你没有指出你是如何实现你的 openGLobj->Arrow 方法的，但是如果你在这上面使用 100% CPU 时间，你可能正在用immediate mode绘制箭头。这确实是 CPU 密集型的，因为您必须为 glBegin() 和 glEnd() 中的每条指令将数据从 CPU 传输到 GPU。如果您使用 GLUT 来绘制数据，那么它也非常低效。
此处的方法是使用 GPU 内存和处理能力来显示您的数据。Phyatt 已经为您指出了一些方向，但我会尝试更具体：使用顶点缓冲区对象 (VBO)。
这个想法是预先分配所需的内存以在 GPU 上显示您的数据，并在需要时更新这块内存。这可能会对代码的效率产生巨大影响，因为您将使用高效的视频卡驱动程序来处理 CPU->GPU 传输。
为了说明这个概念，我将在答案的末尾向您展示一些伪代码，但这绝不是完全正确的。我没有测试它，也没有时间为你实现绘图，但它是一个可以让你理清思路的概念。
class Form
{
public:
Form()
{
// generate a new VBO and get the associated ID
glGenBuffers(1, &vboId);
// bind VBO in order to use
glBindBuffer(GL_ARRAY_BUFFER, vboId);
//Populate the buffer vertices.
generateVertices();
// upload data to VBO
glBufferData(GL_ARRAY_BUFFER_ARB, vertices.size(), vertices.data(), GL_STATIC_DRAW_ARB);
}
~Form()
{
// it is safe to delete after copying data to VBO
delete [] vertices;
// delete VBO when program terminated
glDeleteBuffersARB(1, &vboId);
}
//Implementing as virtual, because if you reimplement it on the child class, it will call the child method :)
//Generally you will not need to reimplement this class
virtual void draw()
{
glBindBuffer(GL_ARRAY_BUFFER, vboId);
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, 0);
//I am drawing the form as triangles, maybe you want to do it in your own way. Do it as you need! :)
//Look! I am not using glBegin() and glEnd(), I am letting the video card driver handle the CPU->GPU
//transfer in a single instruction!
glDrawElements(GL_TRIANGLES, vertices.size(), GL_UNSIGNED_BYTE, 0);
glDisableClientState(GL_VERTEX_ARRAY);
// bind with 0, so, switch back to normal pointer operation
glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
}
private:
//Populate the vertices vector with the form vertices.
//Remember, any geometric form in OpenGL is rendered as primitives (points, quads, triangles, etc).
//The common way of rendering this is to use multiple triangles.
//You can draw it using glBegin() and glEnd() just to debug. After that, instead of rendering the triangles, just put
//the generated vertices inside the vertices buffer.
//Consider that it's at origin. You can use push's and pop's to apply transformations to the form.
//Each form(cone or cilinder) will have its own way of drawing.
virtual void generateVertices() = 0;
GLuint vboId;
std::vector<GLfloat> vertices;
}
class Cone : public Form
{
public:
Cone() : Form() {}
~Cone() : ~Form() {}
private:
void generateVertices()
{
//Populate the vertices with cone's formula. Good exercise :)
//Reference: http://mathworld.wolfram.com/Cone.html
}
GLuint vboId;
std::vector<GLfloat> vertices;
}
class Cilinder : public Form
{
public:
Cone() : Form() {}
~Cone() : ~Form() {}
private:
void generateVertices()
{
//Populate the vertices with cilinders's formula. Good exercise :)
//Reference: http://math.about.com/od/formulas/ss/surfaceareavol_3.htm
}
GLuint vboId;
std::vector<GLfloat> vertices;
}
class Visualizer : public QOpenGLWidget
{
public:
//Reimplement the draw function to draw each arrow for each data using the classes below.
void updateGL()
{
for(uint i = 0; i<data.size(); i++)
{
//I really don't have a clue on how you position your arrows around your world model.
//Keep in mind that those functions glPush, glPop and glMatrix are deprecated. I recommend you reading
//http://duriansoftware.com/joe/An-intro-to-modern-OpenGL.-Chapter-3:-3D-transformation-and-projection.html if you want to implement this in the most efficient way.
glPush();
glMatrix(data[i].transform());
cilinder.draw();
cone.draw();
glPop();
}
}
private:
Cone cone;
Cilinder cilinder;
std::vector<Data> data;
}
最后一点，我不能保证这是最有效的做事方式。可能，如果您有大量数据，您将需要一些数据结构，例如八叉树或场景图来优化您的代码。
I recommend you taking a look at OpenSceneGraph or Visualization ToolKit to see if that methods are not already implemented for you, what would save you a lot of time.