rotating images and pixel collision

[Kitty Hello]

In my case, I ended up making a 8 pixel raster of 1 pixel SPRCOLL calls.

[Ian Price]

I tried one of my games on a few netbooks just before Christmas 2009, when I needed a laptop replacement. Performance was terrible. I was getting over 300FPS on my old lappy and around 30-40FPS on several netbooks.

In saying that though I haven't tried my games on my son's netbook which runs games like Torchlight surprisingly well.

[Hatonastick]

Torchlight runs on a netbook?!?!? 

[Ian Price]

Yep.

[Kitty Hello]

On a PC the reading of alpha pixels is a tad faster, since I can directly read the alpha layer. On the OpenGL|ES of the iPhone I have to read RGBA data (quadripple the size)

[Hatonastick]

Yep.

I might have to seriously look at getting one then and maybe retiring my laptop (I've been meaning to get another desktop for a while now anyway).

[MrTAToad]

This has, I believe rotated pixel perfect collision detection : http://www.virtualrealm.com.au/blogs/xna-rotated-perpixel-collision/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed:+mykre+(Mykres+Space)

Its in C#, but may be possible to convert.  Whilst performance would be poor, taking the advice from the poster at the bottom could help speed things up.

It wouldn't be trivial   And would really be a waste of time...

[Ian Price]

I do that myself actually

However that only works if either object is roughly "square" (ie its dimensions are almost equal). If one (or both) of the objects is rectangular, then this won't work, so alternative solutions should be sought.

[Scott_AW]

Theres some benefits to netbooks, size, weight, and a good way to limit yourself when developing.  I'll have to look into Torchlight.

Not having a powerhouse pc keeps you developement slimmer since you're forced to make things run efficiently.

Still haven't had a chance to put some pixel-collision through some test yet, but thanks for all who gave me plenty of tips to get it started.

[Kryten]

Just wanted to say that I found this thread very useful with my current project, so thanks guys.

Gernot - might be worthwhile updating the SPRCOLL command in the online help to show that it only works with original, non rotated images, and make this thread a sticky as its likely a fairly common problem.