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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CALayer has two additional properties that can improve performance: Efficiently turn the 16 MP image that the user gives you to the 1MP image you need for display. Next, remove a ton of stuff from the zoomdemoViewController class:. Make those changes, then rebuild to check that everything compiles. The original tutorial was written by Scott Gardner. After a few emails back and forth, I figured examplw why: CAReplicatorLayer duplicates a layer a specified number of times, which allows you to create some cool effects.
UIView takes care of many things including layout or handling touch events. CGRect call, compare the saved updateID with the current one. I carefully prioritized generating tiles for the lowest level of detail first, so I would maximize responsiveness to the user. Here the zoomlevel is set to 1. Home About this Blog. At the same time, you tell the layer to not mask its contents, which means that if its size is smaller than its contents the star imagethe image will not be clipped.
Simply because I find it more intuitive to work with degrees than radians. You get the efficient memory use of small pictures, but customers can still zoom in and see the detail of the large image.
As you go through each example below, I recommend you play around with it in the CALayer app, and look at the source code provided. Setting the levelsOfDetail to 1 worked perfectly! The vast majority of the stuff you do in iOS is … well, not explicitly multithreaded, anyway; in fact, AAPL seems to be actively discouraging multithread techniques.
Layer Player also includes playback controls:. Next, there are helper methods to convert degrees to radians and to set the emitter cell position to the midpoint of the view. If the ids differ, schedule a new setNeedsDisplay call.
For example, increasing the levelsOfDetailBias to 5 for the blurry tiled layer above would result in caching levels magnified at 2x, 4x, 8x, 16x and 32x, and the zoomed in layer would look like this:.
It includes controls to manipulate many of CALayer ‘s properties:. As more data is required by the renderer, the layer’s draw in: He was working with full-resolution 10 MP images on an iPad 1. You have to provide the tiles and logic to tell the tiled layer which tiles to grab as the user scrolls around, but the performance gain here is remarkable.
CGRectMake 0, 0, size. When invalidating a view backed by a CATiledLayer, a previous tile remains “stuck” and isn’t correctly invalidated. Additionally, you have a variety of properties at your disposal to customize line thickness, color, dashing, how lines join other lines, exajple if that area should be filled and with what color, and more.
CALayer Tutorial for iOS: Getting Started |
catiledpayer The number of path crossings in the even-odd diagram that form the pentagon shape is even, so the pentagon is not filled, whereas the number path crossings that form each triangle is odd, so the triangles are filled.
Particularly unusual is that the setNeedsDisplay message must be sent to the layer ; the same message passed to the content view has no effect.
Then a TilingViewForImagesized to the original image’s dimensions can be added to a scroll view. Objects used to create true 3D layer hierarchies, rather than the flattened hierarchy rendering model used by other Cqtiledlayer classes.
Zero means to pause, and 1 means the video plays at regular speed 1x. Most videos can typically play at various forward speeds, but exampls less typical that they can play in exxample. You don’t need to actually code anything for the rest of this article, so just sit back, read, and relax: Everything worked great in my tests and on my device. Using my current implementation it works perfectly if the zoomlevel of the scrollview is set to 1.
So each image from the 16 megapixel D, for example, will need 64 MB of RAM to show the picture at full resolution.
CATiledLayer (Part 1) | Things that were not immediately obvious to me
The layer’s tileSize is specified in pixels ; this means that tiles will have exampld view space sizes on normal vs. Set it to true to improve performance when a layer’s contents must be repeatedly redrawn, such as when you work with an emitter layer that continuously renders animated particles. Tiling holds a lot of promise. You cannot directly hit test a transform layer because it doesn’t have a 2D coordinate space to map a touch point to, however, it’s possible to hit test individual sublayers.
More on this below. Add this line to the end of the sizeContent method: This seems to happen when the view is invalidated on the main threadwhile at the same time, the tile render threads are still working on a previous version of the tile.
Note that adjusting the corner radius doesn’t clip the layer’s contents the star image unless the layer’s masksToBounds property is set to catiledlayre.
CALayer Tutorial for iOS: Getting Started
The cached value is based on the previous “data source” just the tile color in this examplerather that the updated data source. And again — since every view is backed by a layer, you can do this kind of thing for any view in your app. This is a handy app that includes examples of 10 different types of CALayer exampel, which you’ll learn about in this article.
Int The number of magnified levels of detail for this layer. With a block of code like this, it’s possible to manipulate the font, font size, color, alignment, wrapping and truncation, as well as animate the changes:.
Alternatively, you can control the locations property with an array of values between 0 and 1 that rxample relative stops where the gradient layer should use the next color in the colors array. What better way to get an overview of all this great API than by taking a guided tour, raywenderlich.