diff --git a/lib/ugui.c3l/src/fifo.c3 b/lib/ugui.c3l/src/fifo.c3
index 59802e5..d9fc52e 100644
--- a/lib/ugui.c3l/src/fifo.c3
+++ b/lib/ugui.c3l/src/fifo.c3
@@ -1,8 +1,10 @@
+module fifo::faults;
+faultdef FULL, EMPTY;
+
 module fifo{Type};
 
 import std::core::mem;
-
-faultdef FULL, EMPTY;
+import std::sort;
 
 // TODO: specify the allocator
 
@@ -27,7 +29,7 @@ fn void Fifo.free(&fifo)
 fn void? Fifo.enqueue(&fifo, Type *elem)
 {
 	if (fifo.count >= fifo.arr.len) {
-		return FULL?;
+		return fifo::faults::FULL?;
 	}
 	usz in = (fifo.out + fifo.count) % fifo.arr.len;
 	fifo.arr[in] = *elem;
@@ -37,7 +39,7 @@ fn void? Fifo.enqueue(&fifo, Type *elem)
 fn Type*? Fifo.dequeue(&fifo)
 {
 	if (fifo.count == 0) {
-		return EMPTY?;
+		return fifo::faults::EMPTY?;
 	}
 	Type *ret = &fifo.arr[fifo.out];
 	fifo.count--;
@@ -63,4 +65,27 @@ macro Type* Fifo.get_ref(&fifo, usz i) @operator(&[])
 macro usz Fifo.len(&fifo) @operator(len)
 {
 	return fifo.count;
+}
+
+fn void? Fifo.sort(&fifo)
+{
+	Type[] arr = mem::new_array(Type, fifo.count);
+	defer mem::free(arr);
+
+	foreach(i, c: fifo) {
+		arr[i] = c;
+	}
+
+	// doesn't keep ordering
+	//sort::quicksort(arr);
+
+	// seems to keep the right order but we will never know...
+	// also since most things are already ordered the time is closer to O(n) than to O(n^2)
+	sort::insertionsort(arr);
+
+	fifo.count = 0;
+	fifo.out = 0;
+	foreach (&c: arr) {
+		fifo.enqueue(c)!;
+	}
 }
\ No newline at end of file
diff --git a/lib/ugui.c3l/src/ugui_cmd.c3 b/lib/ugui.c3l/src/ugui_cmd.c3
index 51120bb..77468cb 100644
--- a/lib/ugui.c3l/src/ugui_cmd.c3
+++ b/lib/ugui.c3l/src/ugui_cmd.c3
@@ -49,6 +49,12 @@ struct Cmd (Printable) {
 	}
 }
 
+fn int Cmd.compare_to(Cmd a, Cmd b)
+{
+	if (a.z_index == b.z_index) return 0;
+	return a.z_index > b.z_index ? 1 : -1;
+}
+
 // implement the Printable interface
 fn usz? Cmd.to_format(Cmd* cmd, Formatter *f) @dynamic
 {
diff --git a/lib/ugui.c3l/src/ugui_core.c3 b/lib/ugui.c3l/src/ugui_core.c3
index 8078218..a1c7e2b 100644
--- a/lib/ugui.c3l/src/ugui_core.c3
+++ b/lib/ugui.c3l/src/ugui_core.c3
@@ -293,7 +293,7 @@ $if DEBUG == 1:
 	// draw mouse position
 	Cmd cmd = {
 		.type = CMD_RECT,
-		.z_index = int.max, // hopefully over everything else
+		.z_index = int.max-1, // hopefully over everything else
 		.rect.rect = {
 			.x = ctx.input.mouse.pos.x - 2,
 			.y = ctx.input.mouse.pos.y - 2,
@@ -304,11 +304,16 @@ $if DEBUG == 1:
 	};
 	ctx.cmd_queue.enqueue(&cmd)!;
 
