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Is The 2d colision pixel perfect?

BlitzMax Forums/BlitzMax Programming/Is The 2d colision pixel perfect?

Uber Jase(Posted 2006) [#1]
Hi,

I'm thinking of buying Blitzmax but first I would like to know is the colision pixel perfect evan with scaling and rotation? And how fast is it with scaling ect?

Thank you


Fetze(Posted 2006) [#2]
Yep, it's pixelperfect, but really slow. If possible, you should avoid it.

Scaling and rotating does'nt take any time because BlitzMax is using Direct3D / OpenGL.

Anyway, Blitzmax is great and if you liked BLitz2D I'd advice you to buy it.


Uber Jase(Posted 2006) [#3]
Has it got scaled/rotated rectangle colision for faster colision detection?


Yan(Posted 2006) [#4]
Yep, it's pixelperfect, but really slow. If possible, you should avoid it.
A bit misleading. Pixel perfect collisions are *always* slow when compared to other, less accurate methods.

I wouldn't say BMax's pixel perfect collisions are particularly slow for a '2D in 3D' system.

[edit]
To answer your second question (you posted whilst I was typing :o))

No, not natively.
[\edit]


Dreamora(Posted 2006) [#5]
Saying that the pixel perfect is slow just means that you aren't doing it in an optimized way.

If you use all optimations you would do with image - image collision test like with the old blitz, then it is lightning fast after all.

(much faster than it actually needs to be as there are normally only few object that receive collisions but many that send *level geometry etc only sends, only player etc receive collision and after all, the receive is the slow part not the send collision!*)


Fetze(Posted 2006) [#6]
[qoute] Saying that the pixel perfect is slow just means that you aren't doing it in an optimized way.[/qoute]

The pixelperfect collision-detecton ->itsself<- IS slow ;)


ImaginaryHuman(Posted 2006) [#7]
How exactly does the pixel collision process work? I am wondering if there is a way to use the depth buffer while drawing to see if things collide in a hardware-accelerated fashion. The only problem then would be figuring out how to read the depth buffer to make changes in program flow, which is probably not fast.


Dreamora(Posted 2006) [#8]
slow != slow compared to polygon collision fetze :-)

Slow in absolute term means that 1000 images that collide with a single player is slow ... and that isn't the case if only the player reads collision for example.