From c10f4c73e48da4f10be75634bdfd87e7ad2012ed Mon Sep 17 00:00:00 2001
From: =?utf8?q?Andr=C3=A9=20Wobst?= <wobsta@users.sourceforge.net>
Date: Wed, 24 May 2006 06:30:57 +0000
Subject: [PATCH] add a pipeGS method to directly pass the PyX output to
 ghostscript

git-svn-id: https://pyx.svn.sourceforge.net/svnroot/pyx/trunk/pyx@2803 069f4177-920e-0410-937b-c2a4a81bcd90
---
 CHANGES           |  1 +
 manual/canvas.tex | 33 +++++++++++++++++++++++++++++++++
 pyx/canvas.py     | 22 ++++++++++++++++++++++
 3 files changed, 56 insertions(+)

diff --git a/CHANGES b/CHANGES
index 46c97d95..994d7bb7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -176,6 +176,7 @@ TODO:
     - remove set method of canvas
   - canvas and document modules:
     - allow file instances as paramter of the writeXXXfile methods (feature request #1419658 by Jason Pratt)
+    - add a pipeGS method to directly pass the PyX output to ghostscript
   - style module:
     - make rellength the default for dash styles
   - random notes:
diff --git a/manual/canvas.tex b/manual/canvas.tex
index a8db14a3..44df70bb 100644
--- a/manual/canvas.tex
+++ b/manual/canvas.tex
@@ -108,6 +108,39 @@ document.
   the given arguments \var{arg} and \var{kwargs}.
 \end{methoddesc}
 
+\begin{methoddesc}{pipeGS}{filename="-", device=None, resolution=100,
+                           gscommand="gs", gsoptions="",
+                           textalphabits=4, graphicsalphabits=4, **kwargs}
+  This method pipes the content of a canvas to the ghostscript
+  interpreter directly to generate other output formats. At least
+  \var{filename} or \var{device} must be set. \var{filename} specifies
+  the bame of the output file. No file extension will be added to that
+  name in any case. When no \var{filename} is specified, the output is
+  written to stdout. \var{device} specifies a ghostscript output
+  device by a string. Depending on your ghostscript configuration
+  \code{"png16"}, \code{"png16m"}, \code{"png256"}, \code{"png48"},
+  \code{"pngalpha"}, \code{"pnggray"}, \code{"pngmono"},
+  \code{"jpeg"}, and \code{"jpeggray"} might be available among
+  others. See the output of \texttt{gs --help} and the ghostscript
+  documentation for more information. When \var{filename} is specified
+  but the device is not set, \code{"png16m"} is used when the filename
+  ends in \texttt{.eps} and \code{"jpeg"} is used when the filename
+  ends in \texttt{.jpg}.
+
+  \var{resolution} specifies the resolution in dpi (dots per inch).
+  \var{gscmd} is the command to be used to invoke ghostscript.
+  \var{gsoptions} are an option string passed to the ghostscript
+  interpreter. \var{textalphabits} are \var{graphicsalphabits} are
+  conventient parameters to set the \texttt{TextAlphaBits} and
+  \texttt{GraphicsAlphaBits} options of ghostscript. You can skip
+  the addition of those option by set their value to \code{None}.
+
+  \var{kwargs} are passed to the \method{writeEPSfile} method (not
+  counting the \var{file} parameter), which is used to generate the
+  input for ghostscript. By that you gain access to the
+  \class{document.page} constructor arguments.
+\end{methoddesc}
+
 For more information about the possible arguments of the
 \class{document.page} constructor, we refer to Sect.~\ref{document}.
 
diff --git a/pyx/canvas.py b/pyx/canvas.py
index a44a08f1..0c27b540 100644
--- a/pyx/canvas.py
+++ b/pyx/canvas.py
@@ -31,6 +31,7 @@ displayed. """
 #
 
 from __future__ import nested_scopes
+import os
 
 class canvasitem:
 
@@ -329,6 +330,7 @@ def _wrappedindocument(method):
         return method(d, file)
     return wrappedindocument
 
+
 class canvas(_canvas):
 
     """a canvas holds a collection of canvasitems"""
@@ -337,3 +339,23 @@ class canvas(_canvas):
     writePSfile = _wrappedindocument(document.document.writePSfile)
     writePDFfile = _wrappedindocument(document.document.writePDFfile)
     writetofile = _wrappedindocument(document.document.writetofile)
+
+    def pipeGS(self, filename="-", device=None, resolution=100,
+               gscommand="gs", gsoptions="",
+               textalphabits=4, graphicsalphabits=4,
+               **kwargs):
+        if device is None:
+            if filename.endswith(".png"):
+                device = "png16m"
+            if filename.endswith(".jpg"):
+                device = "jpeg"
+        gscommand += " -dEPSCrop -dNOPAUSE -dQUIET -dBATCH -r%i -sDEVICE=%s -sOutputFile=%s" % (resolution, device, filename)
+        if gsoptions:
+            gscommand += " %s" % gsoptions
+        if textalphabits is not None:
+            gscommand += " -dTextAlphaBits=%i" % textalphabits
+        if graphicsalphabits is not None:
+            gscommand += " -dGraphicsAlphaBits=%i" % graphicsalphabits
+        gscommand += " -"
+        input = os.popen(gscommand, "w")
+        self.writeEPSfile(input, **kwargs)
-- 
2.11.4.GIT