CATiledLayer uses different set of tiles to handle different levels of zoom This example is exactly what we left from previous part of this tutorial. Based on some further logging I’ve added to the example project, I think the problem is this: The CATiledLayer has two render threads that. Let’s take a look at a CATiledLayer demo. I first ran across the CATiledLayer class when I was looking into a multithreaded, tiled.

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Then set up the emitter layer and cell, and add that cell to the layer, and the layer to the view hierarchy.

CATiledLayer (Part 1)

With those tiles in place, a custom UIView subclass can be created to draw those tile layers:. But hit testing is all a layer can do because it cannot react to recognized gestures. I was proud of what I wrote. Catledlayer the tile index Rendering the tile Rendering the label Tile index computation is only presented as a placeholder; the index is used in the label and passed to some other functions, but never used for anything important.

If you break your high-resolution image into tiles and load only the tiles you need, you can avoid the memory hit of loading catilelayer entire high resolution image. Add this catileelayer to the automatically generated implementation file: An Apple support engineer provided me with a workaround: Truncation defaults to none and can be set catiiledlayer start, end and middle:. A Word of Caution: As always, if you have any questions or comments about this article or working with layers, join in on the discussion below!

A layer that provides a way to asynchronously provide tiles of the layer’s content, potentially cached at multiple levels of detail. The iPad screen has a resolution of a little under one megapixel. Sign up using Facebook. As you probably know, everything you see in an iOS app is a view. However, you can hit test them, as you’ll see in the example code for CATransformLayer. The process of tiling the photo made it too easy to exhaust memory on exampl device.


CATiledLayer (Part 1) | Things that were not immediately obvious to me

CAShapeLayer makes use of scalable vector paths to draw, and it’s much faster than using images. But if the zoomlevel is all the way out 0. This demo completely punts on one of the trickiest problems that would be encountered in a production implementation of CATiledLayer ; no effort is made to associate geometry with the proper tiles. The actual tile rendering code is essentially the same as that in the drawRect: Using the Catilrdlayer Connection Catiledlayefphotographers will import full-resolution images onto their iPads.

A layer that creates a specified number of sublayer copies with varying geometric, temporal, and color transformations. Full-resolution photos can use a lot of memory when displayed — roughly 4 megabytes per megapixel.

Pholio Coder’s Guide: Tiling Large Images

It defaults to 1, and each incremental level caches at half the resolution of the previous level. CALayer has more than just a few properties and methods to tinker with, as well as several subclasses that have unique properties and methods. In my next article, I will describe the more conservative approach to large images that I use in version 2. Sign up using Facebook. Particularly unusual is that the setNeedsDisplay message must be sent to the layer ; the same message passed to the content view has no effect.

The iPad 1 After Version 2. I have to use code to split the large image file into smaller images at runtime. By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies.

Next, set the replicator layer’s number of copies instanceCount and drawing delay.

You can find a great tutorial covering CAMetalLayer here. This basic operation visibility calculation is essential to any rendering engine. The cached esample is based on the catiledlaer “data source” just the tile color in this examplerather that the updated data source. CATiledLayer asynchronously draws layer content in tiles. Efficiently turn the 16 MP image that the user gives you to the 1MP image you need for display. When invalidating a view backed by a CATiledLayer, a previous tile remains “stuck” and isn’t correctly invalidated.


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The following diagram gives you an idea of Pholio used tiling for large photos. Then set the transform layer’s z axis anchor point, rotate the cube and add the cube to the view hierarchy. You use this filter when enlarging the image via contentsGravitywhich can be used to change both size resize, resize aspect, and resize aspect fill and xeample center, top, top-right, right, etc.

ios – CATiledLayer shows previous tiles – Stack Overflow

This property does not exist in runtime environments prior to iOS 4. You may notice that we’re skipping over the next demo in the Layer Player app. CATransformLayer does not flatten its sublayer hierarchy like other layer classes, so it’s handy for drawing 3D structures.

If writing this sort of boilerplate drawing code is not your cup of tea, check out PaintCode ; it generates the code for you by letting you draw using intuitive visual controls or import existing vector SVG or Photoshop PSD files. Hence, setting red to 0 and the green and blue offset values to a negative examplr allows eexample to be the prominent color. In other words, calling pause and setting rate to 0 does the same thing, as calling play and setting rate to 1.