Support alt-az mounts in domes

Author: daleghent

NINA.Core/Enum/MountTypeEnum.cs

@@ -30,5 +30,8 @@ public enum MountTypeEnum {
 
         [Description("LblForkOnWedge")]
         FORK_ON_WEDGE,
+
+        [Description("LblAltitudeAzimuth")]
+        ALT_AZ,
     }
 }

NINA.Core/Locale/Locale.resx

@@ -7185,4 +7185,7 @@ Additionally, it is essential that the ASCOM driver used also supports this 32-b
   <data name="LblCivilDawn" xml:space="preserve">
     <value>Civil dawn</value>
   </data>
+  <data name="LblAltitudeAzimuth" xml:space="preserve">
+    <value>Altitude-Azimuth</value>
+  </data>
 </root>

NINA.Equipment/Equipment/MyDome/DomeSynchronization.cs

@@ -24,8 +24,8 @@ This Source Code Form is subject to the terms of the Mozilla Public
 namespace NINA.Equipment.Equipment.MyDome {
 
     public class DomeSynchronization : IDomeSynchronization {
-        private static double TWO_PI = 2.0 * Math.PI;
-        private static double HALF_PI = Math.PI / 2.0;
+        private const double TWO_PI = 2.0 * Math.PI;
+        private const double HALF_PI = Math.PI / 2.0;
 
         private readonly IProfileService profileService;
 
@@ -43,7 +43,6 @@ public TopocentricCoordinates TargetDomeCoordinates(
             return TargetDomeCoordinates(scopeCoordinates: scopeCoordinates, localSiderealTime: localSiderealTime, siteLatitude: siteLatitude, siteLongitude: siteLongitude, siteElevation: 0, sideOfPier: sideOfPier);
         }
 
-
         /// <summary>
         /// Gets the dome coordinates required so the scope points directly out of the shutter. This works for Alt-Az, EQ mounts, and fork mounts on a wedge
         /// and depends on careful user measurements including:
@@ -77,16 +76,17 @@ public TopocentricCoordinates TargetDomeCoordinates(
             PierSide sideOfPier) {
             scopeCoordinates = scopeCoordinates.Transform(Epoch.JNOW);
             var domeSettings = profileService.ActiveProfile.DomeSettings;
+
             // To calculate the effect of rotations in the southern hemisphere we augment a few of the rotations to pretend as if it were the northern hemisphere,
             // and then add 180 degrees to the final result
-
             var origin = new Vector4(0, 0, 0, 1);
-            Matrix4x4 scopeOriginTranslation;
-            if (domeSettings.MountType == MountTypeEnum.EQUATORIAL) {
-                scopeOriginTranslation = CalculateGEM(scopeCoordinates, localSiderealTime, siteLatitude, sideOfPier);
-            } else {
-                scopeOriginTranslation = CalculateForkOnWedge(scopeCoordinates, localSiderealTime, siteLatitude);
-            }
+
+            var scopeOriginTranslation = domeSettings.MountType switch {
+                MountTypeEnum.EQUATORIAL => CalculateGEM(scopeCoordinates, localSiderealTime, siteLatitude, sideOfPier),
+                MountTypeEnum.FORK_ON_WEDGE => CalculateForkOnWedge(scopeCoordinates, localSiderealTime, siteLatitude),
+                MountTypeEnum.ALT_AZ => CalculateAltAz(scopeCoordinates, siteLatitude, siteLongitude),
+                _ => throw new NotSupportedException($"Unsupported mount type: {domeSettings.MountType}"),
+            };
 
             var scopeApertureOrigin = scopeOriginTranslation * origin;
 
@@ -207,5 +207,40 @@ private Matrix4x4 CalculateGEM(
 
             return mountOffset * latitudeAdjustment * raRotationAdjustment * decRotationAdjustment * gemAdjustment;
         }
+
+        private Matrix4x4 CalculateAltAz(
+            Coordinates scopeCoordinates,
+            Angle siteLatitude,
+            Angle siteLongitude) {
+            var domeSettings = profileService.ActiveProfile.DomeSettings;
+
+            // Alt-Az mounts rotate in altitude (around the y-axis) and azimuth (around the z-axis)
+            // Altitude is Dec, Azimuth is Azimuth derived from RA/Dec + LST
+
+            // Convert scope RA/Dec to horizontal coordinates (Alt/Az)
+            var topocentric = scopeCoordinates.Transform(siteLatitude, siteLongitude, 0d); // elevation not critical here
+
+            // Altitude rotation: scope tilts up from horizontal
+            var altitudeRotation = Matrix4x4.CreateRotationY((float)(-topocentric.Altitude.Radians));
+
+            // Azimuth rotation: scope rotates around the dome’s vertical axis (z-axis)
+            var azimuthRotation = Matrix4x4.CreateRotationZ((float)(-topocentric.Azimuth.Radians));
+
+            // Mount offset from dome center
+            var mountOffset = Matrix4x4.CreateTranslation(new Vector3(
+                (float)domeSettings.ScopePositionNorthSouth_mm,
+                (float)domeSettings.ScopePositionEastWest_mm,
+                (float)domeSettings.ScopePositionUpDown_mm
+            ));
+
+            // Lateral axis offset (side-by-side)
+            var lateralOffset = Matrix4x4.CreateTranslation(new Vector3(
+                0.0f,
+                0.0f,
+                -(float)domeSettings.LateralAxis_mm
+            ));
+
+            return mountOffset * azimuthRotation * altitudeRotation * lateralOffset;
+        }
     }
 }

NINA/View/Options/DomeView.xaml

@@ -152,6 +152,9 @@
                                     <DataTrigger Binding="{Binding ElementName=PART_MountTypeList, Path=SelectedItem}" Value="1">
                                         <Setter Property="Visibility" Value="Collapsed" />
                                     </DataTrigger>
+                                    <DataTrigger Binding="{Binding ElementName=PART_MountTypeList, Path=SelectedItem}" Value="2">
+                                        <Setter Property="Visibility" Value="Collapsed" />
+                                    </DataTrigger>
                                 </Style.Triggers>
                             </Style>
                         </UniformGrid.Style>
@@ -182,6 +185,9 @@
                                     <DataTrigger Binding="{Binding ElementName=PART_MountTypeList, Path=SelectedItem}" Value="0">
                                         <Setter Property="Visibility" Value="Collapsed" />
                                     </DataTrigger>
+                                    <DataTrigger Binding="{Binding ElementName=PART_MountTypeList, Path=SelectedItem}" Value="2">
+                                        <Setter Property="Visibility" Value="Collapsed" />
+                                    </DataTrigger>
                                 </Style.Triggers>
                             </Style>
                         </UniformGrid.Style>