From 5a4168357ceb3e9796e946741540e04296764162 Mon Sep 17 00:00:00 2001
From: Daniel Cohen Gindi <danielgindi@gmail.com>
Date: Fri, 8 Apr 2016 17:30:10 +0300
Subject: [PATCH 1/6] Added horizontal cubic (not exaggerating vertical control
 points)

---
 .../Standard/LineChartDataSet.swift           |  41 +++++--
 .../Data/Interfaces/ILineChartDataSet.swift   |  19 +++-
 .../Classes/Renderers/LineChartRenderer.swift | 104 ++++++++++++++++--
 .../Classes/Data/RealmLineDataSet.swift       |  41 +++++--
 4 files changed, 172 insertions(+), 33 deletions(-)

diff --git a/Charts/Classes/Data/Implementations/Standard/LineChartDataSet.swift b/Charts/Classes/Data/Implementations/Standard/LineChartDataSet.swift
index babdafc289..3795908ada 100644
--- a/Charts/Classes/Data/Implementations/Standard/LineChartDataSet.swift
+++ b/Charts/Classes/Data/Implementations/Standard/LineChartDataSet.swift
@@ -39,6 +39,8 @@ public class LineChartDataSet: LineRadarChartDataSet, ILineChartDataSet
     
     // MARK: - Styling functions and accessors
     
+    public var mode: LineChartMode = LineChartMode.Linear
+    
     private var _cubicIntensity = CGFloat(0.2)
     
     /// Intensity for cubic lines (min = 0.05, max = 1)
@@ -64,16 +66,36 @@ public class LineChartDataSet: LineRadarChartDataSet, ILineChartDataSet
         }
     }
     
-    /// If true, cubic lines are drawn instead of linear
-    public var drawCubicEnabled = false
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
+    public var drawCubicEnabled: Bool
+    {
+        get
+        {
+            return mode == .CubicBezier
+        }
+        set
+        {
+            mode = newValue ? LineChartMode.CubicBezier : LineChartMode.Linear
+        }
+    }
     
-    /// - returns: true if drawing cubic lines is enabled, false if not.
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
     public var isDrawCubicEnabled: Bool { return drawCubicEnabled }
     
-    /// If true, stepped lines are drawn instead of linear
-    public var drawSteppedEnabled = false
-
-    /// - returns: true if drawing stepped lines is enabled, false if not.
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
+    public var drawSteppedEnabled: Bool
+    {
+        get
+        {
+            return mode == .Stepped
+        }
+        set
+        {
+            mode = newValue ? LineChartMode.Stepped : LineChartMode.Linear
+        }
+    }
+    
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
     public var isDrawSteppedEnabled: Bool { return drawSteppedEnabled }
     
     /// The radius of the drawn circles.
@@ -167,9 +189,10 @@ public class LineChartDataSet: LineRadarChartDataSet, ILineChartDataSet
         copy.cubicIntensity = cubicIntensity
         copy.lineDashPhase = lineDashPhase
         copy.lineDashLengths = lineDashLengths
+        copy.lineCapType = lineCapType
         copy.drawCirclesEnabled = drawCirclesEnabled
-        copy.drawCubicEnabled = drawCubicEnabled
-        copy.drawSteppedEnabled = drawSteppedEnabled
+        copy.drawCircleHoleEnabled = drawCircleHoleEnabled
+        copy.mode = mode
         return copy
     }
 }
diff --git a/Charts/Classes/Data/Interfaces/ILineChartDataSet.swift b/Charts/Classes/Data/Interfaces/ILineChartDataSet.swift
index 4a413a760a..38da71b51d 100644
--- a/Charts/Classes/Data/Interfaces/ILineChartDataSet.swift
+++ b/Charts/Classes/Data/Interfaces/ILineChartDataSet.swift
@@ -14,6 +14,15 @@
 import Foundation
 import CoreGraphics
 
+@objc
+public enum LineChartMode: Int
+{
+    case Linear
+    case Stepped
+    case CubicBezier
+    case HorizontalBezier
+}
+
 @objc
 public protocol ILineChartDataSet: ILineRadarChartDataSet
 {
@@ -21,21 +30,23 @@ public protocol ILineChartDataSet: ILineRadarChartDataSet
     
     // MARK: - Styling functions and accessors
     
+    var mode: LineChartMode { get set }
+    
     /// Intensity for cubic lines (min = 0.05, max = 1)
     ///
     /// **default**: 0.2
     var cubicIntensity: CGFloat { get set }
     
-    /// If true, cubic lines are drawn instead of linear
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
     var drawCubicEnabled: Bool { get set }
     
-    /// - returns: true if drawing cubic lines is enabled, false if not.
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
     var isDrawCubicEnabled: Bool { get }
     
-    /// If true, stepped lines are drawn instead of linear
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
     var drawSteppedEnabled: Bool { get set }
     
-    /// - returns: true if drawing stepped lines is enabled, false if not.
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
     var isDrawSteppedEnabled: Bool { get }
 
