renable hsla filter as 'scale-hsla' - refs #1954

CHANGELOG.md

@@ -10,6 +10,8 @@ For a complete change history, see the git log.
 
 - Added `premultiplied` property on mapnik::image_32 / mapnik.Image to enable knowledge of premultiplied status of image buffer.
 
+- Added `scale-hsla` image-filter that allows scaling colors in HSL color space. RGB is converted to HSL (hue-saturation-lightness) and then each value (and the original alpha value) is stretched based on the specified scaling values. An example syntax is `scale-hsla(0,1,0,1,0,1,0,1)` which means no change because the full range will be kept (0 for lowest, 1 for highest). Other examples are: 1) `scale-hsla(0,0,0,1,0,1,0,1)` which would force all colors to be red in hue in the same way `scale-hsla(1,1,0,1,0,1,0,1)` would, 2) `scale-hsla(0,1,1,1,0,1,0,1)` which would cause all colors to become fully saturated, 3) `scale-hsla(0,1,1,1,0,1,.5,1)` which would force no colors to be any more transparent than half, and 4) `scale-hsla(0,1,1,1,0,1,0,.5)` which would force all colors to be at least half transparent. (#1954)
+
 ## 2.2.0
 
 Released June 3rd, 2013

include/mapnik/image_filter.hpp

@@ -483,9 +483,8 @@ void apply_filter(Src & src, colorize_alpha const& op)
     }
 }
 
-/*
 template <typename Src>
-void apply_filter(Src & src, hsla const& transform)
+void apply_filter(Src & src, scale_hsla const& transform)
 {
     using namespace boost::gil;
     bool tinting = !transform.is_identity();
@@ -504,16 +503,24 @@ void apply_filter(Src & src, hsla const& transform)
                 uint8_t & g = get_color(src_it[x], green_t());
                 uint8_t & b = get_color(src_it[x], blue_t());
                 uint8_t & a = get_color(src_it[x], alpha_t());
-                double a2 = a/255.0;
+                double a2 = static_cast<double>(a)/255.0;
                 double a1 = a2;
+                bool alpha_modified = false;
                 if (set_alpha && a2 > 0.01)
                 {
                     a2 = transform.a0 + (a2 * (transform.a1 - transform.a0));
+                    if (a2 <= 0)
+                    {
+                        a = 0;
+                    }
+                    else
+                    {
                         a = static_cast<unsigned>(std::floor((a2 * 255.0) +.5));
                         if (a > 255) a = 255;
-                    if (a < 0) a = 0;
                     }
-                if (tinting && a2 > 0.01)
+                    alpha_modified = true;
+                }
+                if (tinting && a > 1)
                 {
                     double h;
                     double s;
@@ -534,12 +541,12 @@ void apply_filter(Src & src, hsla const& transform)
                     double h2 = transform.h0 + (h * (transform.h1 - transform.h0));
                     double s2 = transform.s0 + (s * (transform.s1 - transform.s0));
                     double l2 = transform.l0 + (l * (transform.l1 - transform.l0));
-                    if (h2 > 1) { std::clog << "h2: " << h2 << "\n"; h2 = 1; }
-                    else if (h2 < 0) { std::clog << "h2: " << h2 << "\n"; h2 = 0; }
-                    if (s2 > 1) { std::clog << "h2: " << h2 << "\n"; s2 = 1; }
-                    else if (s2 < 0) { std::clog << "s2: " << s2 << "\n"; s2 = 0; }
-                    if (l2 > 1) { std::clog << "h2: " << h2 << "\n"; l2 = 1; }
-                    else if (l2 < 0) { std::clog << "l2: " << l2 << "\n"; l2 = 0; }
+                    if (h2 > 1) { h2 = 1; }
+                    else if (h2 < 0) { h2 = 0; }
+                    if (s2 > 1) { s2 = 1; }
+                    else if (s2 < 0) { s2 = 0; }
+                    if (l2 > 1) { l2 = 1; }
+                    else if (l2 < 0) { l2 = 0; }
                     hsl2rgb(h2,s2,l2,r,g,b);
                     // premultiply
                     // we only work with premultiplied source,
@@ -548,7 +555,7 @@ void apply_filter(Src & src, hsla const& transform)
                     g *= a2;
                     b *= a2;
                 }
-                else
+                else if (alpha_modified)
                 {
                     // demultiply
                     if (a1 <= 0.0)
@@ -573,7 +580,6 @@ void apply_filter(Src & src, hsla const& transform)
         }
     }
 }
-*/
 
