eloraiby / delaunay Goto Github PK

in the function :
static int del_init_tri( delaunay_t del, int start )
I think this function is use for creating a initial triangle .
here is the code which confused me :
/
d0->next = d5;
d0->prev = d5;

	d1->next	= d3;
	d1->prev	= d3;

	d2->next	= d4;
	d2->prev	= d4;

	d3->next	= d1;
	d3->prev	= d1;

	d4->next	= d2;
	d4->prev	= d2;

	d5->next	= d0;
	d5->prev	= d0;

*/
why halfedge d0 has same next and prev and why it is d5?
I think it should be:
d0->next = d1;
d0->prev = d2;
d1->next = d2;
d1->prev = d0;
d2->next = d0;
d2->prev = d1;
where I am wrong?
thanks!

It would be good to give this code a version. This will make it easier for me to version the Python package accordingly.

Hi,
Can you add a function which will check if a point is lying outside the delaunay structure?
This will be useful when using this structure for interpolation.

Also, I am checking for below test, Result is not correct:

const int n = 100;
float x1[n1],y1[n1];
float x[n],y[n],value[n];
float point[2_n];
for( int i = 0; i < n1; ++i ) {x1[ i ] = y1[ i ] = i;}
for( int i = 0; i < n; ++i ){
x[ i ] = x1[ i / 10 ];
y[ i ] = y1[ i % 10 ];
}
int j = 0, k= 0;
for(int i=0;i<2_n;i++){
if(i%2 == 0) { point[i] = x[j]; j++;}
else { point[i] = y[k]; k++;}
}
int np = sizeof point/(2*sizeof(float));
delaunay2d(point,np);

[I checked no edge formation between (4,9) and (5.9)]
I guess U are missing case when points lie OnCircle in "del_valid_link" function.

My point cloud input seams to be far from degenerated but triangulation fails with "1: floating point precision error" assert. Please find dataset attached.
delanuay-in.txt

Hellow, I need a help to solve a problem using Del.Triang. Can you help me to write a small programm on C++ (QtCreator). At the entrance I have massive an array of points (2D coordinates), that must be triangulated. And output array of elemets.
(Student of second grade of Saint-Petersburg Polytechnic University)
In advance thank you.

Hi,
Delaunay technique is for making triangles from given points. Example Image posted by you in Readme.md shows squares instead of triangles, which clearly hints OnCircle point case is not taken.

I'm getting

delaunay.c:690: del_valid_left: Assertion `v != u && "1: floating point precision error"' failed.

when using FAST_PREDICATE or EXACT_PREDICATE and

delaunay.c:754: del_valid_right: Assertion `du->pair' failed.

when using LOOSE_PREDICATE.
Code was built with gcc (Debian 4.9.2-10) and -m32 switch with any of -O1, -O2, -O3.

Enabling SSE2 via -msse2 -mfpmath=sse seems to solve the problem. The failing test is here

Hello, I am using your library for a project I am doing and I get an error at line 868 when I build the project.
The error's message is:
"Error 1 error C2440: '=' : cannot convert from 'void *' to 'del_point2d_t *' "

I fixed it by changing line 868 from:
res->points = malloc(sizeof(del_point2d_t) * num_points);
to:
res->points = (del_point2d_t*)malloc(sizeof(del_point2d_t) * num_points);
and it seemed to work.
It's weird how no one else had this error before, so I am not sure if I did something wrong or not.
I am using Visual Studio 2012 on Windows 8 64bit.

Regards, Alex

Hi! I'm not sure that it is the issue, but did you tried to implement yours Divide and Conquer delaunay algorithm in java? It'll be very helpful for me. Thanks!

Thank your code.