What makes me wonder is, how LINE_ADJACENCY is related to rendering cubes.
I would suggest either
a) create a geometry shader that takes GL_POINTS and outputs the cubes as single triangle strip...

You probably can't retrieve the polygon fragments that came out of the fixed function clipping the GPU did. Most of the time it doesn't even clip them, but just rejects fragments outside the frustum...

http://www.cs.umd.edu/gvil/papers/av_ts.pdf (first page)

Read up on glValidateProgram and how bad shader state can cause drawing commands to throw GL_INVALID_OPERATION.
In your case I guess, one of your samplers2D uniforms shares the same texture unit as...

To quote the 4.3 specs:


@kingc8: don't know what your actual bug is, but it pretty much sounds as if the buffer you provide to GL is not as big as it should be. What are the dimensions of your...

The GL 1.1 functions are being exported by opengl32.dll. You may call GetProcAddress() instead to resolve those symbols, if you really need to.

There is no way to control the line thickness from inside a shader. glLineWidth() lets you set a uniform thickness for all line segments, though.

The only way to achieve varying line thinkness...

Try using two FBOs: one with the normal texture attached and one with a renderbuffer of the same format attached. Don't call glReadPixels on the texture-FBO. Instead, use glBlitFramebuffer to blit...

Those cards are probably only supported on very old drivers with many bugs in them :-)

Instead of using GL_GENERATE_MIPMAP you might also use
glGenerateMipmapEXT() (if EXT_framebuffer_object is...

You should read this:
http://archicad-talk.graphisoft.com/files/autodesk_inventor_opengl_to_directx_evolution_788.pdf

Can you cite the corresponding paragraph from the specs?
There is language talking about sampling from incomplete textures, but querying the size of such a texture has not been deemed undefined.

That is probably an unfortunate combination of application error (providing an incomplete texture) and a driver bug (not correctly returning the size of an incomplete texture).

One thing I see is that you don't provide a normalized L into your half vector calculation:

float3 H = normalize( V + L );

Also, you seem to decode the Normal, but don't normalize it to have...

Choosing the same gradient for s and t across all polygons counteracts anisotropic filtering :-) You may as well disable it for the shadow map.
...

Not necessarily! At least not alone. The footprint is heavily dependent on the gradients used to sample the texture. In principle what you're seeing is the same problem as with mipmaps: jumping...

The link doesn't work for me.

A shot in the dark, but I have two ideas:
1. It might be that you're sampling slightly over the edge of the cascade's shadow texture. Try setting GL_CLAMP_TO_EDGE as...

Try to do validation after you have assigned sensible values to all sampler uniforms. To quote the specs:

The only way to pass data, created in the vertex shader, to the fragment shader is varyings. The 'flat' qualifier ensures that there's no interpolation.

I have several objections, though.
1. How...

I think, this doesn't apply to your scenario, as you do downsampling and not blitting between two MSAA buffers.

What this sentence means is that if you blit from MS buffer A to MS buffer B and try...

AFAIK, each sample is just equally weighted. So, if you got 4xMSAA, each sample gets a weight of 0.25.

There is a common misconception about PBOs: they don't magically make image transfers _faster_. They don't help increasing the available bandwidth. PBOs help to do image transfers _asynchronously_,...

Try using GL_DEPTH24_STENCIL8 as your renderbuffer format. When blitting stencil or depth values, the corresponding pixel formats of source and destination MUST match. You might argue that the...

Let me guess, ATI card? Their drivers have a bug that won't allow you to create SRGB renderbuffers.
They know about it for months now, but didn't care to fix.

On this card (Intel, eh?) you have no other chance than to create the next larger power-of-two texture and use a rectangular part of it. There seems to be no support for real render-to-texture also....

You can use WGL_NV_copy_image to transport image data between contexts on separate (NVidia-)GPUs.