MVC - where to put blitting data - actionscript

I'm currently in the process of building a game using the MVC pattern. I am also using full blitting for the first time and have come to a cross roads in my code. I'm questioning where the data for the blitting should go (ie spritesheet, rectangle data etc). I feel like it should be part of the Model but it seems a bit clumsy, when drawing the pixel data in the View, to keep referring to the model for everything (ie model.canvas.copyPixels(model.spriteSheet, model.rectsArray[model.index], model.point) ).
Has anyone had any experience setting up MVC for use with blitting? Would this be the best set up?

One the one hand, graphics data should clearly go in the view. However, it's often also important for things like bounds checking, collision shapes, etc. Therefore I advise to encapsulate the graphics data in a class/module with two interfaces.
One interface provides access to just the graphics in can be given to the view.
The other provides access to the data derived from the graphics and can be given to the model.

Related

How to align SCNScene to a physical table using ARKit?

I'm trying to find the best strategy to align a SCNScene to a physical table. Just like the ARKit app WWWFreeRivers.
Currently I'm just testing out to map a simple plane model, with the same dimensions as the table. If I draw out the plane that ARKit detects, I can see that the plane is not very accurate with the edges. They always go outside of the edges (image below).
So I can't really rely on that plane, to just place the model in the center of this. The model is not rotated correctly either (image below).
I had another idea to use the ARReferenceImage technique, to take a picture of the table top texture, and let ARKit find and match this "image" of the table. But even with wood grain texture, it wasn't enough data for ARKit to recognize it. And ARKit just fails if you have these errors. It doesn't even try to do a bad match.
How can I go about doing this?
Ideas I've had so far:
Take image of table and use ARImageReference feature to match it. This didn't work. Maybe if I add some more interesting feature points to the table, like some sort of QR codes in the corners.
Detect the plane, and then tap the four corners on the table to map out a square, and use this.
Do as the WWW app, just place the object randomly on the plane, and then let the user scale, move and rotate the model to give it correct placement.
Any more ideas? What do you think will be the best approach to this?
Two options I can think of you could use.
You could create an ARWorldMap (iOS12+ only) and use it instead of the ARImageReference, walk around the area while creating a map that subsequent ARKit Sessions will remember. You can experiment slightly as to how to fit your models within the four corners of the table (this is slightly tedious w/o much help from the SceneView editor). However, when you load the saved ARWorldMap and localized against it (just like the ARImageReference), your model should fit within the four corners of the table every time.
If you use something like Unity (and its ARKit plugin), it has much more powerful Editor tools (3D viewer/designer). There are some tools that can help you save the map just like ARWorldMap but then bring in details of the map into the editor so you can line things up right really easily. Placenote's Spatial Capture toolkit can help here. Placenote (iOS11+) creates its own "World Map" but it exposes the visual details in the Unity editor, making it easier to line things up and then localize against (Example). The map is also stored on a managed cloud from the get-go to make sharing across phones much easier.
P.S: Both these options require you to keep the environment generally static (not large lighting changes etc.), though this was a similar constraint to when using ARIMageReference.

Memory Usage of SKSpriteNodes

I'm making a tile-based adventure game in iOS. Currently my level data is stored in a 100x100 array. I'm considering two approaches for displaying my level data. The easiest approach would be to make an SKSpriteNode for each tile. However, I'm wondering if an iOS device has enough memory for 10,000 nodes. If not I can always create and delete nodes from the level data as needed.
I know this is meant to work with Tiled, but the code in there might help you optimize what you are looking to do. I have done my best to optimize for big maps like the one you are making. The big thing to look at is more so how you are creating textures I know that has been a big killer in the past.
Swift
https://github.com/SpriteKitAlliance/SKATiledMap
Object-C
https://github.com/SpriteKitAlliance/SKAToolKit
Both are designed to load in a JSON string too so there is a chance you could still generate random maps without having to use the Tiled Editor as long as you match the expected format.
Also you may want to consider looking at how culling works in the Objective-C version as we found more recently removing nodes from the parent has really optimized performance on iOS 9.
Hopefully you find some of that helpful and if you have any questions feel free to email me.
Edit
Another option would be to look at Object Pooling. The core concept is to create only sprites you need to display and when you are done store them in a collection of sorts. When you need a new sprite you ask the collection for one and if it doesn't have one you create a new one.
For example you need a grass tile and you ask for one and it doesn't have one that has been already created that is waiting to be used so it creates one. You may do this to fill a 9 x 7 grid to fill up your screen. As you move away grass that gets moved off screen gets tossed into the collection to be used again when the new row comes in and needs grass. This works really well if all you are doing is displaying tiles. Not so great if tiles have dynamic properties that need to be updated and are unique in nature.
Here is a great link even if it is for Unity =)
https://unity3d.com/learn/tutorials/modules/beginner/live-training-archive/object-pooling

Valid technique for scalable graphics on iOS?