     /// The radius of the drawn circles.
diff --git a/Charts/Classes/Renderers/LineChartRenderer.swift b/Charts/Classes/Renderers/LineChartRenderer.swift
index 65486f5af3..eec251f35c 100644
--- a/Charts/Classes/Renderers/LineChartRenderer.swift
+++ b/Charts/Classes/Renderers/LineChartRenderer.swift
@@ -72,19 +72,23 @@ public class LineChartRenderer: LineRadarChartRenderer
         }
         
         // if drawing cubic lines is enabled
-        if (dataSet.isDrawCubicEnabled)
+        switch dataSet.mode
         {
-            drawCubic(context: context, dataSet: dataSet)
-        }
-        else
-        { // draw normal (straight) lines
+        case .Linear: fallthrough
+        case .Stepped:
             drawLinear(context: context, dataSet: dataSet)
+            
+        case .CubicBezier:
+            drawCubicBezier(context: context, dataSet: dataSet)
+            
+        case .HorizontalBezier:
+            drawHorizontalBezier(context: context, dataSet: dataSet)
         }
         
         CGContextRestoreGState(context)
     }
     
-    public func drawCubic(context context: CGContext, dataSet: ILineChartDataSet)
+    public func drawCubicBezier(context context: CGContext, dataSet: ILineChartDataSet)
     {
         guard let
             trans = dataProvider?.getTransformer(dataSet.axisDependency),
@@ -168,9 +172,87 @@ public class LineChartRenderer: LineRadarChartRenderer
                 curDy = CGFloat(next.value - prev.value) * intensity
                 
                 // the last cubic
-                CGPathAddCurveToPoint(cubicPath, &valueToPixelMatrix, CGFloat(prev.xIndex) + prevDx, (CGFloat(prev.value) + prevDy) * phaseY,
-                    CGFloat(cur.xIndex) - curDx,
-                    (CGFloat(cur.value) - curDy) * phaseY, CGFloat(cur.xIndex), CGFloat(cur.value) * phaseY)
+                CGPathAddCurveToPoint(cubicPath, &valueToPixelMatrix,
+                                      CGFloat(prev.xIndex) + prevDx,
+                                      (CGFloat(prev.value) + prevDy) * phaseY,
+                                      CGFloat(cur.xIndex) - curDx,
+                                      (CGFloat(cur.value) - curDy) * phaseY,
+                                      CGFloat(cur.xIndex),
+                                      CGFloat(cur.value) * phaseY)
+            }
+        }
+        
+        CGContextSaveGState(context)
+        
+        if (dataSet.isDrawFilledEnabled)
+        {
+            // Copy this path because we make changes to it
+            let fillPath = CGPathCreateMutableCopy(cubicPath)
+            
+            drawCubicFill(context: context, dataSet: dataSet, spline: fillPath!, matrix: valueToPixelMatrix, from: minx, to: size)
+        }
+        
+        CGContextBeginPath(context)
+        CGContextAddPath(context, cubicPath)
+        CGContextSetStrokeColorWithColor(context, drawingColor.CGColor)
+        CGContextStrokePath(context)
+        
+        CGContextRestoreGState(context)
+    }
+    
+    public func drawHorizontalBezier(context context: CGContext, dataSet: ILineChartDataSet)
+    {
+        guard let
+            trans = dataProvider?.getTransformer(dataSet.axisDependency),
+            animator = animator
+            else { return }
+        
+        let entryCount = dataSet.entryCount
+        
+        guard let
+            entryFrom = dataSet.entryForXIndex(self.minX < 0 ? self.minX : 0, rounding: .Down),
+            entryTo = dataSet.entryForXIndex(self.maxX, rounding: .Up)
+            else { return }
+        
+        let diff = (entryFrom == entryTo) ? 1 : 0
+        let minx = max(dataSet.entryIndex(entry: entryFrom) - diff - 1, 0)
+        let maxx = min(max(minx + 2, dataSet.entryIndex(entry: entryTo) + 1), entryCount)
+        
+        let phaseX = animator.phaseX
+        let phaseY = animator.phaseY
+        
+        // get the color that is specified for this position from the DataSet
+        let drawingColor = dataSet.colors.first!
+        
+        // the path for the cubic-spline
+        let cubicPath = CGPathCreateMutable()
+        
+        var valueToPixelMatrix = trans.valueToPixelMatrix
+        
+        let size = Int(ceil(CGFloat(maxx - minx) * phaseX + CGFloat(minx)))
+        
+        if (size - minx >= 2)
+        {
+            var prev: ChartDataEntry! = dataSet.entryForIndex(minx)
+            var cur: ChartDataEntry! = prev
+            
+            if cur == nil { return }
+            
+            // let the spline start
+            CGPathMoveToPoint(cubicPath, &valueToPixelMatrix, CGFloat(cur.xIndex), CGFloat(cur.value) * phaseY)
+            
+            for j in minx + 1 ..< min(size, entryCount)
+            {
+                prev = cur
+                cur = dataSet.entryForIndex(j)
+                
+                let cpx = CGFloat(prev.xIndex) + CGFloat(cur.xIndex - prev.xIndex) / 2.0
+                
+                CGPathAddCurveToPoint(cubicPath,
+                                      &valueToPixelMatrix,
+                                      cpx, CGFloat(prev.value) * phaseY,
+                                      cpx, CGFloat(cur.value) * phaseY,
+                                      CGFloat(cur.xIndex), CGFloat(cur.value) * phaseY)
             }
         }
         
