add pie chart example

SomeChartsAvaloniaExamples/Program.cs

@@ -9,6 +9,6 @@ namespace SomeChartsAvaloniaExamples;
 internal class Program {
 	[STAThread]
 	public static void Main(string[] args) {
-		ElementsExamples.RunPieChart();
+		PieChartExample.Run();
 	}
 }

SomeChartsAvaloniaExamples/src/elements/PieChartExample.cs

@@ -0,0 +1,50 @@
+using SomeChartsUi.data;
+using SomeChartsUi.elements.charts.pie;
+using SomeChartsUi.themes.colors;
+using SomeChartsUi.themes.themes;
+using SomeChartsUiAvalonia.controls.gl;
+
+namespace SomeChartsAvaloniaExamples.elements; 
+
+public static class PieChartExample {
+	private static readonly float[] _series = {1, 16, 9, 33, 2, 3, 2};
+	private static readonly indexedColor[] _colors = {
+		theme.accent0_ind,
+		theme.default3_ind, 
+		theme.default4_ind, 
+		theme.default5_ind,
+		theme.normal_ind,
+		theme.default6_ind,
+		theme.default7_ind,
+	};
+
+	public static void Run() {
+		// call RunAfterStart before running avalonia
+		// it will execute after application open
+		// RunAvalonia() blocks current thread
+		AvaloniaRunUtils.RunAfterStart(AddElements);
+		AvaloniaRunUtils.RunAvalonia();
+	}
+
+	private static void AddElements() {
+		AvaloniaGlChartsCanvas canvas = AvaloniaRunUtils.AddGlCanvas();
+		
+		IChartData<float> values = new ArrayChartData<float>(_series);
+		IChartData<indexedColor> colors = new ArrayChartData<indexedColor>(_colors);
+
+		// pie chart provides additional data to names
+		// {0} - value
+		// {1} - percent (100 is 100%)
+		// {2} - element id
+		// to truncate output of percent you can add ':0.00'
+		IChartManagedData<string> names = new FuncChartManagedData<string>(i => $"#{i}: {{1:0.00}}%", 1);
+		
+		PieChart pie = new(canvas.canvas) {
+			values = values, 
+			colors = colors, 
+			names = names, 
+			isDynamic = true
+		};
+		canvas.AddElement(pie);
+	}
+}

SomeChartsUi/src/elements/charts/pie/PieChart.cs

@@ -2,6 +2,7 @@ using MathStuff;
 using MathStuff.vectors;
 using SomeChartsUi.data;
 using SomeChartsUi.themes.colors;
+using SomeChartsUi.themes.themes;
 using SomeChartsUi.ui.canvas;
 using SomeChartsUi.ui.elements;
 using SomeChartsUi.ui.text;
@@ -10,35 +11,54 @@ namespace SomeChartsUi.elements.charts.pie;
 
 public class PieChart : RenderableBase, IDownsample {
 	private const int _maxQuality = 1024;
-	private TextMesh _textMesh;
-	public IChartData<indexedColor> colors;
+	
+	public IChartData<float> values = null!;
+	public IChartManagedData<string> names = null!;
+	public IChartData<indexedColor> colors = null!;
 
 	public Font font;
-	public float innerScale = 400;
-	public IChartManagedData<string> names;
+	private TextMesh _textMesh;
 
-	public float outerScale = 800;
+	/// <summary>z-axis rotation of chart, in radians</summary>
 	public float rotation;
 
-	public IChartData<float> values;
+	/// <summary>hole size</summary>
+	public float innerScale = 400;
 
