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Re: Cocoa and Computational Expense
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Re: Cocoa and Computational Expense


  • Subject: Re: Cocoa and Computational Expense
  • From: Graham Cox <email@hidden>
  • Date: Mon, 22 Jun 2009 10:10:16 +1000


On 22/06/2009, at 8:08 AM, syntonica wrote:

The paradigm shift from all data available at all times with all the globals you can eat to private data has been a difficult one to make for me.

I think most people who move to object-oriented programming from a classical programming background find this to some extent. But the benefits are enormous, once you let go of the "all you can eat" model. Much less fat, for one thing ;-)


1.  The Field Editor is very expensive to use.
2.  1GHz of G4 just doesn't go as far as it used to.


The problem isn't so much the text editing itself, rather all the graphical rendering that it needs to perform. Back in the 16K day, characters appeared on a screen more or less because the hardware performed that task, pulling characters from a character ROM in response to the direct ascii value in a text buffer. The text editing task much far simpler since a character and its glyph were effectively synonymous and the editor could simply hand off to the text buffer to get the characters displayed.

Now of course, we have a far, far more complex situation, with unicode, multi-lingual text, bi-directonal text, totally random-access editing (not just a line editor), live spell-checking, fractional positioning, arbitrary attributes, glyphs are an abstraction from the characters encoded, glyphs are stored as bezier paths and need to be rasterized to the screen, anti-aliased with a variety of stylistic effects... the list goes on. The text experience is far richer, but the cost is a lot more processing power needed. The fact that you're seeing it performed using only 25% of 1GHz isn't bad!

--Graham


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 >Re: Cocoa and Computational Expense (From: syntonica <email@hidden>)

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