C中交叉线多边形的多边形填充算法

Question

我有多边形填充算法的实现：

//point in polygon algorithm for filling polyons
void fill_polygon(Array *vx,Array *vy){
    int  nodes,  pixelX, pixelY, i, j, swap,polyCorners ;
    double top,bot,right,left,nodeX[1000];
    polyCorners = vx->used;
    if(polyCorners<=2){
        return;
    }
                /*printf("Soltado VX: Used(%d) \n",vx->used);
                for(i=0;i<vx->used;i++){
                    printf("|%d|", vx->array[i]); 

                }
                printf("\n VY: Used(%d) \n",vy->used);
                for(i=0;i<vy->used;i++){
                    printf("|%d|", vy->array[i]); 

                }       
                printf("\n");
                wait(35);   */
    bot = maximum(vy);
    top = minimum(vy);
    right = maximum(vx);
    left = minimum(vx);
    /*printf("Top %d  - Bot %d - Left %d - Right %d \n",top,bot,left,right);
    wait(40);*/
    for (pixelY=top; pixelY<bot; pixelY++) {

        //  Construyendo lista de Nodos de la figura
        nodes=0; j=polyCorners-1;
        for (i=0; i<polyCorners; i++) {
            if (vy->array[i]< (double)pixelY && vy->array[j]>=(double)pixelY
                ||  vy->array[j]<(double) pixelY && vy->array[i]>=(double)pixelY) {

                nodeX[nodes++]=(vx->array[i]+(pixelY-vy->array[i])/(vy->array[j]-vy->array[i])*(vx->array[j]-vx->array[i])); 

            }
            j=i; 
        }   
        //  Ordenamos nodos con bubble sort
        i=0;
        while (i<nodes-1) {
            if (nodeX[i]>nodeX[i+1]) {
              swap=nodeX[i]; nodeX[i]=nodeX[i+1]; nodeX[i+1]=swap; if (i) i--; 
            }

            else {
              i++; 
            }
        }
     // Rellenamos pixeles entre los nodos
        for (i=0; i<nodes; i+=2) {
            if   (nodeX[i]>=right) break;

            if   (nodeX[i+1]> left ) {
                if (nodeX[i  ]< left ) nodeX[i  ]=left ;
                if (nodeX[i+1]> right) nodeX[i+1]=right;
                for (pixelX= (int)nodeX[i]; pixelX<nodeX[i+1]; pixelX++){

                    plot_pixel(pixelX,pixelY,current_color);
                }  
            }
        }       

    }
}

它对普通多边形工作正常，但是当我有一个如下所示的交叉多边形时，它不会填充多边形。 （右边是未填充的多边形，左边是我算法的结果。

当结果应该是这样的时候：