+	/// <summary>pie size</summary>
+	public float outerScale = 800;
+	
+	public bool drawLabels = true;
+
+	/// <summary>length of lines using for labels <br/><br/>depends on outerScale</summary>
+	public float labelLineLength = 2;
+
+	/// <summary>get outerScale for each segment separately</summary>
+	public Func<int, float>? getOuterScale;
+	
+	/// <summary>get innerScale for each segment separately</summary>
+	public Func<int, float>? getInnerScale;
+
+	public indexedColor labelColor = theme.default5_ind;
+	
+	public float downsampleMultiplier { get; set; } = .5f;
+	public float elementScale { get; set; } = 100;
+	
 	public PieChart(ChartsCanvas owner) : base(owner) {
 		_textMesh = canvas.factory.CreateTextMesh(this);
-
 		font = canvas.GetDefaultFont();
 	}
 
-	public float downsampleMultiplier { get; set; } = .5f;
-	public float elementScale { get; set; } = 100;
 
 	protected override unsafe void GenerateMesh() {
-		mesh!.Clear();
-		_textMesh.ClearMeshes();
 		int len = values.GetLength();
 		if (len < 1) return;
-		//if (!IsVisible(offset, scale)) return;
 
-		rotation += .01f;
+		if (!IsVisible()) return;
+		
+		mesh!.Clear();
+		_textMesh.ClearMeshes();
+
 		if (rotation >= MathF.PI * 2) rotation -= MathF.PI * 2;
 		if (rotation < 0) rotation += MathF.PI * 2;
 
@@ -50,8 +70,6 @@ public class PieChart : RenderableBase, IDownsample {
 
 		// * calculate quality (side count)
 		int quality = (int)Math.Clamp(outerScale * canvasScale.avg, 8, _maxQuality);
-		float mulY = 1;
-		// float mulY = owner.valuesScale.X / owner.valuesScale.Y;
 
 		// * calculate mesh data
 		float valueSum = 0;
@@ -81,10 +99,8 @@ public class PieChart : RenderableBase, IDownsample {
 		int iPos = 0;
 		float rotOffset = rotation;
 		for (int i = 0; i < len; i++) {
-			// float curOutScale = GetOutScale(i);
-			// float curOutScale = scale * (i + 20) * .1f;
-			float curOutScale = outerScale;
-			float curInScale = innerScale;
+			float curOutScale = getOuterScale?.Invoke(i) ?? outerScale;
+			float curInScale = getInnerScale?.Invoke(i) ?? innerScale;
 			float rot = pieValues[i] / valueSum * MathF.PI * 2;
 
 			color col = pieColors[i].GetColor();
@@ -97,8 +113,8 @@ public class PieChart : RenderableBase, IDownsample {
 				float cos = MathF.Cos(currentAngle);
 				int vPosCur = vPos + (v << 1);
 
-				mesh.vertices[vPosCur+0] = new(new(sin * curInScale, cos * curInScale * mulY), float3.front, float2.zero, col);
-				mesh.vertices[vPosCur+1] = new(new(sin * curOutScale, cos * curOutScale * mulY), float3.front, float2.zero, col);
+				mesh.vertices[vPosCur+0] = new(new(sin * curInScale, cos * curInScale), float3.front, float2.zero, col);
+				mesh.vertices[vPosCur+1] = new(new(sin * curOutScale, cos * curOutScale), float3.front, float2.zero, col);
 			}
 
 			for (int v = 0; v < curSideCount - 1; v++) {
@@ -113,7 +129,7 @@ public class PieChart : RenderableBase, IDownsample {
 				mesh.indexes[iPosCur + 5] = (ushort)(vPosCur+2);
 			}
 			
-			if (curSideCount > 2) {
+			if (drawLabels && curSideCount > 2) {
 				float lineLen1Mul = outerScale * 3;
 				float lineLen2Mul = outerScale;
 				float midAngle = rotOffset + rot * .5f;
@@ -121,11 +137,9 @@ public class PieChart : RenderableBase, IDownsample {
 				
 				float sin = MathF.Sin(midAngle);
 				float cos = MathF.Cos(midAngle);
-				float lineLen = lineLen1Mul * 2 * .5f;
-				// float lineLen = lineLen1Mul * (canvasScale.x + Math.Clamp(canvasScale.x, .1f, .5f)) * .5f;
+				float lineLen = lineLen1Mul * .5f * labelLineLength;
 				
