Getting together for developing a Game?

[mjohansson]

But without blending you cant do textures with alpha in them? Will you post the code somewere?

 

[slaeshjag]

Exactly. so it's crucial to adjust the graphics to do as little blending as possible. In my attempts, I can fill a screen with about one layer of textured shapes that is alpha blended, anything more make the FPS sink like a stone.


Currently, my only rendering code is the one in this library. It can't do rotations yet however.

 

[ekianjo]

Are we supposed to only talk in the document? I find it slightly confusing and weird.


I dont know if my question got materialized so I repeat it here:

No, we can talk here as well. The document is just there to capture the assumptions so we dont have to go through 20 pages of forums or PMs to remember what we decided Note that at this stage nothing is decided so feel free to discuss the contents I drafted.

 

[Binky]

But without blending you cant do textures with alpha in them? Will you post the code somewere?

The pandora's screen is high enough res to dither sucessfully

 

[mjohansson]

I just made another test with GLES1, 300fps at most, with 12 polygons in line with RGBA texture and blending enabled yielded 150 fps.

 

[mjohansson]

ok, I tested with 1000 polygons, I didnt go behind all of them, but if I start from front and go back framerate dosnt go down until I reach 3 polygon, then it sinks to 150 and stays there for a couple of polys, then go down to 100fps exactly and I went backwards racking up a LOT of polygons for a while, dont know how many but I think more then 100, and fps was still rocksteady 100fps, with probably more then 100 polygons forming sucessive transparency layers covering hole screen.

 

[slaeshjag]

Try a more realistic scenario, small tiles. Stack 300 32x32 textured quads. This is almost a layer of tiles.

 

[mjohansson]

Ill try it tomorrow, need to charge my Pandora, do you mean 300 polygons side by side on the same screen and then stack several layers so its 900 polygons in total, or x2 for quads I mean, or 300 quads on the same screenspace hmm wait, are you drawing 2 polygons with vertices on exact same coordinates? because that will quickly destroy framerate nomatter what depthtest is used I think.

 

[slaeshjag]

I think we should skit depth-test completely. Since we aren't going to be doing any 3D afaik, it's easier to just draw in order.


Just scatter them all over the screen, and try 1, 2 and 3 layers or something. Textured quads is what we're going to use (well, textured triangles,) so it makes sense to test the situation we're likely to be in. A layer on top of it with lots of texture switches (as if you're drawing multiple sprites) and calls should make it sort-of accurate.

 

[mjohansson]

Or I think same plane is same thing, hmm when drawing several layers on top of each other perhaps you should use perspective rendering and give different depth to different layers, no thats not a good idea... I think I accidentally put like thousands of polygons on same coordinates, and framerate sank like a stone, I dont remember if I tryed setting depthFunc to ALWAYS or even turn off depthtest, but if I did I dont think it mattered, or did it? are you using glOrtho? if not try giving different depth to overlapping polys.

 

[slaeshjag]

I'm using projection mode and I draw everything at Z=0

 

[Linux-SWAT]

I'm interested in seeing (and running) the code of all this basic stuff.

 

[mjohansson]

Ok I made one more test, but now battery is flat so I didnt have time to make another test I wanted to do, but I tested putting all polygons with exact same vertice coordinates, 300 triangles, framerate dropped to under 10, I then turned off depthtest and framerate was the same. I then tried giving each triangles vertices +0.001 in the X values for each new triangle, same framerate, I then tryed increasing by +0.1 instead and then framerate went up to 100.


So try doing this, level buildingblocks will never overlap so they can be normal, but give different size for polygon of ships, then a ships vertice coordinates will never be same as a building block, and then parralax layers can be single big sheets and the corner can have different values there also. Since the ships collision detection area can be something else then the polygon vertices and graphics dont need to cover the hole area Either it dosnt matter the size of the actual poly. Im sure framerate should be ok for several layers if no vertice coordinates match for overlapping polys.

 

[pmprog]

I added a few comments to the doc - though it looks like mjohansson or slaeshjag will prob head up the engine

 

[mjohansson]

Well I looked in some few files of Slaeshjags engine and I cant make very much sense of it so I doubt I can be of use, unless he incorporates GLES2 then I would try make some effects, but then again others would probably be able to come up with cooler stuff anyway. We could make wavy water, have ships shimmer in different colors when hit, make multicolored laser rays, lighteffects so if your in a cave the edges of the screen gets darker. Glow effects, sparkles, what else would be cool? You can make fancy stuff with stencil buffert.

 

[slaeshjag]

^ You are now in charge of the engine

 

[mjohansson]

Slaeshjag you said you cant rotate sprites, but if you use GLES1 you can just use glRotatef and glTranslatef if you need to change center of rotation.

 

[mjohansson]

Should I make the entire engine? I suspect everyone will hate what I do, I would only produce a single file and things would be very brute force style I think. It should be possible to just make the rendering shouldnt it? All I need is center positions and sizes of all the content, but mayby its confusing, Im gonna try something tommorrow and then we will see what you think.

 

[slaeshjag]

yes, but atm, I generate coordinates from x/y, I don't center it around 0,0. And it'll cascade down to all rendering code, so I'm waiting with that.


Shaders are way over my head, I don't know how to use them, and honsetly, they scare the living crap out of me. And from what I've read about their performace on our SGX, I doubt they'll be useful. But prove me wrong and it'll be a much nicer-looking game.

 

[mjohansson]

Ill try putting a test together tomorrow and ask someone to compile it and we will see how shaders run.