added another demo ui

TODO

@@ -20,7 +20,7 @@ to maintain focus until mouse release (fix scroll bars)
 [x] The id combination in gen_id() uses an intger division, which is costly, use another combination 
     function that is non-linear and doesn't use division
 [ ] Animations, somehow
-[ ] Maybe cache codepoint converted strings
+[x] Maybe cache codepoint converted strings
 [x] Fix scroll wheel when div is scrolled
 [ ] Be consistent with the initialization methods some are foo.new() and some are foo.init()
 [ ] Implement image loading (.bmp, .ff, .qoi and .png), in the future even lossy images like .jpg
@@ -44,7 +44,7 @@ to maintain focus until mouse release (fix scroll bars)
 [x] Fix how padding is applied in push_rect. In CSS padding is applied between the border and the
     content, the background color is applied starting from the border. Right now push_rect() offsets
     the background rect by both border and padding
-
+[ ] Investigate why the debug pointer (cyan rectangle) disappears... 
 
 ## Layout
 
@@ -55,6 +55,13 @@ to maintain focus until mouse release (fix scroll bars)
 [ ] Correct whitespace handling in text (\t \r etc)
 [ ] Consider a multi-pass recursive approach to layout (like https://github.com/nicbarker/clay)
     instead of the curren multi-frame approach.
+[ ] Implement column/row sizing (min, max)
+[ ] Find a way to concile pixel measurements to the mm ones used in css, for example in min/max sizing
+    of elements
+[ ] Center elements to div (center children_bounds to the center of the div bounds and shift the origin accordingly)
+[ ] Use containing_rect() in position_element() to skip some computing and semplify the function
+[ ] Rename position_element() to layout_element()
+[ ] Make functions to mark rows/columns as full, to fix the calculator demo
 
 ## Input
 
@@ -75,6 +82,7 @@ to maintain focus until mouse release (fix scroll bars)
 [ ] New window command, useful for popups
 [x] Text command returns the text bounds, this way we can avoid the pattern 
     draw_text(a, pos) -> off = compute_bounds(a) -> draw_text(b, pos+off) -> ...
+[ ] Rounded rectangle with different radius for each corner
 
 ## Atlas