From 80a80e7ff354edb999038e88127e809048d9572d Mon Sep 17 00:00:00 2001
From: Martin Gieseking <martin.gieseking@uos.de>
Date: Wed, 5 Jul 2023 10:37:25 +0200
Subject: [PATCH] added special 'dvisvgm:message'

---
 doc/dvisvgm.1                 | 14 ++++++++++++--
 doc/dvisvgm.txt.in            |  6 +++++-
 src/DvisvgmSpecialHandler.cpp | 12 +++++++++++-
 src/DvisvgmSpecialHandler.hpp |  1 +
 4 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/doc/dvisvgm.1 b/doc/dvisvgm.1
index a71477d2..95d062c8 100644
--- a/doc/dvisvgm.1
+++ b/doc/dvisvgm.1
@@ -2,12 +2,12 @@
 .\"     Title: dvisvgm
 .\"    Author: Martin Gieseking <martin.gieseking@uos.de>
 .\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
-.\"      Date: 2023-06-19
+.\"      Date: 2023-07-05
 .\"    Manual: dvisvgm Manual
 .\"    Source: dvisvgm 3.1
 .\"  Language: English
 .\"
-.TH "DVISVGM" "1" "2023\-06\-19" "dvisvgm 3\&.1" "dvisvgm Manual"
+.TH "DVISVGM" "1" "2023\-07\-05" "dvisvgm 3\&.1" "dvisvgm Manual"
 .\" -----------------------------------------------------------------
 .\" * Define some portability stuff
 .\" -----------------------------------------------------------------
@@ -1423,6 +1423,16 @@ allows for applying the current transformation matrix to the bounding box\&.
 This variant of the bbox special assigns an absolute (final) bounding box to the resulting SVG\&. After executing this command, dvisvgm doesn\(cqt further alter the bounding box coordinates, except this special is called again later\&. The points (\fIx1\fR,\fIy1\fR) and (\fIx2\fR,\fIy2\fR) denote the absolute coordinates of two diagonal corners of the rectangle\&. As with the relative special variant described above, the optional modifier
 \fBtransform\fR
 allows for applying the current transformation matrix to the bounding box\&.
+.RE
+.PP
+\fBdvisvgm:message\fR \fImsg\fR
+.RS 4
+Prints the given text
+\fImsg\fR
+to the console\&. It may also contain the macros
+\fI{?\&...}\fR
+mentioned above (see
+\fBdvisvgm:raw\fR)\&.
 .sp
 The following TeX snippet adds two raw SVG elements to the output and updates the bounding box accordingly:
 .sp
diff --git a/doc/dvisvgm.txt.in b/doc/dvisvgm.txt.in
index e0cdbba2..5b31c8d0 100644
--- a/doc/dvisvgm.txt.in
+++ b/doc/dvisvgm.txt.in
@@ -22,7 +22,7 @@ Martin Gieseking <@PACKAGE_BUGREPORT@>
 :man source: dvisvgm
 :man version: @VERSION@
 :man manual: dvisvgm Manual
-:revdate: 2023-06-19 10:59 +0200
+:revdate: 2023-07-05 10:37 +0200
 
 Name
 ----
@@ -880,6 +880,10 @@ dvisvgm offers its own small set of specials. The following list gives a brief o
   The points ('x1','y1') and ('x2','y2') denote the absolute coordinates of two diagonal corners of the rectangle.
   As with the relative special variant described above, the optional modifier +transform+ allows for applying the
   current transformation matrix to the bounding box.
+
+  *dvisvgm:message* 'msg';;
+  Prints the given text 'msg' to the console. It may also contain the macros '{?...}' mentioned above
+  (see *dvisvgm:raw*).
 +
 The following TeX snippet adds two raw SVG elements to the output and updates the bounding box accordingly:
 +
diff --git a/src/DvisvgmSpecialHandler.cpp b/src/DvisvgmSpecialHandler.cpp
index e33d2fb6..0a840385 100644
--- a/src/DvisvgmSpecialHandler.cpp
+++ b/src/DvisvgmSpecialHandler.cpp
@@ -26,6 +26,7 @@
 #include "InputBuffer.hpp"
 #include "InputReader.hpp"
 #include "Length.hpp"
+#include "Message.hpp"
 #include "SpecialActions.hpp"
 #include "SVGTree.hpp"
 #include "utility.hpp"
@@ -181,7 +182,8 @@ bool DvisvgmSpecialHandler::process (const string &prefix, istream &is, SpecialA
 		{"rawput",       &DvisvgmSpecialHandler::processRawPut},
 		{"bbox",         &DvisvgmSpecialHandler::processBBox},
 		{"img",          &DvisvgmSpecialHandler::processImg},
-		{"currentcolor", &DvisvgmSpecialHandler::processCurrentColor}
+		{"currentcolor", &DvisvgmSpecialHandler::processCurrentColor},
+		{"message",      &DvisvgmSpecialHandler::processMessage}
 	};
 	StreamInputReader ir(is);
 	const string cmdstr = ir.getWord();
@@ -469,6 +471,14 @@ void DvisvgmSpecialHandler::processCurrentColor (InputReader &ir, SpecialActions
 }
 
 
+void DvisvgmSpecialHandler::processMessage (InputReader &ir, SpecialActions &actions) {
+	string message = ir.getLine();
+	evaluate_expressions(message, actions);
+	expand_constants(message, actions);
+	Message::mstream() << message << "\n";
+}
+
+
 void DvisvgmSpecialHandler::dviPreprocessingFinished () {
 	string id;
 	if (_currentMacro != _macros.end())
diff --git a/src/DvisvgmSpecialHandler.hpp b/src/DvisvgmSpecialHandler.hpp
index 5c8bbe5b..7edecb12 100644
--- a/src/DvisvgmSpecialHandler.hpp
+++ b/src/DvisvgmSpecialHandler.hpp
@@ -94,6 +94,7 @@ class DvisvgmSpecialHandler : public SpecialHandler {
 		void processBBox (InputReader &ir, SpecialActions &actions);
 		void processImg (InputReader &ir, SpecialActions &actions);
 		void processCurrentColor (InputReader &ir, SpecialActions &actions);
+		void processMessage (InputReader &ir, SpecialActions &actions);
 		void dviPreprocessingFinished () override;
 		void dviBeginPage (unsigned pageno, SpecialActions &actions) override;
 		void dviEndPage (unsigned pageno, SpecialActions &actions) override;