pyopengl-users — Discussion of all PyOpenGL matters.

Re: [PyOpenGL-Users] Exporting 3D extruded text to an OBJ file

[David M. <dvm...@gm...>]

Thanks, I will definitely check that out. I appreciate your help, and I'll
let you know if I have any other questions after I dig a little deeper into
fonttools.

Dave

On Wed, Jan 13, 2010 at 1:37 PM, Mike C. Fletcher <mcf...@vr...>wrote:

> David Morris wrote:
> > I would like to be able to export a string of 3D extruded text as an
> > OBJ or similar 3D file format, and I can't find any examples on the
> > internet.
> >
> > I have played around with the solid_font.py demo in the
> > OpenGLContext/tests/ folder, which uses FontTools to display the text,
> > but I don't know how to get that mesh data back out.
> It's not really set up to make it easy to get out.  Each glyph that's
> created has contour and outline arrays, which are extracted by
> ttfquery.glyph.Glyph, but the advances and the like are all done at the
> Font level (OpenGLContext.scenegraph.text._fonttools and
> OpenGLContext.scenegraph.text.fonttools), without those you'd just have
> characters showing up piled on top of each other.  That said, there's
> only maybe 1000 lines of code in all three modules, so if you want to
> extract the pieces you need you could likely do it in a few hours.  The
> obscure stuff is all over in ttfquery, the stuff in OpenGLContext just
> takes the contours for each glyph and figures out how to render them
> based on a VRML97 font description.
>
> Good luck,
> Mike
>
> --
> ________________________________________________
>  Mike C. Fletcher
>  Designer, VR Plumber, Coder
>  http://www.vrplumber.com
>  http://blog.vrplumber.com
>
>


-- 
Dave Morris
http://dave.showviz.net/
http://3dcamphouston.com/

Re: [PyOpenGL-Users] Exporting 3D extruded text to an OBJ file

[Mike C. F. <mcf...@vr...>]

David Morris wrote:
> I would like to be able to export a string of 3D extruded text as an
> OBJ or similar 3D file format, and I can't find any examples on the
> internet.
>
> I have played around with the solid_font.py demo in the
> OpenGLContext/tests/ folder, which uses FontTools to display the text,
> but I don't know how to get that mesh data back out.
It's not really set up to make it easy to get out.  Each glyph that's
created has contour and outline arrays, which are extracted by
ttfquery.glyph.Glyph, but the advances and the like are all done at the
Font level (OpenGLContext.scenegraph.text._fonttools and
OpenGLContext.scenegraph.text.fonttools), without those you'd just have
characters showing up piled on top of each other.  That said, there's
only maybe 1000 lines of code in all three modules, so if you want to
extract the pieces you need you could likely do it in a few hours.  The
obscure stuff is all over in ttfquery, the stuff in OpenGLContext just
takes the contours for each glyph and figures out how to render them
based on a VRML97 font description.

Good luck,
Mike

-- 
________________________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://www.vrplumber.com
  http://blog.vrplumber.com

Re: [PyOpenGL-Users] PyOpgnGL-3.0.1a2 MSVCR71.dll not found

[Mike C. F. <mcf...@vr...>]

David L. Page wrote:
> Mike--
>
> Thanks. Yes, it is the installer that gave the warning. 
>
> I tried downloading the zip files according to your last suggestion.
>
> It worked for PyOpenGL-3.0.1b2.zip but not for
> PyOpenGL-accelerate-3.0.1b2.zip. Here's the output for th accelerate
> attempt.
>
> f:\PyOpenGL-accelerate-3.0.1b2> python setup.py install
> running install
> running build
> running build_py
> running build_ext
> building 'OpenGL_accelerate.wrapper' extension
> Unable to import Numeric, skipping Numeric extension building
> error: Unable to find vcvarsall.bat
Hmm, you *should* be able to use the PyOpenGL-accelerate .exe installer,
it was built with Python 2.6 (since that's the only thing that can build
a binary extension for itself).  PyOpenGL is cross-version, so it
doesn't necessarily get built with the current version (which I think
was the problem here).  The source install of PyOpenGL-accelerate
requires a C compiler, which is a large download for Win32 systems.

