[Groff] patches for html2 and specific help requested

[Gaius Mulley]

Hi Werner,

Here are some patches for html2. These patches allow groff -Thtml2
to create minimal png files. They also provide a fix to html w.r.t
eqn handling.

I wonder whether I could ask for some help in the following areas:

tmac/tmac.html-tags:

could someone check that the tag generation mechanism is
non intrusive.

src/preproc/html2/pre-html.cc: in function createImage
I'm having difficulty producing transparent png files.
If anyone has done this before - maybe you can drop me
an email.

in src/src/devices/grohtml/html.cc the function
assign_min_max_for_arc works out the smallest box which
will encompass an arc. I wonder whether a groff friend
who is also a mathematician can find a better solution
than my 16 tests :-) this code is also needed in troff
src/roff/troff/node.cc:determine_line_limits. But
I've not copied it yet..

many thanks Gaius


--- groff-cvs/ChangeLog Sun Oct 15 00:57:32 2000
+++ groff-html/ChangeLog        Tue Oct 17 17:17:59 2000
@@ -1,3 +1,9 @@
+2000-10-17  Gaius Mulley  <address@hidden>
+
+       * src/roff/troff/node.cc fixed calculation of opminx
+       and fixed non intrusive eol marker.
+       Added method determine_line_limits.
+       
 2000-10-14  Werner LEMBERG  <address@hidden>
 
        Replace tmac.safer with a real secure solution.
--- groff-cvs/src/roff/troff/node.cc    Fri Aug 25 08:44:08 2000
+++ groff-html/src/roff/troff/node.cc   Tue Oct 17 17:18:51 2000
@@ -752,6 +752,7 @@
   void really_on();
   void really_off();
   void draw(char, hvpair *, int, font_size);
+  void determine_line_limits (char code, hvpair *point, int npoints);
   int get_hpos() { return hpos; }
   int get_vpos() { return vpos; }
 };
@@ -896,6 +897,9 @@
     put(tbuf_kern);
     put(' ');
   }
+  
+  check_output_limits(output_hpos, output_vpos);
+
   for (int i = 0; i < tbuf_len; i++)
     put(tbuf[i]);
   put('\n');
@@ -1061,6 +1065,42 @@
   current_tfont = tf;
 }
 
+/*
+ *  determine_line_limits - works out the smallest box which will contain
+ *                          the entity, code, built from the point array.
+ */
+
+void troff_output_file::determine_line_limits (char code, hvpair *point, int 
npoints)
+{
+  int i, x, y;
+
+  switch (code) {
+
+  case 'c':
+  case 'C':
+    /* only the h field is used when defining a circle */
+    check_output_limits(output_hpos, output_vpos-point[0].h.to_units()/2);
+    check_output_limits(output_hpos+point[0].h.to_units(), 
output_vpos+point[0].h.to_units()/2);
+    break;
+  case 'E':
+  case 'e':
+    check_output_limits(output_hpos, output_vpos-point[1].v.to_units()/2);
+    check_output_limits(output_hpos+point[0].h.to_units(), 
output_vpos+point[1].v.to_units()/2);
+    break;
+  default:
+    /*
+     *  remember this doesn't work for arc..
+     */
+    x=output_hpos;
+    y=output_vpos;
+    for (i=0; i<npoints; i++) {
+      x += point[i].h.to_units();
+      y += point[i].v.to_units();
+      check_output_limits(x, y);
+    }
+  }
+}
+
 void troff_output_file::draw(char code, hvpair *point, int npoints,
                             font_size fsize)
 {
@@ -1088,6 +1128,9 @@
       put(' ');
       put(point[i].v.to_units());
     }
+
+  determine_line_limits(code, point, npoints);
+
   for (i = 0; i < npoints; i++)
     output_hpos += point[i].h.to_units();
   hpos = output_hpos;
@@ -1324,14 +1367,6 @@
 {
   if (printing && output_on)
     really_print_line(x, y, n, before, after, width);
-
-  if (before.to_units() < after.to_units()) {
-    check_output_limits(x.to_units()                 , 
y.to_units()+before.to_units());
-    check_output_limits(x.to_units()+width.to_units(), 
y.to_units()+after.to_units()+n->size());
-  } else {
-    check_output_limits(x.to_units()                 , 
y.to_units()+after.to_units());
-    check_output_limits(x.to_units()+width.to_units(), 
y.to_units()+before.to_units()+n->size());
-  }
   delete_node_list(n);
 }
 
--- groff-cvs/src/roff/troff/env.cc     Fri Aug 25 08:44:08 2000
+++ groff-html/src/roff/troff/env.cc    Tue Oct 17 15:59:41 2000
@@ -1946,8 +1946,9 @@
       if (!illegal_input_char((unsigned char)*p))
        m->append(*p);
     output_pending_lines();
-    output_line(new special_node(*m), 0);
-  }  
+    output(new special_node(*m), !fill, 0, 0, 0);
+    output_pending_lines();
+  }
 }
 
 void environment::do_break()
--- groff-cvs/src/preproc/eqn/main.cc   Fri Mar 10 00:35:32 2000
+++ groff-html/src/preproc/eqn/main.cc  Mon Oct 16 09:43:34 2000
@@ -110,8 +110,8 @@
       }
       restore_compatibility();
       printf(".lf %d\n", current_lineno);
-      graphic_end();
       put_string(linebuf, stdout);
+      graphic_end();
     }
     else if (start_delim != '\0' && linebuf.search(start_delim) >= 0
             && inline_equation(fp, linebuf, str))
--- groff-cvs/src/preproc/html2/pre-html.cc     Mon Oct  9 20:41:59 2000
+++ groff-html/src/preproc/html2/pre-html.cc    Tue Oct 17 17:50:10 2000
@@ -39,6 +39,10 @@
 #include <unistd.h>
 #endif
 
+#ifndef errno
+extern int errno;
+#endif
+
 #ifdef _POSIX_VERSION
 #include <sys/wait.h>
 #define PID_T pid_t
@@ -267,7 +271,7 @@
   char_block *t=head;
   int r;
 
-  writeString(".nr html2enable 1\n");
+  writeString(".nr html2enable 0\n");
   writeString(".nr htmlflip 0\n");
   if (t != 0) {
     do {
@@ -383,14 +387,17 @@
            image_device,
            image_res,
            psFileName,
-           i->X1*image_res/POSTSCRIPTRES,
+           i->X1*image_res/POSTSCRIPTRES-IMAGE_BOARDER_PIXELS,
            i->Y1*image_res/POSTSCRIPTRES-IMAGE_BOARDER_PIXELS,
-           (i->X2-i->X1)*image_res/POSTSCRIPTRES+IMAGE_BOARDER_PIXELS,
-           (i->Y2-i->Y1)*image_res/POSTSCRIPTRES+IMAGE_BOARDER_PIXELS,
+           (i->X2-i->X1)*image_res/POSTSCRIPTRES+2*IMAGE_BOARDER_PIXELS,
+           (i->Y2-i->Y1)*image_res/POSTSCRIPTRES+2*IMAGE_BOARDER_PIXELS,
            TRANSPARENT,
            i->imageName);
-    fprintf(stderr, buffer);
+    // fprintf(stderr, buffer);
     system(buffer);
+  } else {
+    fprintf(stderr, "ignoring image as x1 coord is -1\n");
+    fflush(stderr);
   }
 }