[Mono-bugs] [Bug 58885][Nor] Changed - Graphics class is drawing with wrong colors

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Changed by vladimir@pobox.com.

http://bugzilla.ximian.com/show_bug.cgi?id=58885

--- shadow/58885	2004-06-16 00:46:13.000000000 -0400
+++ shadow/58885.tmp.23937	2004-06-16 05:49:55.000000000 -0400
@@ -131,6 +131,21 @@
 ------- Additional Comments From rkumar@novell.com  2004-06-16 00:46 -------
 Stefan, I wanted to confirm that we are passing the correct values to 
 Cairo or not. But, it is pretty clear here that we are getting it 
 right to Cairo. I don't know why is this problem but I guess it could 
 be a bug related to portability of our encoders (more likely) or 
 Cairo (less likely).
+
+------- Additional Comments From vladimir@pobox.com  2004-06-16 05:49 -------
+When we save PNGs, we don't transform the data in any way; we tell
+libpng to expect data in either R G B or R G B A order (depending on
+whether the source has alpha or not).  On reading the png, we specify
+PNG_TRANSFORM_BGR, to change R G B into B G R.  We don't do this for
+writing, the reasons for which I'm not exactly clear on; it "seems to
+work" on x86, but it's entirely possible that there's a bug there.
+
+Also, it's possible that there's some endian-ness oddness in pixman;
+iccolor.c, pixman_color_to_pixel creates a 32 bit int "pixel" from a
+color struct.  It could be that the masks are wrong for this
+operation, considering that I see no mention of endian-ness anywhere
+within pixman.  (See the various formats in icint.h)
+