Hi Rudi,
hau dir das in dein Header und dann hast Du Zugriff auf alle Informationen und Rechenwege:
#ifndef _SPLINE_H
#define _SPLINE_H
#define DIV_FACTOR 4 //adjust this factor to adjust the curve smoothness
class Curve
{
public:
float Ax,Ay;
float Bx,By;
float Cx,Cy;
int Ndiv;
Curve(float ax,float ay,float bx,float by,float cx,float cy,int ndiv)
{
Ax = ax;
Ay = ay;
Bx = bx;
By = by;
Cx = cx;
Cy = cy;
Ndiv = ndiv;
}
Curve(float ax,float ay,float bx,float by,float cx,float cy)
{
Ax = ax;
Ay = ay;
Bx = bx;
By = by;
Cx = cx;
Cy = cy;
Ndiv = (int)(max(abs((int)Ax),abs((int)Ay))/DIV_FACTOR);
}
Curve()
{
};
void PutCurve(float ax,float ay,float bx,float by,float cx,float cy)
{
Ax = ax;
Ay = ay;
Bx = bx;
By = by;
Cx = cx;
Cy = cy;
Ndiv = (int)(max(abs((int)Ax),abs((int)Ay))/DIV_FACTOR);
}
void draw(HDC hdc,float x,float y)
{
int OrigX,OrigY,NewX,NewY;
float t,f,g,h;
if (Ndiv==0)
Ndiv=1;
OrigX = (int)x;
OrigY= (int)y;
for(register WORD i=1; i<=Ndiv ; i++)
{
t = 1.0f / (float)Ndiv * (float)i;
f = t*t*(3.0f-2.0f*t);
g = t*(t-1.0f)*(t-1.0f);
h = t*t*(t-1.0f);
NewX = (int)(x + Ax*f + Bx*g + Cx*h);
NewY = (int)(y + Ay*f + By*g + Cy*h);
MoveToEx(hdc, OrigX, OrigY, NULL);
LineTo(hdc, NewX, NewY);
OrigX = NewX;
OrigY=NewY;
}
}
int GetCount()
{
if (Ndiv==0)
Ndiv=1;
int PointCount = 1;
for(register WORD i=1; i<=Ndiv ; i++)
{
PointCount++;
}
return PointCount;
}
void GetCurve(float x,float y, POINT points[], int& PointCount)
{
int X,Y;
float t,f,g,h;
if (Ndiv==0)
Ndiv=1;
X = (int)x;
Y= (int)y;
points[PointCount].x = X;
points[PointCount].y = Y;
PointCount++;
for(register WORD i=1; i<=Ndiv ; i++)
{
t = 1.0f / (float)Ndiv * (float)i;
f = t*t*(3.0f-2.0f*t);
g = t*(t-1.0f)*(t-1.0f);
h = t*t*(t-1.0f);
X = (int)(x + Ax*f + Bx*g + Cx*h);
Y = (int)(y + Ay*f + By*g + Cy*h);
points[PointCount].x = X;
points[PointCount].y = Y;
PointCount++;
}
}
};
class Spline
{
public:
float* Px;
float* Py;
float* Ax;
float* Ay;
float* Bx;
float* By;
float* Cx;
float* Cy;
float* k;
float* Mat[3];
WORD NP;
// constructor
Spline(POINT pt[], WORD np)
{
NP = np;
Px = new float[NP];
Py = new float[NP];
Ax = new float[NP];
Ay = new float[NP];
Bx = new float[NP];
By = new float[NP];
Cx = new float[NP];
Cy = new float[NP];
k = new float[NP];
Mat[0] = new float[NP];
Mat[1] = new float[NP];
Mat[2] = new float[NP];
for(register WORD i=0;i<NP ;i++)
{
Px[i] = (float)pt[i].x;
