Professional-Grade Astrology Chart Implementation

 Integrating a Professional Astrology Library

For accurate calculations, we'll use the excellent Swiss Ephemeris (the same library professional astrology software uses):

csharp

// Add this NuGet package:
// dotnet add package SwissEphNet

public class AstrologyCalculator
{
    private SwissEph _swissEph;
    
    public AstrologyCalculator()
    {
        _swissEph = new SwissEph();
        // Set the ephemeris path (you'll need to include the ephemeris files in your app)
        _swissEph.OnLoadFile += (sender, e) => 
        {
            var stream = Assembly.GetExecutingAssembly()
                .GetManifestResourceStream($"AstroTalk.Resources.ephemeris.{e.FileName}");
            if (stream != null)
            {
                e.File = new SwissEphStream(stream);
            }
        };
    }

    public Dictionary<int, PlanetPosition> CalculatePlanetPositions(DateTime birthDate, double longitude, double latitude)
    {
        var positions = new Dictionary<int, PlanetPosition>();
        double[] cusps = new double[13];
        double[] ascmc = new double[10];
        
        // Julian day number for birth date
        int julDay = 0, julMonth = 0, julYear = 0;
        double birthTime = _swissEph.swe_julday(
            birthDate.Year, birthDate.Month, birthDate.Day,
            birthDate.Hour + birthDate.Minute/60.0 + birthDate.Second/3600.0,
            SwissEph.SE_GREG_CAL);
            
        // Calculate house cusps (Placidus system)
        _swissEph.swe_houses(
            birthTime, latitude, longitude, 'P', // 'P' for Placidus
            cusps, ascmc);
            
        // Calculate planet positions (Sun to Pluto)
        for (int planet = SwissEph.SE_SUN; planet <= SwissEph.SE_PLUTO; planet++)
        {
            double[] position = new double[6];
            string error = _swissEph.swe_calc_ut(
                birthTime, planet, SwissEph.SEFLG_SPEED, position);
                
            positions.Add(planet, new PlanetPosition
            {
                Longitude = position[0],
                Latitude = position[1],
                Distance = position[2],
                Speed = position[3],
                Sign = GetSign(position[0]),
                House = GetHouse(position[0], cusps)
            });
        }
        
        return positions;
    }
    
    private int GetSign(double longitude)
    {
        return (int)(longitude / 30) + 1; // 1=Aries, 12=Pisces
    }
    
    private int GetHouse(double longitude, double[] cusps)
    {
        // Simplified house calculation
        for (int i = 1; i <= 12; i++)
        {
            if (longitude < cusps[i] || (i == 12 && longitude >= cusps[12]))
                return i;
        }
        return 1;
    }
}

public class PlanetPosition
{
    public double Longitude { get; set; }
    public double Latitude { get; set; }
    public double Distance { get; set; }
    public double Speed { get; set; }
    public int Sign { get; set; }
    public int House { get; set; }
}

2. Enhanced Birth Chart with House Divisions

csharp

public class ProfessionalBirthChartService
{
    private readonly AstrologyCalculator _calculator;
    
    public ProfessionalBirthChartService()
    {
        _calculator = new AstrologyCalculator();
    }

    public SKImage GenerateProfessionalChart(UserProfile profile)
    {
        var info = new SKImageInfo(1000, 1000);
        using var surface = SKSurface.Create(info);
        var canvas = surface.Canvas;
        
        canvas.Clear(SKColors.White);
        
        // Calculate exact positions
        var positions = _calculator.CalculatePlanetPositions(
            profile.BirthDate + profile.BirthTime,
            profile.BirthLongitude,
            profile.BirthLatitude);
            
        DrawHouses(canvas, positions);
        DrawZodiacWheel(canvas, positions);
        DrawPlanets(canvas, positions);
        DrawAspects(canvas, positions);
        
        return surface.Snapshot();
    }

    private void DrawHouses(SKCanvas canvas, Dictionary<int, PlanetPosition> positions)
    {
        var center = new SKPoint(500, 500);
        float outerRadius = 450;
        
        var housePaint = new SKPaint
        {
            Style = SKPaintStyle.Stroke,
            Color = SKColors.Blue,
            StrokeWidth = 1.5f,
            IsAntialias = true,
            PathEffect = SKPathEffect.CreateDash(new float[] { 5, 3 }, 0)
        };
        
