wrong value from feedback?

OpenGL Development JOGL Development
#1

Hi,
this is my feedback line where i set the token for the vertex…


gl.glPassThrough(1.0f);
		
		gl.glBegin(GL.GL_POINTS);
		  gl.glVertex3f(-1.0f, 1.0f, 0.0f);	
		gl.glEnd();
		
		gl.glPassThrough(2.0f);

now i get this value from the FloatBuffer: 1792.0
i dont know why.
i need the coordinates, but i just get this one value…

i am using this buffer


FloatBuffer feedbackBuffer = BufferUtils.newFloatBuffer(4);
 gl.glFeedbackBuffer(4, GL.GL_3D, feedbackBuffer);

anyone has an idea? ???

PS: byteorder is little endian

#2

1792 is 0x700 which is GL_PASS_THROUGH_TOKEN. Have you looked at the documentation for the feedback buffer?

#3

Hi, yes.
I implented this perspectiv :


glu.gluPerspective(60.0, this.h, 1.0, 20.0);

now i have also the 1793.0 for GL_POINT_TOKEN, plus this Values:

1793.0
3
226.01904
4
190.98096

i think 226 is x
and 190 is y

but i dont know how to work with this values, the originals are -1.0f and 1.0f … hmmm
… hmm why arent them -1.0 and 1.0 ??

#4

From the man page:


Feedback vertex coordinates are in window coordinates except w, which is in clip coordinates