Py[i] = (float)pt[i].y;
}
}
Spline(float px[] , float py[] , int np)
{
NP = np;
Px = new float[NP];
Py = new float[NP];
Ax = new float[NP];
Ay = new float[NP];
Bx = new float[NP];
By = new float[NP];
Cx = new float[NP];
Cy = new float[NP];
k = new float[NP];
Mat[0] = new float[NP];
Mat[1] = new float[NP];
Mat[2] = new float[NP];
for(register WORD i=0;i<NP ;i++)
{
Px[i] = px[i];
Py[i] = py[i];
}
}
~Spline()
{
delete[] Px;
delete[] Py;
delete[] Ax;
delete[] Ay;
delete[] Bx;
delete[] By;
delete[] Cx;
delete[] Cy;
delete[] k;
delete[] Mat[0];
delete[] Mat[1];
delete[] Mat[2];
}
void Generate()
{
float AMag , AMagOld;
// vector A
for(register WORD i=0 ; i<=NP-2 ; i++ )
{
Ax[i] = Px[i+1] - Px[i];
Ay[i] = Py[i+1] - Py[i];
}
// k
AMagOld = (float)sqrt(Ax[0]*Ax[0] + Ay[0]*Ay[0]);
for(register WORD i=0 ; i<=NP-3 ; i++)
{
AMag = (float)sqrt(Ax[i+1]*Ax[i+1] + Ay[i+1]*Ay[i+1]);
k[i] = AMagOld / AMag;
AMagOld = AMag;
}
k[NP-2] = 1.0f;
// Matrix
for(register WORD i=1; i<=NP-2;i++)
{
Mat[0][i] = 1.0f;
Mat[1][i] = 2.0f*k[i-1]*(1.0f + k[i-1]);
Mat[2][i] = k[i-1]*k[i-1]*k[i];
}
Mat[1][0] = 2.0f;
Mat[2][0] = k[0];
Mat[0][NP-1] = 1.0f;
Mat[1][NP-1] = 2.0f*k[NP-2];
//
for(register WORD i=1; i<=NP-2;i++)
{
Bx[i] = 3.0f*(Ax[i-1] + k[i-1]*k[i-1]*Ax[i]);
By[i] = 3.0f*(Ay[i-1] + k[i-1]*k[i-1]*Ay[i]);
}
Bx[0] = 3.0f*Ax[0];
By[0] = 3.0f*Ay[0];
Bx[NP-1] = 3.0f*Ax[NP-2];
By[NP-1] = 3.0f*Ay[NP-2];
//
MatrixSolve(Bx);
MatrixSolve(By);
for(register WORD i=0 ; i<=NP-2 ; i++ )
{
Cx[i] = k[i]*Bx[i+1];
Cy[i] = k[i]*By[i+1];
}
}
void MatrixSolve(float B[])
{
float* Work = new float[NP];
float* WorkB = new float[NP];
for(register WORD i=0;i<=NP-1;i++)
{
Work[i] = B[i] / Mat[1][i];
WorkB[i] = Work[i];
}
for(register WORD j=0 ; j<10 ; j++)
{ /// need convergence judge
Work[0] = (B[0] - Mat[2][0]*WorkB[1])/Mat[1][0];
for(register WORD i=1; i<NP-1 ; i++ )
{
Work[i] = (B[i]-Mat[0][i]*WorkB[i-1]-Mat[2][i]*WorkB[i+1])
/Mat[1][i];
}
Work[NP-1] = (B[NP-1] - Mat[0][NP-1]*WorkB[NP-2])/Mat[1][NP-1];
for(register WORD i=0 ; i<=NP-1 ; i++ )
{
WorkB[i] = Work[i];
}
}
for(register WORD i=0 ; i<=NP-1 ; i++ )
{
B[i] = Work[i];
}
delete[] Work;
delete[] WorkB;
}
void draw(HDC hdc)
{
Curve c;
for(register WORD i=0; i<NP-1 ; i++)
{
c.PutCurve(Ax[i],Ay[i],Bx[i],By[i],Cx[i],Cy[i]);
c.draw(hdc,Px[i],Py[i]);
}
}
int GetCurveCount()
{
Curve c;
int count = 0;
