_TYPE_HARDWARE;
const auto flags = D3D11_CREATE_DEVICE_BGRA_SUPPORT;
ID3D11Device* d3dDevice;
D3D11CreateDevice(nullptr, type, nullptr, flags, nullptr, 0, D3D11_SDK_VERSION, &d3dDevice, nullptr, nullptr);

// Direct2D device creation
IDXGIDevice* dxgiDevice;
d3dDevice->QueryInterface(__uuidof(IDXGIDevice), reinterpret_cast<void**>(&dxgiDevice));
ID2D1Device* d2dDevice;
d2dFactory->CreateDevice(dxgiDevice, &d2dDevice);

// Swap chain creation
DXGI_SWAP_CHAIN_DESC1 desc = {};
desc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
desc.SampleDesc.Count = 1;
desc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
desc.BufferCount = 2;

IDXGIFactory2* dxgiFactory;

IDXGISwapChain1* swapChain;
dxgiFactory->CreateSwapChainForHwnd(d3dDevice, hwnd, &swapChainDesc, nullptr, nullptr, &swapChain);

// Direct2D device context creation
const auto options = D2D1_DEVICE_CONTEXT_OPTIONS_NONE;
ID2D1DeviceContext* deviceContext;
d2dDevice->CreateDeviceContext(options, &deviceContext);

// create render target bitmap from swap chain
IDXGISurface* swapChainSurface;
swapChain->GetBuffer(0, __uuidof(swapChainSurface), reinterpret_cast<void **>(&swapChainSurface));
D2D1_BITMAP_PROPERTIES1 bitmapProperties;
bitmapProperties.dpiX = 0.0f;
bitmapProperties.dpiY = 0.0f;
bitmapProperties.bitmapOptions = D2D1_BITMAP_OPTIONS_TARGET | D2D1_BITMAP_OPTIONS_CANNOT_DRAW;
bitmapProperties.pixelFormat.format = DXGI_FORMAT_B8G8R8A8_UNORM;
bitmapProperties.pixelFormat.alphaMode = D2D1_ALPHA_MODE_IGNORE;
bitmapProperties.colorContext = nullptr;
ID2D1Bitmap1* swapChainBitmap = nullptr;
deviceContext->CreateBitmapFromDxgiSurface(swapChainSurface, &bitmapProperties, &swapChainBitmap);

// set swap chain bitmap as render target of D2D device context
deviceContext->SetTarget(swapChainBitmap);  

D2D single-channel Bitmap Creation:

const D2D1_SIZE_U size = { 512, 512 };
const UINT32 pitch = 512;
D2D1_BITMAP_PROPERTIES1 d2dProperties;
ZeroMemory(&d2dProperties, sizeof(D2D1_BITMAP_PROPERTIES1));
d2dProperties.pixelFormat.alphaMode = D2D1_ALPHA_MODE_IGNORE;
d2dProperties.pixelFormat.format = DXGI_FORMAT_R8_UNORM;
char* sourceData = new char[512*512];

ID2D1Bitmap1* d2dBitmap;
deviceContext->DeviceContextPointer->CreateBitmap(size, sourceData, pitch, d2dProperties, &d2dBitmap); 

Bitmap drawing (FAILING):

deviceContext->BeginDraw();
D2D1_COLOR_F d2dColor = {};
deviceContext->Clear(d2dColor);

// THIS LINE FAILS WITH THE DEBUG BREAKPOINT IF SINGLE CHANNELED
deviceContext->DrawBitmap(bitmap, nullptr, 1.0f, D2D1_INTERPOLATION_MODE_LINEAR, nullptr);

swapChain->Present(1, 0);
deviceContext->EndDraw();