- Different Approach for GUI Elements
Very soon the implementation reached a point (at least on the
iPhone
side) where it was obvious, that there is a lot of functionality missing, when looking for
Tk like widgets. That might be partially because Apple wants to look all their GUI stuff look like they want it to be displayed.
At that time some experiments with
OpenGL ES started.
OpenGL ES is a cut down version of
OpenGL running on
iOS and on
Android and as part of
WebGL in
javascript for browsers too.
The experiments were based on the idea to use screen buffer implementation of
OpenGL ES as a base for displaying pixels on the screen and to use some primitive functions of
OpenGL ES like drawing a line or a rectangle or a polygon and filling some area with colors. For displaying text the idea is to use a freetype font implementation, also available for the
iPhone.
Using that approach, it would be possible to use 3-D elements to be shown and also rotation of text would be very easy using
OpenGL ES functionality.
As
OpenGL ES is also used as a base for some games on
iOS the guess was, that it should be fast enough for the implementation of a
Tk GUI.
Having some small knowledge of
OpenGL from the implementation of
ntkwidget the decision was made to give
OpenGL ES a try, to see, what can be done using that.
