diff --git a/src/jasper/modules/world/src/studio/worldeditor/worldeditor-imgui.cpp b/src/jasper/modules/world/src/studio/worldeditor/worldeditor-imgui.cpp
index ec29b51..43a5b34 100644
--- a/src/jasper/modules/world/src/studio/worldeditor/worldeditor-imgui.cpp
+++ b/src/jasper/modules/world/src/studio/worldeditor/worldeditor-imgui.cpp
@@ -49,33 +49,16 @@ static WorldDoc makeValid(WorldDoc doc) noexcept {
 [[nodiscard]]
 constexpr ox::Point fbPtToTileAddr(
 		ox::Vec2 const&fbPt,
-		ox::Size const&fbSz,
-		ox::Size const&mapSz) noexcept {
-	// fbw - framebuffer width
-	// fbh - framebuffer height
-	// fbx - framebuffer pt x
-	// fby - framebuffer pt y
-	// sw - scaled width
-	// sh - scaled height
-	// mw - map width
-	// mw - map height
-	// mx - map loc x
-	// my - map loc y
-	// sw = fbw / mw
-	// sh = fbh / mh
-	// tile addr x = sw * fbx
-	// tile addr y = sh * fby
-	auto const fbw = static_cast<float>(fbSz.width);
-	auto const fbh = static_cast<float>(fbSz.height);
-	auto const mw = static_cast<float>(mapSz.width);
-	auto const mh = static_cast<float>(mapSz.height);
-	auto const sw = fbw / mw;
-	auto const sh = fbh / mh;
-	auto const fbx = fbPt.x / fbw;
-	auto const fby = fbPt.y / fbh;
+		ox::Vec2 const&mapSz) noexcept {
+	constexpr auto ColumnsOnScrn = 15;
+	constexpr auto RowsOnScrn = 10;
+	auto const fbX = static_cast<float>(fbPt.x);
+	auto const fbY = static_cast<float>(fbPt.y);
+	auto const tw = static_cast<float>(mapSz.x / ColumnsOnScrn);
+	auto const th = static_cast<float>(mapSz.y / RowsOnScrn);
 	return {
-		static_cast<int>(sw * fbx),
-		static_cast<int>(sh * fby),
+		static_cast<int>(fbX / tw),
+		static_cast<int>(fbY / th),
 	};
 }
 
@@ -190,15 +173,18 @@ void WorldEditorImGui::drawWorldView() noexcept {
 	auto const srcH = fbHeight / fbWidth;
 	auto const dstH = paneSize.y / paneSize.x;
 	float xScale{}, yScale{};
+	float fbPaneScale{};
 	if (dstH > srcH) {
 		// crop off width
 		xScale = srcH / dstH;
 		yScale = 1;
+		fbPaneScale = paneSize.y / fbHeight;
 	} else {
 		auto const srcW = fbWidth / fbHeight;
 		auto const dstW = (paneSize.x / paneSize.y);
 		xScale = 1;
 		yScale = srcW / dstW;
+		fbPaneScale = paneSize.x / fbWidth;
 	}
 	ImGui::Image(
 			ig::toImTextureID(fb.color.id),
@@ -208,22 +194,27 @@ void WorldEditorImGui::drawWorldView() noexcept {
 	std::ignore = ig::dragDropTarget([&, this] {
 		oxRequire(objId, ig::getDragDropPayload<WorldTileDragDrop>("WorldTile"));
 		auto const&io = ImGui::GetIO();
-		auto const dropPos = world::dropPos(ox::Vec2(io.MousePos));
-		auto const mw = m_doc.columns * ncore::TileWidth * 2;
-		auto const mh = m_doc.rows * ncore::TileHeight * 2;
-		auto const tileAddr = fbPtToTileAddr(dropPos, fb.size(), {mw, mh});
-		pushCommand<ModifyTilesCommand>(
-			m_doc,
-			m_worldStatic,
-			m_objCache,
-			ox::Vector<ModifyTilesCommand::Mod>{
-				{
-					.layer = m_activeLayer,
-					.tileAddr = tileAddr,
-					.objId = objId.objId,
-					.setId = objId.setId,
-				},
-			});
+		auto const dropPos = world::dropPos(ox::Vec2{io.MousePos});
+		auto const viewSz = m_view.drawSize();
+		auto const tileAddr = fbPtToTileAddr(
+				dropPos,
+				ox::Vec2{
+					static_cast<float>(viewSz.width) * fbPaneScale,
+					static_cast<float>(viewSz.height) * fbPaneScale});
+		if (tileAddr.x < m_doc.columns && tileAddr.y < m_doc.rows) {
+			pushCommand<ModifyTilesCommand>(
+					m_doc,
+					m_worldStatic,
+					m_objCache,
+					ox::Vector<ModifyTilesCommand::Mod>{
+						{
+							.layer = m_activeLayer,
+							.tileAddr = tileAddr,
+							.objId = objId.objId,
+							.setId = objId.setId,
+						},
+					});
+		}
 		oxReturnError(loadWorldStatic(m_objCache, m_doc).moveTo(m_worldStatic));
 		return ox::Error{};
 	});
diff --git a/src/jasper/modules/world/src/studio/worldeditor/worldeditor-imgui.hpp b/src/jasper/modules/world/src/studio/worldeditor/worldeditor-imgui.hpp
index 1c15852..c060fa4 100644
--- a/src/jasper/modules/world/src/studio/worldeditor/worldeditor-imgui.hpp
+++ b/src/jasper/modules/world/src/studio/worldeditor/worldeditor-imgui.hpp
@@ -29,6 +29,11 @@ class WorldEditorImGui: public studio::Editor {
 			ox::String name;
 			uint64_t id{};
 			keel::AssetRef<WorldObjectSet> set;
+			ObjSetRef(ox::String pName, uint64_t pId, keel::AssetRef<WorldObjectSet> pSet):
+				name(std::move(pName)),
+				id(pId),
+				set(std::move(pSet)) {}
+			constexpr ObjSetRef() = default;
 		};
 		ox::Vector<ObjSetRef> m_objSets;
 		WorldStatic m_worldStatic;