Extensions

How do you set up and use extensions like wertex weights etc.

The supported extensions are listed in glext.h, which is in OpenGL.framework on MacOSX.

The list for MacOSX 10.1 is:

#define GL_APPLE_specular_vector 1
#define GL_APPLE_transform_hint 1
#define GL_APPLE_packed_pixel 1
#define GL_APPLE_client_storage 1
#define GL_ARB_transpose_matrix 1
#define GL_ARB_multitexture 1
#define GL_ARB_texture_env_add 1
#define GL_ARB_texture_env_combine 1
#define GL_ARB_texture_cube_map 1
#define GL_ARB_texture_env_dot3 1
#define GL_ARB_texture_compression 1
#define GL_ARB_multisample 1
#define GL_ARB_texture_border_clamp 1
#define GL_EXT_clip_volume_hint 1
#define GL_EXT_rescale_normal 1
#define GL_EXT_blend_color 1
#define GL_EXT_blend_minmax 1
#define GL_EXT_blend_subtract 1
#define GL_EXT_compiled_vertex_array 1
#define GL_EXT_texture_lod_bias 1
#define GL_EXT_abgr 1
#define GL_EXT_bgra 1
#define GL_EXT_texture_filter_anisotropic 1
#define GL_EXT_paletted_texture 1
#define GL_EXT_shared_texture_palette 1
#define GL_EXT_secondary_color 1
#define GL_EXT_texture_compression_s3tc 1
#define GL_EXT_texture_rectangle 1
#define GL_SGIS_texture_edge_clamp 1
#define GL_ATIX_pn_triangles 1
#define GL_NV_register_combiners 1
#define GL_NV_blend_square 1
#define GL_NV_texgen_reflection 1
#define GL_IBM_rasterpos_clip 1

The list for MacOS9 is shorter.

Note that just because an extension is in this list doesn’t mean it’s actually available on the video card you’re using. You always have to check the GL extension string at runtime to determine what you can actually use.

Other than checking the define above at compile time and the extension string at run time, there is nothing else you need to do on the Mac – you can just call the extension functions as any other OpenGL function.

So there are no Vertex Weights then ?? How do you do skinning in HW on MAC ???

You file a feature request to Apple that this extension be exposed (which they ignore, because it is not sufficiently universal).

Then you wait for GL_ARB_vertex_program later this year. Hopefully they’ll provide a software implementation of that, too, so you only have to write one set of code.

This topic was automatically closed 183 days after the last reply. New replies are no longer allowed.