On 12/6/2012 7:05 PM, Aditya Mahajan wrote:
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.
not so efficient but it shows a bit what bitmaps can do
\starttext
\startluacode
local format = string.format
local concat = table.concat
function document.TestBitmap(nx,ny)
nx = math.round(nx/65536)
ny = math.round(ny/65536)
nx = 2 * math.round(nx/2)
ny = 2 * math.round(ny/2)
local r = { }
local dx = 255/nx
local dy = 255/ny
for i=1,ny/2 do
local n = i*dy
local c = { }
for j=1,nx/2 do
c[#c+1] = format("%02x",j*dx+n)
end
for j=nx/2,1,-1 do
c[#c+1] = format("%02x",j*dx+n)
end
c = concat(c,"",1,nx)
r[#r+1] = c
end
for i=ny/2,1,-1 do
local n = i*dy
local c = { }
for j=1,nx/2 do
c[#c+1] = format("%02x",j*dx+n)
end
for j=nx/2,1,-1 do
c[#c+1] = format("%02x",j*dx+n)
end
c = concat(c,"",1,nx)
r[#r+1] = c
end
r = concat(r,"\r",1,ny)
figures.bitmapimage {
data = r,
xresolution = nx,
yresolution = ny,
}
end
\stopluacode
\defineoverlay
[BitMess]
[{\scale
[width=\dimexpr\overlaywidth+2ex,height=\dimexpr\overlayheight+2ex]
{\ctxlua{document.TestBitmap(\number\dimexpr\overlaywidth,\number\dimexpr\overlayheight)}}}]
\framed
[width=10cm,
height=10cm,
frame=off,
background={BitMess,color},
backgroundcolor=white]
{test}
\stoptext
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