C++ Point2::set方法代码示例

int segIntersect(Point2 A, Point2 B, Point2 C, Point2 D, Point2 &InterPt)
{
	Vector2 b, d, dp, bp, c;
	b.set((B.x-A.x) , (B.y-A.y));
	d.set((D.x-C.x) , (D.y-C.y));
	bp.set(b.y , -b.x);
	dp.set(d.y , -d.x);
	c.set((C.x-A.x) , (C.y-A.y));
	
	float t, u, dp_b;
	dp_b=dp.x*b.x + dp.y*b.y;
	if(dp_b != 0)
	{
        t=(dp.x*c.x + dp.y*c.y)/dp_b ;
        u=-(bp.x*c.x + bp.y*c.y)/(bp.x*d.x + bp.y*d.y);
        if((t>0 && t<1) && (u>0 && u<1))
        {
            InterPt.set((A.x+b.x*t) , (A.y+b.y*t));
            return 0;        }
        else
            return 1;
    }
    else
    {
        if((c.x*b.y - c.y*b.x)!=0)
            return -1;
    }
}

float dotProduct(Point2 A, Point2 B)
{
	Point2 ret;
	ret.set((A.getX()*B.getX()),(A.getY()*B.getY()));
	int r = ret.getX() + ret.getY();
	return r;
}

Point2 addPoints(Point2 A, Point2 B)
{
	int x = B.getX() + A.getX();
	int y = B.getY() + A.getY();
	Point2 ret;
	ret.set(x,y);
	return ret;
}

Point2 subtactPoints(Point2 A, Point2 B)
{
	int x = B.getX() - A.getX();
	int y = B.getY() - A.getY();
	Point2 ret;
	ret.set(x,y);
	return ret;
}

void lineTo(Point2 p)
{
	glBegin(GL_LINES);
    glVertex2f(CP.x, CP.y);
    glVertex2f(p.x, p.y);
	glEnd();
	glFlush();
	CP.set(p);
}

Point2 interact(Point2 A, Point2 B, Point2 C, Point2 D)
{
    Point2 inter;
    float a,b,c,d,k1,k2,x,y;
    a=A.y-B.y;
    b=B.x-A.x;
    c=C.y-D.y;
    d=D.x-C.x;
    k1=a*A.x + b*A.y;
    k2=c*C.x + d*C.y;
    
    x=(d*k1 - b*k2)/(a*d - b*c);
    //y=(c*k1 - a*k2)/(b*c -a*d);
    y=( a*k2 -c*k1 )/(a*d - b*c );
    inter.set(x , y);
    return inter;
}

Point2 scalePoint(float A, Point2 B)
{
	Point2 ret;
	ret.set(A*B.getX(), A*B.getY());
	return ret;
}

Point2 getNormal(Point2 A)
{
	Point2 ret;
	ret.set(-A.getY(), A.getX());
	return ret;
}

void moveTo(Point2 p)
{
	CP.set(p);
}

//function that detects mouse clicks and creates the polygon
void myMouseState(int button, int state, int x, int y)
{
	if (initializeComplete == false)
	{
		if ((button == GLUT_LEFT_BUTTON) && (state == GLUT_DOWN))
		{
			polyPoint[numPoints].set((float) x, (float) (WINDOW_HEIGHT-y));
			++numPoints;
		}
		else if ((button == GLUT_RIGHT_BUTTON) && (state == GLUT_DOWN))
			initializeComplete = true;
		glutPostRedisplay();
	}
	else
	{
		switch (button)
		{
		case (GLUT_RIGHT_BUTTON):
			if (state == GLUT_DOWN)
			{
				moveEnabled = false;
				for (int index=0; index<numPoints; index++)
				{
					if ((x < ((int)polyPoint[index].getX() + 20)) &&
						(x > ((int)polyPoint[index].getX() - 20)) &&
						(y < (WINDOW_HEIGHT - (int)polyPoint[index].getY() + 20)) &&
						(y > (WINDOW_HEIGHT - (int)polyPoint[index].getY() - 20)))
					{
						moveEnabled = true;
						polyIndex = index;
					}
				}
			}
			else if (state == GLUT_UP)
			{
				moveEnabled = false;
				if (firstPointDrawn == true)
				{
					//pointInside = true; //remove this--for test only
					Point2 *polyPointPtr;
					polyPointPtr = &polyPoint[0];
					insideOutside(testPoint, polyPointPtr, numPoints);
				}
			}
			break;

