Scroll to keep newly navigated item fully into view NB: We modify rect_rel by the amount we scrolled for, so it is immediately updated.

Helper for ColorPicker4()

traverse the layout to locate the nearest character to a display position

discard the oldest entry in the undo list

find the x/y location of a character, and remember info about the previous row in case we get a move-up event (for page up, we'll have to rescan)

canoncialize the selection so start <= end

find minimum y position if it starts at x1

rects array must be big enough to accommodate all characters in the given ranges

check if a utf8 string contains a prefix which is the utf16 string; if so return length of matching utf8 string

Pass in translated ASCII characters for text input. - with glfw you can get those from the callback set in glfwSetCharCallback() - on Windows you can