Shaders development.

Shaders are really important part of any graphics engine and usually a lot of work is invested into them. But shaders creation pipelines proposed by NVidia and ATI lacks one core ability - they have nothing in common with real engine shaders. You can prototype a shader to some extent using FXComposer or Render Monkey. But when it comes to engine integration - you still modify them by hands and blindly run, hoping for the best.

If your engine has run time editor with "What You See Is What You Play" ability - you already has a good platform for shaders development. And the simplest form of assisting is viewing of render targets contents (which can be achieved by using NVPerfHUD for example). But to make it more interesting than just overlay rendering I've tried the following:

So basically I've attached texture exploration interface (you already need it for texture compression) to renderer outputs. In drop-down list you can select all render targets that renderer internally exposes through it's interface. This interface might look like:

virtual uint Debug_GetNumRenderOutputs() const;
virtual const wchar_t* Debug_GetRenderOutputName(uint index) const;
virtual const ITexture* Debug_RegisterForRenderOutput(const wchar_t* renderOutput);
virtual void Debug_UnregisterForRenderOutput(const wchar_t* renderOutput);

When someones registers for render output, renderer begins to capture render targets contents. Internally it looks like:

void RegisterRenderOutput(const wchar_t* name, ITexture* pTexture);
void RegisterRenderOutput(const wchar_t* name, IDirect3DSurface9* pSurface);

This methods are called in some places through renderer, which checks if render output is registered for capturing. After that it copies RT contents to already created texture, returned in method Debug_RegisterForRenderOutput(). This texture is then displayed by texture exploration UI.

In this way developer can access any render target exposed by renderer, which gets updated in real time. Combined with ability to reload shaders this will create simple and powerful shaders development pipeline.