Re: [pygame] Segfault on loading font from StringIO
On Wed, Jan 4, 2012 at 05:56, Lenard Lindstrom wrote:
> Hi,
>
>
> On 02/01/12 05:45 AM, Radomir Dopieralski wrote:
>>
>> I think that this comment is related to this problem:
>> http://archives.seul.org/pygame/users/Jan-2004/msg00035.html
>
> No, this is a different problem. pygame.font.Font probably could not find
> the default font file and segfaulted rather than throw a nice Python
> exception. This may have been fixed. I can check.
>
>
>> On Mon, Jan 2, 2012 at 13:46, Russell Jones
>> wrote:
>>>
>>> In summary, the font reading function in SDL relies on a filename, so as
>>> it
>>> stands, reading from a file-like object won't work. Covering the buffer
>>> to a
>>> string causes the data to be interpreted as a filename, which
>>> unsurprisingly
>>> gives an IOError saying the font filename can't be read (line 600 of
>>> font.c).
>>>
>>> I had a look on Debian testing in a VM, and it seems to be happening in
>>> SDL_RWFromFile, which is not in font.c, but is called by its functions. I
>>> couldn't see where the error was happening in font.c as there are no
>>> pygame
>>> debug symbols available. I'm guessing it's the line
>>> rw = RWopsFromPython (fileobj)
>>> (RWopsFromPython is from rwobject.c and calls get_standard_rwop, which
>>> calls
>>> either SDL_RWFromFile or SDL_RWFromFP if it can't extract a name from
>>> fileobj)
>>>
>>> It seems likely to be related to this comment in font_init() : /*check if
>>> it
>>> is a valid file, else SDL_ttf segfaults*/. I guess SDL_RWFromMem could be
>>> used with some kind of translation from the buffer, or SDL_RWFromFile
>>> could
>>> be altered to accept a file object. The SDL API spec for FromFile relies
>>> on
>>> a filename, however, and FromFile does the opening of the file itself
>>> using
>>> that.
>>>
>>> Russell
>>>
>>> On 1 January 2012 10:50, Radomir Dopieralski wrote:
Hello everyone,
I'm having a problem loading a font file from a python file-like
object. According to the documentation at
http://www.pygame.org/docs/ref/font.html#pygame.font.Font this should
be possible, however, I get a segmentation fault every time I pass a
file-like object that is not created by opening a real file. I want to
load all my assets from a zip archive, so it's not possible to have a
real file in the filesystem.
A simple test case:
import pygame
import StringIO
pygame.font.init()
f = open("somefont.ttf", "r")
font = pygame.font.Font(f, 8) # Works fine
f.close()
f = open("somefont.ttf", "r")
buffer = StringIO.StringIO(f.read())
f.close()
font = pygame.font.Font(buffer, 8) # Segfault
Is there any way to make it work as documented? If the documentation
is wrong, is there any way to create a pygame font object without
creating a real file in the filesystem?
Thanks,
--
Radomir Dopieralski
>>>
>>>
> The Font type should accept any Python object with read(), seek() and
> close() methods. However, Pygame 1.9.1 and earlier have a Font bug involving
> file like objects that are not actual file objects. Basically, threading is
> improperly handled. It probably worked if early versions of the freetype
> library were single threaded. But freetype now appears to be multithreaded.
> Therefore the segfault. I fixed this for Pygame 1.9.2 (still in development)
> so I get no segfault; it works as advertised.
Thank you very much!
I'm sure that it will be released before I finish my project, so that
really helps a lot.
--
Radomir Dopieralski
Re: [pygame] Segfault on loading font from StringIO
Hi,
On 02/01/12 05:45 AM, Radomir Dopieralski wrote:
I think that this comment is related to this problem:
http://archives.seul.org/pygame/users/Jan-2004/msg00035.html
No, this is a different problem. pygame.font.Font probably could not
find the default font file and segfaulted rather than throw a nice
Python exception. This may have been fixed. I can check.
On Mon, Jan 2, 2012 at 13:46, Russell Jones wrote:
In summary, the font reading function in SDL relies on a filename, so as it
stands, reading from a file-like object won't work. Covering the buffer to a
string causes the data to be interpreted as a filename, which unsurprisingly
gives an IOError saying the font filename can't be read (line 600 of
font.c).
I had a look on Debian testing in a VM, and it seems to be happening in
SDL_RWFromFile, which is not in font.c, but is called by its functions. I
couldn't see where the error was happening in font.c as there are no pygame
debug symbols available. I'm guessing it's the line
rw = RWopsFromPython (fileobj)
(RWopsFromPython is from rwobject.c and calls get_standard_rwop, which calls
either SDL_RWFromFile or SDL_RWFromFP if it can't extract a name from
fileobj)
It seems likely to be related to this comment in font_init() : /*check if it
is a valid file, else SDL_ttf segfaults*/. I guess SDL_RWFromMem could be
used with some kind of translation from the buffer, or SDL_RWFromFile could
be altered to accept a file object. The SDL API spec for FromFile relies on
a filename, however, and FromFile does the opening of the file itself using
that.
