nanogui: Images not drawn (FLTK+nxlib app with nano-X)
Subject:
RE: [nanogui] Images not drawn (FLTK+nxlib app with nano-X)
From:
"Martin Kajdas" ####@####.####
Date:
2 Feb 2006 23:17:46 +0000
Message-Id: <CF2BB830A62F914F848E5AD5FFF57AC22914C0@mkmail.MKPROD.COM>
The problem is with image widths not equal to 16 bit multiples,
i.e. the image of size 32x24 displays fine,
the image of size 24x24 displays only 16x24 pixels (the 8 right most pixels are either transparent or not displayed)
I believe, any width between 17 and 31 will display only 16 pixels.
It is not odd/even issue but 16 bit multiple (works) vs. not 16 bit multiple (clipped).
I will look at your other suggestions tomorrow morning.
Martin
-----Original Message-----
From: Greg Haerr ####@####.####
Sent: Thursday, February 02, 2006 2:57 PM
To: Martin Kajdas
Cc: ####@####.####
Subject: Re: [nanogui] Images not drawn (FLTK+nxlib app with nano-X)
: I verified that the image size and the data is correct when calling
GrArea() function (width=height=24, 48x24 bytes of data match image).
: I used a 24x24 image which displays only 16x24 worth of data.
I thought the problem occured with odd widths, not even widths...
Can you explain a bit more?
: Where should I be looking now? GdArea()?
Yes. There is a possibility that the nxproto.c code could be
chopping/rounding the data down, although I don't think so.
This would be the GrArea code in srvnet.c/client.c.
: One problem I noticed with nxlib (PNG conversion), is that the transparent
color and black color are both zero making the images appear wrong (black
pixels are transparent).
: This would explain another problem with my images.
The image_png.c file should have the transparent member in the
MWIMAGEHDR structure set to -1. You might verify this to
be the case.
Regards,
Greg
