Hello everyone,

I want to get start using OPENGL in P5.

I am not sure how to start it and I can't find any tutorial on the

subject. 

I want to start drawing a gradiant traingle so I found this for

JOGL.  

             

              
                 gl.glBegin(GL.GL_POLYGON);
              
 //We want to draw triangle in gradient color
              
 //So setting the color of first vertex as red
              
 gl.glColor4f(1, 0, 0, 1); 
              
 gl.glVertex2d(100, 100);
              
 //Setting the color of second vertex as green
              
 gl.glColor4f(0, 1, 0, 1);
              
 gl.glVertex2d(100, 200);
              
 //Setting the color of third vertex as blue
              
 gl.glColor4f(0, 0, 1, 1);
              
 gl.glVertex2d(200, 200);
              
 //Our polygon ends here 
              
 gl.glEnd();
              
 gl.glFlush();
             
from
http://wiki.tankaar.com/index.php?title=Drawing_First_2D_Graphics_in_JOGL

but I don't know how to reproduce those line in P5 as I even can't find

a class (I don't know the purpose and difference between PGL, GL,...)

that has the glBegin function.

Can someone give me a hint how to start.

Thanks in advance.

ra