HTH,
Mike
>
> On Sun, Jan 10, 2010 at 11:38 PM, Mike C. Fletcher
> <mcf...@vr... <mailto:mcf...@vr...>> wrote:
>
>     David L. Page wrote:
>     >
>     > I am attempting to install PyOpenGL-3.0.1b2 on a Win7 system with
>     > Python 2.6 installed. I receive an error that msvcr71.dll was not
>     > found upon start of the PyOpenGL install exe.
>     >
>     > I have found online suggestions to download msvcr71.dll from various
>     > sites and then to copy that dll into the win system directory. For
>     > obvious reasons, I am unsatisfied with this solution and haven't
>     > attempted it.
>     >
>     > Does any else have a work around?
>     Hmm, that's a pain.  If I'm reading correctly, there's no VC 2003
>     (7.1)
>     redistributable download on microsoft.com <http://microsoft.com>.
>      So there's no official way
>     to redistribute it?  That doesn't seem very helpful :( .
>      Something has
>     installed it to the Windows folder on my Vista machine, but I've
>     got the
>     MS Free compiler on there, which likely included it.  I seem to recall
>     that Python 2.5 included msvcrt71.dll but that there were problems
>     with
>     redistributions of it (or something like that)... hmm, it's not
>     installed in the Python25 folder, so it could be that's what did the
>     system-level install.
>
>     What's really weird is that PyOpenGL without the accelerator module is
>     pure Python... that is, it's not even compiled, it just uses ctypes to
>     access the dlls.  Maybe in compiling one of the dlls we bundle as data
>     (maybe GLE?) I produced a dependency on vc7's redistributable.  If you
>     move OpenGL/DLLS/gle32.dll and OpenGL/DLLS/glut32.dll do you still get
>     the message?
>
>     Hmm, reading again, you're saying the *installer* is failing... hrmph.
>     Probably built the pure-python installer with Python 2.5 and it linked
>     to the Python 2.5 runtime... why would an installer require an
>     external
>     run-time?  Sigh.  Work-around would be to run the source installation
>     (i.e. download, unpack, run "python setup.py install") or even use
>     "easy_install <thezipfile>" if you want.
>
>     Mike
>
>     --
>     ________________________________________________
>      Mike C. Fletcher
>      Designer, VR Plumber, Coder
>      http://www.vrplumber.com
>      http://blog.vrplumber.com
>
>
>
>
> -- 
> David L. Page
> Knoxville, Tennessee
> dav...@ie... <mailto:dav...@ie...>
> 865.607.8192
>


-- 
________________________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://www.vrplumber.com
  http://blog.vrplumber.com

[PyOpenGL-Users] radar effect on pyopengl

[Cata <cat...@gm...>]

Hi
 I wanna create a radara effect with pyopengl .
Something like http://www.aefreemart.com/uploaded_images/radarScreen-719485.jpg
I thinking to use 2 line and blend effect ...
Do you have some ideas ?
Regards !

Re: [PyOpenGL-Users] Textures usage

[Ian M. <geo...@gm...>]

Hi,

Set 2D View:

#if your screen is 800x600, rect = [0,0,800,600]
glViewport(*rect)
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
gluOrtho2D(rect[0],rect[0]+rect[2],rect[1],rect[1]+rect[3])
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()

Draw textured fullscreen quad.  Make sure you bind to your texture too!

param = glGetFloatv(GL_VIEWPORT)
glBegin(GL_QUADS)
glTexCoord2f(0,0);glVertex2f(param[0],         param[1]         )
glTexCoord2f(1,0);glVertex2f(param[0]+param[2],param[1]         )
glTexCoord2f(1,1);glVertex2f(param[0]+param[2],param[1]+param[3])
glTexCoord2f(0,1);glVertex2f(param[0],         param[1]+param[3])
glEnd()

Ian

Re: [PyOpenGL-Users] Textures usage

[Ian M. <geo...@gm...>]

Best plan is to use a 2D view and then draw a quad going from (0,0) to
(screen_x, screen_y).  I have some code somewhere.