@@ -240,7 +322,7 @@ public class LineChartRenderer: LineRadarChartRenderer
         let valueToPixelMatrix = trans.valueToPixelMatrix
         
         let entryCount = dataSet.entryCount
-        let isDrawSteppedEnabled = dataSet.isDrawSteppedEnabled
+        let isDrawSteppedEnabled = dataSet.mode == .Stepped
         let pointsPerEntryPair = isDrawSteppedEnabled ? 4 : 2
         
         let phaseX = animator.phaseX
@@ -425,7 +507,7 @@ public class LineChartRenderer: LineRadarChartRenderer
     {
         let phaseX = animator?.phaseX ?? 1.0
         let phaseY = animator?.phaseY ?? 1.0
-        let isDrawSteppedEnabled = dataSet.isDrawSteppedEnabled
+        let isDrawSteppedEnabled = dataSet.mode == .Stepped
         var matrix = matrix
         
         var e: ChartDataEntry!
diff --git a/ChartsRealm/Classes/Data/RealmLineDataSet.swift b/ChartsRealm/Classes/Data/RealmLineDataSet.swift
index f0be0688d8..d366ce1a86 100644
--- a/ChartsRealm/Classes/Data/RealmLineDataSet.swift
+++ b/ChartsRealm/Classes/Data/RealmLineDataSet.swift
@@ -29,6 +29,8 @@ public class RealmLineDataSet: RealmLineRadarDataSet, ILineChartDataSet
     
     // MARK: - Styling functions and accessors
     
+    public var mode: LineChartMode = LineChartMode.Linear
+    
     private var _cubicIntensity = CGFloat(0.2)
     
     /// Intensity for cubic lines (min = 0.05, max = 1)
@@ -54,16 +56,36 @@ public class RealmLineDataSet: RealmLineRadarDataSet, ILineChartDataSet
         }
     }
     
-    /// If true, cubic lines are drawn instead of linear
-    public var drawCubicEnabled = false
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
+    public var drawCubicEnabled: Bool
+    {
+        get
+        {
+            return mode == .CubicBezier
+        }
+        set
+        {
+            mode = newValue ? LineChartMode.CubicBezier : LineChartMode.Linear
+        }
+    }
     
-    /// - returns: true if drawing cubic lines is enabled, false if not.
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
     public var isDrawCubicEnabled: Bool { return drawCubicEnabled }
     
-    /// If true, stepped lines are drawn instead of linear
-    public var drawSteppedEnabled = false
-
-    /// - returns: true if drawing stepped lines is enabled, false if not.
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
+    public var drawSteppedEnabled: Bool
+    {
+        get
+        {
+            return mode == .Stepped
+        }
+        set
+        {
+            mode = newValue ? LineChartMode.Stepped : LineChartMode.Linear
+        }
+    }
+    
+    @available(*, deprecated=1.0, message="Use `mode` instead.")
     public var isDrawSteppedEnabled: Bool { return drawSteppedEnabled }
 
     /// The radius of the drawn circles.
@@ -157,9 +179,10 @@ public class RealmLineDataSet: RealmLineRadarDataSet, ILineChartDataSet
         copy.cubicIntensity = cubicIntensity
         copy.lineDashPhase = lineDashPhase
         copy.lineDashLengths = lineDashLengths
+        copy.lineCapType = lineCapType
         copy.drawCirclesEnabled = drawCirclesEnabled
-        copy.drawCubicEnabled = drawCubicEnabled
-        copy.drawSteppedEnabled = drawSteppedEnabled
+        copy.drawCircleHoleEnabled = drawCircleHoleEnabled
+        copy.mode = mode
         return copy
     }
     

From a70624386cb8ea28488153f1ea66b793a2f47fca Mon Sep 17 00:00:00 2001
From: Daniel Cohen Gindi <danielgindi@gmail.com>
Date: Fri, 8 Apr 2016 17:30:33 +0300
Subject: [PATCH 2/6] Added horizontal bezier to the demo

---
 .../Demos/CubicLineChartViewController.m      | 23 +++++++++++++++++++
 .../Classes/Demos/LineChart1ViewController.m  | 12 ++++++++++
 .../Classes/Demos/LineChart2ViewController.m  | 12 ++++++++++
 3 files changed, 47 insertions(+)

diff --git a/ChartsDemo/Classes/Demos/CubicLineChartViewController.m b/ChartsDemo/Classes/Demos/CubicLineChartViewController.m
index ce5cd847a7..3a90aaecd0 100644
--- a/ChartsDemo/Classes/Demos/CubicLineChartViewController.m
+++ b/ChartsDemo/Classes/Demos/CubicLineChartViewController.m
@@ -51,6 +51,8 @@ - (void)viewDidLoad
                      @{@"key": @"toggleFilled", @"label": @"Toggle Filled"},
                      @{@"key": @"toggleCircles", @"label": @"Toggle Circles"},
                      @{@"key": @"toggleCubic", @"label": @"Toggle Cubic"},
+                     @{@"key": @"toggleHorizontalCubic", @"label": @"Toggle Horizontal Cubic"},
+                     @{@"key": @"toggleStepped", @"label": @"Toggle Stepped"},
                      @{@"key": @"toggleHighlight", @"label": @"Toggle Highlight"},
                      @{@"key": @"animateX", @"label": @"Animate X"},
                      @{@"key": @"animateY", @"label": @"Animate Y"},
@@ -185,6 +187,27 @@ - (void)optionTapped:(NSString *)key
         return;
     }
     
