For clarification, gdiplus (gdi+) is different from gdi32 that J gl2 targeted for, so flip_rgb was already needed in pre-j701 gl2 glpixels/glqpixels commands. Changing the byte sequence to rgb with red component in the lowest byte can match the rgb format for graphics library that gtk supported.
Furthermore gdiplus is not that well supported in window platform itself, its performance is poorer than gdi32, since hardware acceleration is not that well supported when compared with gdi32. Gdiplus missed its chance as directx had become the choice for windows platform. Чтв, 17 Мар 2011, Ric Tikkanz писал(а): > If Windows & gdiplus were the primary platforms when these libraries > were designed/created then the current rgb order would have been the > appropriate(/most efficient) choice? > > Sou your question is whether it now makes sense to change the format > for glpixels to bgr order given that cairo is the graphics engine of > choice going forward. i.e. the flip_rgb would instead be required for > gdiplus but not cairo or gdi32? > > > On Thu, Mar 17, 2011 at 1:31 PM, bill lam <[email protected]> wrote: > > Yes, flip_rgb is needed for cairo and gdi32 but not gdiplus. > > J seems had chosen an inefficient way to represent pixsel color as an > > integer. > > > > Not tested on big endian platform. > > > > Чтв, 17 Мар 2011, Ric Tikkanz писал(а): > >> To be honest I'm not sure exactly what you are asking. > >> 256 #.inv 16bff0000 > >> 255 0 0 > >> > >> Are you suggesting that changing the representation of pixel colour in > >> glpixels and glqpixels to bgr rather than rgb would be more efficient? > >> > >> Is this about the fact that different image libraries (gdi, cairo) > >> have a different colour orders in their default storage formats? > >> > >> On Thu, Mar 17, 2011 at 6:45 AM, bill lam <[email protected]> wrote: > >> > glrgb 255 0 0 is a pure red, but the pixel data value as used in glpixels > >> > and glqpixels seemd to be a 16bff0000 for red, Can anyone confirm this? > >> > or > >> > does it need to change to 16bbbggrr format or that glpixel or glqpixel > >> > can > >> > be more efficient? > >> > > >> > -- > >> > regards, > >> > ==================================================== > >> > GPG key 1024D/4434BAB3 2008-08-24 > >> > gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 > >> > ---------------------------------------------------------------------- > >> > For information about J forums see http://www.jsoftware.com/forums.htm > >> > > >> ---------------------------------------------------------------------- > >> For information about J forums see http://www.jsoftware.com/forums.htm > > > > -- > > regards, > > ==================================================== > > GPG key 1024D/4434BAB3 2008-08-24 > > gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm -- regards, ==================================================== GPG key 1024D/4434BAB3 2008-08-24 gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
