Editing works

src/features/editScene/systems/EditorUISystem.cpp

@@ -345,11 +345,23 @@ void EditorUISystem::update(float deltaTime)
 						       normal)) {
 					Ogre::Vector3 hit =
 						ray.getPoint(t);
+					/* Decal at hit (physical);
+					 * brush converts to physical
+					 * coords that visual-map
+					 * back to hit location. */
 					ts->updateBrushDecal(hit, normal,
 						ts->getSculptRadius());
 					if (ImGui::IsMouseDown(
 						ImGuiMouseButton_Left)) {
-						ts->applySculptBrush(hit);
+						Ogre::Vector3 brushPos = hit;
+						brushPos.x =
+							ts->visualToPhysicalX(
+								hit.x);
+						brushPos.z =
+							ts->visualToPhysicalZ(
+								hit.z);
+						ts->applySculptBrush(
+							brushPos);
 					}
 				} else {
 					ts->hideBrushDecal();

src/features/editScene/systems/TerrainSystem.cpp

@@ -1520,7 +1520,7 @@ void TerrainSystem::updateBrushDecal(const Ogre::Vector3 &worldPos,
 			pass->setSceneBlending(
 				Ogre::SBT_TRANSPARENT_ALPHA);
 			pass->setDepthWriteEnabled(false);
-			pass->setDepthCheckEnabled(true);
+			pass->setDepthCheckEnabled(false);
 			pass->setCullingMode(Ogre::CULL_NONE);
 			/* Vertex colours provide the actual colour. */
 			pass->setVertexColourTracking(
@@ -1600,6 +1600,17 @@ void TerrainSystem::hideBrushDecal()
 		m_brushDecalNode->setVisible(false);
 }
 
+/* ------------------------------------------------------------------ */
+/* getTerrainWorldHalfSize                                              */
+/* ------------------------------------------------------------------ */
+
+float TerrainSystem::getTerrainWorldHalfSize() const
+{
+	if (!mTerrainGroup)
+		return 1000.0f;
+	return mTerrainGroup->getTerrainWorldSize() * 0.5f;
+}
+
 /* ------------------------------------------------------------------ */
 /* destroyCollider                                                     */
 /* ------------------------------------------------------------------ */
@@ -1633,6 +1644,33 @@ float TerrainSystem::physicalToVisualZ(float physicalZ) const
 	return 2.0f * pageZ + halfSize - physicalZ;
 }
 
+/* ------------------------------------------------------------------ */
+/* visualToPhysicalX                                                    */
+/* ------------------------------------------------------------------ */
+
+float TerrainSystem::visualToPhysicalX(float visualX) const
+{
+	if (!mTerrainGroup)
+		return visualX;
+	return visualX + mTerrainGroup->getTerrainWorldSize() * 0.5f;
+}
+
+/* ------------------------------------------------------------------ */
+/* visualToPhysicalZ                                                    */
+/* ------------------------------------------------------------------ */
+
+float TerrainSystem::visualToPhysicalZ(float visualZ) const
+{
+	if (!mTerrainGroup)
+		return visualZ;
+	Ogre::Real ws = mTerrainGroup->getTerrainWorldSize();
+	float halfSize = ws * 0.5f;
+	/* Visual page: page 0 covers [-halfSize, halfSize). */
+	float pageV = floorf((visualZ + halfSize) / ws) * ws;
+	/* Physical Z such that the ManualObject displays it at visual Z. */
+	return 2.0f * pageV + halfSize - visualZ;
+}
+
 void TerrainSystem::destroyCollider(uint64_t /*key*/,
 				    TerrainCollider & /*collider*/)
 {

src/features/editScene/systems/TerrainSystem.hpp

@@ -103,11 +103,21 @@ public:
 	 * Same for Z but Z-inverted (see physicalToVisualZ). */
 	float physicalToVisualX(float physicalX) const;
 
+	/* Inverse: physical X corresponding to a given visual world X. */
+	float visualToPhysicalX(float visualX) const;
+
+	/* Half the terrain world size (for coordinate math). */
+	float getTerrainWorldHalfSize() const;
+
 	/* Convert physical heightmap Z to visual display Z.
 	 * Terrain pages render row j at Z = pageMinZ + halfSize - j*step
 	 * but the height data lives at Z = pageMinZ + j*step. */
 	float physicalToVisualZ(float physicalZ) const;
 
+	/* Inverse: physical Z that maps to the given visual world Z.
+	 * Uses visual page indexing, unlike physicalToVisualZ. */
+	float visualToPhysicalZ(float visualZ) const;
+
 private:
 	void activate(struct TerrainComponent &tc,
 		      struct TransformComponent &xform);