+    if ([key isEqualToString:@"toggleStepped"])
+    {
+        for (id<ILineChartDataSet> set in _chartView.data.dataSets)
+        {
+            set.drawSteppedEnabled = !set.isDrawSteppedEnabled;
+        }
+        
+        [_chartView setNeedsDisplay];
+    }
+    
+    if ([key isEqualToString:@"toggleHorizontalCubic"])
+    {
+        for (id<ILineChartDataSet> set in _chartView.data.dataSets)
+        {
+            set.mode = set.mode == LineChartModeCubicBezier ? LineChartModeHorizontalBezier : LineChartModeCubicBezier;
+        }
+        
+        [_chartView setNeedsDisplay];
+        return;
+    }
+    
     [super handleOption:key forChartView:_chartView];
 }
 
diff --git a/ChartsDemo/Classes/Demos/LineChart1ViewController.m b/ChartsDemo/Classes/Demos/LineChart1ViewController.m
index a89de40196..b5a9cb6626 100644
--- a/ChartsDemo/Classes/Demos/LineChart1ViewController.m
+++ b/ChartsDemo/Classes/Demos/LineChart1ViewController.m
@@ -37,6 +37,7 @@ - (void)viewDidLoad
                      @{@"key": @"toggleFilled", @"label": @"Toggle Filled"},
                      @{@"key": @"toggleCircles", @"label": @"Toggle Circles"},
                      @{@"key": @"toggleCubic", @"label": @"Toggle Cubic"},
+                     @{@"key": @"toggleHorizontalCubic", @"label": @"Toggle Horizontal Cubic"},
                      @{@"key": @"toggleStepped", @"label": @"Toggle Stepped"},
                      @{@"key": @"toggleHighlight", @"label": @"Toggle Highlight"},
                      @{@"key": @"animateX", @"label": @"Animate X"},
@@ -220,6 +221,17 @@ - (void)optionTapped:(NSString *)key
         [_chartView setNeedsDisplay];
     }
     
+    if ([key isEqualToString:@"toggleHorizontalCubic"])
+    {
+        for (id<ILineChartDataSet> set in _chartView.data.dataSets)
+        {
+            set.mode = set.mode == LineChartModeCubicBezier ? LineChartModeHorizontalBezier : LineChartModeCubicBezier;
+        }
+        
+        [_chartView setNeedsDisplay];
+        return;
+    }
+    
     [super handleOption:key forChartView:_chartView];
 }
 
diff --git a/ChartsDemo/Classes/Demos/LineChart2ViewController.m b/ChartsDemo/Classes/Demos/LineChart2ViewController.m
index 9085ca9b32..b7f96e306c 100644
--- a/ChartsDemo/Classes/Demos/LineChart2ViewController.m
+++ b/ChartsDemo/Classes/Demos/LineChart2ViewController.m
@@ -37,6 +37,7 @@ - (void)viewDidLoad
                      @{@"key": @"toggleFilled", @"label": @"Toggle Filled"},
                      @{@"key": @"toggleCircles", @"label": @"Toggle Circles"},
                      @{@"key": @"toggleCubic", @"label": @"Toggle Cubic"},
+                     @{@"key": @"toggleHorizontalCubic", @"label": @"Toggle Horizontal Cubic"},
                      @{@"key": @"toggleStepped", @"label": @"Toggle Stepped"},
                      @{@"key": @"toggleHighlight", @"label": @"Toggle Highlight"},
                      @{@"key": @"animateX", @"label": @"Animate X"},
@@ -216,6 +217,17 @@ - (void)optionTapped:(NSString *)key
         [_chartView setNeedsDisplay];
     }
     
+    if ([key isEqualToString:@"toggleHorizontalCubic"])
+    {
+        for (id<ILineChartDataSet> set in _chartView.data.dataSets)
+        {
+            set.mode = set.mode == LineChartModeCubicBezier ? LineChartModeHorizontalBezier : LineChartModeCubicBezier;
+        }
+        
+        [_chartView setNeedsDisplay];
+        return;
+    }
+    
     [super handleOption:key forChartView:_chartView];
 }
 

From 0069c410492ac23248c854fadfb9b1ffb8419361 Mon Sep 17 00:00:00 2001
From: Daniel Cohen Gindi <danielgindi@gmail.com>
Date: Fri, 8 Apr 2016 17:53:30 +0300
Subject: [PATCH 3/6] Make yVals settable