A little background: I'm working on an iOS app that has a variety of status icons for various states. These icons are used in a variety of places and sizes including as UITableViewCell imageViews, as custom MKMapAnnotations and a few other spots. I actually have a couple sets which include a more static status icon as well as ones that have dynamic text injected into the design.
So at first I went the conventional route of using static raster assets, but because the sizes were dynamic this wasn't always the best solution and I wasn't thrilled with the quality of the scaling using CGAffineTransforms. So instead I changed gears a bit and tried something else:
Created a custom UIView subclass for each high level class of icon. It takes as input the model object that derives the status from (I suppose I could have also just used an enum and loaded this into some kind of model constructor but this is how I did it) so it can decide what it needs to draw, then does the necessary drawing in drawRect. Since all of the drawing is based on the view bounds it scales to any reasonable dimensions.
Created a Category which has class method constructors that take the model inputs as well as the size you want to use and constructs the custom views.
Since I also wanted the option to have rasterized versions of these icons to plug into certain places (such as a UITableViewCell imageView) I also created constructors that build the view and return a UIImage using the fast iOS7 snapshotting functions.
So what does this give me? Well here's the pros/cons that I can see.
Pros
Completely scalable graphics that can easily be used in a variety of different scenarios and contexts.
Easy compatibility with adding dynamic info to the graphics such as text. Because I have the exact shape data on everything I'm drawing I don't need to guesstimate on the bounds for a text box since I know how everything is laid out.
Compatibility with situations where I might want a rasterized asset but I still get all the advantages of the dynamic view since I'm not rasterizing it till I need it.
Reduces the size of the application since I don't need to include raster assets.
Cons
The workflow for creating the draw code in the first place isn't ideal. For simple stuff I can do it straight in code but for more complex things I'll need to create the vector asset in Illustrator or Sketch then bring it into PaintCode and clean up the generated draw code into something more streamlined. This is not the most ideal process.
So the question is: does anyone have any better suggestions for how to deal with this sort of situation? I haven't found an enormous amount of material on techniques for this sort of thing and I'm wondering if I'm missing a better way of handling this or if there are any hidden gotchas here...performance doesn't seem to be an issue from my testing with my approach but I haven't tested it on the iPad3 or iPhone 4 yet so there could still be some unknowns.
You could try SVGKit, which draws SVG files, and can export to a UIImage, if desired.

Creating a Geometric Path from 2D points without a graphics context. Possible in iOS?

I am needing a way to test out some heavy mathematical functionality in my code and have come to the point where I need to verify that such code is working properly. I would like to be able to create a path based on an array of points and use this path for testing without a graphics context.
As an example, Java has various classes such as the Path2D class that is completely independent on any kind of context or view unless you need to display the information in some kind of graphics context.
It looks like that Apple doesn't provide any methods that allow you to create, manipulate and change arbitrary geometric shapes but I wanted to come here and make sure.
CGPath and UIBezierPath can both be created without having a current context. But it depends what you want to do as to how much use they will be because their purpose is really for drawing. As such it isn't really easy to get the points back from the path once added.

Composed animations, sprites in iOS

let's say I want to display a customizable (2D, cartoon-like) character, where some properties e.g. eye color, hair style, clothing etc can be chosen from a predefined set of options. Now I want to animate the character. What's the best way to deal with the customization?
1) For example, I could make a sprite sheet for each combination of properties. That's not very memory efficient and not very flexible, but probably gives the best performance.
2) I could compose the character from various layers, where each property only affects one layer. Thus, I could make a sprite-sheet for the body, a collection of sprite-sheets for the eyes (one for each eye color) etc.
2a) In that case, I could merge the selected sprite-sheets in order to generate a single sprite-sheet containing the animation of the customized character.
2b) Alternatively, I could keep the sprite-sheets separate and try to animate them simultaneously as layers. I fear, that this might become a problem performance-wise.
3) I could try to modify the layers programmatically, e.g. use a sprite-sheet for the eyes as a mask and map some texture on it before merging it down to a single sprite-sheet. I would think this is a very flexible approach when it comes to simple properties like eye colors, but might become difficult for things like hair-style. I am aware that this depends much on the character and probably a general answer is difficult.
I assume that my problem is not new, so there is probably a standard approach to it.
Concerning the platform, I'm particularly interested in iOS and try to avoid OpenGL (well, I'm open-minded). Maybe there is a nice framework that can help me here?
Thanks!
Depending on what your working on, you might want to animate part/all of the animations outside in another tool, such as flash. It is much easier to work with a visual environment.
Then there are tools that take swf files, and create sprite sheets that you would then animate in cocos2d.
That is a common game creation workflow.
You problably want to take a look on how to create sprites at cocos2d.
Cocos2d comes with a set of tools that help you to animate single parts and offers abstractions to compose parts (like CCBatchNode or CCNode). Also, it comes with tools that helps you to pack sprites into sprite sheets (e.g Texture Packer) and develop levels (e.g Level Helper).
Cocos2d is an open source framework and it is widely used. You also have cocos3d but I never used it :).

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