Multiple fragment shader outputs

[Kartoffelsaft]

As part of a project I'm working on it'd be very useful for one of my shader programs to be able to output more data than just color/alpha (in this case, I want to output the depth information, but I can foresee myself also wanting to output other data such as whether a fragment is in shade etc.). From searching around, it seems that the way to do this with OpenGL is either to use gl_FragData if you are on earlier versions or layout(...) out vec4 out_data; on later versions (source). However, if I were to add this to the shader code bgfx doesn't seem to have any way of saying what framebuffer it goes to.

So, what I'm wondering is whether this functionality exists, and if not, why not?

[pezcode]

You need to add multiple attachments to a framebuffer, not use multiple framebuffers. Check out the deferred example:

bgfx/examples/21-deferred/deferred.cpp

Line 522 in ed037a7

bgfx::Attachment gbufferAt[3];

https://github.com/bkaradzic/bgfx/blob/master/examples/21-deferred/fs_deferred_geom.sc#L29