4.5 The programming window

To pop up the programming window, click on File=>Program in nip's main image processing window. The window shown in Figure 4.14 should appear.

Figure 4.14: Programming window

Each of the things down the left of the program window (the icon is supposed to look like a tool box) is a toolkit. Each toolkit is a text file containing a set of definitions in nip's programming language. See Chapter 6 for details on the language.

If you open a toolkit, nip shows all of the definitions in that file (the icons are supposed to be spanners, I think). If you click on one of these nip shows the source for that definition in the main part of the program window. After editing a definition, click on File=>Process text to make nip read what you typed, compile it, and update itself.

Click on File=>New=>Tool to add a new definition to a toolkit, click on File=>New=>Toolkit to make a completely new toolkit. You can also right-click on tools and toolkits to get a context menu, and you can left-drag tools to move them around within a toolkit or between toolkits.

Some toolkits are loaded from files when nip starts up, others are built from the VIPS operation database (for example, _arithmetic), and one (called _builtin) contains the functions that are built into nip. If you select a tool and then click on Help=>Documentation for this tool, nip will try to display the relevant section from the VIPS manual in your web browser. Currently, this works only for things in the VIPS operation database: try _arithmetic=>im_add, for example. There's a section in the Preferences workspace to control which web browser nip uses and how it asks for a page.

Toolkits and tools whose names begin with an underscore character are not displayed in the menu bar down the right hand side of the main nip window. The idea is that they represent little utility functions, rather than stuff a user might be interested in. See §6.12.1 for more stuff on how tools and toolkits are displayed.

A final sort of tool has a floppy disc icon next to it. These tools represent scraps of workspace which are loaded when that menu item is selected, see §4.4.5. You can edit them by right-clicking and selecting the Edit item from the context menu.

You can have several programming windows open at the same time (often useful, if confusing). The Edit menu lets you search for patterns across all definitions. The Go to definition of item jumps to the definition of a symbol.

The Debug menu has items which open a trace window (use this to track the actions taken by nip's reduction engine) and which report on unresolved symbols.