Re: [PyOpenGL-Users] Textures usage

[Frédéric <fre...@gb...>]

Le mardi 12 janvier 2010 08:08, Frédéric a écrit :

> In fact, I have a problem with my textures. I think I mis-understood the
> mapping between the textures coordinates and the space coordinates...

My problem is: how do I fill the window with my texture, when neither the 
window nor the texture is a square?

-- 
   Frédéric

   http://www.gbiloba.org

Re: [PyOpenGL-Users] Textures usage

[Frédéric <fre...@gb...>]

Le vendredi 8 janvier 2010 16:10, Frédéric a écrit :

> My question was more about the ratio; as you can see in the code, I
> compute the mapping of the texture from the image size. But then, if I
> want to load a new image with a different ratio, how do I expand/shrink
> the previous one?

In fact, I have a problem with my textures. I think I mis-understood the 
mapping between the textures coordinates and the space coordinates...

Is there a simple tutorial explaining it?

Thanks,

-- 
   Frédéric

   http://www.gbiloba.org

Re: [PyOpenGL-Users] PyOpgnGL-3.0.1a2 MSVCR71.dll not found

[David L. P. <pa...@gm...>]

Mike--

Thanks. Yes, it is the installer that gave the warning.

I tried downloading the zip files according to your last suggestion.

It worked for PyOpenGL-3.0.1b2.zip but not for
PyOpenGL-accelerate-3.0.1b2.zip. Here's the output for th accelerate
attempt.

f:\PyOpenGL-accelerate-3.0.1b2> python setup.py install
running install
running build
running build_py
running build_ext
building 'OpenGL_accelerate.wrapper' extension
Unable to import Numeric, skipping Numeric extension building
error: Unable to find vcvarsall.bat

--Dave




On Sun, Jan 10, 2010 at 11:38 PM, Mike C. Fletcher
<mcf...@vr...>wrote:

> David L. Page wrote:
> >
> > I am attempting to install PyOpenGL-3.0.1b2 on a Win7 system with
> > Python 2.6 installed. I receive an error that msvcr71.dll was not
> > found upon start of the PyOpenGL install exe.
> >
> > I have found online suggestions to download msvcr71.dll from various
> > sites and then to copy that dll into the win system directory. For
> > obvious reasons, I am unsatisfied with this solution and haven't
> > attempted it.
> >
> > Does any else have a work around?
> Hmm, that's a pain.  If I'm reading correctly, there's no VC 2003 (7.1)
> redistributable download on microsoft.com.  So there's no official way
> to redistribute it?  That doesn't seem very helpful :( .  Something has
> installed it to the Windows folder on my Vista machine, but I've got the
> MS Free compiler on there, which likely included it.  I seem to recall
> that Python 2.5 included msvcrt71.dll but that there were problems with
> redistributions of it (or something like that)... hmm, it's not
> installed in the Python25 folder, so it could be that's what did the
> system-level install.
>
> What's really weird is that PyOpenGL without the accelerator module is
> pure Python... that is, it's not even compiled, it just uses ctypes to
> access the dlls.  Maybe in compiling one of the dlls we bundle as data
> (maybe GLE?) I produced a dependency on vc7's redistributable.  If you
> move OpenGL/DLLS/gle32.dll and OpenGL/DLLS/glut32.dll do you still get
> the message?
>
> Hmm, reading again, you're saying the *installer* is failing... hrmph.
> Probably built the pure-python installer with Python 2.5 and it linked
> to the Python 2.5 runtime... why would an installer require an external
> run-time?  Sigh.  Work-around would be to run the source installation
> (i.e. download, unpack, run "python setup.py install") or even use
> "easy_install <thezipfile>" if you want.
>
> Mike
>
> --
> ________________________________________________
>  Mike C. Fletcher
>  Designer, VR Plumber, Coder
>  http://www.vrplumber.com
>  http://blog.vrplumber.com
>
>


-- 
David L. Page
Knoxville, Tennessee
dav...@ie...
865.607.8192

Re: [PyOpenGL-Users] Exporting 3D extruded text to an OBJ file

[David M. <dvm...@gm...>]

I would like to be able to do it programmatically without having to go into
Blender.

