diff --git a/src/DrawingTracer.cc b/src/DrawingTracer.cc
index 3a48363..c282824 100644
--- a/src/DrawingTracer.cc
+++ b/src/DrawingTracer.cc
@@ -232,6 +232,7 @@ void DrawingTracer::draw_char_bbox(GfxState * state, double * bbox)
 
     if (pt_in == 0)
     {
+        transform_bbox_by_ctm(bbox);
         if(on_char_clipped)
             on_char_clipped(bbox, false);
     }
@@ -255,6 +256,7 @@ void DrawingTracer::draw_char_bbox(GfxState * state, double * bbox)
                 on_char_drawn(bbox);
         }
     }
+    DT_DEBUG(printf("DrawingTracer::draw_char_bbox:[%f,%f,%f,%f]\n",bbox[0],bbox[1],bbox[2],bbox[3]));
 }
 
 void DrawingTracer::draw_image(GfxState *state)
diff --git a/src/HTMLRenderer/text.cc b/src/HTMLRenderer/text.cc
index 13f2065..6191554 100644
--- a/src/HTMLRenderer/text.cc
+++ b/src/HTMLRenderer/text.cc
@@ -51,9 +51,14 @@ void HTMLRenderer::drawString(GfxState * state, GooString * s)
     char *p = s->getCString();
     int len = s->getLength();
 
+    //accumulated displacement of chars in this string, in text object space
     double dx = 0;
     double dy = 0;
-    double dx1,dy1;
+    //displacement of current char, in text object space
+    double ddx, ddy;
+    //advance of current char, in glyph space
+    double ax, ay;
+    //origin of current char, in glyph space
     double ox, oy;
 
     int nChars = 0;
@@ -65,14 +70,15 @@ void HTMLRenderer::drawString(GfxState * state, GooString * s)
 
     while (len > 0) 
     {
-        auto n = font->getNextChar(p, len, &code, &u, &uLen, &dx1, &dy1, &ox, &oy);
+        auto n = font->getNextChar(p, len, &code, &u, &uLen, &ax, &ay, &ox, &oy);
 
         if(!(equal(ox, 0) && equal(oy, 0)))
         {
             cerr << "TODO: non-zero origins" << endl;
         }
-
-        tracer.draw_char(state, dx, dy, dx1, dy1); //TODO dx dy seems not correct?
+        ddx = (ax * cur_font_size + cur_letter_space) * cur_horiz_scaling;
+        ddy = ay * cur_font_size;
+        tracer.draw_char(state, dx, dy, ax, ay);
 
         bool is_space = false;
         if (n == 1 && *p == ' ') 
@@ -93,13 +99,13 @@ void HTMLRenderer::drawString(GfxState * state, GooString * s)
         if(is_space && (param.space_as_offset))
         {
             // ignore horiz_scaling, as it has been merged into CTM
-            html_text_page.get_cur_line()->append_offset((dx1 * cur_font_size + cur_letter_space + cur_word_space) * draw_text_scale); 
+            html_text_page.get_cur_line()->append_offset((ax * cur_font_size + cur_letter_space + cur_word_space) * draw_text_scale);
         }
         else
         {
             if((param.decompose_ligature) && (uLen > 1) && all_of(u, u+uLen, isLegalUnicode))
             {
-                html_text_page.get_cur_line()->append_unicodes(u, uLen, (dx1 * cur_font_size + cur_letter_space));
+                html_text_page.get_cur_line()->append_unicodes(u, uLen, ddx);
             }
             else
             {
@@ -112,7 +118,7 @@ void HTMLRenderer::drawString(GfxState * state, GooString * s)
                 {
                     uu = unicode_from_font(code, font);
                 }
-                html_text_page.get_cur_line()->append_unicodes(&uu, 1, (dx1 * cur_font_size + cur_letter_space));
+                html_text_page.get_cur_line()->append_unicodes(&uu, 1, ddx);
                 /*
                  * In PDF, word_space is appended if (n == 1 and *p = ' ')
                  * but in HTML, word_space is appended if (uu == ' ')
@@ -125,8 +131,8 @@ void HTMLRenderer::drawString(GfxState * state, GooString * s)
             }
         }
 
-        dx += dx1;
-        dy += dy1;
+        dx += ddx;
+        dy += ddy;
 
         ++nChars;
         p += n;