Well, I've never used glEnableVertexAttribArray, just old-school vertex/normal/uv arrays.

I'm trying to track down a rendering problem that only seems to happen with Intel graphics cards. (Objects that should be colored sometimes appear white.) I discovered that if, at a certain point...

OK, maybe I can answer my own question about why use PBO if you're going to use threads. I guess the simpler approach would not work well if you have only one processor, because while...

yooyo, thanks, but there are a couple of things that still confuse me.

First, when I started this topic, I referred to an example in the PBO specification, and that example did not use threads. ...

I managed to get Visual Studio to build me a DLL using the SSE2 memory copy function. I made sure it was compiled with optimizations and intrinsics, and verified that it was taking the SSE2 code...

Hmm, Visual Studio is also giving me an error on __sse2_available. I suppose I need to include some header, but what? My Google-fu has failed me.

Looks like my old CodeWarrior compiler can't cope with this. It has never heard of __sse2_available, and gave a bunch of "register spilled" warnings that I didn't know how to deal with. I commented...

I guess I wasn't clear... when I said "the thread at your first link refers to code at a dead link", I didn't mean that your link was itself a dead link, I meant that the thread is talking about code...

I tried the AMD assembly code, and it may be a tad faster, say 12.9 ms rather than 13.5.

D'oh! I now see that CopyMemory is a macro defined to be RtlCopyMemory, and RtlCopyMemory is a macro defined to be memcpy! So maybe Microsoft doesn't have any memory-copy function in a DLL, just a...

Thanks, but the thread at your first link refers to code at a dead link, and an Intel library that was then available for free but is no longer. The second link is designed for AMD processors, and...

I did leave out some relevant details. My image data actually contains 2 side by side images, and I'm uploading each half to separate textures. I realize now that I can be a little smarter and...

Now I'm more confused... I did the timing again, with a somewhat bigger image size (1920 x 1080) and got very different results: about 13.5 ms for the memcpy, but only 0.1 ms for glTexSubImage. ...

That's what I've read, but as stated above, that's not what I measured. So even if I could do the memcpy in zero time, I still wouldn't have a win.

In the ARB_pixel_buffer_object specification, Example 2 shows a way to upload texture data using a PBO. The basic outline is that you create a PBO of the right size, map the PBO into memory, copy...

It's free and does the job, what's not to like?

if you happen to be on a Mac, the Apple developer tools include an app called "OpenGL Driver Monitor" that can show video card capabilities, but I...

Cool, the derivative trick works, so now I can get flat shading on any machine that supports GLSL at all. Thanks!

Interesting. I assume you mean it's been shipping on the Mac for some video cards, as I see it on one of my Macs and not the other (both running Snow Leopard).

Ah. Looks like I'm out of luck, because I'm on the Mac, and so far Apple only supports GLSL 1.20. The "flat" qualifier came in with GLSL 1.30. Thanks anyway.

How would a shader program emulate glShadeModel( GL_FLAT )? I'm not using vertices with varying colors, so it's a question of how to make the lighting constant across a triangle.

I've heard that theory, but in practice I've found that I sometimes need glFlush. Maybe certain drivers don't do the right thing.

I agree about using the back buffer. If you want to try glFlush, you should call it before glReadPixels.

I believe it would be glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA ).



Yes.

When glfreak says "centered in screen space", I assume he/she means that the distance from the leftmost rendered pixel to the left edge of the screen equals the distance from the rightmost rendered...

Thanks a lot! It took a while to get here, but I think this is what I was asking for in my first post. (Come to think of it, I guess I shouldn't have had that 1/n in there. Some part of my brain...