[newbie]help, draw points with different sizes sing buffers

[zerony]

I am trying to write a simple program, which simulates a particle system. I can get it work partially using the same point size. Currently I use vertex buffers to draw particles.  I am wondering whether I can draw points with different sizes using buffers in JOGL.

     gl.glEnableClientState(GL.GL_NORMAL_ARRAY);
     //gl.glEnableClientState(GL.GL_POINT_SIZE_ARRAY_OES); //JOGL-ES support this,  how about JOGL?
     gl.glEnableClientState(GL.GL_VERTEX_ARRAY);
     gl.glNormalPointer(GL.GL_FLOAT, 3*4, nbuffer);
     //gl.glPointSizePointerOES(GL.GL_FLOAT,4,rbuffer);//JOGL-ES support this,  how about JOGL?
     gl.glVertexPointer(3, GL.GL_FLOAT, 0, vbuffer);
     gl.glDrawElements(GL.GL_POINTS, points_list.length, GL.GL_UNSIGNED_INT, IntBuffer.wrap(points_list));
     gl.glDisableClientState(GL.GL_VERTEX_ARRAY);
     //gl.glDisableClientState(GL.GL_POINT_SIZE_ARRAY_OES);//JOGL-ES support this,  how about JOGL?
     gl.glDisableClientState(GL.GL_NORMAL_ARRAY);

How can I fix this problem? Appreciate your help!

[turquoise3232]

Hi,

You can change the point size with the following call :

1	gl.glPointSize(x.xf

But you can also take a look at the GL_POINT_SPRITE functionality to  have a better approach to particles system (at least someone says so).

[zerony]

Hi,

You can change the point size with the following call :

1	gl.glPointSize(x.xf

But you can also take a look at the GL_POINT_SPRITE functionality to  have a better approach to particles system (at least someone says so).

Thank you.
If I have ten thousands of points with different sizes to draw, and I do not use buffers, the efficiency is a big problem. That is why I am trying to get glPointSize work on buffers.

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[lhkbob]

Maybe try using a shader, I think glsl shaders allow you to change point size for each incoming point.