-	// dump the command buffer
-	io::printn("Command Buffer Dump:");
-	foreach(idx, c: ctx.cmd_queue) {
-		io::printfn("\t [%d] = {%s}", idx, c);
-	}
+// dump the command buffer
+//	io::printn("Command Buffer Dump:");
+//	foreach(idx, c: ctx.cmd_queue) {
+//		io::printfn("\t [%d] = {%s}", idx, c);
+//	}
+	ctx.cmd_queue.sort()!;
+//	io::printn("Sorted Command Buffer Dump:");
+//	foreach(idx, c: ctx.cmd_queue) {
+//		io::printfn("\t [%d] = {%s}", idx, c);
+//	}
 $endif
 }
 
diff --git a/lib/ugui.c3l/src/ugui_div.c3 b/lib/ugui.c3l/src/ugui_div.c3
index d4dcae6..4bfd45e 100644
--- a/lib/ugui.c3l/src/ugui_div.c3
+++ b/lib/ugui.c3l/src/ugui_div.c3
@@ -48,7 +48,6 @@ fn void? Ctx.div_begin(&ctx, String label, Rect size, bool scroll_x = false, boo
 	elem.div.scroll_x.enabled = scroll_x;
 	elem.div.scroll_y.enabled = scroll_y;
 	elem.div.z_index = parent.div.z_index + 1;
-	io::printn(elem.div.z_index);
 
 	// 2. layout the element
 	Rect wanted_size = {
diff --git a/lib/ugui.c3l/src/ugui_input.c3 b/lib/ugui.c3l/src/ugui_input.c3
index abad51c..5dcb12b 100644
--- a/lib/ugui.c3l/src/ugui_input.c3
+++ b/lib/ugui.c3l/src/ugui_input.c3
@@ -112,8 +112,8 @@ fn void Ctx.input_mouse_button(&ctx, MouseButtons buttons)
 // Mouse was moved, report absolute position
 fn void Ctx.input_mouse_abs(&ctx, short x, short y)
 {
-	ctx.input.mouse.pos.x = math::clamp(x, 0u16, ctx.width);
-	ctx.input.mouse.pos.y = math::clamp(y, 0u16, ctx.height);
+	ctx.input.mouse.pos.x = math::clamp(x, (short)0, ctx.width);
+	ctx.input.mouse.pos.y = math::clamp(y, (short)0, ctx.height);
 
 	short dx, dy;
 	dx = x - ctx.input.mouse.pos.x;
@@ -135,8 +135,8 @@ fn void Ctx.input_mouse_delta(&ctx, short dx, short dy)
 	mx = ctx.input.mouse.pos.x + dx;
 	my = ctx.input.mouse.pos.y + dy;
 
-	ctx.input.mouse.pos.x = math::clamp(mx, 0u16, ctx.width);
-	ctx.input.mouse.pos.y = math::clamp(my, 0u16, ctx.height);
+	ctx.input.mouse.pos.x = math::clamp(mx, (short)0, ctx.width);
+	ctx.input.mouse.pos.y = math::clamp(my, (short)0, ctx.height);
 
 	ctx.input.events.mouse_move = dx != 0 || dy != 0;
 }
diff --git a/lib/ugui.c3l/src/vtree.c3 b/lib/ugui.c3l/src/vtree.c3
index 0a1e851..d18b749 100644
--- a/lib/ugui.c3l/src/vtree.c3
+++ b/lib/ugui.c3l/src/vtree.c3
@@ -1,3 +1,6 @@
+module vtree::faults;
+faultdef CANNOT_SHRINK, INVALID_REFERENCE, TREE_FULL, REFERENCE_NOT_PRESENT, INVALID_ARGUMENT;
+
 module vtree{ElemType};
 
 import std::core::mem;
@@ -9,7 +12,6 @@ struct VTree {
 	isz[] refs, ordered_refs;
 }
 
-faultdef CANNOT_SHRINK, INVALID_REFERENCE, TREE_FULL, REFERENCE_NOT_PRESENT, INVALID_ARGUMENT;
 
 macro VTree.ref_is_valid(&tree, isz ref) { return (ref >= 0 && ref < tree.refs.len); }
 macro VTree.ref_is_present(&tree, isz ref) { return tree.refs[ref] >= 0; }
@@ -88,14 +90,14 @@ fn void? VTree.resize(&tree, usz newsize)
 {
 	// return error when shrinking with too many elements
 	if (newsize < tree.elements) {
-		return CANNOT_SHRINK?;
+		return vtree::faults::CANNOT_SHRINK?;
 	}
 