---
 .../Implementations/Standard/ChartDataSet.swift    | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/Charts/Classes/Data/Implementations/Standard/ChartDataSet.swift b/Charts/Classes/Data/Implementations/Standard/ChartDataSet.swift
index 4fd28aa2a7..ec199fc00c 100644
--- a/Charts/Classes/Data/Implementations/Standard/ChartDataSet.swift
+++ b/Charts/Classes/Data/Implementations/Standard/ChartDataSet.swift
@@ -64,7 +64,19 @@ public class ChartDataSet: ChartBaseDataSet
     /// the last end value used for calcMinMax
     internal var _lastEnd: Int = 0
     
-    public var yVals: [ChartDataEntry] { return _yVals }
+    /// the array of y-values that this DataSet represents.
+    public var yVals: [ChartDataEntry]
+    {
+        get
+        {
+            return _yVals
+        }
+        set
+        {
+            _yVals = newValue
+            notifyDataSetChanged()
+        }
+    }
     
     /// Use this method to tell the data set that the underlying data has changed
     public override func notifyDataSetChanged()

From 299eaf06b26deda9cc16ba6e7054e0e1c3c80bc7 Mon Sep 17 00:00:00 2001
From: Daniel Cohen Gindi <danielgindi@gmail.com>
Date: Fri, 8 Apr 2016 17:30:49 +0300
Subject: [PATCH 4/6] Made these line demos reuse the dataset and keep styling

---
 .../Demos/CubicLineChartViewController.m      | 48 +++++++-----
 .../Classes/Demos/LineChart1ViewController.m  | 72 +++++++++--------
 .../Classes/Demos/LineChart2ViewController.m  | 77 +++++++++++--------
 3 files changed, 115 insertions(+), 82 deletions(-)

diff --git a/ChartsDemo/Classes/Demos/CubicLineChartViewController.m b/ChartsDemo/Classes/Demos/CubicLineChartViewController.m
index 3a90aaecd0..a802a5f8e6 100644
--- a/ChartsDemo/Classes/Demos/CubicLineChartViewController.m
+++ b/ChartsDemo/Classes/Demos/CubicLineChartViewController.m
@@ -131,25 +131,35 @@ - (void)setDataCount:(int)count range:(double)range
         [yVals1 addObject:[[ChartDataEntry alloc] initWithValue:val xIndex:i]];
     }
     
-    LineChartDataSet *set1 = [[LineChartDataSet alloc] initWithYVals:yVals1 label:@"DataSet 1"];
-    set1.drawCubicEnabled = YES;
-    set1.cubicIntensity = 0.2;
-    set1.drawCirclesEnabled = NO;
-    set1.lineWidth = 1.8;
-    set1.circleRadius = 4.0;
-    [set1 setCircleColor:UIColor.whiteColor];
-    set1.highlightColor = [UIColor colorWithRed:244/255.f green:117/255.f blue:117/255.f alpha:1.f];
-    [set1 setColor:UIColor.whiteColor];
-    set1.fillColor = UIColor.whiteColor;
-    set1.fillAlpha = 1.f;
-    set1.drawHorizontalHighlightIndicatorEnabled = NO;
-    set1.fillFormatter = [[CubicLineSampleFillFormatter alloc] init];
-    
-    LineChartData *data = [[LineChartData alloc] initWithXVals:xVals dataSet:set1];
-    [data setValueFont:[UIFont fontWithName:@"HelveticaNeue-Light" size:9.f]];
-    [data setDrawValues:NO];
-    
-    _chartView.data = data;
+    LineChartDataSet *set1 = nil;
+    if (_chartView.data.dataSetCount > 0)
+    {
+        set1 = (LineChartDataSet *)_chartView.data.dataSets[0];
+        set1.yVals = yVals1;
+        [_chartView notifyDataSetChanged];
+    }
+    else
+    {
+        set1 = [[LineChartDataSet alloc] initWithYVals:yVals1 label:@"DataSet 1"];
+        set1.drawCubicEnabled = YES;
+        set1.cubicIntensity = 0.2;
+        set1.drawCirclesEnabled = NO;
+        set1.lineWidth = 1.8;
+        set1.circleRadius = 4.0;
+        [set1 setCircleColor:UIColor.whiteColor];
+        set1.highlightColor = [UIColor colorWithRed:244/255.f green:117/255.f blue:117/255.f alpha:1.f];
+        [set1 setColor:UIColor.whiteColor];
+        set1.fillColor = UIColor.whiteColor;
+        set1.fillAlpha = 1.f;
+        set1.drawHorizontalHighlightIndicatorEnabled = NO;
+        set1.fillFormatter = [[CubicLineSampleFillFormatter alloc] init];
+        
+        LineChartData *data = [[LineChartData alloc] initWithXVals:xVals dataSet:set1];
+        [data setValueFont:[UIFont fontWithName:@"HelveticaNeue-Light" size:9.f]];
+        [data setDrawValues:NO];
+        
+        _chartView.data = data;
+    }
 }
 
 - (void)optionTapped:(NSString *)key
diff --git a/ChartsDemo/Classes/Demos/LineChart1ViewController.m b/ChartsDemo/Classes/Demos/LineChart1ViewController.m
index b5a9cb6626..3f49281710 100644
--- a/ChartsDemo/Classes/Demos/LineChart1ViewController.m
+++ b/ChartsDemo/Classes/Demos/LineChart1ViewController.m
@@ -143,37 +143,47 @@ - (void)setDataCount:(int)count range:(double)range
         [yVals addObject:[[ChartDataEntry alloc] initWithValue:val xIndex:i]];
     }
     
