feature<CommitGraph>: add polyline display mode

src/Models/Preference.cs

@@ -105,6 +105,11 @@ namespace SourceGit.Models {
             /// </summary>
             public double Height { get; set; } = 600;
 
+            /// <summary>
+            ///     在提交列表视图中是否使用折线代替曲线
+            /// </summary>
+            public bool UsePolylineInGraph { get; set; } = false;
+
             /// <summary>
             ///     将提交信息面板与提交记录左右排布
             /// </summary>

src/Resources/Icons.xaml

@@ -23,6 +23,9 @@
     <Geometry x:Key="Icon.Tree">M1024 610v-224H640v48H256V224h128V0H0v224h128v752h512v48h384V800H640v48H256V562h384v48z</Geometry>
     <Geometry x:Key="Icon.Grid">M30 271l241 0 0-241-241 0 0 241zM392 271l241 0 0-241-241 0 0 241zM753 30l0 241 241 0 0-241-241 0zM30 632l241 0 0-241-241 0 0 241zM392 632l241 0 0-241-241 0 0 241zM753 632l241 0 0-241-241 0 0 241zM30 994l241 0 0-241-241 0 0 241zM392 994l241 0 0-241-241 0 0 241zM753 994l241 0 0-241-241 0 0 241z</Geometry>
 
+    <Geometry x:Key="Icon.Curve">M1017 598c0-25-25-50-50-50c-30 0-50 25-50 50c0 35-10 136-55 186c-25 25-55 35-95 35c-70 0-121-191-161-326c-50-196-100-377-231-377c-186 0-271 286-326 472c-10 40-20 75-30 95c-10 25 5 55 30 65c25 10 55-5 65-30c10-25 20-60 35-105c35-136 116-397 226-397c55 0 105 181 141 301c55 196 110 402 256 402c65 0 121-20 161-65c90-95 85-251 85-256z</Geometry>
+    <Geometry x:Key="Icon.Polyline">M341 475 147 675 65 593l271-284 281 265 254-295 89 77-336 387z</Geometry>
+    
     <Geometry x:Key="Icon.Down">M509 546l271-271 91 91-348 349-1-1-13 13-363-361 91-91z</Geometry>
     <Geometry x:Key="Icon.DoubleDown">M256 224l0 115L512 544l256-205 0-115-256 205L256 224zM512 685l-256-205L256 595 512 800 768 595l0-115L512 685z</Geometry>
     <Geometry x:Key="Icon.Up">M170 831l343-342L855 831l105-105-448-448L64 726 170 831z</Geometry>

src/Resources/Locales/en_US.xaml

@@ -254,7 +254,8 @@
     <sys:String x:Key="Text.Histories">Histories</sys:String>
     <sys:String x:Key="Text.Histories.Search">SEARCH SHA/SUBJECT/AUTHOR. PRESS ENTER TO SEARCH, ESC TO QUIT</sys:String>
     <sys:String x:Key="Text.Histories.SearchClear">CLEAR</sys:String>
-    <sys:String x:Key="Text.Histories.DisplayMode">Toggle Horizontal/Vertical Layout</sys:String>
+    <sys:String x:Key="Text.Histories.GraphMode">Switch Curve/Polyline Graph Mode</sys:String>
+    <sys:String x:Key="Text.Histories.DisplayMode">Switch Horizontal/Vertical Layout</sys:String>
     <sys:String x:Key="Text.Histories.Selected">SELECTED {0} COMMITS</sys:String>
     <sys:String x:Key="Text.Histories.Guide">HISTORIES GUIDE</sys:String>
     <sys:String x:Key="Text.Histories.Guide_1">1. Select single commit to view detail</sys:String>

