Point Order

[jhiggins]

I'm trying to iterate over my points in the same way that houdini would.

so, i have a grid where I get the point list via

GEO_PointList points = getOutputGDP()->points();

And i can get my grid resolution via

GEO_Primitive* source_prim = getOutputGDP()->primitives()(0);

GEO_Hull* hull_surf = (GEO_Hull*)source_prim;

int resx = hull_surf->getNumRows();

int resy = hull_surf->getNumCols();

now its up to me to iterate the points via

for ( int y = 0; y < resy; y++)

{

for ( int x = 0; x < resx; x++)

{

int index = x + resx *y;

....

}

}

but this assumes that the data is ordered this way, and there are

3 other permutations to consider.

which way do I access my point data?

the reason why i'm accessing the array this way is so that I can

easily compare data from neighbouring points.

Is there a better way?

jeff

[George]

Hi Jeff,

Have you considered iterating through the hull itself? Each vertex on the hull can be indexed using row/column and then from the vertex you can grab the GEO_Point that is associated with it. You never have to know the index of the point. For example:

for (r = 0; r < hull->getNumRows(); r++)
{
   for (c = 0; c < hull->getNumCols(); c++)
   {
        const GEO_Point *pt = hull->getVertex(r, c).getPt();
       // ...
   }
}

This way to access neighbouring points, its easy, to just change the index of the vertices.

Hope that helps,

George.

[jhiggins]

Hi Jeff,

Have you considered iterating through the hull itself?  Each vertex on the hull can be indexed using row/column and then from the vertex you can grab the GEO_Point that is associated with it.  You never have to know the index of the point.  For example:

for (r = 0; r < hull->getNumRows(); r++)
{
   for (c = 0; c < hull->getNumCols(); c++)
   {
        const GEO_Point *pt = hull->getVertex(r, c).getPt();
       // ...
   }
}

This way to access neighbouring points, its easy, to just change the index of the vertices.

Hope that helps,

George.

20764[/snapback]

beautifull!!!

thats exactly what i needed

thanks George,

jeff