for(register WORD i=0; i<NP-1 ; i++)
{
c.PutCurve(Ax[i],Ay[i],Bx[i],By[i],Cx[i],Cy[i]);
count += c.GetCount();
}
return count;
}
void GetCurve(POINT points[], int& PointCount)
{
Curve c;
for(WORD i=0; i<NP-1 ; i++)
{
c.PutCurve(Ax[i],Ay[i],Bx[i],By[i],Cx[i],Cy[i]);
c.GetCurve(Px[i],Py[i], points, PointCount);
}
}
//////////// closed cubic spline ////////////////////
void GenClosed()
{
float AMag , AMagOld , AMag0;
// vector A
for(register WORD i= 0 ; i<=NP-2 ; i++ )
{
Ax[i] = Px[i+1] - Px[i];
Ay[i] = Py[i+1] - Py[i];
}
Ax[NP-1] = Px[0] - Px[NP-1];
Ay[NP-1] = Py[0] - Py[NP-1];
// k
AMag0 = AMagOld = (float)sqrt(Ax[0]*Ax[0] + Ay[0]*Ay[0]);
for(register WORD i=0 ; i<=NP-2 ; i++)
{
AMag = (float)sqrt(Ax[i+1]*Ax[i+1] + Ay[i+1]*Ay[i+1]);
k[i] = AMagOld / AMag;
AMagOld = AMag;
}
k[NP-1]=AMagOld/AMag0;
// Matrix
for(register WORD i=1; i<=NP-1;i++)
{
Mat[0][i] = 1.0f;
Mat[1][1] = 2.0f*k[i-1]*(1.0f + k[i-1]);
Mat[2][i] = k[i-1]*k[i-1]*k[i];
}
Mat[0][0] = 1.0f;
Mat[1][0] = 2.0f*k[NP-1]*(1.0f + k[NP-1]);
Mat[2][0] = k[NP-1]*k[NP-1]*k[0];
//
for(register WORD i=1; i<=NP-1;i++)
{
Bx[i] = 3.0f*(Ax[i-1] + k[i-1]*k[i-1]*Ax[i]);
By[i] = 3.0f*(Ay[i-1] + k[i-1]*k[i-1]*Ay[i]);
}
Bx[0] = 3.0f*(Ax[NP-1] + k[NP-1]*k[NP-1]*Ax[0]);
By[0] = 3.0f*(Ay[NP-1] + k[NP-1]*k[NP-1]*Ay[0]);
//
MatrixSolveEX(Bx);
MatrixSolveEX(By);
for(register WORD i=0 ; i<=NP-2 ; i++ )
{
Cx[i] = k[i]*Bx[i+1];
Cy[i] = k[i]*By[i+1];
}
Cx[NP-1] = k[NP-1]*Bx[0];
Cy[NP-1] = k[NP-1]*By[0];
}
///// tridiagonal matrix + elements of [0][0], [N-1][N-1] ////
void MatrixSolveEX(float B[])
{
float* Work = new float[NP];
float* WorkB = new float[NP];
for(register WORD i=0;i<=NP-1;i++)
{
Work[i] = B[i] / Mat[1][i];
WorkB[i] = Work[i];
}
for(register WORD j=0 ; j<10 ; j++)
{ // need judge of convergence
Work[0] = (B[0]-Mat[0][0]*WorkB[NP-1]-Mat[2][0]*WorkB[1])
/Mat[1][0];
for(register int i=1; i<NP-1 ; i++ )
{
Work[i] = (B[i]-Mat[0][i]*WorkB[i-1]-Mat[2][i]*WorkB[i+1])
/Mat[1][i];
}
Work[NP-1] = (B[NP-1]-Mat[0][NP-1]*WorkB[NP-2]-Mat[2][NP-1]*WorkB[0])
/Mat[1][NP-1];
for(register WORD i=0 ; i<=NP-1 ; i++ )
{
WorkB[i] = Work[i];
}
}
for(register WORD i=0 ; i<=NP-1 ; i++ )
{
B[i] = Work[i];
}
delete [] Work;
delete [] WorkB;
}
void drawClosed(HDC hdc)
{
Curve c;
for(register WORD i=0; i<NP ; i++)
{
c.PutCurve(Ax[i],Ay[i],Bx[i],By[i],Cx[i],Cy[i]);
c.draw(hdc ,Px[i],Py[i]);
}
}
};
#endif
