Scoping rules for TEXMAP

[Allen Smith]

This is a proposal for changing the scoping rules for TEXMAP:

Add bolded text:

This texture will remain in effect until:

• An END is given within the current file
  
• The file in which the START is located ends
  
• A STEP command is reached
  

The texture will remain active when processing an included file unless overridden within that file.

and change:

The END command stops using the current texture and restores the previous texture to current status. This means that nested commands with START will form a stack of textures and the END command will pop those textures. However, END cannot appear in a different file from START. If an END command is given in a sub file without a START having been given in that same file, the END stops the use of a texture specified in a calling file, then that texture will be restored to use when the sub file is exitedhas no effect.

These scoping changes are critically important to implementing a hierarchical, object-oriented model to textures. It will be impossible for me to implement the standard as it currently exists. I already have a working implementation of the changes described above (*).

Allen

(*) with the exception of the stack behavior for nested textures, which is a simple enough addition