From 91d80dc7c1e7e7aa6fca57f8f2e23e62d970a26e Mon Sep 17 00:00:00 2001
From: Hermann Kraus <hermr2d2@gmail.com>
Date: Sat, 30 Jun 2012 18:32:59 +0200
Subject: [PATCH] Use UTF16 directly to avoid reencoding and allow easy mapping
 of chars to glyphs.

---
 include/mapnik/text/layout.hpp |  2 +-
 src/text/layout.cpp            | 23 +++++++++++------------
 src/text/shaping.cpp           |  8 ++++----
 3 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/include/mapnik/text/layout.hpp b/include/mapnik/text/layout.hpp
index 2050578d9..2965b7281 100644
--- a/include/mapnik/text/layout.hpp
+++ b/include/mapnik/text/layout.hpp
@@ -14,7 +14,7 @@ namespace mapnik
 struct glyph_info
 {
       font_glyph glyph;
-      uint32_t byte_position;
+      uint32_t char_index; //Position in the string of all characters i.e. before itemizing
       uint32_t x_advance;
 };
 
diff --git a/src/text/layout.cpp b/src/text/layout.cpp
index 3f555421a..607ac61dc 100644
--- a/src/text/layout.cpp
+++ b/src/text/layout.cpp
@@ -21,18 +21,17 @@ void text_layout::break_lines()
 void text_layout::shape_text()
 {
     glyphs_.reserve(itemizer.get_text().length()); //Preallocate memory
-    uint32_t byte_offset = 0;
+    uint32_t offset = 0; //in utf16 code points
     std::list<text_item> const& list = itemizer.itemize();
     std::list<text_item>::const_iterator itr = list.begin(), end = list.end();
     for (;itr!=end; itr++)
     {
         face_set_ptr face_set = font_manager_.get_face_set(itr->format.face_name, itr->format.fontset);
-        //TODO: Difference pixel_sizes, char_sizes
         face_set->set_character_sizes(itr->format.text_size);
         face_ptr face = *(face_set->begin()); //TODO: Implement font sets correctly
         text_shaping shaper(face->get_face()); //TODO: Make this more efficient by caching this object in font_face
 
-        uint32_t bytes = shaper.process_text(itr->str, itr->rtl == UBIDI_DEFAULT_RTL, itr->script);
+        uint32_t chars = shaper.process_text(itr->str, itr->rtl == UBIDI_DEFAULT_RTL, itr->script);
         hb_buffer_t *buffer = shaper.get_buffer();
 
         unsigned num_glyphs = hb_buffer_get_length(buffer);
@@ -41,27 +40,27 @@ void text_layout::shape_text()
         hb_glyph_position_t *positions = hb_buffer_get_glyph_positions(buffer, NULL);
 
         std::string s;
-        std::cout << "Processing item '" << itr->str.toUTF8String(s) << "' (" << uscript_getName(itr->script) << "," << itr->str.length() << "," << num_glyphs << ")\n";
+        std::cout << "Processing item '" << itr->str.toUTF8String(s) << "' (" << uscript_getName(itr->script) << "," << itr->str.length() << "," << num_glyphs << "," << itr->rtl <<  ")\n";
 
         for (unsigned i=0; i<num_glyphs; i++)
         {
             glyph_info tmp;
-            tmp.byte_position = byte_offset + glyphs[i].cluster;
+            tmp.char_index = offset + glyphs[i].cluster;
             tmp.glyph.index = glyphs[i].codepoint;
-            //TODO: tmp.glyph.set_face();
+            tmp.glyph.face = face;
             tmp.x_advance = positions[i].x_advance;
             glyphs_.push_back(tmp);
         }
-        byte_offset += bytes;
+        offset += chars;
     }
-    std::string s;
-    std::cout << "text_length: unicode chars: " << itemizer.get_text().length() << " bytes: " <<itemizer.get_text().toUTF8String(s).length() << " glyphs: " << glyphs_.size()  << "\n";
+    std::cout << "text_length: unicode chars: " << itemizer.get_text().length() << " glyphs: " << glyphs_.size()  << "\n";
     std::vector<glyph_info>::const_iterator itr2 = glyphs_.begin(), end2 = glyphs_.end();
     for (;itr2 != end2; itr2++)
     {
-        std::cout << "glyph codepoint:" << itr2->glyph.index <<
-                 " cluster: " << itr2->byte_position <<
-                 " x_advance: "<< itr2->x_advance << "\n";
+        std::cout << "'" << (char) itemizer.get_text().charAt(itr2->char_index) <<
+                 "' glyph codepoint:" << itr2->glyph.index <<
+                 " cluster: " << itr2->char_index <<
+                 " x_advance: "<< itr2->x_advance/64.0 << "\n";
     }
 }
 
diff --git a/src/text/shaping.cpp b/src/text/shaping.cpp
index c25ffca4f..180e4cdcc 100644
--- a/src/text/shaping.cpp
+++ b/src/text/shaping.cpp
@@ -36,16 +36,16 @@ uint32_t text_shaping::process_text(UnicodeString const& text, bool rtl, UScript
     if (!font_) return 0;
     hb_buffer_reset(buffer_);
 
-    std::string s;
-    text.toUTF8String(s);
-    hb_buffer_add_utf8(buffer_, s.c_str(), s.length(), 0, -1);
+    uint32_t length = text.length();
+
+    hb_buffer_add_utf16(buffer_, text.getBuffer(), length, 0, -1);
     hb_buffer_set_direction(buffer_, rtl?HB_DIRECTION_RTL:HB_DIRECTION_LTR);
     hb_buffer_set_script(buffer_, hb_icu_script_to_script(script));
 #if 0
     hb_buffer_set_language(buffer, hb_language_from_string (language, -1));
 #endif
     hb_shape(font_, buffer_, 0 /*features*/, 0 /*num_features*/);
-    return s.length();
+    return length;
 }
 
 void text_shaping::free_data(void *data)