Ref the More Advanced Example at

ooops - my first post - wont allow me a url just google Imlib2 documentation and go to the docs.enlightenment.org link


Have Imlib2 installed on my Centos 5 system and all works fine. I am able to use it for my immediate needs but do not understand fully how it works. Perhaps there are others in the same boat - anyway here are my questions.

1 What exactly is specified in an update added to the update list when responding to a motion_notify event? Is it just a rectangle?

2 Why is the same code executed for each update? Is it because the answer to 1 above is yes - and so we must redraw the whole thing each time just ti get the bit we want to blend to the updated image?

3 Is this really quicker than just redrawing the whole thing from scratch? - which we now seem to do several times - about 4 on average according to some mods I made to count how many iterations of the update loop occurred!

4 I added a call to imlib_image_create_scaled_image_from_drawable() to get a thumbnail sized jpg - it was fine except that the text was missing although visible in the window. Why? Should it have been treated differently and blended before the rendering?


I have been at this programming lark since 1965 when I joined IBM. Ever since I have never liked to not fully understand what is going on. I feel I have some basic misunderstanding and am expecting a "Doh!" moment.


So sock it too me guys!

John

OK so I have worked it out for myself!

Yes updates are just rectangles.

Although it seems wasteful to redraw everything for each update Imlib2's cache helps as the loading of the background and icon images will come from the cache. What is saved is the amount of data that needs to be written to the window. Extra time is spent working out which bits change and time saved by only changing those bits. Probably also important is that the amount of data thrown at the window is much less so the system will seem more responsive - particularly for a large window.

The problem with the Text not appearing does not seem to exist! Mental aberration on programmers part??? Am I finally cracking up!
John