On 12/6/2012 7:05 PM, Aditya Mahajan wrote:
On Thu, 6 Dec 2012, Peter Rolf wrote:
Hi all,
a first version of the 'drops'-module (MkIV only) is available at
https://www.wuala.com/indiego/public/ConTeXt/drops/?key=caiCGLasLFmJ
Taken from the included documentation..
[..]
'drops' is a small extension for ConTeXt, that allows you to add drop
shadows to rectangular regions (so called boxshadows). A working
installation of ImageMagick (IM) is required to create the shadow
graphics. The supported color spaces are CMYK, RGB and Gray, the file
formats are limited to PNG and JPG.
[..]
Read the manual for detailed information.
Nice.
The attached example is just a small test file for the 'rotation'
parameter (a compensation for the object rotation, so that the shadow
stays at the given direction). You will find other examples in the
documentation and there is also a 'pile' example with the complete
source. The 'presets' pdf contains the predefined setups for different
shadow (or frame) types and it's source is a good starting point for
your own experiments.
This is a first draft, but most things work quite stable. If you want to
help, test as much as possible. :-)
*You need a recent version of ImageMagick for this module.*
I always thought that shadows were possible to do in PDF (after all TikZ
does it using some type of PDF primitives). Since you are the PDF
expert, I am interested in knowing why you choose to go the ImageMagic
route.
Some tricks are possible with functions that repeat bitmap patterns in
clever ways but I lost the code that does it. If Peter can tell us what
graphics are needed we can also make them directly as the img library
has that possibility (we use it in mojca's gnuplot module)
Anyhow, as you are the math magician, here's a start:
\starttext
\startluacode
local format = string.format
function document.TestBitmap(nx,ny)
local r = { }
local s = 1/nx
for i=1,ny do
local c = { }
for j=1,nx/2 do
c[#c+1] = format("%02x",j*s*255)
end
for j=nx/2,1,-1 do
c[#c+1] = format("%02x",j*s*255)
end
c = table.concat(c,"",1,nx)
r[#r+1] = c
end
r = table.concat(r,"\r",1,ny)
print(r)
context(r)
end
\stopluacode
\startMPcode
draw
textext("\bitmapimage[x=100,y=100,color=gray]{\ctxlua{document.TestBitmap(100,100)}}")
xsized 10cm ;
\stopMPcode
\stoptext
So, what's needed is some edge related jugling.
Hans
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