-				float lineLen2 = MathF.Cos(midAngle) * lineLen2Mul * 2;
-				// float lineLen2 = MathF.Cos(midAngle) * lineLen2Mul * canvasScale.x;
+				float lineLen2 = MathF.Cos(midAngle) * lineLen2Mul;
 				float line2Angle = MathF.PI * .25f;
 				if (midAngle >= MathF.PI) {
 					lineLen = -lineLen;
@@ -133,10 +147,10 @@ public class PieChart : RenderableBase, IDownsample {
 				}
 				if (midAngle is >= MathF.PI * .5f and <= MathF.PI * .5f * 3) line2Angle = -line2Angle;
 				
-				float2 lineStart = new(sin * curOutScale, cos * curOutScale * mulY);
-				float2 line2 = new(MathF.Sin(line2Angle) * lineLen2, MathF.Cos(line2Angle) * lineLen2 * mulY);
+				float2 lineStart = new(sin * curOutScale, cos * curOutScale);
+				float2 line2 = new(MathF.Sin(line2Angle) * lineLen2, MathF.Cos(line2Angle) * lineLen2);
 				float2 lineEnd = new(lineStart.x + line2.x, lineStart.y + line2.y);
-				float2 lineEnd2 = new(lineStart.x + lineLen - curOutScale * canvasScale.x * MathF.CopySign(MathF.Sin(midAngle), lineLen), lineStart.y + line2.y);
+				float2 lineEnd2 = new(lineStart.x + lineLen - curOutScale * labelLineLength * MathF.CopySign(MathF.Sin(midAngle), lineLen), lineStart.y + line2.y);
 				float2 labelPos = new(lineEnd2.x, lineEnd2.y + 4);
 
 				float thickness = 1f / canvasScale.avg;
@@ -144,7 +158,7 @@ public class PieChart : RenderableBase, IDownsample {
 				AddLine(mesh, lineEnd, lineEnd2, thickness, col.WithAlpha(255));
 
 				string name = string.Format(names.GetValue(i), pieValues[i], pieValues[i] / valueSum * 100, i);
-				_textMesh.GenerateMesh(name, font, 16 / canvasScale.avg, col, new(labelPos));
+				_textMesh.GenerateMesh(name, font, 16 / canvasScale.avg, labelColor.GetColor(), new(labelPos));
 			}
 			
 			vPos += curSideCount * 2;
@@ -157,6 +171,13 @@ public class PieChart : RenderableBase, IDownsample {
 
 	protected override void AfterDraw() {
 		base.AfterDraw();
-		_textMesh.Draw();
+		
+		if (IsVisible()) _textMesh.Draw();
+	}
+
+	private bool IsVisible() {
+		float approximateSize = outerScale;
+		if (drawLabels) approximateSize += (outerScale + 1) * labelLineLength;
+		return IsVisibleWithTransform(float2.zero, approximateSize);
 	}
 }

SomeChartsUi/src/ui/elements/RenderableBaseUtils.cs

@@ -89,6 +89,9 @@ public abstract partial class RenderableBase {
 
 	protected static void Free<T>(T[] arr) => ArrayPool<T>.Shared.Return(arr);
 	protected static unsafe void FreeMem<T>(T* arr) where T : unmanaged => NativeMemory.Free(arr);
+	
+	protected bool IsVisible(float2 a, float2 s) => canvas.transform.worldBounds.Contains(a.x, a.y, s.x, s.y);
+	protected bool IsVisibleWithTransform(float2 a, float2 s) => canvas.transform.worldBounds.Contains(a.x + transform.position.x, a.y + transform.position.y, s.x * transform.scale.x, s.y * transform.scale.y);
 
 	public RenderableBase WithPosition(float2 v) {
 		((ChartPropertyValue<Transform>)transform).value.position = v;