VectorDraw常见问题整理:如何围绕某个点旋转折线中的顶点?
Cheng Liang
阅读 1,582 次
10月10日发布
VectorDraw Developer Framework(VDF)是一个用于应用程序可视化的图形引擎库。有了VDF提供的功能,您可以轻松地创建、编辑、管理、输出、输入和打印2D和3D图形文件。
VectorDraw web library (javascript)不仅能打开CAD图纸,而且能显示任何支持HTML5标准平台上的通用矢量对象,如Windows,安卓,iOS和Linux。无需任何安装,VectorDraw web library (javascript)就可以运行在任何支持canvas标签和Javascript的主流浏览器(Chrome, Firefox, Safari, Opera, Dolphin, Boat等等)中。这意味着可以用DXF,DWG,DGN,SKP(Google的Sketchup),VDML等多种格式在任何台式、平板电脑,智能手机和便携式笔记本上展现出你的业务。
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问:
如何(通过代码)可以围绕某个点旋转折线中的某些顶点,保持其他顶点相同?
答:
这个问题非常简单,您可以尝试以下代码:
private void MyButton_Click(object sender, EventArgs e)
{
vdDocument doc = vdFramedControl1.BaseControl.ActiveDocument; doc.New();
Vertexes vrts = new Vertexes();
vrts.Add(1,1,0,0);vrts.Add(1,4,0,0);vrts.Add(4,4,0,0);vrts.Add(5,3,0,0);
vdPolyline pl = new vdPolyline(doc, vrts);
doc.Model.Entities.AddItem(pl);
pl.Invalidate();
//--------------- created the polyline ---------
// rotate it for 45 degrees anti-clockwise around vertex[1]
Vertexes orig_vert = new Vertexes(pl.VertexList);//get the vertex list of the polyline that will be changed
gPoint pt1 = new gPoint(orig_vert[1] as gPoint);
// Vertexes from Item 2 and above will change
Vertexes keep = new Vertexes();
keep.Add(new Vertex(orig_vert[0]));
keep.Add(new Vertex(orig_vert[1]));
double orig_angle = pt1.GetAngle( orig_vert[2] as gPoint); // new angle
orig_angle += VectorDraw.Geometry.Globals.DegreesToRadians(45.0d);
Matrix mat = new Matrix();
mat.TranslateMatrix(-1.0d * pt1);
mat.RotateZMatrix(orig_angle);
mat.TranslateMatrix(pt1);
mat.Transform(orig_vert); // this will produce the new vertexes
for (int i = 0; i < 2; i++)
{
orig_vert[i] = keep[i]; // restore the vertexes that didn't changed
}
pl.VertexList = orig_vert;
pl.Update();
pl.Invalidate();
}