#241 dtAnim improvements

[Peter Amstutz]

Attached are several fixes to dtAnim which I hope will be considered for inclusion into Delta 3D:

- Adds ReleaseGLObjects() to dtAnim::Cal3DDatabase and dtAnim::Cal3DLoader
This is necessary to reset OpenGL handles if the application needs to re-create the OpenGL context, for example when reconfiguring the OpenGL window.

- Fixed a couple of bugs that prevented Cal3D hardware submeshes for working properly.&nbps; Because the space available to store uniforms in the shader is limited and can be exceeded if a character has many bones, cal3d can split a single character mesh into multiple meshes affected by a subset of bones.&nbps; This

- Bone weights and bone indices are denoted in shader as vertex attributes rather than packed into texture coordinates.

- Adds VBO_Offset_ constants instead of literal offsets so the layout of the vertex buffer can be more easily modified

- Added support for tangent space vectors to be associated with vertices.&nbps; This is necessary to support normal mapping in the fragment shader.

- Provides an updated hardware vertex shader for characters based on these changes

[Peter Amstutz]

[Anonymous]

Originally by: r.erik.johnson

Hi, thanks for the changes!

I hate to ask, but can you re-attach your changes as an SVN patch file? It's troublesome trying to figure out which SVN revision your changes came from. Having a SVN patch is *much* easier and less error prone when it comes to validating your changes.

Much appreciated,
Erik

[Peter Amstutz]

Here you go.&nbps; Creating the patch also allowed me to go back and clean it up a bit.

[Peter Amstutz]

[Anonymous]

Originally by: r.erik.johnson

Perfect, thanks. It will take awhile to digest the changes and verify everything is backwards compatible, but we'll get started on it.

Thanks,
Erik