Added more logic to cg_to_glsl converter to find cgc in o3d/third_party/cgc/...

Added more logic to cg_to_glsl converter to find cgc in o3d/third_party/cgc/
as a last resort. This will allow the converter to always be run as part of
the build process.

BUG=none
TEST=manual testing on Mac and Windows
TBR=amarinichev


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=45737

[Ken Russell (switch to Gerrit), 2010-04-27 20:47:18]

Please review. Thanks.

[Alexey Marinichev, 2010-04-27 21:28:16]

http://codereview.chromium.org/1773008/diff/1/2
File cg_to_glsl/convert.py (right):

http://codereview.chromium.org/1773008/diff/1/2#newcode33
cg_to_glsl/convert.py:33: for i in range(0, 5):
range(5)

http://codereview.chromium.org/1773008/diff/1/2#newcode41
cg_to_glsl/convert.py:41: paths = [ '/usr/bin/cgc',
Does chrome style prefer "[ x ]" over "[x]"?

http://codereview.chromium.org/1773008/diff/1/2#newcode60
cg_to_glsl/convert.py:60: cg_root = os.path.join(o3d_root, 'third_party', 'cg',
'files')
'third_party/cg/files' would be more readable.

http://codereview.chromium.org/1773008/diff/1/2#newcode65
cg_to_glsl/convert.py:65: for exe in exes:
relative_paths = ['linux/bin/cgc', ....]
for exe in (os.path.join(cgc_root, relative_paths)):
 ...

http://codereview.chromium.org/1773008/diff/1/2#newcode69
cg_to_glsl/convert.py:69: stderr=open(os.devnull, 'w'))
Is checking if the path exists not enough?  Do you really have to try to execute
it?

http://codereview.chromium.org/1773008/diff/1/2#newcode245
cg_to_glsl/convert.py:245: def main(cg_shader, CGC):
I used all caps CGC to show it's a constant that's never supposed to change.  I
think it would make sense to either leave it as CGC and not pass it as an extra
argument, or rename it to cgc_path and drag it along.  I'd prefer to keep it
global.

[Alexey Marinichev, 2010-04-27 23:24:09]

http://codereview.chromium.org/1773008/diff/1/2
File cg_to_glsl/convert.py (right):

http://codereview.chromium.org/1773008/diff/1/2#newcode65
cg_to_glsl/convert.py:65: for exe in exes:
Um, that's not exactly what I meant...  You can call os.path.join inside the
loop.
On 2010/04/27 21:28:16, Alexey Marinichev wrote:
> relative_paths = ['linux/bin/cgc', ....]
> for exe in (os.path.join(cgc_root, relative_paths)):
>  ...

[Ken Russell (switch to Gerrit), 2010-04-28 02:30:49]

http://codereview.chromium.org/1773008/diff/1/2
File cg_to_glsl/convert.py (right):

http://codereview.chromium.org/1773008/diff/1/2#newcode33
cg_to_glsl/convert.py:33: for i in range(0, 5):
On 2010/04/27 21:28:16, Alexey Marinichev wrote:
> range(5)

Done. Will send you a separate CL with this and the other changes.

http://codereview.chromium.org/1773008/diff/1/2#newcode41
cg_to_glsl/convert.py:41: paths = [ '/usr/bin/cgc',
On 2010/04/27 21:28:16, Alexey Marinichev wrote:
> Does chrome style prefer "[ x ]" over "[x]"?

Not sure. I'll get rid of the surrounding spaces.

http://codereview.chromium.org/1773008/diff/1/2#newcode60
cg_to_glsl/convert.py:60: cg_root = os.path.join(o3d_root, 'third_party', 'cg',
'files')
On 2010/04/27 21:28:16, Alexey Marinichev wrote:
> 'third_party/cg/files' would be more readable.

Unclear to me whether that is guaranteed to be functionally equivalent.

http://codereview.chromium.org/1773008/diff/1/2#newcode65
cg_to_glsl/convert.py:65: for exe in exes:
On 2010/04/27 23:24:09, Alexey Marinichev wrote:
> Um, that's not exactly what I meant...  You can call os.path.join inside the
> loop.
> On 2010/04/27 21:28:16, Alexey Marinichev wrote:
> > relative_paths = ['linux/bin/cgc', ....]
> > for exe in (os.path.join(cgc_root, relative_paths)):
> >  ...

See above regarding my concern about funcional equivalence in particular on
non-Cygwin versions of Python on Windows.

http://codereview.chromium.org/1773008/diff/1/2#newcode69
cg_to_glsl/convert.py:69: stderr=open(os.devnull, 'w'))
On 2010/04/27 21:28:16, Alexey Marinichev wrote:
> Is checking if the path exists not enough?  Do you really have to try to
execute
> it?

Unfortunately it's not enough. All three versions live in workspaces checked out
on any of these three platforms.

http://codereview.chromium.org/1773008/diff/1/2#newcode245
cg_to_glsl/convert.py:245: def main(cg_shader, CGC):
On 2010/04/27 21:28:16, Alexey Marinichev wrote:
> I used all caps CGC to show it's a constant that's never supposed to change. 
I
> think it would make sense to either leave it as CGC and not pass it as an
extra
> argument, or rename it to cgc_path and drag it along.  I'd prefer to keep it
> global.

I like to avoid globals so I've changed it to cgc_path everywhere.