一段OpenGL的简单代码

这是基于OpenGL的代码，把它放进draw中即可。渲染出来的效果还不错

 #define  PI 3.14159

 #define  N  100

 void test::Draw()

 {

   glClearColor(0.0f, 0.0f, 0.0f, 1.0f);            // 设置刷新背景色

   glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);// 刷新背景

   glLoadIdentity();

   glEnable( GL_BLEND );

   glBlendFunc( GL_SRC_ALPHA, GL_ONE );

   glDisable( GL_DEPTH_TEST );

   glDisable( GL_TEXTURE_2D );

 #pragma region 圆圈轨迹

   glPushMatrix();

     glColor4f(1.0f,1.0f,1.0f,1.0f);

     float step,zstep;

     step=1.0*PI/N;

     zstep=1.0/N;

     glBegin(GL_LINES);

       float factor=2.0f;

       float length=3.0f;

       float HOT=2.0f;

       float COLD=0.0f;

       GLfloat z=0.0f;

       while (factor>)

       {

         setColor(length,HOT,COLD);

         for (int i=;i<(int)(*N);i++)

         {

           GLfloat x=factor*cos(step*i);

           GLfloat y=factor*sin(step*i);

           //GLfloat z=zstep*i;

           glVertex3f(x,y,z);

           glVertex3f(x,y,z+length);

         }

         factor=factor-0.05f;

         length=length-0.1f;

       }

     glEnd();

   glPopMatrix();

 #pragma endregion

 }

 void test::setColor(float t,float HOT,float COLD)

 {

   float r,g,b;

   r=(t-COLD)/(HOT-COLD);

   g=0.0;

   b=1.0-r;

   glColor3f(r,g,b);

 }