        // Draw house divisions
        for (int i = 1; i <= 12; i++)
        {
            float angle = GetHouseAngle(i, positions);
            float radian = (float)(angle * Math.PI / 180);
            
            var endPoint = new SKPoint(
                center.X + (float)(outerRadius * Math.Sin(radian)),
                center.Y - (float)(outerRadius * Math.Cos(radian)));
                
            canvas.DrawLine(center, endPoint, housePaint);
            
            // Label houses
            var textPaint = new SKPaint
            {
                Color = SKColors.Blue,
                TextSize = 18,
                IsAntialias = true
            };
            
            canvas.DrawText($"H{i}",
                center.X + (float)((outerRadius - 30) * Math.Sin(radian)),
                center.Y - (float)((outerRadius - 30) * Math.Cos(radian)),
                textPaint);
        }
    }
    
    private float GetHouseAngle(int houseNumber, Dictionary<int, PlanetPosition> positions)
    {
        // This would use the actual house cusps from the calculator
        // Simplified for example:
        return houseNumber * 30; // 30° per house
    }
}

3. Interactive Chart with Tap Gestures

csharp

public class InteractiveChartView : SKCanvasView
{
    public event EventHandler<PlanetTappedEventArgs> PlanetTapped;
    
    private Dictionary<SKRect, int> _planetHitAreas = new Dictionary<SKRect, int>();
    private SKImage _currentChart;
    
    protected override void OnPaintSurface(SKPaintSurfaceEventArgs e)
    {
        base.OnPaintSurface(e);
        
        if (_currentChart != null)
        {
            e.Surface.Canvas.DrawImage(_currentChart, 0, 0);
            _planetHitAreas.Clear();
            
            // Store planet positions for hit testing
            foreach (var planet in _currentChart.PlanetPositions)
            {
                var rect = new SKRect(
                    planet.X - 20, planet.Y - 20,
                    planet.X + 20, planet.Y + 20);
                    
                _planetHitAreas[rect] = planet.Id;
            }
        }
    }
    
    public void UpdateChart(SKImage chart)
    {
        _currentChart = chart;
        InvalidateSurface();
    }
    
    public void OnTouch(SKPoint point)
    {
        foreach (var hitArea in _planetHitAreas)
        {
            if (hitArea.Key.Contains(point))
            {
                PlanetTapped?.Invoke(this, new PlanetTappedEventArgs(hitArea.Value));
                return;
            }
        }
    }
}

public class PlanetTappedEventArgs : EventArgs
{
    public int PlanetId { get; }
    
    public PlanetTappedEventArgs(int planetId)
    {
        PlanetId = planetId;
    }
}

// Usage in XAML:
<controls:InteractiveChartView PlanetTapped="OnPlanetTapped"/>

// In code-behind:
private void OnPlanetTapped(object sender, PlanetTappedEventArgs e)
{
    var planetInfo = GetPlanetInfo(e.PlanetId);
    DisplayAlert(planetInfo.Name, planetInfo.Description, "OK");
}

4. Accurate Aspect Calculations

csharp

public class AspectCalculator
{
    public List<Aspect> CalculateAspects(Dictionary<int, PlanetPosition> positions)
    {
        var aspects = new List<Aspect>();
        var planets = positions.Keys.ToList();
        
        for (int i = 0; i < planets.Count; i++)
        {
            for (int j = i + 1; j < planets.Count; j++)
            {
                var planet1 = planets[i];
                var planet2 = planets[j];
                
                double angle = Math.Abs(positions[planet1].Longitude - positions[planet2].Longitude);
                angle = angle > 180 ? 360 - angle : angle;
                
                var aspect = IdentifyAspect(angle);
                if (aspect != null)
                {
                    aspects.Add(new Aspect
                    {
                        Planet1 = planet1,
                        Planet2 = planet2,
                        Type = aspect.Value,
                        Angle = angle
                    });
                }
            }
        }
        