 	// pack the vector when shrinking to avoid data loss
 	if ((int)newsize < tree.size()) {
 		// FIXME: packing destroys all references to elements of vec
 		//        so shrinking may cause dangling pointers
-		return CANNOT_SHRINK?;
+		return vtree::faults::CANNOT_SHRINK?;
 	}
 
 	usz old_size = tree.size();
@@ -120,18 +122,18 @@ fn isz? VTree.add(&tree, ElemType elem, isz parent)
 {
 	// invalid parent
 	if (!tree.ref_is_valid(parent)) {
-		return INVALID_REFERENCE?;
+		return vtree::faults::INVALID_REFERENCE?;
 	}
 
 	// no space left
 	if (tree.elements >= tree.size()) {
-		return TREE_FULL?;
+		return vtree::faults::TREE_FULL?;
 	}
 
 	// check if the parent exists
 	// if there are no elements in the tree the first add will set the root
 	if (!tree.ref_is_present(parent) && tree.elements != 0) {
-		return REFERENCE_NOT_PRESENT?;
+		return vtree::faults::REFERENCE_NOT_PRESENT?;
 	}
 
 	// get the first free spot
@@ -143,7 +145,7 @@ fn isz? VTree.add(&tree, ElemType elem, isz parent)
 		}
 	}
 	if (free_spot < 0) {
-		return TREE_FULL?;
+		return vtree::faults::TREE_FULL?;
 	}
 
 	// finally add the element
@@ -159,7 +161,7 @@ fn isz? VTree.add(&tree, ElemType elem, isz parent)
 fn usz? VTree.prune(&tree, isz ref)
 {
 	if (!tree.ref_is_valid(ref)) {
-		return INVALID_REFERENCE?;
+		return vtree::faults::INVALID_REFERENCE?;
 	}
 
 	if (!tree.ref_is_present(ref)) {
@@ -193,7 +195,7 @@ fn usz VTree.nuke(&tree)
 fn usz? VTree.subtree_size(&tree, isz ref)
 {
 	if (!tree.ref_is_valid(ref)) {
-		return INVALID_REFERENCE?;
+		return vtree::faults::INVALID_REFERENCE?;
 	}
 
 	if (!tree.ref_is_present(ref)) {
@@ -215,17 +217,17 @@ fn usz? VTree.subtree_size(&tree, isz ref)
 fn isz? VTree.children_it(&tree, isz parent, isz *cursor)
 {
 	if (cursor == null) {
-		return INVALID_ARGUMENT?;
+		return vtree::faults::INVALID_ARGUMENT?;
 	}
 
 	// if the cursor is out of bounds then we are done for sure
 	if (!tree.ref_is_valid(*cursor)) {
-		return INVALID_REFERENCE?;
+		return vtree::faults::INVALID_REFERENCE?;
 	}
 
 	// same for the parent, if it's invalid it can't have children
 	if (!tree.ref_is_valid(parent) || !tree.ref_is_present(parent)) {
-		return INVALID_REFERENCE?;
+		return vtree::faults::INVALID_REFERENCE?;
 	}
 
 	// find the first child, update the cursor and return the ref
@@ -253,7 +255,7 @@ fn isz? VTree.children_it(&tree, isz parent, isz *cursor)
 fn isz? VTree.level_order_it(&tree, isz ref, isz *cursor)
 {
 	if (cursor == null) {
-		return INVALID_ARGUMENT?;
+		return vtree::faults::INVALID_ARGUMENT?;
 	}
 
 	isz[] queue = tree.ordered_refs;
@@ -300,11 +302,11 @@ fn isz? VTree.level_order_it(&tree, isz ref, isz *cursor)
 fn isz? VTree.parentof(&tree, isz ref)
 {
 	if (!tree.ref_is_valid(ref)) {
-		return INVALID_REFERENCE?;
+		return vtree::faults::INVALID_REFERENCE?;
 	}
 
 	if (!tree.ref_is_present(ref)) {
-		return REFERENCE_NOT_PRESENT?;
+		return vtree::faults::REFERENCE_NOT_PRESENT?;
 	}
 
 	return tree.refs[ref];
@@ -313,11 +315,11 @@ fn isz? VTree.parentof(&tree, isz ref)
 fn ElemType? VTree.get(&tree, isz ref)
 {
 	if (!tree.ref_is_valid(ref)) {
-		return INVALID_REFERENCE?;
+		return vtree::faults::INVALID_REFERENCE?;
 	}
 
 	if (!tree.ref_is_present(ref)) {
-		return REFERENCE_NOT_PRESENT?;
+		return vtree::faults::REFERENCE_NOT_PRESENT?;
 	}
 
 	return tree.vector[ref];