Add Bracket Annotation (#108)

* add bracket annotation

* coordinate update

* update

* bfix

* bfix

* test bfix

* bfix

* bfix: Fix line chart cross both axes regression test. (pow function overload fix)

Co-authored-by: Karthik Ramesh Iyer <Karthik.iyer2@yandex.com>

Author: WilliamHYZhang

Sources/SwiftPlot/PlotStyleHelpers.swift

@@ -55,7 +55,7 @@ public struct Coordinate {
 }
 
 public protocol CoordinateResolver {
-	func resolve(_ coordinate: Coordinate) -> Point
+    func resolve(_ coordinate: Coordinate) -> Point
 }
 
 public protocol Annotation {
@@ -69,7 +69,7 @@ public enum Direction {
     case west
 }
 
-public protocol AnchorableAnnotation : Annotation {
+public protocol AnchorableAnnotation: Annotation {
     var direction: Direction { get set }
     var margin: Float { get set }
     mutating func resolve(renderer: Renderer, center: Point)
@@ -107,7 +107,7 @@ struct Box: Annotation, AnchorableAnnotation {
     }
 }
 
-struct Text : Annotation, AnchorableAnnotation {
+struct Text: Annotation, AnchorableAnnotation {
     public var text = ""
     public var color = Color.black
     public var size: Float = 15
@@ -157,7 +157,7 @@ struct Text : Annotation, AnchorableAnnotation {
     }
 }
 
-struct Arrow : Annotation {
+struct Arrow: Annotation {
     public var color = Color.black
     public var start = Point(0.0, 0.0)
     public var end = Point(0.0, 0.0)
@@ -277,3 +277,44 @@ struct Arrow : Annotation {
         self.overrideAnchor = overrideAnchor
     }
 }
+
+struct Bracket: Annotation {
+    public var color = Color.black
+    public var start = Coordinate()
+    public var end = Coordinate()
+    public var strokeWidth: Float = 3
+    public var isDashed: Bool = false
+    public var legLength: Float = 15
+    public var anchorableAnnotation: AnchorableAnnotation?
+    public mutating func draw(resolver: CoordinateResolver, renderer: Renderer) {
+        // Calculate leg points.
+        let startPoint = resolver.resolve(start), endPoint = resolver.resolve(end)
+        var startLegPoint = startPoint + Point(0.0, -strokeWidth/2-legLength)
+        let startLegRotateAngle = -atan2(endPoint.x - startPoint.x, endPoint.y - startPoint.y)
+        startLegPoint = rotatePoint(point: startLegPoint, center: startPoint, angleRadians: startLegRotateAngle + 0.5 * Float.pi)
+        var endLegPoint = endPoint + Point(0.0, -strokeWidth/2-legLength)
+        endLegPoint = rotatePoint(point: endLegPoint, center: endPoint, angleRadians: startLegRotateAngle + 0.5 * Float.pi)
+        
+        // Draws bracket.
+        renderer.drawPolyline(Polyline(startLegPoint, startPoint, endPoint, endLegPoint)!,
+                              strokeWidth: strokeWidth,
+                              strokeColor: color,
+                              isDashed: isDashed)
+
+        // Calculate anchor point.
+        let anchorPoint = Point((startPoint.x + endPoint.x)/2, (startPoint.y + endPoint.y)/2)
+
+        // Draws AnchorableAnnotation if specified.
+        anchorableAnnotation?.resolve(renderer: renderer, center: anchorPoint)
+        anchorableAnnotation?.draw(resolver: resolver, renderer: renderer)
+    }
+    public init(color: Color = .black, start: Coordinate = Coordinate(), end: Coordinate = Coordinate(), strokeWidth: Float = 5, isDashed: Bool = false, legLength: Float = 15, anchorableAnnotation: AnchorableAnnotation? = nil) {
+        self.color = color
+        self.start = start
+        self.end = end
+        self.strokeWidth = strokeWidth
+        self.isDashed = isDashed
+        self.legLength = legLength
+        self.anchorableAnnotation = anchorableAnnotation
+    }
+}

