在opengl中绘制一个图形

Question

我想用我的代码创建一个图形(2d图形),如何在opengl中创建一个简单的2d图形？我是opengl的新手,所以也许你可以解释一下我的代码是如何工作的.顺便说一句,这是我的代码:

    #include <iostream>
using namespace std;

int main ()
{
      double dt = 0.10;    //(it is constant)
      double t = 0.00;

      double dx = 0.10;    //(it is constant)
      double x = 0.00;

      double ddy = 1.00;   //(it is constant)
      double dy = 0.00;
      double y = 1.00;

      cout<<"t   = "<<t<<endl;
      cout<<"dx  = "<<dx<<endl;
      cout<<"x   = "<<x<<endl;
      cout<<"dy  = "<<dy<<endl;
      cout<<"y   = "<<y<<endl;
      cout<<endl;

      while(t<=5) 
      {
                  x = x + dx*dt;
                  dy = dy - ddy * dt * dt;
                  y = y + dy * dt;

                  if (y<=-1)
                  {
                             y = -y;
                             dy = -dy * 0.70;
                  }
      t  = t + dt;

      cout<<"t   = "<<t<<endl;
      cout<<"dx  = "<<dx<<endl;
      cout<<"x   = "<<x<<endl;
      cout<<"dy  = "<<dy<<endl;
      cout<<"y   = "<<y<<endl;
      cout<<endl;

      }
      system("pause");
}

Answer 1

可能你应该看看这里http://en.wikibooks.org/wiki/OpenGL_Programming/Scientific_OpenGL_Tutorial_01

有很好的信息可以开始绘制曲线.因为你有一个参数化曲线,只需将你的x,y存储在一个顶点缓冲对象(VBO)中,其大小为你想要在曲线上的点数,并像这样绘制VBO:

glDrawArrays(GL_LINE_STRIP, 0, nbPoints);

这将使连续的断线连接所有点.