I don't mean to be harsh but you spent time making the inside great but the outside is the opposite.Are you sure about its simplicity? Do you know how much I engaged in even for a simple flood fill algorithm, how long it took to make the text area with multiple line work properly. It is easy to add a simple window without worriying about inner working of layers, activeness of GUI objects with any high level API but doing all GUI stuff from the scratch is not that much simple task.For correct pixels mouse over to be processed, it is essential to take into account the positions of sliders and degree of zoom.Providing possibility to select an area for duplicating, deleting, moving, scaling and rotating is another story. Writing a font library that includes methods from loading of fonts up to specifying the presentation style of the text is not as simple as you think.I wrote a library even for string operations which doesn't involves just conventional functions but provides a rich method collection of encryption which might have a potential use for creating various file structure with its a solid infrastructure.Maybe, It seems that all these work is a bit complex, hard and a serious challenge to me because I am a newbie in this field of graphic programming.
I dealed with 3D Model Creator too, and it was not so much trying except texture mapping, light mapping and organizing the 3D interface to edit surfaces, triangles, lines and points rather than writing algorithms for basic shapes or functions such as ellipsoid, surface shifting/rotating or writing a an OBJ loader in order to use external models in program.(I doubt the last sentence is suitable to context because the sentence is long and it doesn't sound good even though it is logically correct :) Sorry for my possible poor English. I may be a little idiot. )
As shippou said, it's simple, not interesting though.