Implement offsets and multiline rendering.

include/mapnik/vertex_cache.hpp

@@ -25,6 +25,7 @@
 // mapnik
 #include <mapnik/pixel_position.hpp>
 #include <mapnik/debug.hpp>
+#include <mapnik/offset_converter.hpp>
 
 // agg
 #include "agg_basics.h"
@@ -32,10 +33,18 @@
 // stl
 #include <vector>
 #include <utility>
+#include <cmath>
+
+//boost
+#include <boost/shared_ptr.hpp>
+#include <boost/make_shared.hpp>
 
 namespace mapnik
 {
 
+class vertex_cache;
+typedef boost::shared_ptr<vertex_cache> vertex_cache_ptr;
+
 /** Caches all path points and their lengths. Allows easy moving in both directions. */
 class vertex_cache
 {
@@ -62,6 +71,7 @@ public:
         double position_in_segment;
         pixel_position current_position;
         pixel_position segment_starting_point;
+        double position_;
         friend class vertex_cache;
     public:
         pixel_position const& position() const { return current_position; }
@@ -91,7 +101,7 @@ public:
     bool next_subpath();
 
     /** Moves all positions to a parallel line in the specified distance. */
-    void set_offset(double offset);
+    vertex_cache &get_offseted(double offset, double region_width);
 
 
     /** Skip a certain amount of space.
@@ -125,8 +135,11 @@ private:
     double position_in_segment_;
     mutable double angle_;
     mutable bool angle_valid_;
+    vertex_cache_ptr offseted_line_;
+    double position_;
 };
 
+
 template <typename T>
 vertex_cache::vertex_cache(T &path)
         : current_position_(),
@@ -139,7 +152,9 @@ vertex_cache::vertex_cache(T &path)
           first_subpath_(true),
           position_in_segment_(0.),
           angle_(0.),
-          angle_valid_(false)
+          angle_valid_(false),
+          offseted_line_(),
+          position_(0.)
 {
     path.rewind(0);
     unsigned cmd;
@@ -248,9 +263,22 @@ bool vertex_cache::previous_segment()
     return true;
 }
 
-void vertex_cache::set_offset(double offset)
+vertex_cache & vertex_cache::get_offseted(double offset, double region_width)
 {
-    MAPNIK_LOG_DEBUG(vertex_cache) << "set_offset: unimplemented\n";
+    if (fabs(offset) < 0.01)
+    {
+        return *this;
+    }
+    //TODO: Cache offseted lines
+    offset_converter<vertex_cache> converter(*this);
+    converter.set_offset(offset);
+    offseted_line_ = vertex_cache_ptr(new vertex_cache(converter));
+    offseted_line_->rewind_subpath(); //TODO: Multiple subpath support
+    double seek = (position_ + region_width/2.) * offseted_line_->length() / length() - region_width/2.;
+    if (seek < 0) seek = 0;
+    if (seek > offseted_line_->length()) seek = offseted_line_->length();
+    offseted_line_->move(seek);
+    return *offseted_line_;
 }
 
 bool vertex_cache::forward(double length)
@@ -275,6 +303,7 @@ bool vertex_cache::backward(double length)
 
 bool vertex_cache::move(double length)
 {
+    position_ += length;
     length += position_in_segment_;
     while (length >= current_segment_->length)
     {
@@ -300,6 +329,7 @@ void vertex_cache::rewind_subpath()
     position_in_segment_ = 0;
     segment_starting_point_ = current_position_;
     angle_valid_ = false;
+    position_ = 0;
 }
 
 void vertex_cache::rewind(unsigned)
@@ -331,6 +361,7 @@ vertex_cache::state vertex_cache::save_state() const
     s.position_in_segment = position_in_segment_;
     s.current_position = current_position_;
     s.segment_starting_point = segment_starting_point_;
+    s.position_ = position_;
     return s;
 }
 
@@ -340,6 +371,7 @@ void vertex_cache::restore_state(state const& s)
     position_in_segment_ = s.position_in_segment;
     current_position_ = s.current_position;
     segment_starting_point_ = s.segment_starting_point;
+    position_ = s.position_;
     angle_valid_ = false;
 }
 

src/text/face.cpp

@@ -78,7 +78,7 @@ void font_face::glyph_dimensions(glyph_info &glyph) const
     matrix.yx = (FT_Fixed)( 0 * 0x10000L );
     matrix.yy = (FT_Fixed)( 1 * 0x10000L );
 
