From f571cd976366ddfd7540f2584be917b5776d71f3 Mon Sep 17 00:00:00 2001
From: Dane Springmeyer <dane@dbsgeo.com>
Date: Thu, 3 May 2012 16:45:40 -0400
Subject: [PATCH] fixup clamping logic for markers symbolizer and sync with agg
 implementation

---
 src/grid/process_markers_symbolizer.cpp | 48 ++++++++++++++++++-------
 1 file changed, 35 insertions(+), 13 deletions(-)

diff --git a/src/grid/process_markers_symbolizer.cpp b/src/grid/process_markers_symbolizer.cpp
index 7c57b80b4..ca094af0d 100644
--- a/src/grid/process_markers_symbolizer.cpp
+++ b/src/grid/process_markers_symbolizer.cpp
@@ -71,7 +71,8 @@ void grid_renderer<T>::process(markers_symbolizer const& sym,
     agg::trans_affine tr;
     boost::array<double,6> const& m = sym.get_transform();
     tr.load_from(&m[0]);
-    tr = agg::trans_affine_scaling(scale_factor_*(1.0/pixmap_.get_resolution())) * tr;
+    unsigned int res = pixmap_.get_resolution();
+    tr = agg::trans_affine_scaling(scale_factor_*(1.0/res)) * tr;
     std::string filename = path_processor_type::evaluate(*sym.get_filename(), *feature);
     marker_placement_e placement_method = sym.get_marker_placement();
     marker_type_e marker_type = sym.get_marker_type();
@@ -87,6 +88,11 @@ void grid_renderer<T>::process(markers_symbolizer const& sym,
             double y1 = bbox.miny();
             double x2 = bbox.maxx();
             double y2 = bbox.maxy();
+            double w = (*mark)->width();
+            double h = (*mark)->height();
+            // clamp sizes
+            w = std::max(w,4.0);
+            h = std::max(w,4.0);
 
             agg::trans_affine recenter = agg::trans_affine_translation(-0.5*(x1+x2),-0.5*(y1+y2));
             tr.transform(&x1,&y1);
@@ -104,11 +110,27 @@ void grid_renderer<T>::process(markers_symbolizer const& sym,
             for (unsigned i=0; i<feature->num_geometries(); ++i)
             {
                 geometry_type & geom = feature->get_geometry(i);
-                if (geom.num_points() <= 1)
+                if (placement_method == MARKER_POINT_PLACEMENT || geom.num_points() <= 1)
                 {
-                    MAPNIK_LOG_WARN(grid_renderer) << "grid_renderer: markers_symbolizer points do not yet support SVG markers";
+                    double x;
+                    double y;
+                    double z=0;
+                    geom.label_interior_position(&x, &y);
+                    prj_trans.backward(x,y,z);
+                    t_.forward(&x,&y);
+                    extent.re_center(x,y);
 
-                    continue;
+                    if (sym.get_allow_overlap() ||
+                        detector_.has_placement(extent))
+                    {
+
+                        render_marker(feature,
+                                      pixmap_.get_resolution(),
+                                      pixel_position(x - 0.5 * w, y - 0.5 * h),
+                                      **mark,
+                                      tr,
+                                      sym.get_opacity());
+                    }
                 }
 
                 path_type path(t_,geom,prj_trans);
@@ -131,20 +153,17 @@ void grid_renderer<T>::process(markers_symbolizer const& sym,
     }
     else
     {
-        stroke const& stroke_ = sym.get_stroke();
-        double strk_width = stroke_.get_width();
 
         double w;
         double h;
-        unsigned int res = pixmap_.get_resolution();
-        if (res != 1) {
-            // clamp to at least 4 px otherwise interactive pixels can be too small
-            double min = static_cast<double>(4/pixmap_.get_resolution());
+        // clamp to at least 4 px otherwise interactive pixels can be too small
+        if (res == 1) {
+            w = std::max(sym.get_width(),4.0);
+            h = std::max(sym.get_height(),4.0);
+        } else {
+            double min = static_cast<double>(4.0/res);
             w = std::max(sym.get_width()/res,min);
             h = std::max(sym.get_height()/res,min);
-        } else {
-            w = sym.get_width()/res;
-            h = sym.get_height()/res;
         }
 
         double rx = w/2.0;
@@ -153,6 +172,9 @@ void grid_renderer<T>::process(markers_symbolizer const& sym,
         arrow arrow_;
         box2d<double> extent;
 
+        stroke const& stroke_ = sym.get_stroke();
+        double strk_width = stroke_.get_width();
+
         double dx = w + (2*strk_width);
         double dy = h + (2*strk_width);