Geometry Boost List: [ggl] spacial index construction interface

Subject: [ggl] spacial index construction interface
From: Barend Gehrels (barend)
Date: 2011-02-23 06:22:10

Hi Adam,

I will answer in fragments.

> I've added test visualizing the rtree using GLUT, but only to the 
> https://svn.boost.org/svn/boost/sandbox-branches/geometry/index_080_nhch/ 
> branch. To run it you'll neeed e.g. this: 
> http://www.opengl.org/resources/libraries/glut/glutdlls37beta.zip.

Just had a look there.

First this is quite cool! ;-)

Second the BOOST_GEOMETRY_INDEX_RTREE_ENABLE_GL_DRAW define makes the 
rtree a bit messy. Can you extract that somehow? I understand why it is 
there now, because it calls itself recursively, but that might be solved 
otherwise.

Third, hmm, I thought it would be nice to demonstrate the combination of 
Boost.Geometry with GL as it is done with Qt
<http://barendgehrels.blogspot.com/2011/02/qt-world-mapper-with-boostgeometry.html>

Meaning to convert a Boost.Geometry point automatically to a GL-point like

BOOST_GEOMETRY_REGISTER_POINT_2D_GET_SET(QPointF,double, cs::cartesian, x, y, setX, setY)

But in GL no point concepts but just c-arrays are used. Bruno once 
created an adaption headerfile for them. Using them can draw a box like 
this:

GLfloat ll[2], lr[2], ul[2], ur[2];
geometry::assign_box_corners(it->first, ll, lr, ul, ur);

glBegin(GL_LINE_LOOP);
glVertex2fv(ll);
glVertex2fv(lr);
glVertex2fv(ur);
glVertex2fv(ul);
glEnd();

Not exactly better but just shorter and maybe nicer. Or alternatively it 
can be used in a gl rectangle drawing routine.

Would be nice for the examples too (like Qt - glut worldmapper). Anyway 
this whole point is not related to the spatial index at all so do with 
it what you like.

Regards, Barend

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