-    FT_Set_Transform(face_, &matrix, &pen); //TODO: Matrix is always only set to the identity matrix. This seems to be useless.
+    FT_Set_Transform(face_, &matrix, &pen);
 
     if (FT_Load_Glyph (face_, glyph.glyph_index, FT_LOAD_NO_HINTING)) return;
     if (FT_Get_Glyph(face_->glyph, &image)) return;

src/text/layout.cpp

@@ -218,12 +218,12 @@ void text_layout::clear()
 
 double text_layout::height() const
 {
-    return height_; //TODO
+    return height_;
 }
 
 double text_layout::width() const
 {
-    return width_; //TODO
+    return width_;
 }
 
 text_layout::const_iterator text_layout::begin() const

src/text/placement_finder_ng.cpp

@@ -296,7 +296,7 @@ bool placement_finder_ng::single_line_placement(vertex_cache &pp, text_upright_e
     double base_offset = alignment_offset().y + info_->properties.displacement.y;
     glyph_positions_ptr glyphs = boost::make_shared<glyph_positions>();
 
-    double offset = base_offset + layout_.height();
+    double offset = base_offset + layout_.height()/2.;
     unsigned upside_down_glyph_count = 0;
 
     std::vector<box2d<double> > bboxes;
@@ -306,8 +306,11 @@ bool placement_finder_ng::single_line_placement(vertex_cache &pp, text_upright_e
     for (; line_itr != line_end; line_itr++)
     {
         double char_height = (*line_itr)->max_char_height();
-        offset -= (*line_itr)->height();
-        pp.set_offset(offset);
+        //Only subtract half the line height here and half at the end because text is automatically
+        //centered on the line
+        offset -= (*line_itr)->height()/2;
+        vertex_cache &off_pp = pp.get_offseted(offset, sign*layout_.width());
+        vertex_cache::scoped_state off_state(off_pp); //TODO: Remove this when a clean implementation in vertex_cache::get_offseted was done
 
         double last_cluster_angle = 999;
         signed current_cluster = -1;
@@ -321,10 +324,10 @@ bool placement_finder_ng::single_line_placement(vertex_cache &pp, text_upright_e
             glyph_info const& glyph = *glyph_itr;
             if (current_cluster != glyph.char_index)
             {
-                if (!pp.move(sign * layout_.cluster_width(current_cluster))) return false;
+                if (!off_pp.move(sign * layout_.cluster_width(current_cluster))) return false;
                 current_cluster = glyph.char_index;
                 //Only calculate new angle at the start of each cluster!
-                angle = normalize_angle(pp.angle(sign * layout_.cluster_width(current_cluster)));
+                angle = normalize_angle(off_pp.angle(sign * layout_.cluster_width(current_cluster)));
                 rot.init(angle);
                 if ((info_->properties.max_char_angle_delta > 0) && (last_cluster_angle != 999) &&
                         fabs(normalize_angle(angle-last_cluster_angle)) > info_->properties.max_char_angle_delta)
@@ -336,7 +339,7 @@ bool placement_finder_ng::single_line_placement(vertex_cache &pp, text_upright_e
             }
             if (abs(angle) > M_PI/2) upside_down_glyph_count++;
 
-            pixel_position pos = pp.current_position() + cluster_offset;
+            pixel_position pos = off_pp.current_position() + cluster_offset;
             //Center the text on the line
             pos.y = -pos.y - char_height/2.0*rot.cos;
             pos.x =  pos.x + char_height/2.0*rot.sin;
@@ -349,6 +352,8 @@ bool placement_finder_ng::single_line_placement(vertex_cache &pp, text_upright_e
             bboxes.push_back(bbox);
             glyphs->push_back(glyph, pos, rot);
         }
+        //See comment above
+        offset -= (*line_itr)->height()/2;
     }
     s.restore();
     if (orientation == UPRIGHT_AUTO && (upside_down_glyph_count > layout_.get_text().length()/2))
@@ -429,7 +434,6 @@ box2d<double> placement_finder_ng::get_bbox(glyph_info const& glyph, pixel_posit
           (0/ymin)          (width/ymin)
           Add glyph offset in y direction, but not in x direction (as we use the full cluster width anyways)!
     */
-    std::cout << glyph.offset << glyph.width << "," << glyph.ymin << glyph.ymax << "\n";
     double width = layout_.cluster_width(glyph.char_index);
     if (glyph.width <= 0) width = -width;
     pixel_position tmp, tmp2;