Russell
On 1 January 2012 10:50, Radomir Dopieralski wrote:
Hello everyone,
I'm having a problem loading a font file from a python file-like
object. According to the documentation at
http://www.pygame.org/docs/ref/font.html#pygame.font.Font this should
be possible, however, I get a segmentation fault every time I pass a
file-like object that is not created by opening a real file. I want to
load all my assets from a zip archive, so it's not possible to have a
real file in the filesystem.
A simple test case:
import pygame
import StringIO
pygame.font.init()
f = open("somefont.ttf", "r")
font = pygame.font.Font(f, 8) # Works fine
f.close()
f = open("somefont.ttf", "r")
buffer = StringIO.StringIO(f.read())
f.close()
font = pygame.font.Font(buffer, 8) # Segfault
Is there any way to make it work as documented? If the documentation
is wrong, is there any way to create a pygame font object without
creating a real file in the filesystem?
Thanks,
--
Radomir Dopieralski
The Font type should accept any Python object with read(), seek() and
close() methods. However, Pygame 1.9.1 and earlier have a Font bug
involving file like objects that are not actual file objects. Basically,
threading is improperly handled. It probably worked if early versions of
the freetype library were single threaded. But freetype now appears to
be multithreaded. Therefore the segfault. I fixed this for Pygame 1.9.2
(still in development) so I get no segfault; it works as advertised.
Lenard Lindstrom
Re: [pygame] Segfault on loading font from StringIO
I think that this comment is related to this problem:
http://archives.seul.org/pygame/users/Jan-2004/msg00035.html
On Mon, Jan 2, 2012 at 13:46, Russell Jones wrote:
> In summary, the font reading function in SDL relies on a filename, so as it
> stands, reading from a file-like object won't work. Covering the buffer to a
> string causes the data to be interpreted as a filename, which unsurprisingly
> gives an IOError saying the font filename can't be read (line 600 of
> font.c).
>
> I had a look on Debian testing in a VM, and it seems to be happening in
> SDL_RWFromFile, which is not in font.c, but is called by its functions. I
> couldn't see where the error was happening in font.c as there are no pygame
> debug symbols available. I'm guessing it's the line
> rw = RWopsFromPython (fileobj)
> (RWopsFromPython is from rwobject.c and calls get_standard_rwop, which calls
> either SDL_RWFromFile or SDL_RWFromFP if it can't extract a name from
> fileobj)
>
> It seems likely to be related to this comment in font_init() : /*check if it
> is a valid file, else SDL_ttf segfaults*/. I guess SDL_RWFromMem could be
> used with some kind of translation from the buffer, or SDL_RWFromFile could
> be altered to accept a file object. The SDL API spec for FromFile relies on
> a filename, however, and FromFile does the opening of the file itself using
> that.
>
> Russell
>
> On 1 January 2012 10:50, Radomir Dopieralski wrote:
>>
>> Hello everyone,
>>
>> I'm having a problem loading a font file from a python file-like
>> object. According to the documentation at
>> http://www.pygame.org/docs/ref/font.html#pygame.font.Font this should
>> be possible, however, I get a segmentation fault every time I pass a
>> file-like object that is not created by opening a real file. I want to
>> load all my assets from a zip archive, so it's not possible to have a
>> real file in the filesystem.
>>
>> A simple test case:
>>
>> import pygame
>> import StringIO
>>
>> pygame.font.init()
>>
>> f = open("somefont.ttf", "r")
>> font = pygame.font.Font(f, 8) # Works fine
>> f.close()
>>
>> f = open("somefont.ttf", "r")
>> buffer = StringIO.StringIO(f.read())
>> f.close()
>> font = pygame.font.Font(buffer, 8) # Segfault
>>
>> Is there any way to make it work as documented? If the documentation
>> is wrong, is there any way to create a pygame font object without
>> creating a real file in the filesystem?
>>
>> Thanks,
>> --
>> Radomir Dopieralski
>
>
Re: [pygame] Segfault on loading font from StringIO
In summary, the font reading function in SDL relies on a filename, so as it
stands, reading from a file-like object won't work. Covering the buffer to
a string causes the data to be interpreted as a filename, which
unsurprisingly gives an IOError saying the font filename can't be read
(line 600 of font.c).
