Comments on: Image manipulation and drawing using Quartz in the background threads http://www.codingventures.com/2009/08/image-manipulation-and-drawing-using-quartz-in-the-background-threads/ Kerem Karatal’s musings on code, technology and more… Mon, 12 Jul 2010 07:42:48 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Alexander86 http://www.codingventures.com/2009/08/image-manipulation-and-drawing-using-quartz-in-the-background-threads/comment-page-1/#comment-131 Alexander86 Sat, 12 Sep 2009 07:38:30 +0000 http://www.codingventures.com/?p=166#comment-131 <p>Some time ago I worked on a "graphics-driven" project and found the same way to make off-screen drawings. Very usefull article.</p> Some time ago I worked on a “graphics-driven” project and found the same way to make off-screen drawings. Very usefull article.

]]> By: keremk http://www.codingventures.com/2009/08/image-manipulation-and-drawing-using-quartz-in-the-background-threads/comment-page-1/#comment-107 keremk Tue, 04 Aug 2009 21:15:40 +0000 http://www.codingventures.com/?p=166#comment-107 <p>UIKit is not thread safe, but CoreGraphics (mostly) is. In this case, I am creating many images in the background. This is basically piece of some code that displays thumbnails of images in a vertically scrolling view (sort of like image gallery app) with some adornments such as shadows, borders etc. In this case moving this image generation code to the UI thread makes the app unresponsive, as each image generation blocks the UI thread and makes the scrolling jerky. It is best to handle that in the background thread along with downloading of the images in the first place.</p> UIKit is not thread safe, but CoreGraphics (mostly) is. In this case, I am creating many images in the background. This is basically piece of some code that displays thumbnails of images in a vertically scrolling view (sort of like image gallery app) with some adornments such as shadows, borders etc. In this case moving this image generation code to the UI thread makes the app unresponsive, as each image generation blocks the UI thread and makes the scrolling jerky. It is best to handle that in the background thread along with downloading of the images in the first place.

]]> By: Hendrik http://www.codingventures.com/2009/08/image-manipulation-and-drawing-using-quartz-in-the-background-threads/comment-page-1/#comment-106 Hendrik Tue, 04 Aug 2009 19:17:41 +0000 http://www.codingventures.com/?p=166#comment-106 <p>As far as I understand, none of UIKit is thread safe. So it might be best to do the UIImage creation on the main thread via performSelectorOnMainThread:</p> <p>That's what (I think) I do in my own code.</p> As far as I understand, none of UIKit is thread safe. So it might be best to do the UIImage creation on the main thread via performSelectorOnMainThread:

That’s what (I think) I do in my own code.

]]> By: ultrasurf http://www.codingventures.com/2009/08/image-manipulation-and-drawing-using-quartz-in-the-background-threads/comment-page-1/#comment-105 ultrasurf Tue, 04 Aug 2009 00:52:26 +0000 http://www.codingventures.com/?p=166#comment-105 <p>useful information. It’s really good</p> useful information. It’s really good

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