Address CodeRabbit feedback on #2081

- Rename SolvePnPMethod.IPPE_SQUARE to IppeSquare: once an acronym is
  glued to another word to form a compound member name, this repo's
  enum-naming convention PascalCases the whole compound rather than
  leaving part of it in caps (see .github/copilot-instructions.md).
- Use a positive-Z tvec in the new synthetic poses so the projected
  points sit in front of the camera instead of behind it.
- Strengthen SolvePnPTestByArrayMethods/IppeSquare to reproject with
  the recovered pose and assert it matches the input points, instead
  of only asserting the call doesn't throw. Confirmed this actually
  matters: with the old AP3P/IPPE values, SolvePnP silently dispatches
  to a different native solver that still completes without throwing,
  so a throws-only assertion doesn't catch it - the reprojection check
  does.

Author: shimat

src/OpenCvSharp/Modules/geometry/Enum/SolvePnPMethod.cs

@@ -50,7 +50,7 @@ public enum SolvePnPMethod
     ///   - point 2: [squareLength / 2, -squareLength / 2, 0]
     ///   - point 3: [-squareLength / 2, -squareLength / 2, 0]
     /// </summary>
-    IPPE_SQUARE = 5,
+    IppeSquare = 5,
 
     /// <summary>
     /// Method is based on the paper "A Consistently Fast and Globally Optimal Solution to the

test/OpenCvSharp.Tests/calib3d/Calib3dTest.cs

@@ -489,7 +489,7 @@ public void SolvePnPTestByArray(bool useExtrinsicGuess)
     public void SolvePnPTestByArrayMethods(SolvePnPMethod method)
     {
         var rvec = new double[] { 3, 0, 0 };
-        var tvec = new double[] { 0, 0, -10 };
+        var tvec = new double[] { 0, 0, 10 };
         var cameraMatrix = new double[,]
         {
             { 1, 0, 0 },
@@ -509,13 +509,23 @@ public void SolvePnPTestByArrayMethods(SolvePnPMethod method)
         Cv2.ProjectPoints(objPts, rvec, tvec, cameraMatrix, dist, out var imgPts, out _);
 
         Cv2.SolvePnP(objPts, imgPts, cameraMatrix, dist, ref rvec, ref tvec, flags: method);
+
+        // Verify the recovered pose actually reprojects onto imgPts (rather than just "didn't throw"):
+        // a stale/misdirected enum value can silently dispatch to a different native solver that
+        // still runs to completion without throwing, but produces a wrong pose.
+        Cv2.ProjectPoints(objPts, rvec, tvec, cameraMatrix, dist, out var reprojected, out _);
+        for (var i = 0; i < imgPts.Length; i++)
+        {
+            Assert.Equal(imgPts[i].X, reprojected[i].X, 3);
+            Assert.Equal(imgPts[i].Y, reprojected[i].Y, 3);
+        }
     }
 
     [Fact]
     public void SolvePnPTestByArrayIppeSquare()
     {
         var rvec = new double[] { 3, 0, 0 };
-        var tvec = new double[] { 0, 0, -10 };
+        var tvec = new double[] { 0, 0, 10 };
         var cameraMatrix = new double[,]
         {
             { 1, 0, 0 },
@@ -534,7 +544,14 @@ public void SolvePnPTestByArrayIppeSquare()
 
         Cv2.ProjectPoints(objPts, rvec, tvec, cameraMatrix, dist, out var imgPts, out _);
 
-        Cv2.SolvePnP(objPts, imgPts, cameraMatrix, dist, ref rvec, ref tvec, flags: SolvePnPMethod.IPPE_SQUARE);
+        Cv2.SolvePnP(objPts, imgPts, cameraMatrix, dist, ref rvec, ref tvec, flags: SolvePnPMethod.IppeSquare);
+
+        Cv2.ProjectPoints(objPts, rvec, tvec, cameraMatrix, dist, out var reprojected, out _);
+        for (var i = 0; i < imgPts.Length; i++)
+        {
+            Assert.Equal(imgPts[i].X, reprojected[i].X, 3);
+            Assert.Equal(imgPts[i].Y, reprojected[i].Y, 3);
+        }
     }
 
     [Fact]