Isosurfaces from 3D functions
computing triangulated isosurfaces of a given function f(x,y,z).
Using the gts_isosurface_cartesian() function, it is possible to build a triangulated isosurface of a given user-defined function. As its name indicates this function assumes that the values of the user-defined function are defined for points located on a regular cartesian grid described by the #GtsCartesianGrid parameter. The triangles describing the isosurface are computed for each pair of successive planes z and z+dz in a pipelined manner. Consequently only two planes need to be stored in memory at any time. This allows to construct isosurfaces for datasets too large to fit in main memory.
A regular cartesian grid is defined by the number of points in each direction, the spatial increment in each direction and the coordinates of the first point.
@nx: Number of points in direction x.
@ny: Number of points in direction y.
@nz: Number of points in direction z.
@x: x coordinate of the first point.
@dx: Increment in direction x.
@y: y coordinate of the first point.
@dy: Increment in direction y.
@z: z coordinate of the first point.
@dz: Increment in direction z.
@p:
@nx:
@ny:
@nx:
@ny:
@Returns:
@g:
A GtsIsoSlice is an opaque data structure containing the coordinates of the points located on the isosurface for a given slice of the user-defined function.
@nx:
@ny:
@Returns:
@slice:
@plane1:
@plane2:
@f1:
@f2:
@iso:
@klass:
@slice:
@g:
@f1:
@f2:
@iso:
@klass:
@slice:
@slice1:
@slice2:
@surface:
This user-defined function is passed to the gts_isosurface_cartesian()
function. Given a particular #GtsCartesianGrid @g it must fill the array @a
with the values of the function for the plane z=@g.z (or for the corresponding
index @i). This function is always called in order by gts_isosurface_cartesian(), i.e. @i varies from 0 to @g.nz - 1 with an increment of one (and similarly @g.z is incremented every time by @g.dz).
@a: the 2D array to be filled.
@g: a #GtsCartesianGrid.
@i: the z direction index of the plane to be filled.
@data: user data.
@surface:
@g:
@f:
@data:
@iso:
@surface:
@g:
@f:
@data:
@iso:
@surface:
@g:
@f:
@data:
@iso:
@surface:
@g:
@f:
@data:
@iso: