Hi Bruce,<br><br>transparent colours in therion are transparent only between scraps, but are completely opaque within the scrap. The method used is a "transparency knockout group": all objects in the group are drawn as if they were opaque and only the topmost color is drawn transparently over the lower scrap (Adobe PDF Reference describes this method in detail).<br>
<br>I don't remember why we don't support local transparency too, but most probably because there might be disturbing interference between e.g. transparent water and transparent scrap background.<br><br>Martin<br>
<br><br><div class="gmail_quote">On Sat, Nov 10, 2012 at 9:55 AM, Bruce <span dir="ltr"><<a href="mailto:bruce@tomo.co.nz" target="_blank">bruce@tomo.co.nz</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">Taking inspiration from Martins recent post on
transparent colours I thought I might make my custom point water and area water
transparent, or at least behave better with ‘transparency on’ than
the standard non-transparent colours. Alas the code compiles without fuss,
but the result is identical to the result when using standard (opaque) colour
definitions.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">In my layout I have, in the order called…<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">Define the area and point water <u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">def p_water (expr
pos,theta,sc,al)=<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">
U:=(.425u,.3u);<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">
T:=identity aligned al rotated theta scaled sc shifted pos;<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> pickup
PenD;<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">
p:=fullcircle xscaled (1.2u) yscaled (0.8u) randomized (0.1u) rotated
uniformdeviate (-45);<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> %if
known colour_water_bg: thfill p withcolor colour_water_bg; else: thfill p
withcolor white; fi; <u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> <span style="background:yellow">if known tr_colour_water_bg: thfill p
withtransparentcolor tr_colour_water_bg; else: thfill p
withtransparentcolor tr_white; fi;</span> <u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> thfill
p withpattern pattern_water; %%% withcolor black; %but with failed
attempt at black hatch<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> thdraw
p; %outline<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">enddef; <u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">def a_water (expr Path) =<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> T:=identity;<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> % thclean Path;<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> pickup PenD;<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> % if known
colour_water_bg: thfill Path withcolor colour_water_bg; else: thfill Path
withcolor white; fi; <u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> <span style="background:yellow">if known tr_colour_water_bg: thfill Path
withtransparentcolor tr_colour_water_bg; else: thfill Path
withtransparentcolor tr_white; fi;</span> <u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> thfill Path
withpattern pattern_water; <u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> %%thdraw
Path; %outline, not needed as area drawn is defined by line border anyway<u></u><u></u></span></font></p>
<p class="MsoNormal" style="margin-left:36.0pt"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">enddef;<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">Optionally define the colours (the tr_white not
needed as it is defined in the default distribution)<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> !color
colour_water_bg; %! forces interpretation as metapost<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> colour_water_bg
:= (0.86,1,1); %light blue<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> def_transparent_rgb(tr_colour_water_bg,
0.86, 1, 1);<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">and then<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">
transparency on <u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"> opacity
50 <u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">Everything in these examples is in a single scrap.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">I have checked that my code is being used by changing
the colours, for example from tr_white to tr_black etc and these changes are
reflected properly, it’s just that they are not transparent.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">In Adobe Reader it looks like this (below) (the water
on the right is definitely not transparent – the rock place bottom is
obscured)<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">Adobe also seems to make the colours and line weights
different to the others – incorrectly I suspect.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">If I run this example with transparency off (but
still using my custom transparent colours), the result is identical EXCEPT all
the colours are much more intense.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><img src="cid:image004.gif@01CDBF8E.0FE46520" height="329" width="352"> <u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">In Foxit Reader it looks like this (below) with
transparency on (Foxit always makes everything transparent when transparency is
on, so it is not really a test) So again, no difference whether using
transparent colour definitions or non-transparent.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">When transparency is off, it looks exactly the same
as in Adobe.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><img src="cid:image005.jpg@01CDBF8E.0FE46520" height="315" width="350"><u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">In Evince it looks like this (after about 1 minute to
load the modest file-Evince also behaves just like Foxit, but has a problem
with hatches extending out into the bounding box as well)<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><img src="cid:image006.gif@01CDBF8E.0FE46520" height="326" width="349"><u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">So as you can see the viewing software may be masking
(a little) what Therion is really trying to do, however it seems to be somewhat
like either almost everything is opaque, or almost everything is transparent,
and the promise that transparent colours seem to offer some more control cannot
be realised?<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">What I would like is something closer to what Adobe
is rendering (with the finer line work of Foxit) , but with the ‘rock-border
place bottom’ showing through the water when the water is defined with a
transparent colour.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">I guess when transparency is on, water and sump
should always be transparent to underlying objects, but closed rock-borders and
the rocks in ‘area blocks’ should never be. After all that maybe
I need to be looking at the rock-border and area blocks definitions?<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">Any ideas why transparent colours make no difference
at all?<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">Any ideas how to make the rocks in area blocks and
closed rock-borders opaque to any objects (in the same scrap) beneath them
without messing up the transparency of other objects?<span class="HOEnZb"><font color="#888888"><u></u><u></u></font></span></span></font></p><span class="HOEnZb"><font color="#888888">
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ">Bruce<u></u><u></u></span></font></p>
<p class="MsoNormal"><font face="Arial"><span style="font-size:10.0pt;font-family:Arial" lang="EN-NZ"><u></u> <u></u></span></font></p>
</font></span></div>
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