I had a look on Debian testing in a VM, and it seems to be happening in
SDL_RWFromFile, which is not in font.c, but is called by its functions. I
couldn't see where the error was happening in font.c as there are no pygame
debug symbols available. I'm guessing it's the line
rw = RWopsFromPython (fileobj)
(RWopsFromPython is from rwobject.c and calls get_standard_rwop, which
calls either SDL_RWFromFile or SDL_RWFromFP if it can't extract a name from
fileobj)
It seems likely to be related to this comment in font_init() : /*check if
it is a valid file, else SDL_ttf segfaults*/. I guess SDL_RWFromMem could
be used with some kind of translation from the buffer, or SDL_RWFromFile
could be altered to accept a file object. The SDL API spec for FromFile
relies on a filename, however, and FromFile does the opening of the file
itself using that.
Russell
On 1 January 2012 10:50, Radomir Dopieralski wrote:
> Hello everyone,
>
> I'm having a problem loading a font file from a python file-like
> object. According to the documentation at
> http://www.pygame.org/docs/ref/font.html#pygame.font.Font this should
> be possible, however, I get a segmentation fault every time I pass a
> file-like object that is not created by opening a real file. I want to
> load all my assets from a zip archive, so it's not possible to have a
> real file in the filesystem.
>
> A simple test case:
>
> import pygame
> import StringIO
>
> pygame.font.init()
>
> f = open("somefont.ttf", "r")
> font = pygame.font.Font(f, 8) # Works fine
> f.close()
>
> f = open("somefont.ttf", "r")
> buffer = StringIO.StringIO(f.read())
> f.close()
> font = pygame.font.Font(buffer, 8) # Segfault
>
> Is there any way to make it work as documented? If the documentation
> is wrong, is there any way to create a pygame font object without
> creating a real file in the filesystem?
>
> Thanks,
> --
> Radomir Dopieralski
>
Re: [pygame] Segfault on loading font from StringIO
I had a little play with this, and the following segfaults, too (on OS X
10.7 w/ Macports Python 2.7 and pygame 1.9.1)
import pygame
import io
pygame.font.init()
f = open("/opt/local/share/wine/fonts/symbol.ttf", "r")
font = pygame.font.Font(f, 8) # Works fine
f.close()
f = open("/opt/local/share/wine/fonts/symbol.ttf", "rb")
buffer = io.BytesIO()
c=f.read()
print(len(c))
while len(c) != 0:
buffer.write(c)
c=f.read()
print(len(c))
f.close()
buffer.seek(0)
font = pygame.font.Font(buffer, 8) # Segfault
Similarly with StringIO.StringIO()
Russell
On 1 January 2012 10:50, Radomir Dopieralski wrote:
> Hello everyone,
>
> I'm having a problem loading a font file from a python file-like
> object. According to the documentation at
> http://www.pygame.org/docs/ref/font.html#pygame.font.Font this should
> be possible, however, I get a segmentation fault every time I pass a
> file-like object that is not created by opening a real file. I want to
> load all my assets from a zip archive, so it's not possible to have a
> real file in the filesystem.
>
> A simple test case:
>
> import pygame
> import StringIO
>
> pygame.font.init()
>
> f = open("somefont.ttf", "r")
> font = pygame.font.Font(f, 8) # Works fine
> f.close()
>
> f = open("somefont.ttf", "r")
> buffer = StringIO.StringIO(f.read())
> f.close()
> font = pygame.font.Font(buffer, 8) # Segfault
>
> Is there any way to make it work as documented? If the documentation
> is wrong, is there any way to create a pygame font object without
> creating a real file in the filesystem?
>
> Thanks,
> --
> Radomir Dopieralski
>
Re: [pygame] Segfault on loading font from StringIO
Hi guys, could someone please give me the address I email to start a new thread
because the one I keep trying to email is not working
-Zack
On Jan 1, 2012, at 5:50 AM, Radomir Dopieralski wrote:
> Hello everyone,
>
> I'm having a problem loading a font file from a python file-like
> object. According to the documentation at
> http://www.pygame.org/docs/ref/font.html#pygame.font.Font this should
> be possible, however, I get a segmentation fault every time I pass a
> file-like object that is not created by opening a real file. I want to
> load all my assets from a zip archive, so it's not possible to have a
> real file in the filesystem.
>
> A simple test case:
>
> import pygame
> import StringIO
>
> pygame.font.init()
>
> f = open("somefont.ttf", "r")
> font = pygame.font.Font(f, 8) # Works fine
> f.close()
>
> f = open("somefont.ttf", "r")
> buffer = StringIO.StringIO(f.read())
> f.close()
> font = pygame.font.Font(buffer, 8) # Segfault
>
> Is there any way to make it work as documented? If the documentation
> is wrong, is there any way to create a pygame font object without
> creating a real file in the filesystem?
>
> Thanks,
> --
> Radomir Dopieralski
