Re: textures in Lout

[Mark Summerfield]

On Thursday 31 October 2002 23:51, Jeff Kingston wrote:
> The next release of Lout, due out in the next few weeks,  will
> have textures (known in PostScript as patterns).  When requested,
> these cause areas that would otherwise appear in solid colour
> to be textured.
>
> Wherever there is currently a "paint" option there will be a
> corresponding "texture" option.  There is also a "@Texture"
> symbol analogous to "@Colour".
>
> If you are interested in textures, please take a look at
>
>     ftp://ftp.it.usyd.edu.au/jeff/lout/textures.ps
>
> and let me have your comments and suggestions.  This is an excerpt
> from the next version of the User's Guide, describing how to get
> textures.

The text seems clear and straightforward to me. I'd suggest you change
"You can use the CMYK system if you know what that is" to "You can also
use the CMYK system". Also "Here now is the list of all" to "Here is the
list of all the".

> One area I would welcome guidance on is the particular set of
> textures that people need easy access to.  I've implemented
> stripes, dots, chessboard, brickwork, and a texture made of a
> sequence of characters.  All textures can be shifted, scaled,
> and rotated.  It would be easy to add more textures.  Is there
> a standard set of textures?

The ones I'm aware of are:
- horizontal | lines
- vertical - lines
- diagonal / lines
- diagonal \ lines
- squares
- criss-cross X lines
- squares with a diagonal line (from OpenOffice; see attached .png)
- pin-cushions (from Kontour; see attached .png)

There are also gradients, i.e. draw a line in the start colour,
gradually drawing successive lines to get closer and closer to the
finish colour.

> Another area we could discuss is the degree of support for
> patterns in PostScript implementations.  My printer is fine
> but my on-screen viewer (gv circa 1997) does not show patterns.

I use gv when roughing out my pages, and acroread when I want to do
final tweaking, because acroread seems to be more accurate. Like you I
can't see the textures in gv, so I haven't been able to see the textures
at all! Which viewer do you use to see them with?

BTW Is there any chance of having a line colour option for lines (e.g.
diagram link lines); I have had the need for coloured lines arise a few
times now.

Thanks.

PS When I use ghostscript to convert textures.ps into PDF, I get the
following:

% ps2pdf textures.ps textures.pdf

Unexpected interpreter error -8.
Error object: (f80)op(0)0x809e334
Operand stack at 0x829bc18:
0x829027c: 0x12 str  -nLwrx--- 0x0003 0x0841e466 = ABC
Execution stack at 0x829bbdc:
0x8291be4: 0x0f oper --F---e-- 0x0000 0x08092e24 = %interp_exit
0x8291bec: 0x0d name --S---e-- 0x0361 0x0827fae8 = .runexec2
0x8291bf4: 0x03 file --G-rx--- 0x0001 0x0838eba0
0x8291bfc: 0x05 mpry --G-rxe-- 0x0006 0x082d0556
0x8291c04: 0x0e null --F---e-- 0x0003 0x0809ec40
0x8291c0c: 0x0e null --F------ 0xbfff 0x00000000
0x8291c14: 0x0b int  --F------ 0x0002 0x00000002 = 2
0x8291c1c: 0x0f oper --F---e-- 0x0000 0x0809e2dc = %stopped_push
0x8291c24: 0x03 file --G-rxe-- 0x0001 0x0838eba0
0x8291c2c: 0x05 mpry --G-rxe-- 0x0002 0x082d0e6c
0x8291c34: 0x06 spry --G-rxe-- 0x0002 0x082d0df2
Dictionary stack at 0x829bb84:
0x829b884: 0x02 dict --Gwrx--- 0x0000 0x082823d4
0x829b88c: 0x02 dict --Gwrx--- 0x0000 0x082e29b0
0x829b894: 0x02 dict --Lwrx--- 0x0000 0x0828be2c

I don't know enough about gs or postscript to know if this is just a
fluke or a problem.

-- 
Mark.

snapshot1.png
Description: PNG image

snapshot2.png
Description: PNG image