Qt QWT3D 之三维动态曲线的实现

QWT3D 和QWT 都是QT的同门师弟，QWT3D主要信赖于QT中的QGLWidget类,可以直接使用opengl 命令，QWT3D的编译比较简单，在此不再赘述，下面展示一下QWT3D自带的例子运行效果：

下面是经典的，牛逼的MESH例子，生成经典的帽子曲面等

QWT3D例子展示就到此为至吧，不然童鞋又说我喧宾夺主了。下面进入正题。

2、上述几个类中都是绘制曲面的例子，都使用到SurfacePlot类，SurfacePlot类应该可以定位于一个曲面绘制功能类，使用该类可以方便绘制曲面。

为了实现曲线的绘制，

1）实现派生类Line3D

 1 //////////////////////////////////////////////////////////////
 2 
 3 //  Line3D.h
 4 
 5 class QWT3D_EXPORT Line3D: public VertexEnrichment
 6 {
 7 public:
 8 Line3D();
 9 Line3D(double thick,bool smooth);
10 Qwt3D::Enrichment * clone() const{ return new Line3D(*this);}
11 
12 void configure(double thick, bool smooth);
13 void drawBegin();
14 void drawEnd();
15 virtual void draw(Qwt3D::Triple const&);
16 
17 virtual void draw();
18 
19 virtual void add(Qwt3D::Triple const & t);
20 virtual void setLineColor(RGBA color);
21 
22 private:
23 bool smooth_;
24 double lineThick;
25 GLboolean oldstate_;
26 
27 std::vector<Qwt3D::Triple> lineData;
28 
29 RGBA rgba;
30 };

 1 //////////////////////////////////////////////////////
 2 
 3 //Line3D.cpp
 4 
 5 Qwt3D::Line3D::Line3D()
 6 {
 7 
 8 
 9 rgba.a = 1;
10 rgba.b = 0.3;
11 rgba.r = 0.6;
12 rgba.g = 1;
13 }
14 Qwt3D::Line3D::Line3D(double thick,bool smooth)
15 {
16 lineThick = thick;
17 smooth_  = smooth;
18 rgba.a = 1;
19 rgba.b = 0.3;
20 rgba.r = 0.6;
21 rgba.g = 1;
22 }
23 
24 void Qwt3D::Line3D::configure(double thick, bool smooth)
25 {
26 lineThick = thick;
27 smooth_  = smooth;
28 
29 }
30 
31 void Qwt3D::Line3D::drawBegin()
32 {
33 setDeviceLineWidth(lineThick);
34 
35 oldstate_ = glIsEnabled(GL_LINE_SMOOTH);
36 if (smooth_)
37 glEnable(GL_LINE_SMOOTH);
38 else
39 glDisable(GL_LINE_SMOOTH);
40 
41 //glPointSize(10);
42 glBegin( GL_LINE_STRIP);
43 
44 }
45 
46 void Qwt3D::Line3D::drawEnd()
47 {
48 glEnd();
49 
50 
51 if (oldstate_)
52 glEnable(GL_LINE_SMOOTH);
53 else
54 glDisable(GL_LINE_SMOOTH);
55 }
56 
57 
58 void Qwt3D::Line3D::draw(Qwt3D::Triple const& pos)
59 {
60 
61 glColor4d(rgba.r,rgba.g,rgba.b,rgba.a);
62 
63 glVertex3d(pos.x,pos.y,pos.z);
64 
65 }
66 
67 void Qwt3D::Line3D::draw()
68 {
69 for (int i = 0; i < lineData.size(); i ++)
70 {
71 draw(lineData[i]);
72 }
73 }
74 
75 void Qwt3D::Line3D::add(Qwt3D::Triple const & t)
76 {
77 lineData.push_back(t);
78 }
79 
80 void Qwt3D::Line3D::setLineColor(RGBA color)
81 {
82 this->rgba = color;
83 }

类成员变量 lineData 保存三维线的点集

2）为了让Line3D 被　SurfacePlot　调用，需对SurfacePlot::createEnrichment(Enrichment& p) 扩展，为了兼容QWT3D原来的功能，将

 1 SurfacePlot::createEnrichment(Enrichment& p) 函数实现片断
 2 
 3  VertexEnrichment* ve = (VertexEnrichment*)&p; 
 4   if (actualData_p->datatype == Qwt3D::POLYGON)
 5   {
 6     for (unsigned i = 0; i != actualDataC_->normals.size(); ++i) 
 7    ve->draw(actualDataC_->nodes[i]);
 8   }
 9   else if (actualData_p->datatype == Qwt3D::GRID)
10   {
11     int step = resolution();
12     for (int i = 0; i <= actualDataG_->columns() - step; i += step) 
13       for (int j = 0; j <= actualDataG_->rows() - step; j += step) 
14   ve->draw(Triple(actualDataG_->vertices[i][j][0],
15              actualDataG_->vertices[i][j][1],
16                                   actualDataG_->vertices[i][j][2]));
17   }
18 
19 修改为：
20 
21  VertexEnrichment* ve = (VertexEnrichment*)&p; 
22   if (actualData_p->datatype == Qwt3D::POLYGON)
23   {
24     for (unsigned i = 0; i != actualDataC_->normals.size(); ++i) 
25    ve->draw(actualDataC_->nodes[i]);
26   }
27   else if (actualData_p->datatype == Qwt3D::GRID)
28   {
29     int step = resolution();
30     for (int i = 0; i <= actualDataG_->columns() - step; i += step) 
31       for (int j = 0; j <= actualDataG_->rows() - step; j += step) 
32   ve->draw(Triple(actualDataG_->vertices[i][j][0],
33              actualDataG_->vertices[i][j][1],
34                                   actualDataG_->vertices[i][j][2]));
35   }
36   else if (actualData_p->datatype == Qwt3D::LINE3D_STYLE)  /// 新增片断，这样在不暴露Line3D 三维曲线类的点集的情况下，绘制三维曲线
37   {
38  p.draw();  
39   }

3、使用方法动态绘制三维曲线

1）定义

1 Qwt3D::Line3D _l3d;
2 
3        SurfacePlot plot;
4 
5       myLine1 = dynamic_cast<Qwt3D::Line3D *>(plot.addEnrichment(_l3d));
6 
7         myLine1->configure(3,true);
8 myLine1->setLineColor(Qwt3D::RGBA(1,0,0,1));