Dave

On Mon, Jan 11, 2010 at 5:13 PM, Ian Mallett <geo...@gm...> wrote:

> Blender can make 3D fonts, and has a .obj exporter.
>



-- 
Dave Morris
http://dave.showviz.net/
http://3dcamphouston.com/

Re: [PyOpenGL-Users] Exporting 3D extruded text to an OBJ file

[Ian M. <geo...@gm...>]

Blender can make 3D fonts, and has a .obj exporter.

Re: [PyOpenGL-Users] Textures usage

[Frédéric <fre...@gb...>]

Le vendredi 8 janvier 2010 15:12, Frédéric a écrit :

> > It appears that the CPU is not used by my process. I'm not sure, but it
> > seems to be a kernel-space usage (orange in the Gkrellm default
> > theme)...
>
> It is 80% system usage, 20% process usage...

Someone on another ml suggested me to use strace to see where the system 
spend all its time. But the results don't show anything usefull. During a 
10s run, I get:

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 91.73    0.267082           1    385350           sched_yield
  2.73    0.007951           9       882         2 ioctl
  1.42    0.004130           0     13364           futex
  1.18    0.003442           2      2046      1744 open
  1.07    0.003113          10       307           mmap2
  0.72    0.002089           7       311           close
  0.58    0.001693          13       129           munmap
  0.42    0.001216           2       723       539 stat64
  0.08    0.000227           0      1404       189 read
  0.04    0.000109           4        25           brk
  0.02    0.000061           6        10           getdents64
  0.01    0.000028           0       298           write
  0.01    0.000023           0       337           fstat64
  0.00    0.000000           0         1           execve
  0.00    0.000000           0         9           chdir
  0.00    0.000000           0         3           time
  0.00    0.000000           0         1           lseek
  0.00    0.000000           0        75        49 access
  0.00    0.000000           0         2           pipe
  0.00    0.000000           0       964           gettimeofday
  0.00    0.000000           0         5         2 readlink
  0.00    0.000000           0         1           fstatfs
  0.00    0.000000           0        17           uname
  0.00    0.000000           0         9           mprotect
  0.00    0.000000           0        11           _llseek
  0.00    0.000000           0         5           readv
  0.00    0.000000           0        15           writev
  0.00    0.000000           0       363           poll
  0.00    0.000000           0        69           rt_sigaction
  0.00    0.000000           0         1           rt_sigprocmask
  0.00    0.000000           0        11           getcwd
  0.00    0.000000           0         1           getrlimit
  0.00    0.000000           0        54         3 lstat64
  0.00    0.000000           0         7           geteuid32
  0.00    0.000000           0        31           fcntl64
  0.00    0.000000           0         1           set_thread_area
  0.00    0.000000           0         1           set_tid_address
  0.00    0.000000           0         5           socket
  0.00    0.000000           0         5         2 connect
  0.00    0.000000           0         2           shutdown
  0.00    0.000000           0         3           shmat
------ ----------- ----------- --------- --------- ----------------
100.00    0.291164                406858      2530 total

As you can see, systems calls used less than 3% of the CPU! So, what are 
these system calls I can see in Gkrellm?

The same person also suggested me to have a look at OpenGL lib support. Here 
is what I get with glxinfo:

name of display: :0.0
display: :0  screen: 0
direct rendering: Yes
server glx vendor string: NVIDIA Corporation
server glx version string: 1.4
client glx vendor string: NVIDIA Corporation
client glx version string: 1.4
GLX version: 1.3
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce FX 5200/PCI/SSE2
OpenGL version string: 2.0.2 NVIDIA 87.76

I think all is fine (as other applications, like GoogleEarth or Phun works 
smoothly).

