G.T.A.2 Map Editor

[phibermon]

If the source image is exactly this, but it's stored as NPOT, then it's almost certainly *supposed* to be offset from the center due to it's use in the game (try some other images, try some cars etc). If not then there simply must be additional information in the game data somewhere that gives you the true image size.

The point is that you shouldn't have to remove any pixels, if it's NPOT then why didn't they save it clipped to the visible pixels in the first place? why did they waste space? and if so, where's the additional information telling them what the usable portion of the image is?

Removing black pixels is not a good idea, you can't be sure that the original artist didn't actually have some blank pixels down one side, this can't possibly be the solution because why would they have this additional costly step in a commercial game when they could of just stored the image without unused pixels?

Again, if this is the source image then it's supposed to look like (A) (with transparency) in the game, your solution is correct, it's correctly mapping the source image you posted to the quad only by modifying the texture coods. it's the source image that has the blank space, not as a result of your calculations.

[hwnd]

I think you are almost there, but it's unclear why some other also have offset. Like peds:
Right side has offset:



In my friends renderer he deals with "alignment"
He draws peds with alignment like this:

   if (align){         VBO.Add(Vector3f(pos.x+w/2,pos.y+h/2,pos.z),Vector2f(texEntry->U2,texEntry->V2));
            VBO.Add(Vector3f(pos.x+w/2,pos.y-h/2,pos.z),Vector2f(texEntry->U2,texEntry->V1));
            VBO.Add(Vector3f(pos.x-w/2,pos.y-h/2,pos.z),Vector2f(texEntry->U1,texEntry->V1));
            
            VBO.Add(Vector3f(pos.x+w/2,pos.y+h/2,pos.z),Vector2f(texEntry->U2,texEntry->V2));
            VBO.Add(Vector3f(pos.x-w/2,pos.y-h/2,pos.z),Vector2f(texEntry->U1,texEntry->V1));
            VBO.Add(Vector3f(pos.x-w/2,pos.y+h/2,pos.z),Vector2f(texEntry->U1,texEntry->V2));
}

He does some addition and dividing. "Pos" struct is (X,Y,Z) position to draw ped at, "W" is ped sprite width (NPOT).

I should try to make minimal app with this VBO and use my texture, maybe it actually solve this.
Im not sure.



EDIT

Ok, i think you are correct that this actually should be like this.
if you look at the ped above, it's centered. I tried some other peds and objects.
They seem to be centered enough.

I think that's it. It's just supposed to be like that.

Another ex:
Black borders but c. car is centered:



Thank you for helping.

[phibermon]

it looks like VBO in this example is a class he's created that constructs a GL VBO. his sucessive .Add calls are equivlent to your glvertex3f + gltexcoord2f calls, pos would be the sprite position on the map, w/h are the size of the quad that is rendered (note that he's actually creating two triangles here to make a quad.

but without knowing how his w+h are calculated and how the texEntry U1,V1,U2,V2 values are created, I can't give you any more information.

I've looked up on GTA files and rendering, I've found :

http://brain.wireos.com/?p=1673

A GTA 2 .Sty parser (and looking at that, are you parsing .sty files or have you converted them to textures you're using?)

and

http://gtamp.com/gta2/tools/

which contains a link to gta1-gta2-tool-source-code.7z released by jernej, inside that archive there's tons of code dealing with GTA1 and 2 data files.

I can't be certain without extensive study, but his STY editor does seem to suggest that there's additional offset information that comes with each sprite defintion.

[phibermon]

Only just saw your Edit, brilliant I'm really happy that I could of helped but feel free to post any further questions you might have and I'll do my best.

And I also know why there's black borders, there's additional animations for sprites, like car doors opening etc and if you were to go thru all the images (such as a ped walking) you'd probably see that all the pixels get used eventually across all the frames of animation etc

because animations must be stored in an array of images of exact dimensions, you'll have some frames that don't seem centred etc

[hwnd]

The brain.wireos sty reader is the one i use because he wrote this for me. And the code is so fast.

And thanks to this im able to render these sprites and stuff. But yes for emergency lights on cars etc, its a bit complicated but nothing impossible i guess. Atm i just want to render sprites/game objects on map.

But npot textures scared me. But now it seems OK.

Btw, just for the info, from the STY docs:

"5.1 Sprite Graphics Data
Sprites are stored as uncompressed 256-colour graphics upto 32 pages of 64K each. Each page is 256x256 pixels. The maximum size of a sprite is 128x64 and the minimum is 2x2. The width and height can have any value inbetween as long it is an even number."

[User137]

I know you are still using bit of your own texture loading, but i'll still give short example how nxPascal would do NPOT. You can download Delphi source and exe here. I made it as simple as possible but based on the game template:
https://docs.google.com/file/d/0B7FI...NlYWRvLW8/edit

There is no scaling of any kind, demo loads in 119x53 texture with 12 patterns in 6x2 grid. There is SkipWidth and Height of 1 because i drew it quickly with a green 1 pixel wide grid, which i had to take off because bi-linear rendering makes the grid show when drawn.

To summarize key points:

n:=tex.AddTexture('anim', GetPath('textures\anim.png'), true);
tex.SetPattern(n, 19, 26, 1, 1);
...
pattern:=(pattern+1) mod 12;
nx.DrawRotate((i mod 30)*15.0+20, (i div 30)*15.0+20, pattern, 0, 0.5, 0.5);
// I drew 1000 of these patterns, 30 per row, each centered around coords 0.5, 0.5 of the pattern, that's exactly in the middle.

[phibermon]

well filtering a texture atlas is always going to give you issues like you describe, keeping a transparent border around sub-textures is the usual generic solution, GL_CLAMP_TO_EDGE won't help you as you're not necessarily addressing the texture up to it's edge for all sub-images.

Caveats you must accept for the performance gains of a texture atlas.

I'm working in OpenGL 4.x currently and I don't support anything less than 3. I did that specifically because I didn't have to jump through all the hoops. I'm guaranteed to have NPOT support, guaranteed to have uniform buffers, tessellation stages on 4.x hardware blah blah blah

it's so much less of a headache than GL1.x GL2.x, GLES etc

And it's only a matter of time before GL2.x is about as common as Glide (3DFX) plus the next itteration of GLES will be in the GL3.x/4.x style.

If you're working on projects with epic timescales, you've got to plan 3/4 years ahead. If you don't then you end up like GLScene with almost no ability to switch to the current versions (GL3 is old now) except a significant re-write of many parts.

I mean look at all those epic game titles from the 90s, games coming out in 1997/98 that ran in DOS!

You've got to think ahead, I'd advise anybody to throw GL1.x and 2.X out of the window immediately (pun intended) and work in a GL3 core profile at the very least. Doesn't matter if your card doesn't support it, that's what Mesa is for. And if you miss immediate mode functions for debugging purpouses, use a delphi/lazarus form with your window to display stuff or just re-implement immediate mode functionality on top of VBOs and shaders, I did that and never looked back.