OpenGL里画线

xShandow

<>在OpenGL里画线语句:
4 G( M9 |( f0 \) t4 E" {glBegin(GL_LINES);
   glVertex2f(x,y);
   glVertex2f(a,b);
glEnd();</P>
<>注意:目前只讨论OpenGL 2D模式.

下面是一个画线实例和效果图
#define GL_PI 3.1415f</P>
& Z8 W/ W. T& M5 t7 b' D; g<>void Draw()
- E: v% I3 ^0 z+ E5 f{
GLfloat x,y,angle;</P>
: \& ^6 h+ N4 B& Y<> glPushMatrix();</P>
<> glTranslatef(300,200,0);
/ ~4 s' l  ?' q3 o; p glColor3f(0.6f,0.6f,0.1f);
glBegin(GL_LINES);
  for(angle=0.0f;angle&lt;3*GL_PI;angle+=0.5f)
  {
4 p# m& B; ^. E   x=150.0f*sin(angle);
   y=150.0f*cos(angle);</P>
<>   glVertex2f(x,y);</P>
9 g  T: N, p/ u! N2 E7 a- n. `<>   x=150.0f*sin(angle+3.1415f);
: L7 f0 l7 a; S1 r, Y" n   y=150.0f*cos(angle+3.1415f);
7 f! S! f" g4 D' H5 _8 c6 n7 T   glVertex2f(x,y);
& y+ `1 a/ c0 k! i3 O0 o: o  }
  
& F0 d( u% E. @3 r( _+ f9 V glEnd();</P>
<> glPopMatrix();
}
</P>