Writing color and depth in GLSL 1.40

[ijc12]

Hi

I’m trying to write to both a color and depth buffer in a fragment shader where both are bound to a FBO.
Color is bound as a color attachment, and depth as a depth attachment.

In older GLSL versions you would use:

gl_FragData[0] = colordata;
gl_FragDepth = depthdata;

But in GLSL 1.40 gl_FragData is depreciated and you need a user defined out variable for color buffers. However when I use this I get the linker error: “built-in and user-defined fragment shader outputs may not be used at the same time”.

Looking trough the GLSL 1.40 documentation it doesn’t seem like gl_FragDepth has been depreciated, so in order to write depth I have (?) to use a built-in shader output, which apparently is not going to work when a user defined output is also used.

Does anyone know how to do this correctly in GLSL 1.40, or is the NVIDIA linker at fault?

Thanks

[Alfonse_Reinheart]

It’d help if we could see your fragment shader code.

[ijc12]

The code isn’t that interesting, I’m just trying to write both a color value and a depth value in a single pass, which in GLSL < 1.30 would be something like:

void main()
{		
	float depth;
	vec4 someData;
	
	gl_FragData[0] = someData;
	gl_FragDepth = depth;
}

and in GLSL >= 1.30

out vec4 fragData;

void main()
{		
	float depth;
	vec4 someData;
	
	fragData = someData;
	gl_FragDepth = depth;
}

However it doesn’t allow me to run the second example because of the linker error. So I was wondering if maybe you should use a user defined out variable for depth as well, or if there is a problem with the linker.

I just noticed OpenGL 3.2 is already out (I was using 3.1) so I installed that to see if it would fix things, but now I’m getting a ton more depreciation errors in my shaders, which would work perfectly fine in 3.1, arg .

I’m at the point were I think maybe I should fully upgrade all my stuff to the new standards (which is going to be some work) instead of this mixed compatibility mode I am using now, but I’m not really sure of the benefits. Seems to me your going to have to emulate a lot of stuff in your own code that OpenGL used to do for you in the past

[Brolingstanz]

OpenGL 3.2 + GLSL 1.5 core is peaches and cream.

[Ilian_Dinev]

Works for me on:
GL3.1 + glsl #version 140
GL3.2 + glsl #version 150
GL3.2 + glsl #version 150 core

190.57 drivers, haven’t tried .58 yet

[ijc12]

After upgrading to opengl 3.2 (while also converting everything to forward compatibility mode) the shader now runs correctly. So it seems like it was a linker bug in the nvidia opengl 3.1 drivers.