src/Resources/Locales/zh_CN.xaml

@@ -254,6 +254,7 @@
     <sys:String x:Key="Text.Histories">历史记录</sys:String>
     <sys:String x:Key="Text.Histories.Search">查询提交指纹、信息、作者。回车键开始，ESC键取消</sys:String>
     <sys:String x:Key="Text.Histories.SearchClear">清空</sys:String>
+    <sys:String x:Key="Text.Histories.GraphMode">切换曲线/折线显示</sys:String>
     <sys:String x:Key="Text.Histories.DisplayMode">切换横向/纵向显示</sys:String>
     <sys:String x:Key="Text.Histories.Selected">已选中{0}项提交</sys:String>
     <sys:String x:Key="Text.Histories.Guide">操作说明</sys:String>

src/Resources/Styles/ToggleButton.xaml

@@ -90,8 +90,8 @@
                         <Path 
                             x:Name="Icon" 
                             Style="{DynamicResource Style.Icon}"
-                            Height="{TemplateBinding Width}"
+                            Width="{TemplateBinding Width}"
-                            Width="{TemplateBinding Height}"
+                            Height="{TemplateBinding Height}"
                             Fill="{TemplateBinding Foreground}"
                             Data="{DynamicResource Icon.Orientation}"
                             RenderTransformOrigin=".5,.5">
@@ -114,4 +114,32 @@
             </Setter.Value>
         </Setter>
     </Style>
+
+    <Style x:Key="Style.ToggleButton.CommitGraphMode" TargetType="{x:Type ToggleButton}">
+        <Setter Property="Background" Value="Transparent"/>
+        <Setter Property="BorderBrush" Value="Transparent"/>
+        <Setter Property="BorderThickness" Value="0"/>
+
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="{x:Type ToggleButton}">
+                    <Grid Background="Transparent">
+                        <Path 
+                            x:Name="Icon" 
+                            Style="{DynamicResource Style.Icon}"
+                            Width="{TemplateBinding Width}"
+                            Height="{TemplateBinding Height}"
+                            Fill="{TemplateBinding Foreground}"
+                            Data="{DynamicResource Icon.Curve}"/>
+                    </Grid>
+
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsChecked" Value="True">
+                            <Setter TargetName="Icon" Property="Data" Value="{DynamicResource Icon.Polyline}"/>
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
 </ResourceDictionary>

src/Views/Controls/CommitGraph.cs

@@ -235,12 +235,30 @@ namespace SourceGit.Views.Controls {
         protected override void OnRender(DrawingContext dc) {
             if (data == null) return;
 
+            dc.PushTransform(new TranslateTransform(0, -startY));
+
+            // 计算边界
             var top = startY;
             var bottom = startY + ActualHeight;
 
-            dc.PushTransform(new TranslateTransform(0, -startY));
+            // 绘制线
+            if (Models.Preference.Instance.Window.UsePolylineInGraph) {
+                DrawPolyLine(dc, top, bottom);
+            } else {
+                DrawCurveLine(dc, top, bottom);
+            }
 
-            // 绘制曲线
+            // 绘制点
+            var dotFill = FindResource("Brush.Contents") as Brush;
+            foreach (var dot in data.Dots) {
+                if (dot.Center.Y < top) continue;
+                if (dot.Center.Y > bottom) break;
+
+                dc.DrawEllipse(dotFill, PENS[dot.Color], dot.Center, 3, 3);
+            }
+        }
+    
+        private void DrawCurveLine(DrawingContext dc, double top, double bottom) {
             foreach (var line in data.Lines) {
                 var last = line.Points[0];
                 var size = line.Points.Count;
@@ -265,8 +283,6 @@ namespace SourceGit.Views.Controls {
                             ctx.QuadraticBezierTo(new Point(cur.X, last.Y), cur, true, false);
                         } else if (cur.X < last.X) {
                             if (i < size - 1) {
-                                cur.Y += HALF_HEIGHT;
-
                                 var midY = (last.Y + cur.Y) / 2;
                                 var midX = (last.X + cur.X) / 2;
                                 ctx.PolyQuadraticBezierTo(new Point[] {
@@ -290,7 +306,6 @@ namespace SourceGit.Views.Controls {
                 dc.DrawGeometry(null, pen, geo);
             }
 
