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- !Pottery
- ********
-
- Version 2.10 3rd September 1993
- By Richard Seago
- With routines from Rob Miller of BBC Acorn User (May 1990)
-
- Pottery is a program which allows you to create solids of rotation from a
- simple path defined by a few mouse clicks.
-
- Pottery has two windows. One in which you design the outline of your shape,
- and one in which you see what it looks like. The black one is the one which
- displays the shape. Because the program trys to use 256 colours it needs one
- of these modes to show the solid properly but it will try its best with the
- ColourTrans module in other modes and for printing (which produces best
- results with grey on a monochrome printer).
-
- The left hand side of the edit window contains the functions. The long,
- vertical, black line is the axis about which the solids are formed. The
- functions are (from top to bottom):
-
- i) Line - this draws a line on the edit window and a three dimensional
- shape in the draw window.
-
- ii) Move - this draws a faint line in the edit window and allows gaps in
- the picture in the draw window.
-
- iii) Grey - this word changes telling you which hue the currently selected
- colours will produce on screen.
-
- iv) Blue - this selects/deselects the blue component of the shape's
- colour.
-
- v) Red - this selects/deselects the red component of the shape's colour.
-
- vi) Green - this selects/deselects the green component of the shape's
- colour.
-
- The shape is entered as a continuous path. The path can be started at the
- top or bottom of the edit window, although the direction should be kept
- consistent through out because of the way that the shape is drawn. If the
- shape is drawn top down, in order to represent it correctly on screen the
- entire shape must be redrawn. This can slow things down for complex shapes
- so you may wish to turn off continous update. This option is in the 'Update'
- sub-menu which can be called up from the display window. There are no such
- problems if you draw bottom up, because the shapes are drawn in order that
- you might look at them from slightly above.
-
- Each segment has a seperate colour characteristic which is set before it is
- drawn. However, this can be changed by clicking with Menu on the point
- before the segment you wish to change the colour of. The selected segment
- will turn orange, the colour may then be changed via the Colour sub-menu.
-
- The last point in the path may be deleted or the entire path cleared. You
- may also drag any point with Adjust to change its position. If the program
- gets behind with updating the sprite, or you have turned off the continuous
- update option, you will have to select 'Update' from the draw menu to see
- the shape properly - this may take a few moments.
-
- The sprite is also completely redrawn when you click Select on the iconbar
- icon. Adjust will open the edit window only. The windows can be closed
- separately, and no data will be lost. Mostly, however, the program is self
- explanatory and should display helpful messages if something's wrong.
-
- The program can load and save in its own file format which can be treated as
- if it had just been created. The program can also save the 3D shape as a
- sprite file. The sprite will be saved as a sprite in whatever mode is
- currently in use.
-
- A second method of inputting shapes into !Pottery is from a shape
- description file in the form of a text file. This allows greater accuracy
- and can be editted as if it were an ordinary !Pottery file. However it
- cannot be saved back as a text file. The file does not have to be
- filetyped as text as long as the format of the file is correct. The text
- file should be of the format:
-
- Shape - This is a literal keyword and is case sensitive,
- it allows !Pottery to determine what sort of file
- has been loaded. It should always be the first
- word of the file and the file should be continued
- on the next line. Comments may be added but not on
- the first line of file. Any line whose first word
- is not one of those below, will be treated as a
- comment.
-
- gcol <colour> - This keyword allows you to set the colour of the
- path segments upto the next gcol. The <colour>
- parameter is a word from the following list:
- grey or white
- magenta
- cyan
- yellow
- green
- blue
- red
- clear or black (has the same effect as a
- move)
-
- move xxx,yyy - This keyword moves the drawing cursor to the point
- xxx,yyy. It is up to the user to ensure that the
- points lie within the viewing area, as no error is
- produced otherwise.
-
- draw xxx,yyy - This keyword draws from the previous cursor to the
- point xxx,yyy. The same constraints as above
- apply.
-
- All these commands (and parameters) are case sensitive - if they are not
- correct they will be ignored as comments.
-
- The print option uses RISC OS printer drivers. The printing of the shapes is
- not done from the sprite but from the outline so the best image possible
- should be produced on all printers.
-
- If you should change modes within the desktop, !Pottery will take a few
- moments to readjust, making sure that the sprite appears the same size and
- in the best colours possible. It will also warn you on entering (or starting
- up in) a non-256 colour mode that it cannot do its best when drawing the
- shape in that mode.
-
- The program is slightly naughty in that it uses RMA space to hold the
- sprite. This has never caused me any problems, and I don't see why it
- should.
-
- I can only say that the best way to get to grips with !Pottery is to try it.
- The sprites produced can be very effective.
-