Could it be a hardware limitation? I can imagine this on the above one (P4, 
GeForce FX 5200), but I have similar results on my Q6600 + GeForce 8400 
GS...

Could someone make a test and tell me if he has the same behaviour?

Thanks,

-- 
   Frédéric

   http://www.gbiloba.org

[PyOpenGL-Users] Exporting 3D extruded text to an OBJ file

[David M. <dvm...@gm...>]

I would like to be able to export a string of 3D extruded text as an OBJ or
similar 3D file format, and I can't find any examples on the internet.

I have played around with the solid_font.py demo in the OpenGLContext/tests/
folder, which uses FontTools to display the text, but I don't know how to
get that mesh data back out.

Any ideas would be greatly appreciated, thanks,

-- 
Dave Morris

Re: [PyOpenGL-Users] Rolling spectrogram with pyopengl

[Frédéric <fre...@gb...>]

On vendredi 11 décembre 2009, Silverstein wrote:

> > Thanks for your comment. I understand your idea about the FFT. However
> > in my case profiling tells that drawing is the bottleneck, not
> > processing. To give you a more precise idea, here is the result
> > of cProfile on my application:
> > http://imgur.com/deMyT.png
> 
> Can you say a bit about what tool you are using to do the profiling and
> where I can get it?  It looks very useful.

I second this demand, for my textures problem...

-- 
    Frédéric

    http://www.gbiloba.org

Re: [PyOpenGL-Users] PyOpgnGL-3.0.1a2 MSVCR71.dll not found

[Mike C. F. <mcf...@vr...>]

David L. Page wrote:
>
> I am attempting to install PyOpenGL-3.0.1b2 on a Win7 system with
> Python 2.6 installed. I receive an error that msvcr71.dll was not
> found upon start of the PyOpenGL install exe.
>
> I have found online suggestions to download msvcr71.dll from various
> sites and then to copy that dll into the win system directory. For
> obvious reasons, I am unsatisfied with this solution and haven't
> attempted it.
>
> Does any else have a work around?
Hmm, that's a pain.  If I'm reading correctly, there's no VC 2003 (7.1)
redistributable download on microsoft.com.  So there's no official way
to redistribute it?  That doesn't seem very helpful :( .  Something has
installed it to the Windows folder on my Vista machine, but I've got the
MS Free compiler on there, which likely included it.  I seem to recall
that Python 2.5 included msvcrt71.dll but that there were problems with
redistributions of it (or something like that)... hmm, it's not
installed in the Python25 folder, so it could be that's what did the
system-level install.

What's really weird is that PyOpenGL without the accelerator module is
pure Python... that is, it's not even compiled, it just uses ctypes to
access the dlls.  Maybe in compiling one of the dlls we bundle as data
(maybe GLE?) I produced a dependency on vc7's redistributable.  If you
move OpenGL/DLLS/gle32.dll and OpenGL/DLLS/glut32.dll do you still get
the message?

Hmm, reading again, you're saying the *installer* is failing... hrmph. 
Probably built the pure-python installer with Python 2.5 and it linked
to the Python 2.5 runtime... why would an installer require an external
run-time?  Sigh.  Work-around would be to run the source installation
(i.e. download, unpack, run "python setup.py install") or even use
"easy_install <thezipfile>" if you want.

Mike

-- 
________________________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://www.vrplumber.com
  http://blog.vrplumber.com

[PyOpenGL-Users] PyOpgnGL-3.0.1a2 MSVCR71.dll not found

[David L. P. <pa...@gm...>]

I am attempting to install PyOpenGL-3.0.1b2 on a Win7 system with Python 2.6
installed. I receive an error that msvcr71.dll was not found upon start of
the PyOpenGL install exe.

I have found online suggestions to download msvcr71.dll from various sites
and then to copy that dll into the win system directory. For obvious
reasons, I am unsatisfied with this solution and haven't attempted it.