		case (GLUT_LEFT_BUTTON):
			if (state == GLUT_DOWN)
			{
				//pointInside = false; //remove this--for test only
				Point2 *polyPointPtr;
				polyPointPtr = &polyPoint[0];
				testPoint.set((float) x, (float) (WINDOW_HEIGHT-y));
				firstPointDrawn = true;
				insideOutside(testPoint, polyPointPtr, numPoints);
			}
			break;

		default:
			break;
		}
	}

	void GetRelationTable(MPMesh* pMesh, MPMesh::FaceHandle curFace, MPMesh::FaceHandle seedFace, 
		Relation* relationSeed, unsigned nMesh, Octree<>* pOctree, Relation*& output)
	{
		// 讨论相邻的两个三角形，如何从一个三角形导出另一个三角形的关系表的问题
		output = new Relation[nMesh];
		memcpy(output, relationSeed, sizeof(Relation)*nMesh);

		if (seedFace == curFace) return;

		ISectTriangle* triSeed = pMesh->property(pMesh->SurfacePropHandle, seedFace);
		ISectTriangle* triCur = pMesh->property(pMesh->SurfacePropHandle, curFace);
		if (!triSeed || (!triSeed->coplanarTris.size() && !triSeed->segs.size()))
		{
			assert(triCur);
			MarkNARelation(triCur, output);
		}
        else
		{
			int index = TestNeighborIndex(pMesh, seedFace, curFace);
			assert(index != -1);
			Vec3d* v[3];
			unsigned nv = triSeed->vertices.size();
			GetCorners(pMesh, seedFace, v[0], v[1], v[2]); 
			int a = triSeed->xi;
			int b = triSeed->yi;
#ifdef _DEBUG
			Vec3d* u[3];
			GetCorners(pMesh, curFace, u[0], u[1], u[2]); 
#endif
			Point2 p[3];
			p[0].set((*v[0])[a], (*v[0])[b]);
			p[1].set((*v[1])[a], (*v[1])[b]);
			p[2].set((*v[2])[a], (*v[2])[b]);

			a = (index+1)%3;
			b = (index+2)%3;

			Point2 testPoint;
			testPoint.set(p[a].x()+p[b].x()-p[index].x(), p[a].y()+p[b].y()-p[index].y());

            // 首先用BSP把所有的关系都弄出来
			for (auto& pair: triSeed->segs)
				output[pair.first] = BSP2DInOutTest(pair.second.bsp, &testPoint);

            // 如果存在共面，那么BSP的测量是不准确的，所以置0
            for (auto& pair2: triSeed->coplanarTris)
            {
                if (output[pair2.first] == REL_NOT_AVAILABLE)
                    output[pair2.first] = REL_UNKNOWN;
            }

            // 对所有的相交元置-1
			if (triCur) MarkNARelation(triCur, output);

            std::vector<unsigned> errorList;
            // 这个时候，按道理来说，所有的关系已经确定
            // 但因为存在误差，可能存在为0的关系
            for (auto& pair2: triSeed->coplanarTris)
            {
                if (output[pair2.first] == REL_UNKNOWN)
                    errorList.push_back(pair2.first);
            }

            if (errorList.size())
            {
                Vec3d *g[3];
                GetCorners(pMesh, curFace, g[0], g[1], g[2]);
                auto bc = (*g[0]+*g[1]+*g[2])/3.0;
                for (auto index: errorList)
                    output[index] = PolyhedralInclusionTest(bc, pOctree, index, pOctree->pMesh[index]->bInverse);
            }
		}
	}