App.xaml

<Application
    x:Class="ShadowMapping.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:ShadowMapping">
    <Application.Resources>
        <Style x:Key="CircleSlider" TargetType="Slider">
            <Setter Property="Background" Value="CornflowerBlue"/>
            <Setter Property="BorderBrush" Value="CornflowerBlue"/>
            <Setter Property="BorderThickness" Value="2"/>
            <Setter Property="Foreground" Value="Gold"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="Slider">
                        <Grid Margin="{TemplateBinding Padding}">
                            <Grid.Resources>
                                <Style x:Key="SliderThumbStyle" TargetType="Thumb">
                                    <Setter Property="BorderThickness" Value="2"/>
                                    <Setter Property="BorderBrush" Value="Gold"/>
                                    <Setter Property="Foreground" Value="Gold"/>
                                    <Setter Property="Template">
                                        <Setter.Value>
                                            <ControlTemplate TargetType="Thumb">
                                                <Ellipse StrokeThickness="2" Stroke="{TemplateBinding BorderBrush}" Fill="{TemplateBinding Foreground}"/>
                                            </ControlTemplate>
                                        </Setter.Value>
                                    </Setter>
                                </Style>
                            </Grid.Resources>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="Auto"/>
                                <RowDefinition Height="*"/>
                            </Grid.RowDefinitions>
                            <Grid x:Name="SliderContainer" Background="Transparent" Grid.Row="1">
                                <Grid x:Name="HorizontalTemplate">
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition Width="Auto"/>
                                        <ColumnDefinition Width="Auto"/>
                                        <ColumnDefinition Width="*"/>
                                    </Grid.ColumnDefinitions>
                                    <Grid.RowDefinitions>
                                        <RowDefinition Height="17"/>
                                        <RowDefinition Height="Auto"/>
                                        <RowDefinition Height="17"/>
                                    </Grid.RowDefinitions>
                                    <Rectangle x:Name="HorizontalTrackRect" Grid.ColumnSpan="3" Fill="{TemplateBinding Background}" Grid.Row="1" Height="10" RadiusX="5" RadiusY="5"/>
                                    <Rectangle x:Name="HorizontalDecreaseRect" Fill="{TemplateBinding Background}" Grid.Row="1" Height="10" RadiusX="5" RadiusY="5"/>
                                    <Rectangle x:Name="HorizontalBorder" Grid.ColumnSpan="3" Grid.Row="1" Stroke="{TemplateBinding BorderBrush}"
                                StrokeThickness="{TemplateBinding BorderThickness}" Height="10" RadiusX="5" RadiusY="5"/>
                                    <Thumb x:Name="HorizontalThumb" AutomationProperties.AccessibilityView="Raw" Background="{ThemeResource SliderThumbBackgroundThemeBrush}"
                                Grid.Column="1" DataContext="{TemplateBinding Value}" Grid.Row="1" Style="{StaticResource SliderThumbStyle}" Height="25" Width="25"/>
                                </Grid>
                                <Grid x:Name="VerticalTemplate" Visibility="Collapsed">
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition Width="17"/>
                                        <ColumnDefinition Width="Auto"/>
                                        <ColumnDefinition Width="17"/>
                                    </Grid.ColumnDefinitions>
                                    <Grid.RowDefinitions>
                                        <RowDefinition Height="*"/>
                                        <RowDefinition Height="Auto"/>
                                        <RowDefinition Height="Auto"/>
                                    </Grid.RowDefinitions>
                                    <Rectangle x:Name="VerticalTrackRect" Grid.Column="1" Fill="{TemplateBinding Background}" Grid.RowSpan="3" Width="10" RadiusX="5" RadiusY="5"/>
                                    <Rectangle x:Name="VerticalDecreaseRect" Grid.Column="1" Fill="{TemplateBinding Background}" Grid.Row="2"/>
                                    <Rectangle x:Name="VerticalBorder" Grid.RowSpan="3" Grid.Column="1"  Stroke="{TemplateBinding BorderBrush}"
                                StrokeThickness="{TemplateBinding BorderThickness}" Width="10" RadiusX="5" RadiusY="5" />
                                    <Thumb x:Name="VerticalThumb" AutomationProperties.AccessibilityView="Raw" Background="{ThemeResource SliderThumbBackgroundThemeBrush}"
                                Grid.Column="1" DataContext="{TemplateBinding Value}" Grid.Row="1" Style="{StaticResource SliderThumbStyle}" Height="25" Width="25"/>
                                </Grid>
                            </Grid>
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </Application.Resources>
</Application>