Most likely the iPhone GLES simulator is just the native OpenGL renderer with additional error checking and some functions removed (immediate mode, etc).

So your code will be running full speed on...

They are just uniforms, the driver updates them for you.

It's possible that the user has their display set to 16 bit color which would cause ChoosePixelFormat to return a Microsoft software accelerated rendering context.

The equivalent vertex shader code for that glTexGen setup is:

gl_TexCoord[0].s = dot(gl_Vertex, gl_ObjectPlaneS[0]);
gl_TexCoord[0].t = dot(gl_Vertex, gl_ObjectPlaneT[0]);
gl_TexCoord[0].p =...

GLint value;
glGetIntegerv(GL_ACTIVE_TEXTURE_ARB, &value)

One possible implementation would be to use a 1x1 RGBA cubemap like this:


GLfloat faceData[] = { 1.0, 0.0, 0.0, 1.0,
1.0, 0.0, 0.0, 0.0,
...

From the OpenGL spec:
MAX_TEXTURE_COORDS is 8 for the GeForce 8800 so you will see an OpenGL error if you specify a value greater than GL_TEXTURE7.

The glClientActiveTexture function only needs...

1) The TEXUNITn semantic when specified after a sampler definition specifies which texture unit you are sampling from. You don't need to use cgGlSetTextureParameter, it is a convenience function.
...

Yep, it's just a regular matrix, you can put whatever data you want in it.

FX Composer 2.0 will let you write GLSL shaders, yes.

Yes, the Cg 1.5 compiler can do this.

Most likely the for loops end up executing more than GL_MAX_PROGRAM_EXEC_INSTRUCTIONS_NV instructions and at that point, the GPU sets the finally color to whatever is in the R0 register (likely the...

Do you mean using the vertex buffer object functions added to OpenGL 1.5 (glBufferData, glGenBuffers, etc...) vs using the ARB_vertex_buffer_object functions (glBufferDataARB, glGenBuffersARB,...

You shouldn't have any problem using geometry shaders with VBOs, what is the exact error your seeing? Are you getting a GL_INVALID_OPERATION when you call glDrawArrays?

DDS is just a file format, it can store uncompressed textures, DXTC/S3TC (same format) textures, cubemaps, 3D textures, textures with mipmaps, etc...

The S3TC/DXTC texture compression algorithm...

You can get this information by using glGetTexLevelParameter.

Create the texture as normal, upload the image data via glTexImage*, then do something like this:
For GL_ALPHA_FLOAT16_ATI you...

Internal assembly error is generally a compiler bug. Have you tried the latest NVIDIA drivers? It's possible this has already been fixed.

1) You do not have to call glEnable(texture target) when using shaders, only when using the fixed function pipeline.

2) Your vertex shader would need to compute your texture coordinate like so:
...

With the fp20 profile the texture coordinates and texture image units are bound together (i.e. you must use TEXCOORD0 to sample from TEXUNIT0, TEXCOORD1 to sample from TEXUNIT1, etc).

To make your...

You can set the uniform using the profile specific uniform function:

arbvp1/vp40: glProgramLocalParameter4fARB(GL_VERTEX_PROGRAM_ARB, 0, ...);
vp20/vp30:...

Cg compiles to assembly text for various OpenGL extensions and I believe if the extension supports it, you'll be able to use global uniforms.

Half data types just work for profiles that support...

You should be seeing a GL_INVALID_ENUM error from this call:
When the format parameter is set to GL_DEPTH_STENCIL_EXT or GL_DEPTH24_STENCIL8_EXT the type must be GL_UNSIGNED_INT_24_8_EXT.

To recompute eye linear texture coordinates the same was as the fixed function you need to do this:
which can be simplified to:
given the values you set for your eye plane.

You are not required to use power of 2 textures for vertex texturing, the GL_ARB_texture_non_power_of_two extension allows you to load NPOT textures for all texture targets (1D, 2D, 3D, etc).

Of...

You can assing a uniform to a specific constant register using the Cn semantic.

For example:

uniform bool bAddAmbient : C21;

1.5 allows you to take a Cg file and compile it into GLSL vertex and fragment shaders.

For example:

cgc -profile glslf -entry waterfrag water_frag.cg -o water_frag.glsl