#5846: Fix texture being messed up by 90 degree rotations of brushes.…

… Freezetransform is triggering a second evaluation of the current transformation (which is identity) - this was messing up the texDefTransformed() algorithm since the winding vertices were still at the old position. The face normal ended up being parallel to the face plane. The quick solution here is to ignore identity transforms in Face::transform.

radiantcore/brush/BrushNode.cpp

@@ -486,7 +486,12 @@ void BrushNode::evaluateTransform()
         }
         else
         {
-            m_brush.transform(calculateTransform());
+            auto transform = calculateTransform();
+
+            if (transform != Matrix4::getIdentity())
+            {
+                m_brush.transform(transform);
+            }
         }
 	}
 	else
@@ -562,7 +567,7 @@ void BrushNode::onPostRedo()
 
 void BrushNode::_onTransformationChanged()
 {
-	m_brush.transformChanged();
+    m_brush.transformChanged();
 
     _renderableVertices.queueUpdate();
 	_renderableComponentsNeedUpdate = true;

test/TextureManipulation.cpp

@@ -1,5 +1,6 @@
 #include "RadiantTest.h"
 
+#include <optional>
 #include "itransformable.h"
 #include "ishaders.h"
 #include "ishaderclipboard.h"
@@ -829,14 +830,26 @@ TEST_F(TextureManipulationTest, RotateFuncStaticBrush90)
 
     auto& faceAfter = *algorithm::findBrushFaceWithNormal(brush, { 1, 0, 0 });
 
+    std::optional<Vector2> distance;
     auto old = oldVertices.begin();
     for (const auto& vertex : faceAfter.getWinding())
     {
         // Assume the 3D coordinates have changed
         EXPECT_FALSE(math::isNear(vertex.vertex, old->vertex, 0.01));
 
-        // The texture coordinates should remain unchanged (due to texture lock)
-        EXPECT_TRUE(math::isNear(vertex.texcoord, old->texcoord, 0.01));
+        // The texture coordinates should remain equivalent (due to texture lock)
+        // The absolute coordinates in UV space might be off by some integer number
+        // We expect the distance to the previous coordinates to be the same
+        if (distance.has_value())
+        {
+            EXPECT_TRUE(math::isNear(distance.value(), vertex.texcoord - old->texcoord, 0.01));
+        }
+        else
+        {
+            distance = vertex.texcoord - old->texcoord;
+        }
+
+        ++old;
     }
 }