-    LineChartDataSet *set1 = [[LineChartDataSet alloc] initWithYVals:yVals label:@"DataSet 1"];
-    
-    set1.lineDashLengths = @[@5.f, @2.5f];
-    set1.highlightLineDashLengths = @[@5.f, @2.5f];
-    [set1 setColor:UIColor.blackColor];
-    [set1 setCircleColor:UIColor.blackColor];
-    set1.lineWidth = 1.0;
-    set1.circleRadius = 3.0;
-    set1.drawCircleHoleEnabled = NO;
-    set1.valueFont = [UIFont systemFontOfSize:9.f];
-    //set1.fillAlpha = 65/255.0;
-    //set1.fillColor = UIColor.blackColor;
-    
-    NSArray *gradientColors = @[
-                        (id)[ChartColorTemplates colorFromString:@"#00ff0000"].CGColor,
-                        (id)[ChartColorTemplates colorFromString:@"#ffff0000"].CGColor
-                        ];
-    CGGradientRef gradient = CGGradientCreateWithColors(nil, (CFArrayRef)gradientColors, nil);
-    
-    set1.fillAlpha = 1.f;
-    set1.fill = [ChartFill fillWithLinearGradient:gradient angle:90.f];
-    set1.drawFilledEnabled = YES;
-    
-    CGGradientRelease(gradient);
-    
-    NSMutableArray *dataSets = [[NSMutableArray alloc] init];
-    [dataSets addObject:set1];
-    
-    LineChartData *data = [[LineChartData alloc] initWithXVals:xVals dataSets:dataSets];
-    
-    _chartView.data = data;
+    LineChartDataSet *set1 = nil;
+    if (_chartView.data.dataSetCount > 0)
+    {
+        set1 = (LineChartDataSet *)_chartView.data.dataSets[0];
+        set1.yVals = yVals;
+        [_chartView notifyDataSetChanged];
+    }
+    else
+    {
+        set1 = [[LineChartDataSet alloc] initWithYVals:yVals label:@"DataSet 1"];
+        
+        set1.lineDashLengths = @[@5.f, @2.5f];
+        set1.highlightLineDashLengths = @[@5.f, @2.5f];
+        [set1 setColor:UIColor.blackColor];
+        [set1 setCircleColor:UIColor.blackColor];
+        set1.lineWidth = 1.0;
+        set1.circleRadius = 3.0;
+        set1.drawCircleHoleEnabled = NO;
+        set1.valueFont = [UIFont systemFontOfSize:9.f];
+        //set1.fillAlpha = 65/255.0;
+        //set1.fillColor = UIColor.blackColor;
+        
+        NSArray *gradientColors = @[
+                                    (id)[ChartColorTemplates colorFromString:@"#00ff0000"].CGColor,
+                                    (id)[ChartColorTemplates colorFromString:@"#ffff0000"].CGColor
+                                    ];
+        CGGradientRef gradient = CGGradientCreateWithColors(nil, (CFArrayRef)gradientColors, nil);
+        
+        set1.fillAlpha = 1.f;
+        set1.fill = [ChartFill fillWithLinearGradient:gradient angle:90.f];
+        set1.drawFilledEnabled = YES;
+        
+        CGGradientRelease(gradient);
+        
+        NSMutableArray *dataSets = [[NSMutableArray alloc] init];
+        [dataSets addObject:set1];
+        
+        LineChartData *data = [[LineChartData alloc] initWithXVals:xVals dataSets:dataSets];
+        
+        _chartView.data = data;
+    }
 }
 
 - (void)optionTapped:(NSString *)key
diff --git a/ChartsDemo/Classes/Demos/LineChart2ViewController.m b/ChartsDemo/Classes/Demos/LineChart2ViewController.m
index b7f96e306c..02d16b5582 100644
--- a/ChartsDemo/Classes/Demos/LineChart2ViewController.m
+++ b/ChartsDemo/Classes/Demos/LineChart2ViewController.m
@@ -121,26 +121,15 @@ - (void)setDataCount:(int)count range:(double)range
         [xVals addObject:[@(i) stringValue]];
     }
     
-    NSMutableArray *yVals = [[NSMutableArray alloc] init];
+    NSMutableArray *yVals1 = [[NSMutableArray alloc] init];
     
     for (int i = 0; i < count; i++)
     {
         double mult = range / 2.0;
         double val = (double) (arc4random_uniform(mult)) + 50;
-        [yVals addObject:[[ChartDataEntry alloc] initWithValue:val xIndex:i]];
+        [yVals1 addObject:[[ChartDataEntry alloc] initWithValue:val xIndex:i]];
     }
     
