I seem to have this psychological need to whine...

[elfs]

Just a few days ago I was complaining about how little progress I've been making on my stories over December, and now suddenly I've proofread three stories and have a four-week schedule for releasing them. In the past two days I've written 5350 words in the third Aimee' novel, Aimee': Old County. In the past week I've written another 2000 words for The Reef (my 18th century pirate-chick-vs-Lovecraftian-evil novel in which one character firmly announces, "Bloody Beth was a myth!", just so you know where that's going), wrote a thousand words into The Comet (the sequel to Mobility, although I still don't have a conflict or crisis there), and a thousand words into another Reservationist story, Content, Industrious, Prosperous, Boring.

I've also been looking into using Xconq for some programming ideas, but since my first love is arcade game design, I've been having trouble finding anything on the rotation and collision of a non-uniform sprite. Anyone know anything about the subject? I've been systematically building games available through Freshmeat to see if anything stands out, but so far nothing has.

Comments

[mouser.livejournal.com]

3D space or 2D space? And do you mean sprite as a BMP (or whatever)?

[elfs.livejournal.com]

2D space, at this point. I'm just looking for straightforward algorithms to
detect the collision of two defined geometric shapes in a plane. A lot of
them seem to assume that no matter what the orientation of your object, it
occupied a defined rectangular space with sides parallel to the display, and
that's the space within which a collision is considered "true." This doesn't
work when you want your spaceship/tank/boat/whatever to have an arbitrary
orientation about a radial point.

[mouser.livejournal.com]

Ok - term definition that I use:

Sprite: pixel-wise picture of an object - this may not be what you are describing.

If it's a Sprite as above, the easiest way to check collision (yes, assuming NO rotation) is to do the rough check based the TOP/BOTTOM LEFT/RIGHT solution I'm sure you are describing, then if it's true, check if any drawn pixel would overlay any pixel of the second object. Properly done, it's still rather quick. (Predefined masks where you can bitwise AND them together help tremendously, as do other techniques.)

If it's rendered via triangles (the most common method) on the fly, keep the list of triangles you used to create each object and see of there are any intersections between the two lists.

I recommend the book "3D Math Primer for Graphics and Game Development" by Fletcher Dunn ( AMAZON (http://www.amazon.com/gp/product/1556229119/sr=1-4/qid=1137214341/ref=sr_1_4/002-4116708-0714447?%5Fencoding=UTF8)) for more ideas.

[mouser.livejournal.com]

http://bash.org/?14258