better accuracy with new positioning method, but break text selection in Chrome

share/all.css

@@ -20,6 +20,16 @@
 #pdf-main .l {
   position:absolute;
   white-space:pre;
+  font-size:0;
+  transform-origin:0% 100%;
+  -ms-transform-origin:0% 100%;
+  -moz-transform-origin:0% 100%;
+  -webkit-transform-origin:0% 100%;
+  -o-transform-origin:0% 100%;
+}
+#pdf-main span {
+  vertical-align: baseline;
+  line-height:0;
 }
 #pdf-main ._ {
   color:transparent;

src/BackgroundRenderer.cc

@@ -19,11 +19,13 @@ void BackgroundRenderer::drawChar(GfxState *state, double x, double y,
   CharCode code, int nBytes, Unicode *u, int uLen)
 {
     auto font = state->getFont();
+    /*
     if((font->getType() == fontType3) 
             || (font->getWMode()) 
             || (uLen == 0) 
             || (!all_of(u, u+uLen, isLegalUnicode))
       )
+      */
     {
         SplashOutputDev::drawChar(state, x, y, dx, dy, originX, originY, code, nBytes, u, uLen);
     }

src/HTMLRenderer/export.cc

@@ -31,17 +31,6 @@ void HTMLRenderer::export_remote_font(long long fn_id, const string & suffix, co
 
     allcss_fout << format(")format(\"%1%\");}.f%|2$x|{font-family:f%|2$x|;") % fontfileformat % fn_id;
 
-    double a = font->getAscent();
-    double d = font->getDescent();
-    double r = _is_positive(a-d) ? (a/(a-d)) : 1.0;
-
-    for(const string & prefix : {"", "-ms-", "-moz-", "-webkit-", "-o-"})
-    {
-        allcss_fout << prefix << "transform-origin:0% " << (r*100.0) << "%;";
-    }
-
-    allcss_fout << "line-height:" << (a-d) << ";";
-
     allcss_fout << "}" << endl;
 }
 
@@ -74,17 +63,6 @@ void HTMLRenderer::export_local_font(long long fn_id, GfxFont * font, const stri
     else if(font->isItalic())
         allcss_fout << "font-style:italic;";
 
-    double a = font->getAscent();
-    double d = font->getDescent();
-    double r = _is_positive(a-d) ? (a/(a-d)) : 1.0;
-
-    for(const string & prefix : {"", "-ms-", "-moz-", "-webkit-", "-o-"})
-    {
-        allcss_fout << prefix << "transform-origin:0% " << (r*100.0) << "%;";
-    }
-
-    allcss_fout << "line-height:" << (a-d) << ";";
-
     allcss_fout << "}" << endl;
 }
 

src/HTMLRenderer/state.cc

@@ -102,7 +102,7 @@ void HTMLRenderer::check_state_change(GfxState * state)
 
         if(!(new_fn_id == cur_fn_id))
         {
-            new_line_status = max(new_line_status, LineStatus::DIV);
+            new_line_status = max(new_line_status, LineStatus::SPAN);
             cur_fn_id = new_fn_id;
         }
 
@@ -166,7 +166,7 @@ void HTMLRenderer::check_state_change(GfxState * state)
 
         if(!(_equal(new_draw_font_size, draw_font_size)))
         {
-            new_line_status = max(new_line_status, LineStatus::DIV);
+            new_line_status = max(new_line_status, LineStatus::SPAN);
             draw_font_size = new_draw_font_size;
             cur_fs_id = install_font_size(draw_font_size);
         }
@@ -328,7 +328,7 @@ void HTMLRenderer::prepare_line(GfxState * state)
 
         // horizontal position
         // try to merge with the last line if possible
-        double target = (cur_tx - draw_tx) * draw_scale;
+        double target = cur_tx - draw_tx;
         if(abs(target) < param->h_eps)
         {
             // ignore it
@@ -338,7 +338,7 @@ void HTMLRenderer::prepare_line(GfxState * state)
             // don't close a pending span here, keep the styling
 
             double w;
-            auto wid = install_whitespace(target, w);
+            auto wid = install_whitespace(target * draw_scale, w);
             html_fout << format("<span class=\"_ _%|1$x|\">%2%</span>") % wid % (target > 0 ? " " : "");
             draw_tx += w / draw_scale;
         }
@@ -348,33 +348,30 @@ void HTMLRenderer::prepare_line(GfxState * state)
     {
         // have to open a new tag
         
-        if(new_line_status == LineStatus::SPAN)
-        {
-            html_fout << "<span class=\"";
-        }
-        else if (new_line_status == LineStatus::DIV)
+        if (new_line_status == LineStatus::DIV)
         {
             // TODO: recheck descent/ascent
             double x,y; // in user space
             state->transform(state->getCurX(), state->getCurY(), &x, &y);
 
-            html_fout << format("<div style=\"bottom:%1%px;top:%2%px;left:%3%px;\" class=\"l ") 
-                % (y + state->getFont()->getDescent() * draw_font_size)
-                % (pageHeight - y - state->getFont()->getAscent() * draw_font_size)
-                % x;
+            html_fout << format("<div style=\"bottom:%1%px;left:%2%px;\" class=\"l t%|3$x|\"><em></em>") 
+                % y % x % cur_tm_id;
 
-            html_fout << format("t%|1$x| f%|2$x| s%|3$x| ") % cur_tm_id % cur_fn_id % cur_fs_id;
+        }
+        else if(new_line_status == LineStatus::SPAN)
+        {
+            // pass
         }
         else
         {
             assert(false && "Bad value of new_line_status");
         }
 
-        html_fout << format("c%|1$x| l%|2$x| w%|3$x|") % cur_color_id % cur_ls_id % cur_ws_id;
+        html_fout << format("<span class=\"f%|1$x| s%|2$x| c%|3$x| l%|4$x| w%|5$x|\">") 
+            % cur_fn_id % cur_fs_id % cur_color_id % cur_ls_id % cur_ws_id;
 
-        html_fout << "\">";
-
-        line_status = new_line_status;
+        //line_status = new_line_status;
+        line_status = LineStatus::SPAN;
     }
 
 }