LWJGL 0.5 Released

[cfmdobbie]

HAHA! <-- the evil kind

Ah, that'll be a "Muhaha" then!


Yeah, I can't move the window around either.  But then again I don't have a mouse cursor when the window is focused, so how would I do so anyway?

[Matzon]

Yeah, I can't move the window around either.  But then again I don't have a mouse cursor when the window is focused, so how would I do so anyway?

I already fixed it, and committed it...

Since the window steals the cursor (as it should do) - you would have to alt+tab to loose focus, and you can then hold and drag the window. As soon as you let go, it will steal back the cursor - like any other app.

[alexz]

And I think his wrong, the framebuffer alpha is exactly used to blend the incoming pixel with the one already stored in the framebuffer. If not for blending, what's the use for alpha in the pixel format of the framebuffer?

- elias

I think if there is no alpha channel in the framebuffer the destination alpha is always 1 in the blending equations (BTW for widely used additive blending only incoming alpha counts).

And why do you need framebuffer with alpha channel? To blend it with underlaying windows (the original purpose for this, which came from SGI stations, IMO)?
For the gaming rendering to a texture with alpha channel is enough (to generate procedural fire texture, for instance)... That's why framebuffer with alpha channel is a rare thing for the modern game-oriented cards... or am I mistaken?  

Games published by our own members! Check 'em out!

[princec]

Using alpha in the framebuffer is a rare specialist case. I used it in the terrain demo to do some clever blending tricks. You basically don't need it for 99% of anything you do and you can't have it on 16 bit colour modes anyway in any cards available today, so it can have a bit of an impact on performance.

Cas

[elias]

Well then it makes much more sense that cfmdobbie don't have alpha on his card. I simply assumed that alpha bits were required to get any meaning from the blending equations.

- elias

[Micke]

Matzon; I guess the fixes you made aren't in the 0.5 release? So in order for me to get them (I'm as lazy as they come) I'll need to download some files specifically and recompile? (I know jack-shyt about CVS, apart from being this lazy) My co-developer's computer (W2K, Matrox G200) freezes every now and then when he's LWJGLing, and I figured this fix just might easy some of his rear entry pains... So! What do I do to get the latest?

/M

[Matzon]

I guess the fixes you made aren't in the 0.5 release?

correct, however we will most likely do a 0.5.1 release soon

So in order for me to get them (I'm as lazy as they come) I'll need to download some files specifically and recompile?

You need to download the source archive, get the latest org_lwjgl_display.cpp from CVS, setup a project to compile the files - all in all not 1 minute work - might want to wait for 0.5.1.

My co-developer's computer (W2K, Matrox G200) freezes every now and then when he's LWJGLing, and I figured this fix just might easy some of his rear entry pains...

Well Matrox isn't know for the best OGL support... but I really don't know why he is getting freezes (Garbage Collection?)

[starlord]

i have linux box with c/c++ compiler can i do
cross-platform build to windows with it?
i hate installing visual studio again and possibly download service packs

[elias]

I don't think that's possible - and even if it is I'd reckon it's much more painful than installing vs and service packs.

Btw, remember to install the latest SDK from microsoft, or else some of the lwjgl files won't compile! At least, that's what happened to me with visual studio 6 (probably not a problem on the .net version).

- elias

[cfmdobbie]

Well then it makes much more sense that cfmdobbie don't have alpha on his card. I simply assumed that alpha bits were required to get any meaning from the blending equations.

Yeah, that was my assumption too.  The reality (as Alex says) is that alpha bits requested when opening an OpenGL rendering context are only requesting alpha bits on the display surface itself.

I guess the side effect of this is that I won't be able to do things like pull RGBA data from the framebuffer with gl.readPixels - there's no transparency data there.

Games published by our own members! Check 'em out!

[Micke]

I think I'll just wait for 0.5.1 (Since I'm not the one having the problem ;-). And I wasn't very clear about the freezes - they're of the kind "I wouldn't know my computer was on if it wasn't for the noise and the power led". And yes, the Matrox drivers seem to be somewhere between totally useless and quite bad.

/M

[alexz]

I guess the side effect of this is that I won't be able to do things like pull RGBA data from the framebuffer with gl.readPixels - there's no transparency data there.

I believe that you are able to get RGBA from RGB framebuffer (gl.readPixels, gl.copyTexImage2D, gl.copyTexSubImage2D) but you're right: the pixels are opaque. To do the trick you need rendering to texture...  