 template <typename Src>
 void apply_filter(Src & src, gray const& op)

include/mapnik/image_filter_grammar.hpp

@@ -67,8 +67,8 @@ struct image_filter_grammar :
     qi::rule<Iterator, ContType(), qi::ascii::space_type> start;
     qi::rule<Iterator, ContType(), qi::ascii::space_type> filter;
     qi::rule<Iterator, qi::locals<int,int>, void(ContType&), qi::ascii::space_type> agg_blur_filter;
-    //qi::rule<Iterator, qi::locals<double,double,double,double,double,double,double,double>,
-    //         void(ContType&), qi::ascii::space_type> hsla_filter;
+    qi::rule<Iterator, qi::locals<double,double,double,double,double,double,double,double>,
+             void(ContType&), qi::ascii::space_type> scale_hsla_filter;
     qi::rule<Iterator, qi::locals<mapnik::filter::colorize_alpha, mapnik::filter::color_stop>, void(ContType&), qi::ascii::space_type> colorize_alpha_filter;
     qi::rule<Iterator, qi::ascii::space_type> no_args;
     qi::uint_parser< unsigned, 10, 1, 3 > radius_;

include/mapnik/image_filter_types.hpp

@@ -28,7 +28,6 @@
 #include <mapnik/color.hpp>
 // boost
 #include <boost/variant.hpp>
-#include <boost/variant/variant_fwd.hpp>
 // stl
 #include <vector>
 #include <ostream>
@@ -54,10 +53,9 @@ struct agg_stack_blur
     unsigned ry;
 };
 
-/*
-struct hsla
+struct scale_hsla
 {
-    hsla(double _h0, double _h1,
+    scale_hsla(double _h0, double _h1,
          double _s0, double _s1,
          double _l0, double _l1,
          double _a0, double _a1) :
@@ -81,14 +79,6 @@ struct hsla
         return (a0 == 0 &&
                 a1 == 1);
     }
-    std::string to_string() const {
-        std::ostringstream s;
-        s << h0 << "x" << h1 << ";"
-          << s0 << "x" << s1 << ";"
-          << l0 << "x" << l1 << ";"
-          << a0 << "x" << a1;
-        return s.str();
-    }
     double h0;
     double h1;
     double s0;
@@ -98,7 +88,6 @@ struct hsla
     double a0;
     double a1;
 };
-*/
 
 struct color_stop
 {
@@ -124,7 +113,7 @@ typedef boost::variant<filter::blur,
                        filter::x_gradient,
                        filter::y_gradient,
                        filter::invert,
-                       //filter::hsla,
+                       filter::scale_hsla,
                        filter::colorize_alpha> filter_type;
 
 inline std::ostream& operator<< (std::ostream& os, blur)
@@ -145,16 +134,14 @@ inline std::ostream& operator<< (std::ostream& os, agg_stack_blur const& filter)
     return os;
 }
 
-/*
-inline std::ostream& operator<< (std::ostream& os, hsla const& filter)
+inline std::ostream& operator<< (std::ostream& os, scale_hsla const& filter)
 {
-    os << "hsla(" << filter.h0 << 'x' << filter.h1 << ':'
+    os << "hsla-transform(" << filter.h0 << 'x' << filter.h1 << ':'
                   << filter.s0 << 'x' << filter.s1 << ':'
                   << filter.l0 << 'x' << filter.l1 << ':'
                   << filter.a0 << 'x' << filter.a1 << ')';
     return os;
 }
-*/
 
 inline std::ostream& operator<< (std::ostream& os, emboss)
 {
@@ -198,7 +185,27 @@ inline std::ostream& operator<< (std::ostream& os, invert)
     return os;
 }
 
-inline std::ostream& operator<< (std::ostream& os, filter_type const& filter);
+template <typename Out>
+struct to_string_visitor : boost::static_visitor<void>
+{
+    to_string_visitor(Out & out)
+    : out_(out) {}
+
+    template <typename T>
+    void operator () (T const& filter_tag)
+    {
+        out_ << filter_tag;
+    }
+
+    Out & out_;
+};
+
+inline std::ostream& operator<< (std::ostream& os, filter_type const& filter)
+{
+    to_string_visitor<std::ostream> visitor(os);
+    boost::apply_visitor(visitor, filter);
+    return os;
+}
 
