GLSL compiler error

Gaming and Visualization Technologies APIs OpenGL
1

I get the strangest error when trying to compile the following code:

void pack_u16(in float depth, out float byte_a, out float byte_b)
{        
    float tmp = depth / 256.0f;
    byte_a = floor(tmp) / 256.0f;
    byte_b = frac(tmp);
    
}

float unpack_u16(in float byte_a, in float byte_b)
{
    return ((byte_a * 256.0f) * 256.0f) + (byte_b * 256.0f);
}

void pack_16bit_normal_component(in float n, out float byte_a, out float byte_b)
{
    n = ((n * 0.5f) + 0.5f) * 65535.0f;

    pack_u16(n, byte_a, byte_b);
}

float unpack_16bit_normal_component(in float byte_a, in float byte_b)
{
    return ((unpack_u16(byte_a, byte_b) / 65535.0f) - 0.5f) * 2.0f;
}

vec4 pack_normalxy_into_rgba8(float normal1, float normal2)
{
    vec4 ret;
    pack_16bit_normal_component(normal1, ret.x, ret.y);
    pack_16bit_normal_component(normal2, ret.z, ret.w);
    return ret;
}

vec4 unpack_normalxy_from_rgba8(vec4 packed)
{
    return vec4(  unpack_16bit_normal_component(packed.x, packed.y),
                    unpack_16bit_normal_component(packed.z, packed.w),
                    0.0f,
                    0.0f);
}

The error I get is:

0(297) : error C1012: abstract parameters not allowed in function definition “unpack_normalxy_from_rgba8”

I’ve tried to figure out what an abstract parameter even means, but I assume it suggests ‘vec4’ is not defined in the context? I’m using 64-bit W7 with a GTX 690 driver version 320.18.

It works perfectly fine on my other ATI card.

Thanks in advance.

2

Solved it!

It turned out you cannot use variables with name ‘packed’. The compiler doesn’t complain about it being a reserved keyword, however it fails to compile with

C0000: syntax error, unexpected ‘.’ expecting ‘::’ at token ‘.’.

I did a find and replaced on packed and it worked out just fine. The function was actually:

vec4 PackObjectDepth(in float ObjectId, in float NormalGroupId, in float depth)
{    
    vec4 packed;
    packed.x = ObjectId;
    packed.y = NormalGroupId;
    // we packedto multiply the depth by a factor, otherwise we would have a raster on small distances
    // normal minimal raster is 1 / 255 (0.00392)
    depth = depth * depthScale;
    pack_u16(depth, packed.z, packed.w);
    return packed;
}
3

ARE YOU SERIOUS NVIDIA ??
It’s been more than 15 years now and this is still actual ?? This makes no sense. I banged my head on the wall because of this compilation error only to eventually find someone that worked around this nonsense by themselves.

At least add a warning

4

Nvidia are not responsible for the opengl standard treating packed as a storage qualifier to influence struct alignment.