        return aspects;
    }
    
    private AspectType? IdentifyAspect(double angle)
    {
        // Standard orbs
        var aspects = new Dictionary<AspectType, double[]>
        {
            { AspectType.Conjunction, new[] { 0, 8 } },
            { AspectType.Sextile, new[] { 60, 4 } },
            { AspectType.Square, new[] { 90, 6 } },
            { AspectType.Trine, new[] { 120, 6 } },
            { AspectType.Opposition, new[] { 180, 8 } }
        };
        
        foreach (var aspect in aspects)
        {
            if (Math.Abs(angle - aspect.Value[0]) <= aspect.Value[1])
                return aspect.Key;
        }
        
        return null;
    }
}

public enum AspectType
{
    Conjunction,
    Sextile,
    Square,
    Trine,
    Opposition
}

public class Aspect
{
    public int Planet1 { get; set; }
    public int Planet2 { get; set; }
    public AspectType Type { get; set; }
    public double Angle { get; set; }
}

5. Complete Professional Chart Drawing

csharp

private void DrawProfessionalChart(SKCanvas canvas, Dictionary<int, PlanetPosition> positions, List<Aspect> aspects)
{
    var center = new SKPoint(500, 500);
    float chartRadius = 450;
    
    // 1. Draw outer wheel with degrees
    DrawDegreeWheel(canvas, center, chartRadius);
    
    // 2. Draw house divisions
    DrawHouseSystem(canvas, center, chartRadius, positions);
    
    // 3. Draw zodiac signs with decans
    DrawZodiacWithDecans(canvas, center, chartRadius - 50);
    
    // 4. Draw aspects
    DrawAllAspects(canvas, center, chartRadius - 100, aspects, positions);
    
    // 5. Draw planets with retrograde indicators
    DrawPlanetsWithInfo(canvas, center, chartRadius - 120, positions);
    
    // 6. Draw aspect grid legend
    DrawAspectLegend(canvas, new SKPoint(50, 800));
}

private void DrawPlanetsWithInfo(SKCanvas canvas, SKPoint center, float radius, 
    Dictionary<int, PlanetPosition> positions)
{
    var planetPaint = new SKPaint
    {
        Color = SKColors.Black,
        TextSize = 24,
        IsAntialias = true,
        TextAlign = SKTextAlign.Center
    };
    
    var retroPaint = new SKPaint
    {
        Color = SKColors.Red,
        TextSize = 12,
        IsAntialias = true,
        TextAlign = SKTextAlign.Center
    };
    
    foreach (var planet in positions)
    {
        float angle = (float)planet.Value.Longitude;
        float radian = (float)(angle * Math.PI / 180);
        
        // Planet symbol
        canvas.DrawText(GetPlanetSymbol(planet.Key),
            center.X + (float)(radius * Math.Sin(radian)),
            center.Y - (float)(radius * Math.Cos(radian)),
            planetPaint);
            
        // Retrograde indicator
        if (planet.Value.Speed < 0)
        {
            canvas.DrawText("R",
                center.X + (float)((radius - 20) * Math.Sin(radian)),
                center.Y - (float)((radius - 20) * Math.Cos(radian)),
                retroPaint);
        }
        
        // Degree minute annotation
        var degreePaint = new SKPaint
        {
            Color = SKColors.Gray,
            TextSize = 10,
            IsAntialias = true
        };
        
        string degreeText = $"{planet.Value.Longitude % 30:0°00'}";
        canvas.DrawText(degreeText,
            center.X + (float)((radius - 40) * Math.Sin(radian)),
            center.Y - (float)((radius - 40) * Math.Cos(radian)),
            degreePaint);
    }
}

Implementation Notes

1. Ephemeris Files: You'll need to include the Swiss Ephemeris data files (SE1_00.SEP through SE1_10.SEP) as embedded resources.

2. Performance: For mobile devices, consider:

   • Pre-rendering static elements

   • Implementing a caching system for charts

   • Using hardware acceleration

3. Customization: Add settings for:

   • Different house systems (Placidus, Koch, Equal)

   • Aspect orbs and allowed aspects

   • Chart styles (traditional, modern, etc.)

4. Animation: For enhanced UX, consider animating planet movements when showing transits or progressions.