#5878: RenderableSemiCircle uses Matrix4 for axis substitution

Instead of using a RemapPolicy struct passed via a template parameter
(which results in a separate copy of this non-trivial constructor being
generated for each axis), pass in a simple Matrix4 which is used to
substitute the axes.

radiantcore/selection/manipulators/Renderables.h

@@ -171,20 +171,36 @@ class RenderableLineStrip :
 };
 
 /// Line strip in the shape of a semicircle
-template<typename RemapPolicy>
 class RenderableSemiCircle :
     public RenderableLineStrip
 {
 public:
-    RenderableSemiCircle(std::size_t segments, double radius, const Matrix4& localToWorld) :
-        RenderableLineStrip((segments << 2) + 1, localToWorld)
+
+    /**
+     * @brief Construct a new RenderableSemiCircle object
+     *
+     * @param segments
+     * Number of linear segments to divide the semicircle into.
+     *
+     * @param radius
+     * Radius of the semicircle in world units.
+     *
+     * @param localToWorld
+     * Local space transformation matrix.
+     *
+     * @param axisRemap
+     * Optional matrix to reassign axes, used to orient the semicircle in 3D space.
+     */
+    RenderableSemiCircle(std::size_t segments, double radius, const Matrix4& localToWorld,
+                         const Matrix4& axisRemap)
+    : RenderableLineStrip((segments << 2) + 1, localToWorld)
     {
         const double increment = math::PI / double(segments << 2);
 
         std::size_t count = 0;
         double x = radius;
         double y = 0;
-        RemapPolicy::set(_rawPoints[segments << 2], -radius, 0, 0);
+        _rawPoints[segments << 2] = axisRemap * Vertex3(-radius, 0, 0);
 
         while (count < segments) {
             auto& i = _rawPoints[count];
@@ -193,17 +209,17 @@ class RenderableSemiCircle :
             auto& k = _rawPoints[count + (segments << 1)];
             auto& l = _rawPoints[(segments << 1) - (count + 1) + (segments << 1)];
 
-            RemapPolicy::set(i, x, -y, 0);
-            RemapPolicy::set(k, -y, -x, 0);
+            i = axisRemap * Vertex3(x, -y, 0);
+            k = axisRemap * Vertex3(-y, -x, 0);
 
             ++count;
 
             const double theta = increment * count;
             x = radius * cos(theta);
             y = radius * sin(theta);
 
-            RemapPolicy::set(j, y, -x, 0);
-            RemapPolicy::set(l, -x, -y, 0);
+            j = axisRemap * Vertex3(y, -x, 0);
+            l = axisRemap * Vertex3(-x, -y, 0);
         }
     }
 };

radiantcore/selection/manipulators/RotateManipulator.cpp

@@ -14,6 +14,19 @@ namespace
     constexpr static auto CircleSegments = 8;
     constexpr static auto CircleRadius = 64.0;
     const Vector4 AngleTextColour(0.75, 0, 0, 1);
+
+    static const Matrix4 REMAP_YZX = Matrix4::byRows(
+        0, 0, 1, 0,
+        1, 0, 0, 0,
+        0, 1, 0, 0,
+        0, 0, 0, 1
+    );
+    static const Matrix4 REMAP_ZXY = Matrix4::byRows(
+        0, 1, 0, 0,
+        0, 0, 1, 0,
+        1, 0, 0, 0,
+        0, 0, 0, 1
+    );
 }
 
 RotateManipulator::RotateManipulator(ManipulationPivot& pivot, std::size_t segments, float radius) :
@@ -23,9 +36,9 @@ RotateManipulator::RotateManipulator(ManipulationPivot& pivot, std::size_t segme
     _rotateAxis(*this),
 	_translatePivot(_pivotTranslatable),
     _localPivotPoint(0,0,0),
-    _circleX(CircleSegments, CircleRadius, _local2worldX),
-    _circleY(CircleSegments, CircleRadius, _local2worldY),
-    _circleZ(CircleSegments, CircleRadius, _local2worldZ),
+    _circleX(CircleSegments, CircleRadius, _local2worldX, REMAP_YZX),
+    _circleY(CircleSegments, CircleRadius, _local2worldY, REMAP_ZXY),
+    _circleZ(CircleSegments, CircleRadius, _local2worldZ, Matrix4::getIdentity()),
     _circleScreen(CircleSegments, CircleRadius * 1.15, _pivot2World._viewpointSpace),
     _circleSphere(CircleSegments, CircleRadius, _pivot2World._viewpointSpace),
 	_pivotPoint(_localPivotPoint, _pivot2World._worldSpace),
@@ -116,7 +129,7 @@ void RotateManipulator::onPreRender(const RenderSystemPtr& renderSystem, const V
     }
 
     _pivot2World.update(_pivot.getMatrix4(), volume.GetModelview(), volume.GetProjection(), volume.GetViewport());
-    
+
     updateCircleTransforms();
     updateColours();
     updateAngleText();

radiantcore/selection/manipulators/RotateManipulator.h

@@ -34,9 +34,9 @@ class RotateManipulator :
 	Vector3 _axisScreen;
     Vertex3 _localPivotPoint;
 
-    RenderableSemiCircle<RemapYZX> _circleX;
-    RenderableSemiCircle<RemapZXY> _circleY;
-    RenderableSemiCircle<RemapXYZ> _circleZ;
+    RenderableSemiCircle _circleX;
+    RenderableSemiCircle _circleY;
+    RenderableSemiCircle _circleZ;
 	RenderableCircle _circleScreen;
 	RenderableCircle _circleSphere;
     RenderablePoint _pivotPoint;