Websites which helped me a lot

Computer technology

Good programming tutorials, Java, python etc
www.zetcode.com

Emulation tutorials covers NES, GB.
http://codeslinger.co.uk/pages/blog/wordpress

OpenGL, 3d game tutorials, NeHe ( Neon, Helium)
http://nehe.gamedev.net/
http://www.gamedev.net/

Game competition
http://www.ludumdare.com/

Indie Games
http://www.tigsource.com/

Game development resources like arts, music

http://www.ambrosine.com/resource.php

For geek computer users
http://www.geek.com/

Good Linux stuff, books etc.
http://www.linuxtropia.org/




Science

Very good tutorial on Waves and signals
http://www.doctronics.co.uk/signals.htm

Science projects - for science lovers
http://www.scitoys.com/




Music

Mod, XM, IT, S3M Module musics
http://www.modarchive.org/

Game music remixes
http://www.ocremix.org
http://remix.thasauce.net

Game music collection
http://www.gamemp3s.net

Snes music collection
http://snesmusic.org/v2/

Emulators, console musics, roms utils etc
http://www.zophar.net




Arts

Ocean of artists
www.deviantart.com




Hardware

Hardware projects, circuits, pin-outs
http://www.epanorama.net/
http://www.pinouts.ru/




Books

http://safari5.bvdep.com/
http://www.gutenberg.org/
http://www.bartleby.com/



Research papers
http://arxiv.org/

Others

Lots of free contents of almost everything, must visit
http://www.freebyte.com/

Differentiate rotation and pinch gesture

For guessing gestures manually in programming i have found by logging how IOS sdk does it internally. As we can see in the below picture -





















Gesture is decided by first motion of fingers. But in many cases a blended approach can also be used. Means on X-axis motion doing rotation and Y-axis motion doing Pinch.

There is nothing more to write because other methods can use filtering and algorithm to smartly differentiate gestures.  Like managing a Rectangular band over the two touch points and calculating the motion of fingers strictly inside rectangular boundaries.

We know, if we don't use first motion, then there will be delay in gesture recognition.