ocmath_mesh_in_polygon

1 Description
2 Syntax
3 Parameters
4 Return
5 Examples
6 Remark
7 See Also
8 header to Include
9 Reference

Description

The function generates a triangular mesh of a closed polygonal region.

Syntax

int ocmath_mesh_in_polygon( int nVertices, const double * pxVertices, const double * pyVertices, int nEdgePts, int * nMeshPts, double * pxMesh, double * pyMesh )

Parameters

nVertices: [input] the number of vertices in the input boundary.
pxVertices: [input] the X coordinates in the input boundary.
pyVertices: [input] the Y coordinates in the input boundary.
nEdgePts: [input] how many points are interpolated in the boundary; more boundary points, finer the mesh.
nMeshPts: [modify] on input, the size of pxMesh and pyMesh buffer; on output, the total number of mesh points.
pxMesh: [output] the buffer to receive X coordinates of mesh, the initial size is nMeshPts.
pyMesh: [output] the buffer to receive Y coordinates of mesh, the initial size is nMeshPts.

Return

OE_NOERROR = 0 Succeed.

OE_SIZE_LT = -1 nEdgePts is smaller than *nMeshPts, or nEdgePts is too small to generate interior points.

OE_NULL_POINTER = -11 pxVertices, pyVertices, pxMesh, or pyMesh must not be NULL.

NE_MESH_ERROR = 2099 Inccorrect boundary input, or nMeshPts is not large enough.

Examples

EX1

#include <wks2mat.h>
#define MAX_MESH_PTS    2000
int ocmath_mesh_in_polygon_ex1(int nEdgePts = 100, double dSmooth = 0.02)
{    
    int iRet;
    // Step1. Generating mesh in the given polygon.
    // Assume there is worksheet named "Boundary", which contains boundary data.
    vector vxMesh, vyMesh;
    int nvmax = MAX_MESH_PTS;
    
    Worksheet wksBd("Boundary");
    Dataset dsX(wksBd, 0);
    Dataset dsY(wksBd, 1);
    vector vxVertices(dsX), vyVertices(dsY);
    int nvb = vxVertices.GetSize();
    
    vxMesh.SetSize(nvmax);
    vyMesh.SetSize(nvmax);
    iRet = ocmath_mesh_in_polygon(nvb, vxVertices, vyVertices, nEdgePts, &nvmax, vxMesh, vyMesh);
    if (OE_NOERROR != iRet)
    {
        printf("Error occurs when calling nag mesh funcion!\n");
        return -1;
    }
    vxMesh.SetSize(nvmax);
    vyMesh.SetSize(nvmax);
    
    // Step2. Gridding XYZ triplets on the generated mesh by using TPS method.
    // Assume that XYZ triplets are contained in the active layer.
    vector vX, vY, vZ;
    Worksheet wks = Project.ActiveLayer();
    Dataset ds1(wks, 0), ds2(wks, 1), ds3(wks, 2);
    vX=ds1; vY=ds2; vZ=ds3;
    
    ocmath_strTPS strTPS;
    double dReg;
    vector vzMesh(nvmax);
    iRet = ocmath_tps_fit(vX.GetSize(), vX, vY, vZ, dSmooth, &strTPS, &dReg);
    if( iRet == OE_NOERROR )
    {
        iRet = ocmath_tps_eval(nvmax, vxMesh, vyMesh, vzMesh, &strTPS);
    }
    ocmath_tps_free(&strTPS);
    
    // Step3. Put result data to a new worksheet
    Worksheet wksResult;
    wksResult.Create();
    wksResult.SetSize(-1,3);
    Dataset d1(wksResult,0), d2(wksResult,1), d3(wksResult,2);
    d1 = vxMesh;
    d2 = vyMesh;
    d3 = vzMesh;

    return iRet;
}