功能：有效边表转换算法 参数说明： vertices2---顶点列表 VertexNum ---顶点数目备注： DrawPixelint x int y --绘制像素点x yvoid CPolygon_ConversionViewActive_Edge_Table_Conersionint Vertices2 int VertexNum return;补全代码vector类

void CPolygon_ConversionView::Active_Edge_Table_Conersion(int Vertices[][2], int VertexNum) { //将顶点列表存入vector中 vector VertexList; for (int i = 0; i < VertexNum; i++) { VertexList.push_back(CPoint(Vertices[i][0], Vertices[i][1])); }

//求出多边形的最大最小Y值
int minY = INT_MAX, maxY = INT_MIN;
for (int i = 0; i < VertexNum; i++)
{
    if (Vertices[i][1] < minY)
        minY = Vertices[i][1];
    if (Vertices[i][1] > maxY)
        maxY = Vertices[i][1];
}

//初始化AET和ET
vector<Edge> AET, ET;
for (int i = 0; i < VertexNum; i++)
{
    Edge edge;
    edge.yMax = VertexList[i].y;
    int nextIndex = (i + 1) % VertexNum;
    //确定边的上端点和下端点
    if (VertexList[i].y < VertexList[nextIndex].y)
    {
        edge.x = VertexList[i].x;
        edge.yMin = VertexList[i].y;
        edge.k = (float)(VertexList[nextIndex].x - VertexList[i].x) / (VertexList[nextIndex].y - VertexList[i].y);
    }
    else
    {
        edge.x = VertexList[nextIndex].x;
        edge.yMin = VertexList[nextIndex].y;
        edge.k = (float)(VertexList[i].x - VertexList[nextIndex].x) / (VertexList[i].y - VertexList[nextIndex].y);
    }
    ET.push_back(edge);
}

//从y= minY开始扫描
for (int y = minY; y <= maxY; y++)
{
    //将ET中yMin值为y的边添加到AET中
    for (auto it = ET.begin(); it != ET.end();)
    {
        if (it->yMin == y)
        {
            AET.push_back(*it);
            it = ET.erase(it);
        }
        else
        {
            it++;
        }
    }

    //按照x值从小到大对AET中的边排序
    sort(AET.begin(), AET.end(), [](const Edge& a, const Edge& b) { return a.x < b.x; });

    //处理完全在当前扫描线上的边
    for (auto it = AET.begin(); it != AET.end();)
    {
        if (it->yMax == y)
        {
            it = AET.erase(it);
        }
        else
        {
            it++;
        }
    }

    //绘制当前扫描线与AET中边的交点
    for (int i = 0; i < AET.size(); i += 2)
    {
        int xStart = (int)(AET[i].x + 0.5);
        int xEnd = (int)(AET[i + 1].x + 0.5);
        for (int x = xStart; x <= xEnd; x++)
        {
            DrawPixel(x, y);
        }
    }

    //更新AET中边的x值
    for (auto& edge : AET)
    {
        edge.x += edge.k;
    }
}

}