Does any else have a work around?

--Dave


-- 
David L. Page
dav...@ie...

Re: [PyOpenGL-Users] Textures usage

[Frédéric <fre...@gb...>]

On vendredi 08 janvier 2010, Gijs wrote:

> > Ok, I will first try glCopyTexImage2D. From where should I call it?
> > Should it be in a GL-specific context? What if the image ratio change?
> > How do I handle this? Can I resize the texture?
> 
> Well, depends on your implementation where you'd want to put the 
> glCopyTex command, but probably somewhere after or before the drawing 
> function.

My goal is to make a slideshow program. So, new images are loaded according 
to the timeline... But I presume that I can't use opengl functions outside 
initializeGL(), resizeGL() or paintGL() methods, in my callback binded to 
that timeline?

> If you want to draw a texture that has dimensions of 512x512 
> on a 640x480 screen, OpenGL just resizes the texture accordingly. The 
> final image might look a bit crushed or stretched, depending on the 
> resolution that you draw at and the original resolution of your
>  texture,  so you might need something like mipmapping to fix this. But
>  try it without mipmapping first.

My question was more about the ratio; as you can see in the code, I compute 
the mapping of the texture from the image size. But then, if I want to load 
a new image with a different ratio, how do I expand/shrink the previous 
one?

-- 
    Frédéric

    http://www.gbiloba.org

Re: [PyOpenGL-Users] Textures usage

[Gijs <in...@bs...>]

On 1/8/10 16:12 , Frédéric wrote:
> Le vendredi 8 janvier 2010 15:04, Frédéric a écrit :
>
>    
>> It appears that the CPU is not used by my process. I'm not sure, but it
>> seems to be a kernel-space usage (orange in the Gkrellm default theme)...
>>      
> It is 80% system usage, 20% process usage...
>
> Resizing the windows shows a strange thing:
>
>      height=351 ->  5% CPU
>      height=357 ->  100% CPU
>
> Why such a big step?
>
>    
No idea :) I'd call that a bug but without having extra information 
about what's happening, I don't know for sure. Maybe Google has an answer.

Re: [PyOpenGL-Users] Textures usage

[Gijs <in...@bs...>]

On 1/8/10 16:04 , Frédéric wrote:
> Le vendredi 8 janvier 2010 14:29, Gijs a écrit :
>
>> I haven't done any QT programming, so I could be wrong, but your code
>> shouldn't even require a couple of %'s of your CPU. The work that your
>> script does is hardly CPU-intensive and if your timer really updates
>> your frame every 1/50th of a second, then the CPU hardly does anything.
>> If on the other hand somehow OpenGL does updates without any sleeptime
>> inbetween, then it would explain the CPU usage. So I would check the
>> timer function or at least check how often your draw function is called.
>
> It appears that the CPU is not used by my process. I'm not sure, but it
> seems to be a kernel-space usage (orange in the Gkrellm default theme)...
>
>> Some optimizations might be to move the glBlendFunc out of the drawing
>> function to the init function. If you don't change the blending function
>> somewhere else, then setting it once is enough since it is a global
>> setting (not something that you need to set everytime you call
>> glEnable(GL_BLEND)). You can also move glLoadIdentity to the init
>> function if you don't call glRotate/glTranslate/glScale commands in
>> other parts of your code. Also, though I'm not completely sure on this,
>> you should be able to clear your screen without having to disable/enable
>> dither and blending every time. Put the enable calls in the init section
>> and see what happens.
>
> Thanks for the tips.
>
>> There are many ways to change a texture though I'm not sure your video
>> card would support all of them. Shaders, PBOs, and FBOs are the usual
>> way to do this but check and see if your FX5200 supports those.
>> Otherwise you'd need to use the standard OpenGL calls like
>> glCopyTexImage2D.
>
> Ok, I will first try glCopyTexImage2D. From where should I call it? Should
> it be in a GL-specific context? What if the image ratio change? How do I
> handle this? Can I resize the texture?
>
Well, depends on your implementation where you'd want to put the 
glCopyTex command, but probably somewhere after or before the drawing 
function. If you want to draw a texture that has dimensions of 512x512 
on a 640x480 screen, OpenGL just resizes the texture accordingly. The 
final image might look a bit crushed or stretched, depending on the 
resolution that you draw at and the original resolution of your texture, 
so you might need something like mipmapping to fix this. But try it 
without mipmapping first.

