// p0, p1, p2: triangle tesselation

void TriangleTesselation(CVector &p0, CVector &p1, CVector &p2, int nTesselation)

{

    CVector dv1 = (p2 - p0) / nTesselation;

    CVector dv2 = (p2 - p1) / nTesselation;

 

    for (int j=0; j<nTesselation; j++)

    {

        CVector x1  = p0 + j*dv1;

        CVector x2  = p0 + (j+1)*dv1;

        CVector dx1 = ((p1-p0) + (dv2-dv1)*j);

        CVector dx2 = ((p1-p0) + (dv2-dv1)*(j+1));

 

        glBegin(GL_TRIANGLE_STRIP);

        for (int i=0; i<nTesselation-j; i++)

        {

            CVector u1 = x1 + ((float) i / (nTesselation-j))*dx1;

            CVector u2 = x2;

            if (nTesselation-j-1 != 0)

                u2 += ((float) i / (nTesselation-j-1))*dx2;

 

            glVertex3fv(u1.arr);

            glVertex3fv(u2.arr);

        }

        glVertex3fv((x1+dx1).arr);

 

        glEnd();

 

    }

}

 

 

// p0, p1, p2: triangle tesselation

procedure TriangleTesselation(p0: T3DPoint; p1: T3DPoint; p2: T3DPoint; nTesselation: integer);

var

  dv1: T3DPoint;

  dv2: T3DPoint;

  x1: T3DPoint;

  x2: T3DPoint;

  dx1: T3DPoint;

  dx2: T3DPoint;

  u1: T3DPoint;

  u2: T3DPoint;

  e1: T3DPoint;

  j: integer;

  i: integer;

begin

    dv1 := VectorDiv( VectorSubtract(p2,p0) , nTesselation);

    dv2 := VectorDiv( VectorSubtract(p2,p1) , nTesselation);

 

    for j:=0 to nTesselation-1 do

    begin

        x1  := VectorAdd(p0 , VectorMul(dv1, j) );

        x2  := VectorAdd(p0 , VectorMul(dv1, (j+1) ) );

        dx1 := VectorAdd(VectorSubtract(p1,p0) , VectorMul( VectorSubtract(dv2,dv1) ,j));

        dx2 := VectorAdd(VectorSubtract(p1,p0) , VectorMul( VectorSubtract(dv2,dv1) ,(j+1)));

 

        glBegin(GL_TRIANGLE_STRIP);

        for i:=0 to nTesselation-j-1 do

        begin

            u1 := VectorAdd(x1 , VectorMul(dx1, ( i / (nTesselation-j) ) ) );

            u2 := x2;

            if (nTesselation-j-1 <> 0) then

                u2 := VectorAdd(u2 , VectorDiv(dx2, ( i / (nTesselation-j-1)) ) );

 

            glVertex2f(u1.x, u1.y);

            glVertex2f(u2.x, u2.y);

        end;

                                e1:=VectorAdd(x1,dx1);

        glVertex2f(e1.x,e1.y);

 

        glEnd();

 

    end;

end;

 

 

// returns the difference of two vectors

function VectorSubtract(V1, V2: T3dPoint): T3dPoint; register;

begin

  Result.x := V1.x - V2.x;

  Result.y := V1.y - V2.y;

  Result.z := V1.z - V2.z;

end;

 

// returns the addition of two vectors

function VectorAdd(V1, V2: T3dPoint): T3dPoint; register;

begin

  Result.x := V1.x + V2.x;

  Result.y := V1.y + V2.y;

  Result.z := V1.z + V2.z;

end;

 

// returns the multiplication of a vector with an single

function VectorMul(V: T3DPoint; S: single): T3dPoint; register;

begin

  Result.x := V.x * S;

  Result.y := V.y * S;

  Result.z := V.z * S;

end;

 

// returns the division of a vector with an single

function VectorDiv(V: T3DPoint; S: single): T3dPoint; register;

begin

  Result.x := V.x / S;

  Result.y := V.y / S;

  Result.z := V.z / S;

end;