On 22 Sep 2013, at 16:18, David Rowland <[email protected]> wrote:
> > On Sep 22, 2013, at 4:20 AM, Dave <[email protected]> wrote: > >> >> On 21 Sep 2013, at 21:38, Markus Spoettl <[email protected]> wrote: >> >>> Hi, >>> >>> I have a UIView on iOS that shares (a lot of) code with an NSView I have on >>> OSX. That code relies on a LLO (lower left origin) coordinate system and >>> it's not an option to change that. >> >> I'm in a similar position, in fact I have a lot of code that is ULO based >> and a lot of code that is LLO based. If I has only a single wish that would >> enable me to change something about Cocoa it would be that it always ULO or >> as a second wish that iOS used LLO as well. >> >> I'd really like to know why LLO was chosen for the Mac in the first place, >> and, why in iOS they chose to do the opposite? >> >> Anyone understand why/how this happened? > > The earliest interface was the Teletype machine. It used a roll of low-grade > paper and could print 80 characters on one line. Carriage return moved the > print head to the first column, line feed moved the paper up one line. > > The first electronic terminals were often "glass teletypes" with 80 columns > and 24 rows. The cursor could be placed anywhere, and the convention was line > 1 at the top and line 24 at the bottom. I believe that is where the inverted > coordinates began. Bitmapped screens mimicked the TTY. Later creations like > OpenGL respected the older, mathematical model, and we are now caught between. No, I worked on these early teletype emulators, they had 0,0 (e.g. VT100 and friends) as top left on the ones that could address the cursor!. Dave _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