Tests/SwiftPlotTests/Annotation/annotation-bracket.swift

@@ -0,0 +1,52 @@
+@testable import SwiftPlot
+import Foundation
+import SVGRenderer
+#if canImport(AGGRenderer)
+import AGGRenderer
+#endif
+#if canImport(QuartzRenderer)
+import QuartzRenderer
+#endif
+
+@available(tvOS 13, watchOS 13, *)
+extension AnnotationTests {
+
+  func testAnnotationBracket() throws {
+
+    let fileName = "_35_bracket_annotation"
+
+    var lineGraph = LineGraph<Float, Float>(enablePrimaryAxisGrid: true)
+    lineGraph.addFunction(sin, minX: -5.0, maxX: 5.0, label: "sin(x)", color: .lightBlue)
+    lineGraph.plotTitle.title = "FUNCTION"
+    lineGraph.plotLabel.xLabel = "X-AXIS"
+    lineGraph.plotLabel.yLabel = "Y-AXIS"
+    lineGraph.plotLineThickness = 3.0
+
+    lineGraph.addAnnotation(annotation: Bracket(start: Coordinate(point: Point(150.0, 607.0)),
+                                                end: Coordinate(point: Point(630.0, 607.0)),
+                                                anchorableAnnotation: Text(text: "Period",
+                                                                           direction: .south)))
+    lineGraph.addAnnotation(annotation: Bracket(start: Coordinate(point: Point(900, 585.0)),
+                                                end: Coordinate(point: Point(900, 340.0)),
+                                                anchorableAnnotation: Text(text: "Amplitude",
+                                                                           direction: .east)))
+    let svg_renderer = SVGRenderer()
+    try lineGraph.drawGraphAndOutput(fileName: svgOutputDirectory+fileName,
+                                     renderer: svg_renderer)
+    verifyImage(name: fileName, renderer: .svg)
+    #if canImport(AGGRenderer)
+    let agg_renderer = AGGRenderer()
+    try lineGraph.drawGraphAndOutput(fileName: aggOutputDirectory+fileName,
+                                     renderer: agg_renderer)
+    verifyImage(name: fileName, renderer: .agg)
+    #endif
+    /*
+    #if canImport(QuartzRenderer)
+    let quartz_renderer = QuartzRenderer()
+    try lineGraph.drawGraphAndOutput(fileName: coreGraphicsOutputDirectory+fileName,
+                                     renderer: quartz_renderer)
+    verifyImage(name: fileName, renderer: .coreGraphics)
+    #endif
+    */
+  }
+}

Tests/SwiftPlotTests/LineChart/linechart-regressiontests.swift

@@ -2,7 +2,7 @@ import SwiftPlot
 import Foundation
 
 extension LineChartTests {
-  
+
   func testLineChart_positiveYOrigin() throws {
     let x:[Float] = [0, 1, 2, 3]
     let y:[Float] = [70, 80, 95, 100]
@@ -16,7 +16,7 @@ extension LineChartTests {
 
     try renderAndVerify(lineGraph, size: Size(width: 300, height: 300))
   }
-  
+
   func testLineChart_positiveYOrigin_secondary() throws {
     let x:[Float] = [0, 1, 2, 3]
     let y:[Float] = [70, 80, 95, 100]
@@ -32,10 +32,10 @@ extension LineChartTests {
     lineGraph.plotLineThickness = 3.0
     lineGraph.enablePrimaryAxisGrid = true
     lineGraph.enableSecondaryAxisGrid = true
-    
+
     try renderAndVerify(lineGraph, size: Size(width: 400, height: 400))
   }
-  
+
   func testLineChart_negativeYOrigin() throws {
     let x:[Float] = [0, 1, 2, 3]
     let y:[Float] = [-70, -80, -95, -100]
@@ -49,7 +49,7 @@ extension LineChartTests {
 
     try renderAndVerify(lineGraph, size: Size(width: 300, height: 300))
   }
-  
+
   func testLineChart_positiveXOrigin() throws {
     let x:[Float] = [5, 6, 7, 8]
     let y:[Float] = [70, 80, 95, 100]
@@ -63,7 +63,7 @@ extension LineChartTests {
 
     try renderAndVerify(lineGraph, size: Size(width: 300, height: 300))
   }
-  
+
   func testLineChart_negativeXOrigin() throws {
     let x:[Float] = [-5, -6, -7, -8]
     let y:[Float] = [-70, -80, -95, -100]
@@ -77,7 +77,7 @@ extension LineChartTests {
 
