Added a "plot svg" command that, when used in conjuction with the

Cairo graphics package (magic -d XR), will map the display onto
an SVG surface and save it to a file using the Cairo SVG backend.
Due to the simplicity of the mapping, there are no options to this
plot command;  it just creates a file that is a (scalable!)
replica of the layout window.

graphics/grTCairo1.c

@@ -22,6 +22,7 @@
 #include <X11/keysym.h>
 
 #include <cairo/cairo-xlib.h>
+#include <cairo/cairo-svg.h>
 
 #include "tcltk/tclmagic.h"
 #include "utils/main.h"
@@ -342,9 +343,47 @@ GrTCairoFlush ()
 }
 
 /*
+ *---------------------------------------------------------
+ * Generate SVG graphics output
  *---------------------------------------------------------
  */
 
+void
+GrTCairoPlotSVG (char *filename, MagWindow *mw)
+{
+    int screenw, screenh;
+    cairo_surface_t *wind_surface;
+    cairo_t *wind_context;
+
+    TCairoData *tcairodata = (TCairoData *)mw->w_grdata2;
+
+    if (tcairodata == NULL)
+    {
+	TxError("Must be running in mode \"-d XR\" (CAIRO) to get SVG output.\n");
+	return;
+    }
+
+    screenw = mw->w_screenArea.r_xtop - mw->w_screenArea.r_xbot;
+    screenh = mw->w_screenArea.r_ytop - mw->w_screenArea.r_ybot;
+
+    wind_surface = tcairodata->surface;
+    wind_context = tcairodata->context;
+    tcairodata->surface = (cairo_surface_t *)cairo_svg_surface_create(filename,
+		(double)screenw, (double)screenh);
+    tcairodata->context = cairo_create(tcairodata->surface);
+    WindRedisplay(mw);
+    WindUpdate();
+
+    cairo_surface_destroy(tcairodata->surface);
+    cairo_destroy(tcairodata->context);
+    tcairodata->surface = wind_surface;
+    tcairodata->context = wind_context;
+    WindRedisplay(mw);
+    WindUpdate();
+
+    return;
+}
+
 /*
  *---------------------------------------------------------
  * Set the Cairo projection matrix for a window

plot/plotCmd.c

@@ -67,6 +67,9 @@ static char rcsid[] __attribute__ ((unused)) = "$Header: /usr/cvsroot/magic-8.0/
 typedef enum {
 	POSTSCRIPT=0,
 	PLOTPNM,
+#ifdef HAVE_LIBCAIRO
+	PLOTSVG,
+#endif
 #ifdef GREMLIN
 	STYLE_GREMLIN,
 #endif
@@ -94,12 +97,19 @@ CmdPlot(w, cmd)
     float width;
     int iwidth, scale;
 
+#ifdef HAVE_LIBCAIRO
+    extern void GrTCairoPlotSVG();
+#endif
+
     static char *cmdPlotOption[] =
     {	
 	"postscript file [layers]    generate PostScript file for what's\n\
                                      underneath the box",				
 	"pnm file [width [layers]]   generate PNM file for what's\n\
 		                     underneath the box",
+#ifdef HAVE_LIBCAIRO
+	"svg file		     generate SVG file for the whole window",
+#endif
 #ifdef GREMLIN
 	"gremlin file [layers]	     generate gremlin file for what's\n\
 		                     underneath the box",
@@ -138,6 +148,9 @@ CmdPlot(w, cmd)
 #ifdef GREMLIN
 		|| (option == STYLE_GREMLIN)
 #endif
+#ifdef HAVE_LIBCAIRO
+		|| (option == PLOTSVG)
+#endif
 #ifdef VERSATEC
 	        || (option == STYLE_VERSATEC)
 #endif
@@ -192,7 +205,7 @@ CmdPlot(w, cmd)
 	    }
 	    PlotPS(cmd->tx_argv[2], &scx, &mask, crec->dbw_bitmask);
 	    return;
-	    
+
 #ifdef GREMLIN
 	case STYLE_GREMLIN:
 	    if ((cmd->tx_argc != 3) && (cmd->tx_argc != 4))
@@ -250,6 +263,18 @@ CmdPlot(w, cmd)
 	    return;
 #endif
 
+#ifdef HAVE_LIBCAIRO
+	case PLOTSVG:
+	    if (cmd->tx_argc > 3)
+	    {
+		TxError("Too many arguments:\n    plot %s\n",
+			cmdPlotOption[PLOTSVG]);
+		return;
+	    }
+	    GrTCairoPlotSVG(cmd->tx_argv[2], window);
+	    return;
+#endif
+	    
 	case PLOTPNM:
 	    if (cmd->tx_argc > 5)
 	    {