-    LineChartDataSet *set1 = [[LineChartDataSet alloc] initWithYVals:yVals label:@"DataSet 1"];
-    set1.axisDependency = AxisDependencyLeft;
-    [set1 setColor:[UIColor colorWithRed:51/255.f green:181/255.f blue:229/255.f alpha:1.f]];
-    [set1 setCircleColor:UIColor.whiteColor];
-    set1.lineWidth = 2.0;
-    set1.circleRadius = 3.0;
-    set1.fillAlpha = 65/255.0;
-    set1.fillColor = [UIColor colorWithRed:51/255.f green:181/255.f blue:229/255.f alpha:1.f];
-    set1.highlightColor = [UIColor colorWithRed:244/255.f green:117/255.f blue:117/255.f alpha:1.f];
-    set1.drawCircleHoleEnabled = NO;
-    
     NSMutableArray *yVals2 = [[NSMutableArray alloc] init];
     
     for (int i = 0; i < count; i++)
@@ -150,26 +139,50 @@ - (void)setDataCount:(int)count range:(double)range
         [yVals2 addObject:[[ChartDataEntry alloc] initWithValue:val xIndex:i]];
     }
     
-    LineChartDataSet *set2 = [[LineChartDataSet alloc] initWithYVals:yVals2 label:@"DataSet 2"];
-    set2.axisDependency = AxisDependencyRight;
-    [set2 setColor:UIColor.redColor];
-    [set2 setCircleColor:UIColor.whiteColor];
-    set2.lineWidth = 2.0;
-    set2.circleRadius = 3.0;
-    set2.fillAlpha = 65/255.0;
-    set2.fillColor = UIColor.redColor;
-    set2.highlightColor = [UIColor colorWithRed:244/255.f green:117/255.f blue:117/255.f alpha:1.f];
-    set2.drawCircleHoleEnabled = NO;
-    
-    NSMutableArray *dataSets = [[NSMutableArray alloc] init];
-    [dataSets addObject:set2];
-    [dataSets addObject:set1];
-    
-    LineChartData *data = [[LineChartData alloc] initWithXVals:xVals dataSets:dataSets];
-    [data setValueTextColor:UIColor.whiteColor];
-    [data setValueFont:[UIFont systemFontOfSize:9.f]];
+    LineChartDataSet *set1 = nil, *set2 = nil;
     
-    _chartView.data = data;
+    if (_chartView.data.dataSetCount > 0)
+    {
+        set1 = (LineChartDataSet *)_chartView.data.dataSets[0];
+        set2 = (LineChartDataSet *)_chartView.data.dataSets[1];
+        set1.yVals = yVals1;
+        set2.yVals = yVals2;
+        [_chartView notifyDataSetChanged];
+    }
+    else
+    {
+        set1 = [[LineChartDataSet alloc] initWithYVals:yVals1 label:@"DataSet 1"];
+        set1.axisDependency = AxisDependencyLeft;
+        [set1 setColor:[UIColor colorWithRed:51/255.f green:181/255.f blue:229/255.f alpha:1.f]];
+        [set1 setCircleColor:UIColor.whiteColor];
+        set1.lineWidth = 2.0;
+        set1.circleRadius = 3.0;
+        set1.fillAlpha = 65/255.0;
+        set1.fillColor = [UIColor colorWithRed:51/255.f green:181/255.f blue:229/255.f alpha:1.f];
+        set1.highlightColor = [UIColor colorWithRed:244/255.f green:117/255.f blue:117/255.f alpha:1.f];
+        set1.drawCircleHoleEnabled = NO;
+        
+        set2 = [[LineChartDataSet alloc] initWithYVals:yVals2 label:@"DataSet 2"];
+        set2.axisDependency = AxisDependencyRight;
+        [set2 setColor:UIColor.redColor];
+        [set2 setCircleColor:UIColor.whiteColor];
+        set2.lineWidth = 2.0;
+        set2.circleRadius = 3.0;
+        set2.fillAlpha = 65/255.0;
+        set2.fillColor = UIColor.redColor;
+        set2.highlightColor = [UIColor colorWithRed:244/255.f green:117/255.f blue:117/255.f alpha:1.f];
+        set2.drawCircleHoleEnabled = NO;
+        
+        NSMutableArray *dataSets = [[NSMutableArray alloc] init];
+        [dataSets addObject:set2];
+        [dataSets addObject:set1];
+        
+        LineChartData *data = [[LineChartData alloc] initWithXVals:xVals dataSets:dataSets];
+        [data setValueTextColor:UIColor.whiteColor];
+        [data setValueFont:[UIFont systemFontOfSize:9.f]];
+        
+        _chartView.data = data;
+    }
 }
 
 - (void)optionTapped:(NSString *)key

From 3883db7d9913bd5bcaeddd7f9e517409646bac3e Mon Sep 17 00:00:00 2001
From: Daniel Cohen Gindi <danielgindi@gmail.com>
Date: Fri, 8 Apr 2016 17:55:21 +0300
Subject: [PATCH 5/6] Docs

---
 .../Data/Implementations/Standard/LineChartDataSet.swift       | 3 +++
 Charts/Classes/Data/Interfaces/ILineChartDataSet.swift         | 3 +++
 ChartsRealm/Classes/Data/RealmLineDataSet.swift                | 3 +++
 3 files changed, 9 insertions(+)

diff --git a/Charts/Classes/Data/Implementations/Standard/LineChartDataSet.swift b/Charts/Classes/Data/Implementations/Standard/LineChartDataSet.swift
index 3795908ada..5270d57241 100644
--- a/Charts/Classes/Data/Implementations/Standard/LineChartDataSet.swift
+++ b/Charts/Classes/Data/Implementations/Standard/LineChartDataSet.swift
@@ -39,6 +39,9 @@ public class LineChartDataSet: LineRadarChartDataSet, ILineChartDataSet
     
