Hi,
I've been trying to improve a dot drawing routine
and I tried the vertex array method but it slows
performance by a factor of 2. My testing machine
runs Mac OSX 10.3.9 and has PyOpenGL version 2.0.2.01 .
I tried allocating the xyData array 2 ways and both have
the same performance
1) xyData = RandomArray.uniform(0.0,1.0, (NUM_POINTS,2))
2) xyData = Numeric.zeros( (NUM_POINTS,2), 'd')
and the code looks as
if use_vertex_array == False:
glColor4f(1.0, 0.0, 0.0,1.0);
glBegin(GL_POINTS);
for i in range(NUM_POINTS):
glVertex3f(xstart[i],ystart[i],zstart[i]);
glEnd()
else:
# Pass a pointer to the start of the point-coordinate array:
glColor4f(0.0, 1.0, 0.0,1.0);
xyData[:,0] = xstart
xyData[:,1] = ystart
glVertexPointerd(xyData);
glEnableClientState(GL_VERTEX_ARRAY);
glDrawArrays(GL_POINTS, 0, len(xstart));
glDisableClientState(GL_VERTEX_ARRAY);
By timing parts of the code it spends most of it's time in
glVertexPointerd(xyData);
the call to glDrawArrays(GL_POINTS, 0, len(xstart)); is quite fast.
Am I doing something wrong here? Any help would be
greatly appreciated. Thanks,
Doug Taylor
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