can i write glsl code in .cg/.cgfx file?

[yaoyansi]

hi, all
I see the following code in Cg Refercence Manual -> cg Profile -> glslv :
glslv void main(float4 position : POSITION,
out float4 opos : POSITION)
{
opos = mul(gl_ModelViewMatrix, position);
}


My question is, does it mean that I can wirte glsl code in .cg/.cgfx file?

Then I write the following code in my .cgfx file:
glslv void main(
uniform float pointRadius,
uniform float pointScale,
uniform vec4 eyePos
)
{
vec4 wpos = vec4(gl_Vertex.xyz, 1.0);
gl_Position = gl_ModelViewProjectionMatrix * wpos;

// calculate window-space point size
vec4 eyeSpacePos = gl_ModelViewMatrix * wpos;
float dist = length(eyeSpacePos.xyz);
gl_PointSize = pointRadius * (pointScale / dist);

gl_TexCoord[0] = gl_MultiTexCoord0;
gl_TexCoord[1] = eyeSpacePos;

gl_FrontColor = gl_Color;
}

But there are serveal errors when i compile this code in FxComposer.
Error error C5059 stdlib "gl_" variables are not accessible
Error error C5059 stdlib "gl_" variables are not accessible


It seems that the variables which contain prefix "gl_" are not recognised by the compiler.

so, can I wirte glsl code in .cg/.cgfx file?

Thank you.

[CortS]

I don't know about mixing GLSL and Cg/CgFX, though it certainly seems like it's possible if the compiler isn't throwing a huge fit.

However, the error messages you're seeing may be unrelated. Most of the built-in gl_* variables (including the ones you're using in the sample above) are now deprecated as of GLSL 1.30. FxComposer may be adhering to a more recent version of the GLSL standard, in which case the use of those variables is indeed an error. All GL state variables (e.g. gl_ModelViewMatrix) must now be explicitly declared passed in as normal uniform variables, and all vertex attributes (e.g. gl_Vertex, gl_MultiTexCoord0) must be explicitly mapped using glBindAttribLocation() and friends.

Alternatively, there may be some way to force FxComposer into compatibility mode...

[Dark Photon]

I see the following code in Cg Refercence Manual -> cg Profile -> glslv ...

My question is, does it mean that I can [write] glsl code in .cg/.cgfx file?

Check out this post by Ilian Dinev. This speaks to using GLSL in Cg, and gives examples. Also potentially useful: this

But there are [several] errors when i compile this code in FxComposer. ... It seems that the variables which contain prefix "gl_" are not [recognized] by the compiler.

They work for me, cross-compiling GLSL to asm for checking dead code elimination and such. Try a command-line like this:

cgc -oglsl -strict -glslWerror -profile gpu_vp vert.glsl
cgc -oglsl -strict -glslWerror -profile gpu_fp frag.glsl