- 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
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
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
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.