Skip to content

didierbrun/DBPathRecognizer

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

39 Commits
 
 
 
 
 
 
 
 
 
 
 
 

Repository files navigation

DBPathRecognizer

Demo

ScreenShot

Installation

Simply add the file DBPathRecognizer.swift to your project

Basic usage

Start by creating a new DBPathRecognizer instance

// Create the path 8-directions path recognizer with a delta move sensibility of 16 pt
let recognizer = DBPathRecognizer(sliceCount: 8, deltaMove: 16.0)

Note that you can specify a max cost to recognize the gestures. It means that if a gesture has a score greater than costMax, it will be ignored.

let recognizer = DBPathRecognizer(sliceCount: 8, deltaMove: 16.0, costMax: 40)

Add some path model to the recognizer. Each path is defined by a direction-sequence and an associated data object (AnyObject).

recognizer.addModel(PathModel(directions: [7, 1], datas:"A"))
recognizer.addModel(PathModel(directions: [2,6,0,1,2,3,4,0,1,2,3,4], datas:"B"))
recognizer.addModel(PathModel(directions: [4,3,2,1,0], datas:"C"))
recognizer.addModel(PathModel(directions: [4,3,2,1,0,4,3,2,1,0], datas:"E"))

For example, here the model for the letter E :

ScreenShot

Record a touch move sequence into the dedicated Path structure :

// Create the path
var path:Path = Path()

// Add a point (from touch location)
path.addPoint(PathPoint(x:100, y:100)) 

// You can also use the convenient method addPointFromRaw(var rawDatas:[Int])
path.addPointFromRaw(rawPoints)

Finally, tell the recognizer to find the best model :

var gesture:PathModel? = self.recognizer!.recognizePath(path)
        
if gesture != nil {
    // The best gesture is recognized
} else {
    // No gesture recognized (score is too low)
}

Custom filter

While adding a model, you can specify a custom filter. The filter callback method, if specified, will give you a last chance to modify / analyze the datas to determine a new score.

For example, the letter D & P have a similar draw-direction-path, however you can discriminate each one by detecting the position of the last point (up -> it's a P, down -> it's a D). The PathInfos struct transmitted to the filter function will help you to determine the new score.

Your custom filter function should conform to this signature : ((score:Int, infos:PathInfos) -> newScore:Int) :

recognizer.addModel(PathModel(directions: [2,6,7,0,1,2,3,4], datas:"P", filter:{
            (cost:Int, infos:PathInfos) -> Int in
                // Determine new cost
                return cost
        }));

Free path

In this sample project I've used the Graffiti alphabet for the didactic aspect. However, PathRecognizer is a generic algorithm, you can add any free path to control an interface / game :

ScreenShot

About

Gesture recognizer tool [Swift / iOS]

Resources

License

Stars

Watchers

Forks

Packages

No packages published

Languages