Pixmap practical size limitation?

2002-04-18 Thread Jerry Miller

In modifying an existing application, which contained
one (scrolled) DrawingArea and two (scrolled) Text
widgets, I wanted to use multicolor text and decided
to use two more DrawingArea widgets to accomplish
this.  However, only the 2000x2000 original Pixmap
is reliably written for the refreshment of the original
DrawingArea.

In order to accommodate the potentially long and/or
wide range of text in the emulated Text widgets, I
created a Pixmap of size 5000x4000 and 1x2000,
respectively.  To be sure it wasn't something in the
rendition of the text strings that was at fault in their
unpredictable behavior, I drew a black 20x100
rectangle in the upper left corner of each Pixmap
immediately after creation.  Only the one for the
2000x2000 Pixmap appears in the associated
DrawingArea window.

Other than their sizes (and the variable names,
of course), there is virtually no difference between
these Pixmaps.  In fact, if I temporarily change
the dimensions of the other two to 2000x2000,
I find that their behavior becomes reliable once
again.

None of the X documentation mentions any
size limitations for the Pixmap, whose datatype
is opaque.  (Thanks a lot, MIT!)  Even if
there were one, it should generate a predictable
error message, rather than an unpredictable
behavior.  Anyway, even if unsigned int
referred to 16 bits on my computer (which it
does not), these dimensions would still be
within range - for that matter, they would even
be accommodated by signed short!

Is this a known bug?  If so, can I get around it,
albeit kludgily, by declaring 21 variables of type
Pixmap and doing redundant XDrawString()
calls to be sure that any that might fall withing
the bounds of the write will be updated, or is
there a limit on the _total_ amount of memory
available for Pixmap data?

I am running under Windows NT4, SP3, with
the Hummingbird Window Manager, v.6.1.
(The window manager supplied with cygwin
is impractical for any sophisticated applications.)





RE: Pixmap practical size limitation?

2002-04-18 Thread Harold Hunt

Jerry,

This is a Cygwin/XFree86-specific mailing list.  Your question about whether
40 MB to 80 MB pixmaps are allowed is a general XFree86/X question that
should be asked and answered by general XFree86/X mailing lists or
documentation.

Please check out these websites for more information and mailing list
addresses:
http://xfree86.org/
http://www.x.org/

You might also want to look in books, etc. for an answer.

Sorry we can't help,

Harold

 -Original Message-
 From: [EMAIL PROTECTED]
 [mailto:[EMAIL PROTECTED]]On Behalf Of Jerry Miller
 Sent: Thursday, April 18, 2002 2:57 PM
 To: [EMAIL PROTECTED]
 Subject: Pixmap practical size limitation?


 In modifying an existing application, which contained
 one (scrolled) DrawingArea and two (scrolled) Text
 widgets, I wanted to use multicolor text and decided
 to use two more DrawingArea widgets to accomplish
 this.  However, only the 2000x2000 original Pixmap
 is reliably written for the refreshment of the original
 DrawingArea.

 In order to accommodate the potentially long and/or
 wide range of text in the emulated Text widgets, I
 created a Pixmap of size 5000x4000 and 1x2000,
 respectively.  To be sure it wasn't something in the
 rendition of the text strings that was at fault in their
 unpredictable behavior, I drew a black 20x100
 rectangle in the upper left corner of each Pixmap
 immediately after creation.  Only the one for the
 2000x2000 Pixmap appears in the associated
 DrawingArea window.

 Other than their sizes (and the variable names,
 of course), there is virtually no difference between
 these Pixmaps.  In fact, if I temporarily change
 the dimensions of the other two to 2000x2000,
 I find that their behavior becomes reliable once
 again.

 None of the X documentation mentions any
 size limitations for the Pixmap, whose datatype
 is opaque.  (Thanks a lot, MIT!)  Even if
 there were one, it should generate a predictable
 error message, rather than an unpredictable
 behavior.  Anyway, even if unsigned int
 referred to 16 bits on my computer (which it
 does not), these dimensions would still be
 within range - for that matter, they would even
 be accommodated by signed short!

 Is this a known bug?  If so, can I get around it,
 albeit kludgily, by declaring 21 variables of type
 Pixmap and doing redundant XDrawString()
 calls to be sure that any that might fall withing
 the bounds of the write will be updated, or is
 there a limit on the _total_ amount of memory
 available for Pixmap data?

 I am running under Windows NT4, SP3, with
 the Hummingbird Window Manager, v.6.1.
 (The window manager supplied with cygwin
 is impractical for any sophisticated applications.)