Direct2D performance

Question

So, I've been working on a project for a while now in DirectX11, but some people have been suggesting that I should be doing it in Direct2D. So, I've been playing with the idea in my project. What I've ended up with is HORRIFIC performance. Is Direct2D intended for use with hundreds of thousands of verteces? Because that's what I'm using.

Answer 1

Direct2D gives you a simple to use API to draw high quality 2d graphics, but it comes at a cost in performance compared to some fine tuned dx11 rendering.

Here is a primitive cost per draw for reference

• FillRoundedRectangle (1 pixel corner) : 96
• DrawRoundedRectancle: 264
• FillRectangle : 6
• DrawRectangle : 190
• FillEllipse : 204
• DrawEllipse : 204
• Line (whatever vertical/size...) : 46
• Bezier : from 312 -> 620

Direct2d is built on a feature level 10 device, and builds vertices in an internal buffer (only case where it uses instancing is to draw text).

So if you need to batch primitives an instanced drawer can yield a pretty hefty performance gain (as personal example, my timeline keyframe rendering went down from 15ms to 2ms swapping the draws from d2d to custom dx11 instanced shader).

If you are on windows 8, you can easily mix direct2d and direct3d in the same "viewport", so it can be worth a look (in my use case I use dx11 and structured buffers based instancing for all heavy parts, and swap to a direct2d context for text and other small bits).

If you need to draw custom geometry (specially with a reasonably high polygon count),it's best to stick to Direct3D11,since it's totally designed for it.