Is it implemented in LWJGL 0.5 (I have not checked yet)?

[Orangy Tang]

I'm reasonably certain that render-to-texture won't allow you to get framebuffer/destination alpha if its not avalible normally. Regardless of that, render-to-texture should be possible with LWJGL, but its a real pain even in 'normal' openGL, i gave up after a while and resorted to using gl.copyTexSubImage from the framebuffer instead.

Theres rumour that theres some ARB extensions in the works to standardise render to texture, but they could be a while (although the new vertex buffer extension seem to have just appeared )

[elias]

(although the new vertex buffer extension seem to have just appeared )

You don't mean a standard way to do what NV_vertex_array_range, does, do you? If so, please link me :-) I really hate that ati and nvidia does the same in two completely different ways...

- elias

[Orangy Tang]

Why yes i do

http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/009033.html

[gregorypierce]

Okay folks,  the Mac port is being worked on but is currently moving very slowly as I'm wrapped up with CNN stuff. As soon as things calm down a bit, I will be able to give more information about status.

[princec]

As soon as things calm down a bit!!!
Our respective idiots-in-charge have started a war!
Ho hum.

Cas

[zparticle]

I'm trying to run the examples and everyone of them gives me an error similar to the one below. The machine I'm trying it on seems to only support 16 and 32 bit modes. Anyway I can get around this?

java.lang.Exception: Problem starting loop
       at BaseWindow.start(Unknown Source)
       at MovingStarBitmaps.main(Unknown Source)
Caused by: java.lang.Exception: Problem initialising Lesson
       at BaseWindow.createGLWindow(Unknown Source)
       ... 2 more
Caused by: java.lang.Exception: Failed to set display mode to 640 x 480 x 24 @72Hz 8bit alpha, 24bit depth, 8bit stencil

       at org.lwjgl.Display.create(Unknown Source)
       ... 3 more

[elias]

Some display mode fixes went into lwjgl 0.6 - you might want to wait for it. You aren't by any chance use win9x?

- elias

[zparticle]

nope all of the systems I have access to are Win2K

[princec]

zp, hack out the LWJGL classes from A.F. and use my .dll if you want most of 0.6.

Cas

[zparticle]

Okay I got it to run on my home machine, so that is good. However I am unable to locate the source code for the examples. I downloaded:

lwjgl-docs-0.5.zip
lwjgl-media.zip
lwjgl-source-0.5.zip
lwjgl-win32-0.5.zip

I'm I just blind? Where are the example .java files? Also are the examples supposed to be in windowed mode?

[Matzon]

However I am unable to locate the source code for the examples

Argh - apparently the src drop didn't include the examples dir :/ - I'll fix this later tonight.

Until then go to chmans excellent site:
http://chman-area.tuxfamily.org/

[zparticle]

Thanks for the pointer, that site will help a lot.

[whome]

What is A.F? Can I get hacked classes and .dll, please?

I have Matrox Millennium G400 and it tends to have problems with Java-based Opengl libraries. I could try a hacked version of v0.5.

I always get "stencil depth" error:
This application requires a greater stencil depth.
java.lang.Exception: Problem starting loop
at BaseWindow.start(Unknown Source)
at Blending.main(Unknown Source)
Caused by: java.lang.Exception: Problem initialising Lesson
       at BaseWindow.createGLWindow(Unknown Source)
       ... 2 more
Caused by: java.lang.Exception: Failed to set display mode to 640 x 480 x 32 @75
Hz 0bit alpha, 0bit depth, 8bit stencil
       at org.lwjgl.Display.create(Unknown Source)
       ... 3 more

zp, hack out the LWJGL classes from A.F. and use my .dll if you want most of 0.6.
Cas  

[zparticle]

A.F. == Alien Flux (a game by princec) look in the Your Games Here section for the latest Alpha release.

[javatypo]

when is 0.6 coming out anyway?

[elias]

Real Soon Now (tm) (I hope)

- elias

[javatypo]

awesome.. i hope it is more stable than b4

[whome]

I made few test with the following test program. Don't know whether it gives you gurus ideas about solving G400 problems.

http://www.java-gaming.org/cgi-bin/JGOForums/YaBB.cgi?board=share;action=display;num=1036791657;start=0

Is it possible to force A.F to use given displaymode, so that I could testrun it with my machine. Command-line parameter to force settings or something...