destructible landscapes/terrains and glTexSubImage2D

[baedert]

Hi

I’m currently trying to do some destructable landscape. For this I use a big(1024x1024px) texture.
There are some bombs which going to explode, so I wanted to remove a part of the texture(=set this round part transparent, so you can see the background).
The problem is, that I can’t really create a round image

I mean, the image i give to glTexSubImage2D just replaces the pixels in the original texture, and that’s not really, what I want

I really hope, you know what I mean - and a way to do it :>

[bobjob]

Im guessing its 2D?

If its only in regards to rendering and its openGL. I think you could probably use a texture with alpha channels (for exposive mark), make sure depth testing is on, draw with color(0, 0, 0, 0) or a blend function that would make the main color invisible (for explosive mark), when you draw the map and only pass if NOT_EQUAL, LESS or something like that

[baedert]

I just changed the technique to the second here: http://gmc.yoyogames.com/index.php?showtopic=44353 (5th post):

http://upload.gm-school.uni.cc/index.php?a...ensei/Examples& - Use large land blocks which are split to half the size when in contact with an explosion, making it so there aren’t as many objects on the screen as if you just had many small objects on the screen. You start with several 128128 sprites. When hit, they divide into 4 sprites (6464), and then if they are still in contact with the explosion that is divided in 4, etc If a dirt is 2*2 and it is in contact with the explosion, the object is destroyed. This method is sometimes fast, but not always reliable.

I’m currently at this point: http://planschkuh.pl.ohost.de/screen43.jpg
it works quite well, no texturing at this point and a little bit noobish and dirty code from me
And it’s also a little bit slow with lots of quads(0.108s with 2000 quads). And some errors occur, but I’ll maybe write some article, tutorial or something about this technique