-            // 绘制合并线
             foreach (var link in data.Links) {
                 if (link.End.Y < top) continue;
                 if (link.Start.Y > bottom) break;
@@ -304,14 +319,43 @@ namespace SourceGit.Views.Controls {
                 geo.Freeze();
                 dc.DrawGeometry(null, PENS[link.Color], geo);
             }
+        }
 
-            // 绘制点
+        private void DrawPolyLine(DrawingContext dc, double top, double bottom) {
-            var dotFill = FindResource("Brush.Contents") as Brush;
+            foreach (var line in data.Lines) {
-            foreach (var dot in data.Dots) {
+                var last = line.Points[0];
-                if (dot.Center.Y < top) continue;
+                var size = line.Points.Count;
-                if (dot.Center.Y > bottom) break;
 
-                dc.DrawEllipse(dotFill, PENS[dot.Color], dot.Center, 3, 3);
+                if (line.Points[size - 1].Y < top) continue;
+                if (last.Y > bottom) continue;
+
+                var geo = new StreamGeometry();
+                var pen = PENS[line.Color];
+                using (var ctx = geo.Open()) {
+                    ctx.BeginFigure(last, false, false);
+
+                    var ended = false;
+                    for (int i = 1; i < size; i++) {
+                        var cur = line.Points[i];
+                        if (cur.Y > bottom) {
+                            cur.Y = bottom;
+                            ended = true;
+                        }
+
+                        ctx.LineTo(cur, true, false);
+                        if (ended) break;
+                        last = cur;
+                    }
+                }
+
+                geo.Freeze();
+                dc.DrawGeometry(null, pen, geo);
+            }
+
+            foreach (var link in data.Links) {
+                if (link.End.Y < top) continue;
+                if (link.Start.Y > bottom) break;
+                dc.DrawLine(PENS[link.Color], link.Start, link.End);
             }
         }
     }

src/Views/Widgets/Histories.xaml

@@ -180,10 +180,19 @@
 
             <!-- Right Top Button -->
             <StackPanel HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,6,0,0" Orientation="Horizontal">
+                <ToggleButton
+                    Style="{StaticResource Style.ToggleButton.CommitGraphMode}"
+                    Foreground="{StaticResource Brush.FG2}"
+                    Width="16" Height="16"
+                    ToolTip="{StaticResource Text.Histories.GraphMode}"
+                    IsChecked="{Binding Source={x:Static models:Preference.Instance}, Path=Window.UsePolylineInGraph, Mode=TwoWay}"
+                    Checked="ChangeGraphMode" Unchecked="ChangeGraphMode"/>
+                
                 <ToggleButton
                     Style="{StaticResource Style.ToggleButton.SplitDirection}"
                     Foreground="{StaticResource Brush.FG2}"
                     Width="16" Height="16"
+                    Margin="8,0,0,0"
                     ToolTip="{StaticResource Text.Histories.DisplayMode}"
                     IsChecked="{Binding Source={x:Static models:Preference.Instance}, Path=Window.MoveCommitInfoRight, Mode=TwoWay, Converter={StaticResource InverseBool}}"
                     Checked="ChangeOrientation" Unchecked="ChangeOrientation"/>

src/Views/Widgets/Histories.xaml.cs

@@ -143,6 +143,11 @@ namespace SourceGit.Views.Widgets {
 
             layout.InvalidateArrange();
         }
+
+        public void ChangeGraphMode(object sender, RoutedEventArgs e) {
+            graph.InvalidateVisual();
+            e.Handled = true;
+        }
         #endregion
 
         #region SEARCH_BAR

src/Views/Widgets/RevisionCompare.xaml

@@ -15,11 +15,11 @@
 
         <Grid Grid.Row="0">
             <Grid.ColumnDefinitions>
-                <ColumnDefinition Width="64"/>
+                <ColumnDefinition Width="80"/>
                 <ColumnDefinition Width="*"/>
                 <ColumnDefinition Width="48"/>
                 <ColumnDefinition Width="*"/>
-                <ColumnDefinition Width="64"/>
+                <ColumnDefinition Width="80"/>
             </Grid.ColumnDefinitions>
 
             <Border