Just got the new iPad (or we called it: the iPad 3) in hand today and I’m stunned by it’s new retina display. There’s not such a fever like when the iPad 2 was released, I guess since the new iPad is almost identical to iPad 2 in appearance, people will consider about the fact that they won’t be able to show it off. In term of general performance, iPad 3 does not stand out to the previous iPad, or it could be worse in term of 3D – OpenGL performance according to some reviews. From a programmer’s point of view, this could easily be understood since doubling the resolution means 4 times the memory and processing power for each graphics API, which also means Apple has been pushing things over the Moore law’s limit!

Personally I’m not really a passionate fan of these Mắc – Xinh – Tốt [ 1 ] (Macintosh) assets, but professionally as a computer – graphics coder, I’ve always admired the prestigous 2D graphics tradition come with Apple’s products. Back to the retina display, on the left is a reduced – size screenshot of this blog taken on the iPad 3 (see full version here, it would take some times to load).

2048 x 1536 is a huge resolution that does magic to the vector things, e.g: displaying fonts! Not only the screen is much sharper, even at first look, its color tone appears to be truer, and the new iPad gamut covers 44% more into the sRGB color space compared to the previous iPad. The second picture: funny capture of Walter Isaacson’s Steve Jobs autobiography put on – top the God of Wealth’s altar in our office!

Having written myself numerous UI widgets, from simple to complex, from Windows to Linux, from 2D to 3D… but I’ve just started writing iOS widgets not too long ago. Making iOS widgets is really fun, for we have supports from the most powerful 2D graphics system ever built, that is CoreGraphics (Quartz 2D). The code, hosted on github, is released under MIT license, check it out for a demo project, I hope that these widgets would be useful somewhere, but yes, I know, don’t complain about the code quality, most is written in a rush and still have flaws in it, use at your own discretion!

1.   XFilePathHeader

This tabular header let you quickly browse a hierachy structure (like file system directories). The levels are shown as tabs, tap on a tab to jump to a parent folder, tap on the “Home” icon to jump to root folder.

2.   XSegmentedControl

The Apple’s standard UISegmentedControl only displays text, not image. This class lets you use image along with text (or image or text alone) in any orders (image then text, or text then image).

3.   XProgressTextField

This is a copy of Safari’s address textfield which shows a progress bar while the webpage is loading. Would continue to add more of these miscellaneous tiny widgets just for fun when I have time.

Finished with my survey on vectorial graphics, in details, about rendering SVG using Quartz, OpenGL (ES) on Mac, iOS and some Android flatforms. I’d had the chances to systematize more my knowledge on vectorial: path, stroke, anti – aliasing, solid, gradient and pattern fill, etc… Todays, people’s all talking about 3D, OpenGL, DirectX, etc… While few mentions much about 2D stuffs, I’ve traced back some historical evolution paths, since I believe that it’s through history would we understand technologies.

In the beginning, there was… PostScript

It was John Warnock who kindled the idea, he joined Xerox in 1978 and an early version of PostScript (named InterPress) became the language to drive a laser printer. Laser printer was then a revolutionary device, which offers extraordinary graphics compared to the capability of dot or matrix printers. Warnock left and founded Adobe in 1982, the company that produced well – known graphics softwares including Illustrator, king of the vectorial editors.

Then there was DPS, PDF and Quartz

But it was Steve Job who realized the superiority of PostScript and urged John Warnock to popularize it. When Steve Jobs left Apple and started NeXT, he co – developed with Adobe DPS – Display PostScript, a derivative of PostScript – the language that drives the NeXT computer’s graphics system. When Steve has got back to Apple, DPS then evolved into what is now known as PDF, and Quartz is the C binding that bridges traditional Unix programmers to the Mac graphics world.

The X window system

The X’s designers also started with a PostScript RedBook in hand. But due to various reasons including the lack of in – depth consensus about vectorial, X maintains until now low level of PostScript support. The X server can only handle basic PostScript commands (it can’t even draw splines). X took a hybrid approach using both vectorial and raster – based solutions to the problem. Also the Unix root has an impact: X is the only true client/server windowing system to the current day.

The Windows’ GDI

Born to be the youngest of all graphics systems, GDI learns nothing from it predecessors. Neither it is device and resolution independent (like Macs) nor a true client/server system (like X). GDI sticks to screen and the pixel unit with quite a lot implementation flaws. These flaws won’t become obvious until we come to serious editing, publishing and printing: text documents and graphics designs would never has the on – screen – display and printing qualities we would expect, though various 3^rd party softwares would come to rescue somewhat the situations.

Then, things change with time

The 2D graphics systems on Mac, Windows, Unix… all has different origins, and all targets different real – world problem domains. All has hardware acceleration to various levels and qualities, and it’s hard to compare them in some cases. To the present day, no system is known to keep the original idealistic model that uses pure PostScript: X has been mixed from the beginning, Mac & iOS have switched to raster to some extent, GDI is essentially pixel – based. Then come the wind of change! It would be another story, another evolution path, but today, 3D hardwares has become quite popular with reasonable prices. It’s counter – intuitive to treat 2D as a separate part from 3D, and the trend is merging 2D to become a subset of 3D rendering. However, the process hasn’t been very easy, it would take some more time to reach maturity:

• WPF (Windows Presentation Foundation): first came with Windows Vista, GDI now runs as part of DirectX 3D rendering environment. Vista was not a success indeed!

• QuartzGL: Quartz2D runs on top of OpenGL since OS X 10.2 (Jaguar). However, QuartzGL is not enabled by default even in the current version (10.6 – Snow Leopard) since it’s still quite buggy.

• GLX & AIGLX: both has some implementation problems and is competing to each other to become the official 3D extension for X.