Re: [PyOpenGL-Users] Textures usage

[Frédéric <fre...@gb...>]

Le vendredi 8 janvier 2010 15:04, Frédéric a écrit :

> It appears that the CPU is not used by my process. I'm not sure, but it
> seems to be a kernel-space usage (orange in the Gkrellm default theme)...

It is 80% system usage, 20% process usage...

Resizing the windows shows a strange thing:

    height=351 -> 5% CPU
    height=357 -> 100% CPU

Why such a big step?

-- 
   Frédéric

   http://www.gbiloba.org

Re: [PyOpenGL-Users] Textures usage

[Frédéric <fre...@gb...>]

Le vendredi 8 janvier 2010 14:29, Gijs a écrit :

> I haven't done any QT programming, so I could be wrong, but your code
> shouldn't even require a couple of %'s of your CPU. The work that your
> script does is hardly CPU-intensive and if your timer really updates
> your frame every 1/50th of a second, then the CPU hardly does anything.
> If on the other hand somehow OpenGL does updates without any sleeptime
> inbetween, then it would explain the CPU usage. So I would check the
> timer function or at least check how often your draw function is called.

It appears that the CPU is not used by my process. I'm not sure, but it 
seems to be a kernel-space usage (orange in the Gkrellm default theme)...

> Some optimizations might be to move the glBlendFunc out of the drawing
> function to the init function. If you don't change the blending function
> somewhere else, then setting it once is enough since it is a global
> setting (not something that you need to set everytime you call
> glEnable(GL_BLEND)). You can also move glLoadIdentity to the init
> function if you don't call glRotate/glTranslate/glScale commands in
> other parts of your code. Also, though I'm not completely sure on this,
> you should be able to clear your screen without having to disable/enable
> dither and blending every time. Put the enable calls in the init section
> and see what happens.

Thanks for the tips.

> There are many ways to change a texture though I'm not sure your video
> card would support all of them. Shaders, PBOs, and FBOs are the usual
> way to do this but check and see if your FX5200 supports those.
> Otherwise you'd need to use the standard OpenGL calls like
> glCopyTexImage2D.

Ok, I will first try glCopyTexImage2D. From where should I call it? Should 
it be in a GL-specific context? What if the image ratio change? How do I 
handle this? Can I resize the texture?

-- 
   Frédéric

   http://www.gbiloba.org

Re: [PyOpenGL-Users] Textures usage

[Gijs <in...@bs...>]

On 1/8/10 14:30 , Frédéric wrote:
> Le vendredi 8 janvier 2010 12:55, Frédéric a écrit :
>
>    
>> I'm still trying to made crossfade between 2 images, using opengl
>> textures, but it does not work fine. Here is my code :
>>      
> Ok, I found my mistake: the first texture is at z index 0, so I changed:
>
>      glOrtho(0., 1., 1., 0., 0., 10.)
>
> to:
>
>      glOrtho(0., 1., 1., 0., -10., 10.)
>
> and it now works.
>
> Is there a way to optimize this code? On my old computer (P4 / GeForce FX
> 5200), it takes 100% of the CPU with only a 640x480 windows. If I resize it
> to 320x200, it does not take more than 5%...
>
> My next step will be to update the textures as the pictures change; what is
> the best way to do this?
>
>    
Hello Frédéric,

I haven't done any QT programming, so I could be wrong, but your code 
shouldn't even require a couple of %'s of your CPU. The work that your 
script does is hardly CPU-intensive and if your timer really updates 
your frame every 1/50th of a second, then the CPU hardly does anything. 
If on the other hand somehow OpenGL does updates without any sleeptime 
inbetween, then it would explain the CPU usage. So I would check the 
timer function or at least check how often your draw function is called.

