Capture Framebuffer - Get result in shader?

[SpiderPig]

If I capture a screenshot with framebuffer->Capture(), is there a way I get the result within a shader without first getting it as a pixmap, then converting it to a texture, then giving it to a material?

if (window->KeyHit(KEY_SPACE)) framebuffer->Capture();

auto caps = framebuffer->GetCaptures();
for (auto pixmap : caps)
{
    auto path = GetPath(PATH_DESKTOP) + "/screenshot.jpg";
    pixmap->Save(path);
    RunFile(path);
}

Maybe something like this might be possible?

FRAGMENT SHADER

if (capture_result_handle != -1){
	vec4 capture_color = texture(capture_result_handle, frag_coords)
}

 

[Josh]

Can't you just use camera->SetRenderTarget to render to a texture?

[SpiderPig]

Not really, I want to capture a screen shot before I open my inventory and then use that result as a background for my inventory that will be blurred.  Like the window transparent effect in the editor.  It won't be real time but that's fine.  I'm just worried about spending the time waiting for the capture to be ready as a pixmap and then going through all the conversion and re-upload to the GPU when it's already there.

[Josh]

This would not be too difficult to do, if you just had a hook that got called in the right place...

[SpiderPig]

You mean like a render hook that displayed the inventory when the capture was ready for the inventory shader to use?

[SpiderPig]

Is this something I can do now or are you needing to implement something for it to work?

[Josh]

This would require changes to the engine.

[SpiderPig]

Ah okay.  No problem

[klepto2]

Just an idea, you can use 2 cameras for this. 

1. the normal realtime camera

2. a non realtime camera where you set the rendertarget to a new TextureBuffer. 

to the second camera you you attach the blur posteffect and assign the colorbuffer from the first (original) framebuffer via SetUnifrom("color", fb->GetColorAttachment(0)).

whenever you open the inventory, you render the second camera once and the Texturebuffer of the second camera will have the processed blurred image. This could be extended to also work in realtime. as the 2nd camera can be using a complete empty world or a comeplere unique renderlayer, so no processing power is lost.

[SpiderPig]

This sounds like a good idea!  Especially if it could be done real time.  I'll see if I can get it working.  Thanks!

[SpiderPig]

I don't think the framebuffer has a GetColorAttachment method

[SpiderPig]

But the camera rendering once with the blur post effect does work.