 MAPNIK_DECL bool generate_image_filters(std::back_insert_iterator<std::string> & sink, std::vector<filter_type> const& v);
 

src/image_filter_grammar.cpp

@@ -88,8 +88,8 @@ image_filter_grammar<Iterator,ContType>::image_filter_grammar()
         |
         agg_blur_filter(_val)
         |
-        //hsla_filter(_val)
-        //|
+        scale_hsla_filter(_val)
+        |
         colorize_alpha_filter(_val)
         ;
 
@@ -100,16 +100,14 @@ image_filter_grammar<Iterator,ContType>::image_filter_grammar()
         [push_back(_r1,construct<mapnik::filter::agg_stack_blur>(_a,_b))]
         ;
 
-    /*
-    hsla_filter = lit("hsla")
+    scale_hsla_filter = lit("scale-hsla")
         >> lit('(')
-        >> double_[_a = _1] >> lit('x') >> double_[_b = _1] >> lit(';')
-        >> double_[_c = _1] >> lit('x') >> double_[_d = _1] >> lit(';')
-        >> double_[_e = _1] >> lit('x') >> double_[_f = _1] >> lit(';')
-        >> double_[_g = _1] >> lit('x') >> double_[_h = _1] >> lit(')')
-        [push_back(_r1, construct<mapnik::filter::hsla>(_a,_b,_c,_d,_e,_f,_g,_h))]
+        >> double_[_a = _1] >> lit(',') >> double_[_b = _1] >> lit(',')
+        >> double_[_c = _1] >> lit(',') >> double_[_d = _1] >> lit(',')
+        >> double_[_e = _1] >> lit(',') >> double_[_f = _1] >> lit(',')
+        >> double_[_g = _1] >> lit(',') >> double_[_h = _1] >> lit(')')
+        [push_back(_r1, construct<mapnik::filter::scale_hsla>(_a,_b,_c,_d,_e,_f,_g,_h))]
         ;
-    */
 
     colorize_alpha_filter = lit("colorize-alpha")[_a = construct<mapnik::filter::colorize_alpha>()]
         >> lit('(')

src/image_filter_types.cpp

@@ -34,28 +34,6 @@ namespace mapnik {
 
 namespace filter {
 
-template <typename Out>
-struct to_string_visitor : boost::static_visitor<void>
-{
-    to_string_visitor(Out & out)
-    : out_(out) {}
-
-    template <typename T>
-    void operator () (T const& filter_tag)
-    {
-        out_ << filter_tag;
-    }
-
-    Out & out_;
-};
-
-inline std::ostream& operator<< (std::ostream& os, filter_type const& filter)
-{
-    to_string_visitor<std::ostream> visitor(os);
-    boost::apply_visitor(visitor, filter);
-    return os;
-}
-
 bool generate_image_filters(std::back_insert_iterator<std::string>& sink, std::vector<filter_type> const& filters)
 {
     using boost::spirit::karma::stream;

tests/visual_tests/styles/marker-with-background-image-and-hsla-transform.xml

@@ -1,6 +1,9 @@
 <Map srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs" background-image="../../data/images/checker.jpg">
 
-    <Style name="ellipse" image-filters="hsla(0x.5;.5x1;0x.5;0x1)">
+    <Style name="ellipse"
+      direct-image-filters=" scale-hsla(0,1,0,1,0,1,0,.5)"
+      image-filters="scale-hsla(.1,.9,.5,1,.5,1,.2,1)"
+      >
         <Rule>
             <MarkersSymbolizer
               width="240"

tests/visual_tests/test.py

@@ -102,7 +102,7 @@ files = {
     'marker-on-line-spacing-eq-width-overlap': {'sizes':[(600,400)]},
     'marker_line_placement_on_points':{},
     'marker-with-background-image': {'sizes':[(600,400),(400,600),(257,256)]},
-    #'marker-with-background-image-and-hsla-transform': {'sizes':[(600,400),(400,600),(257,256)]},
+    'marker-with-background-image-and-hsla-transform': {'sizes':[(600,400),(400,600),(257,256)]},
     'marker-on-hex-grid': {'sizes':[(600,400),(400,600),(257,256)]},
     'whole-centroid': {'sizes':[(600,400)],
         'bbox': mapnik.Box2d(736908, 4390316, 2060771, 5942346)},