     try renderAndVerify(lineGraph, size: Size(width: 300, height: 300))
   }
-  
+
   func testLineChart_positiveXOrigin_secondary() throws {
     let x:[Float] = [0, 1, 2, 3]
     let y:[Float] = [70, 80, 95, 100]
@@ -94,10 +94,10 @@ extension LineChartTests {
     lineGraph.plotLineThickness = 3.0
     lineGraph.enablePrimaryAxisGrid = true
     lineGraph.enableSecondaryAxisGrid = true
-    
+
     try renderAndVerify(lineGraph, size: Size(width: 400, height: 400))
   }
-  
+
   func testLineChart_negativeXOrigin_unsorted() throws {
     let x:[Float] = [-8, -7, -6, -5]
     let y:[Float] = [70, 80, 95, 100]
@@ -111,7 +111,7 @@ extension LineChartTests {
 
     try renderAndVerify(lineGraph, size: Size(width: 300, height: 300))
   }
-  
+
   func testLineChart_crossX() throws {
     func someFunction(_ x: Float) -> Float { (x * x) + 10 }
     var lineGraph_func = LineGraph<Float,Float>(enablePrimaryAxisGrid: true)
@@ -126,7 +126,7 @@ extension LineChartTests {
     lineGraph_func.plotLabel.yLabel = "Y-AXIS"
     try renderAndVerify(lineGraph_func, size: Size(width: 400, height: 400))
   }
-  
+
   func testLineChart_crossY() throws {
     func someFunction(_ x: Float) -> Float { 5 * cos(2 * x * x) / x }
     var lineGraph_func = LineGraph<Float,Float>(enablePrimaryAxisGrid: true)
@@ -141,22 +141,22 @@ extension LineChartTests {
     lineGraph_func.plotLabel.yLabel = "Y-AXIS"
     try renderAndVerify(lineGraph_func, size: Size(width: 400, height: 400))
   }
-  
+
   func testLineChart_crossBothAxes() throws {
     var lineGraph = LineGraph<Float,Float>(enablePrimaryAxisGrid: true,
                                            enableSecondaryAxisGrid: false)
     let clamp: ClosedRange<Float>? = -150...150
-    lineGraph.addFunction({ pow($0, 2) }, minX: -5, maxX: 5, clampY: clamp, label: "2", color: .lightBlue)
-    lineGraph.addFunction({ pow($0, 3) }, minX: -5, maxX: 5, clampY: clamp, label: "3", color: .orange)
-    lineGraph.addFunction({ pow($0, 4) }, minX: -5, maxX: 5, clampY: clamp, label: "4", color: .red)
-    lineGraph.addFunction({ pow($0, 5) }, minX: -5, maxX: 5, clampY: clamp, label: "5", color: .brown)
-    lineGraph.addFunction({ pow($0 , 6) }, minX: -5, maxX: 5, clampY: clamp, label: "6", color: .purple)
-    lineGraph.addFunction({ pow($0 , 7) }, minX: -5, maxX: 5, clampY: clamp, label: "7", color: .green)
+    lineGraph.addFunction({ Float(truncating: pow(Decimal(Double($0)), Int(2)) as NSNumber) }, minX: -5, maxX: 5, clampY: clamp, label: "2", color: .lightBlue)
+    lineGraph.addFunction({ Float(truncating: pow(Decimal(Double($0)), Int(3)) as NSNumber) }, minX: -5, maxX: 5, clampY: clamp, label: "3", color: .orange)
+    lineGraph.addFunction({ Float(truncating: pow(Decimal(Double($0)), Int(4)) as NSNumber) }, minX: -5, maxX: 5, clampY: clamp, label: "4", color: .red)
+    lineGraph.addFunction({ Float(truncating: pow(Decimal(Double($0)), Int(5)) as NSNumber) }, minX: -5, maxX: 5, clampY: clamp, label: "5", color: .brown)
+    lineGraph.addFunction({ Float(truncating: pow(Decimal(Double($0)), Int(6)) as NSNumber) }, minX: -5, maxX: 5, clampY: clamp, label: "6", color: .purple)
+    lineGraph.addFunction({ Float(truncating: pow(Decimal(Double($0)), Int(7)) as NSNumber) }, minX: -5, maxX: 5, clampY: clamp, label: "7", color: .green)
     lineGraph.plotTitle.title = "y = x^n"
     lineGraph.plotLabel.xLabel = "x"
     lineGraph.plotLabel.yLabel = "y"
             lineGraph.backgroundColor = .transparent
-    
+
     try renderAndVerify(lineGraph, size: Size(width: 800, height: 400))
   }
 }