     // MARK: - Styling functions and accessors
     
+    /// The drawing mode for this line dataset
+    ///
+    /// **default**: Linear
     public var mode: LineChartMode = LineChartMode.Linear
     
     private var _cubicIntensity = CGFloat(0.2)
diff --git a/Charts/Classes/Data/Interfaces/ILineChartDataSet.swift b/Charts/Classes/Data/Interfaces/ILineChartDataSet.swift
index 38da71b51d..3f33357e8f 100644
--- a/Charts/Classes/Data/Interfaces/ILineChartDataSet.swift
+++ b/Charts/Classes/Data/Interfaces/ILineChartDataSet.swift
@@ -30,6 +30,9 @@ public protocol ILineChartDataSet: ILineRadarChartDataSet
     
     // MARK: - Styling functions and accessors
     
+    /// The drawing mode for this line dataset
+    ///
+    /// **default**: Linear
     var mode: LineChartMode { get set }
     
     /// Intensity for cubic lines (min = 0.05, max = 1)
diff --git a/ChartsRealm/Classes/Data/RealmLineDataSet.swift b/ChartsRealm/Classes/Data/RealmLineDataSet.swift
index d366ce1a86..94d01fbb9a 100644
--- a/ChartsRealm/Classes/Data/RealmLineDataSet.swift
+++ b/ChartsRealm/Classes/Data/RealmLineDataSet.swift
@@ -29,6 +29,9 @@ public class RealmLineDataSet: RealmLineRadarDataSet, ILineChartDataSet
     
     // MARK: - Styling functions and accessors
     
+    /// The drawing mode for this line dataset
+    ///
+    /// **default**: Linear
     public var mode: LineChartMode = LineChartMode.Linear
     
     private var _cubicIntensity = CGFloat(0.2)

From 7b5462ee6b1401234f446831d966be9fd4842a14 Mon Sep 17 00:00:00 2001
From: Daniel Cohen Gindi <danielgindi@gmail.com>
Date: Sat, 9 Apr 2016 22:07:58 +0300
Subject: [PATCH 6/6] DRYed some code here...

---
 .../Classes/Renderers/LineChartRenderer.swift | 24 ++-----------------
 1 file changed, 2 insertions(+), 22 deletions(-)

diff --git a/Charts/Classes/Renderers/LineChartRenderer.swift b/Charts/Classes/Renderers/LineChartRenderer.swift
index eec251f35c..106f45c7c6 100644
--- a/Charts/Classes/Renderers/LineChartRenderer.swift
+++ b/Charts/Classes/Renderers/LineChartRenderer.swift
@@ -138,12 +138,12 @@ public class LineChartRenderer: LineRadarChartRenderer
             // let the spline start
             CGPathMoveToPoint(cubicPath, &valueToPixelMatrix, CGFloat(cur.xIndex), CGFloat(cur.value) * phaseY)
             
-            for j in minx + 1 ..< min(size, entryCount - 1)
+            for j in minx + 1 ..< min(size, entryCount)
             {
                 prevPrev = prev
                 prev = cur
                 cur = next
-                next = dataSet.entryForIndex(j + 1)
+                next = entryCount > j + 1 ? dataSet.entryForIndex(j + 1) : cur
                 
                 if next == nil { break }
                 
@@ -152,26 +152,6 @@ public class LineChartRenderer: LineRadarChartRenderer
                 curDx = CGFloat(next.xIndex - prev.xIndex) * intensity
                 curDy = CGFloat(next.value - prev.value) * intensity
                 
-                CGPathAddCurveToPoint(cubicPath, &valueToPixelMatrix, CGFloat(prev.xIndex) + prevDx, (CGFloat(prev.value) + prevDy) * phaseY,
-                    CGFloat(cur.xIndex) - curDx,
-                    (CGFloat(cur.value) - curDy) * phaseY, CGFloat(cur.xIndex), CGFloat(cur.value) * phaseY)
-            }
-            
-            if (size > entryCount - 1)
-            {
-                prevPrev = dataSet.entryForIndex(entryCount - (entryCount >= 3 ? 3 : 2))
-                prev = dataSet.entryForIndex(entryCount - 2)
-                cur = dataSet.entryForIndex(entryCount - 1)
-                next = cur
-                
-                if prevPrev == nil || prev == nil || cur == nil { return }
-                
-                prevDx = CGFloat(cur.xIndex - prevPrev.xIndex) * intensity
-                prevDy = CGFloat(cur.value - prevPrev.value) * intensity
-                curDx = CGFloat(next.xIndex - prev.xIndex) * intensity
-                curDy = CGFloat(next.value - prev.value) * intensity
-                
-                // the last cubic
                 CGPathAddCurveToPoint(cubicPath, &valueToPixelMatrix,
                                       CGFloat(prev.xIndex) + prevDx,
                                       (CGFloat(prev.value) + prevDy) * phaseY,