Some optimizations might be to move the glBlendFunc out of the drawing 
function to the init function. If you don't change the blending function 
somewhere else, then setting it once is enough since it is a global 
setting (not something that you need to set everytime you call 
glEnable(GL_BLEND)). You can also move glLoadIdentity to the init 
function if you don't call glRotate/glTranslate/glScale commands in 
other parts of your code. Also, though I'm not completely sure on this, 
you should be able to clear your screen without having to disable/enable 
dither and blending every time. Put the enable calls in the init section 
and see what happens.

There are many ways to change a texture though I'm not sure your video 
card would support all of them. Shaders, PBOs, and FBOs are the usual 
way to do this but check and see if your FX5200 supports those. 
Otherwise you'd need to use the standard OpenGL calls like glCopyTexImage2D.

Regards, Gijs//

Re: [PyOpenGL-Users] Textures usage

[Frédéric <fre...@gb...>]

Le vendredi 8 janvier 2010 12:55, Frédéric a écrit :

> I'm still trying to made crossfade between 2 images, using opengl
> textures, but it does not work fine. Here is my code :

Ok, I found my mistake: the first texture is at z index 0, so I changed:

    glOrtho(0., 1., 1., 0., 0., 10.)

to:

    glOrtho(0., 1., 1., 0., -10., 10.)

and it now works.

Is there a way to optimize this code? On my old computer (P4 / GeForce FX 
5200), it takes 100% of the CPU with only a 640x480 windows. If I resize it 
to 320x200, it does not take more than 5%...

My next step will be to update the textures as the pictures change; what is 
the best way to do this?

-- 
   Frédéric

   http://www.gbiloba.org

[PyOpenGL-Users] Textures usage

[Frédéric <fre...@gb...>]

Hi,

I'm still trying to made crossfade between 2 images, using opengl textures, 
but it does not work fine. Here is my code :

    http://www.pycasso.org/browser/trunk/proto/crossFadeOpenGL.py

I only see the second texture. Where is my mistake?

Thanks,

-- 
   Frédéric

   http://www.gbiloba.org

Re: [PyOpenGL-Users] textures from image files

[Gijs <in...@bs...>]

On 5-1-2010 9:57, Jef Mangelschots wrote:
> PIL 1.1.6 supposedly has a module name ImageGL to convert image files 
> to OpenGL textures.
> This somehow does not work for me for lack of the _imaginggl module.
> This is supposedly part of imToolkit according to the comment but 
> google never heard of it.
>
> How can I convert image files (e.g. JPG) to PyOpenGL textures ?
> can I do it with PIL (if so, how) or do I need something else ?
>
> Jef
Hello Jef,

I am using the following function to load PNG files into OpenGL using PIL:
def initPixelData(filename, tex_type = GL_TEXTURE_RECTANGLE_ARB):
   img = Image.open(filename)
   pixels = array(img.getdata(), 'B')
   w, h = img.size
   pixels = pixels[::-1].ravel()  # -> pixels.reverse()

   # this probably does not always work, but at least it works for RGB 
and RGBA
   exec("mode = GL_"+img.mode)

   # Create texture / set texture parameters / put the data into the 
texture / disable texture and return
   texid = int(glGenTextures(1))
   glActiveTexture(GL_TEXTURE0)
   glEnable(tex_type)
   glBindTexture(tex_type, texid)
   glTexParameterf(tex_type, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
   glTexParameterf(tex_type, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
   glTexImage2D(tex_type, 0, GL_RGB, w, h, 0, GL_RGB, GL_UNSIGNED_BYTE, 
pixels)
   glBindTexture(tex_type, 0)

   return texid, w, h

You might have to alter it a bit, depending on the type of your images, 
but it should give you a general idea how to do it.

Regards, Gijs