Define a function in point wrangle

[AntoineSfx]

How do you define a VEX function in a pointwrangle node ?

 

Using this:

int[]
myfunc(
int input,
int ptnum)
{ int  result[];
   return result;
}

Houdini complains about a syntax error at myfunc. What is the correct syntax, and where is it documented ?

[fencer]

myfunc(int input; int ptnum)

[coltonmil]

Hey Antoine,

Reference for VEX in general and the syntax for defining functions can be found here:

http://www.sidefx.com/docs/houdini/vex/lang

 

[AntoineSfx]

So this was an error (; instead of ,) but I still can't get this to compile, because of the array type as return type:

int [] myfunc(int input; int ptnum)
{ int  result[];
   return result;
}

 

[fencer]

13 minutes ago, AntoineSfx said:

So this was an error (; instead of ,) but I still can't get this to compile, because of the array type as return type:

int [] myfunc(int input; int ptnum)
{ int  result[];
   return result;
}

 

not sure that vex allows return array

[AntoineSfx]

37 minutes ago, fencer said:

not sure that vex allows return array

actually ..  a lot a functions do that. I need a more powerful version of neighbours, hence the question in the first place.

[Sepu]

If you are looking for something faster you might want to look at 
 

http://www.sidefx.com/docs/houdini/vex/functions/pgfind.html or pcfind

[julian johnson]

function int[] test()
{
        int result[] = {1,2,3};
        return result;
};

i[]@test = test();

I get syntax errors using the 'normal' array syntax in the documentation i.e. a simple int[] test(){}; but if you disambiguate using the 'function' syntax it seems to work..

[AntoineSfx]

On 27/01/2018 at 8:39 AM, julian johnson said:

function int[] test()
{
        int result[] = {1,2,3};
        return result;
};

i[]@test = test();

I get syntax errors using the 'normal' array syntax in the documentation i.e. a simple int[] test(){}; but if you disambiguate using the 'function' syntax it seems to work..

This solves my problem. May I ask where you have found this ? Is there a BNF for VEX ?

Edited January 28, 2018 by AntoineSfx

[julian johnson]

I found this in the documentation:

http://www.sidefx.com/docs/houdini/vex/arrays.html

Not sure what a BNR is :-)

[AntoineSfx]

3 hours ago, julian johnson said:

I found this in the documentation:

http://www.sidefx.com/docs/houdini/vex/arrays.html

Not sure what a BNR is :-)

ok. Typo.. I meant BNF, the formal definition of the language (Backus normal form)

Also, the use case of the keyword function is for nested functions.

So I assume the whole VEX block is really run inside a parallel for loop over prim / points ..

Edited January 28, 2018 by AntoineSfx

[julian johnson]

//
// VEX Code Generated by Houdini 16.5.268
// Date: Sun Jan 28 16:23:25 2018
// File: C:/Users/johnson/untitled
// Node: /obj/geo1/attribwrangle2/attribvop1
//

#ifndef VOP_OP
#define VOP_OP
#endif
#ifndef VOP_CVEX
#define VOP_CVEX
#endif

#pragma opname attribvop1
#pragma oplabel "Local Vop Code"
#pragma opmininputs 1
#pragma opmaxinputs 1


#include <math.h>
void 
_obj_geo1_attribwrangle2_attribvop1_snippet1(int _bound_test[])
{
    
    function int[] test()
    {
            int result[] = {1,2,3};
            return result;
    };
    
    _bound_test = test();
    
}

cvex
obj_geo1_attribwrangle2_attribvop1(export int test[] = {})
{
    
    // Code produced by: snippet1
    _obj_geo1_attribwrangle2_attribvop1_snippet1(test);
}

 

Looks like a nested function when you expand the inner VOP node to VEX...