Custom application

To write a custom application the programmer must supply the following three routines:

• myinit(): called once at the start of the application. Recommending for fetching parameters, reading data from files, initializing display variables, and adding custom controls.
• mydraw(): called at the start of the program and each time a display control is changed. This routine redraws the entire display object in user coordinates. The drawing is initially scaled to fit the window.
• mycommand(command,value): Receives all command codes and optional values.

(Customization is the same as SEP-61 with one major change: The file mybutton for configuring control interfaces has been replaced by calling UICommandAdd() within myinit().)

These are the graphics and user interface routines available to the custom routines:

        *GraphicsSetRotate (x,y,z)
        *GraphicsSetScale (x,y,z)
        *GraphicsSetShift (x,y,z)
        *GraphicsSetLight (x,y,z)
        *UICommandAdd (com_type,control,label,code)
        Erase ()
        PointList (vert,nvert)
        LineList (vert,nline)
        PolyLine (vert,nvert)
        Polygon (vert,nvert)
        *PatchList (vert,npatch,patch_size)
        *Mesh (vert,nvert,patch,npatch,patch_size)
        *Raster2D (where,width,height,array)
        *RasterList (where,width,height,array,npatch)
        Text (where,text)
        TextAlign (halign,valign)
        Fat (fat)
        Color (color)
        *Shade (shade)
        
        com_type = LABEL, TEXT, MENU, ITEM, SLIDER;
        control = MENUBAR, CONTROL3D, CUSTOM;
        Vector3D vert[], where[];
        string label, code, text, color;
        float x, y, z, width, height, shade;
        int nvert, patch[], patch_size, npatch, fat, width[], height[];
        byte array[][];

        * added or changed since SEP--61