Working with future mapnik, but oddly implemented, rastercolorizer

lib/carto/functions.js

@@ -12,6 +12,25 @@ tree.functions = {
     hsl: function (h, s, l) {
         return this.hsla(h, s, l, 1.0);
     },
+    // Only require val
+    stop: function (val) {
+        if (arguments.length > 1) var color = arguments[1];
+        if (arguments.length > 2) var mode = arguments[2];
+
+        return {
+            is: 'tag',
+            val: val,
+            color: color,
+            mode: mode,
+            toString: function(env) {
+                return '\n\t<stop value="' + val.eval(env) + '"' +
+                    (color ? ' color="' + color.eval(env) + '" ' : '') +
+                    (mode ? ' mode="' + mode.eval(env) + '" ' : '') +
+                    '/>';
+
+            }
+        };
+    },
     hsla: function (h, s, l, a) {
         h = (number(h) % 360) / 360;
         s = number(s); l = number(l); a = number(a);

lib/carto/tree/call.js

@@ -6,6 +6,7 @@
 tree.Call = function Call(name, args, index) {
     this.name = name;
     this.args = args;
+    this.is = 'call';
     this.index = index;
 };
 tree.Call.prototype = {
@@ -34,7 +35,7 @@ tree.Call.prototype = {
         }
 
         if (this.name in tree.functions) { // 1.
-            if (tree.functions[this.name].length === args.length) {
+            if (tree.functions[this.name].length < args.length) {
                 return tree.functions[this.name].apply(tree.functions, args);
             } else {
                 env.error({

lib/carto/tree/definition.js

@@ -111,6 +111,9 @@ tree.Definition.prototype.symbolizersToXML = function(env, symbolizers, zoom) {
             if (x && x.serialization && x.serialization === 'content') {
                 selfclosing = false;
                 tagcontent = attributes[key].eval(env).toXML(env, true);
+            } else if (x && x.serialization && x.serialization === 'tag') {
+                selfclosing = false;
+                tagcontent = attributes[key].eval(env).toXML(env, true);
             } else {
                 xml += attributes[key].eval(env).toXML(env) + ' ';
             }

lib/carto/tree/reference.js

@@ -113,6 +113,12 @@ tree.Reference.validValue = function(env, selector, value) {
                 }
             }
             return true;
+        } else if (tree.Reference.selector(selector).type == 'tags') {
+            if (!value.value) return false;
+            for (i = 0; i < value.value[0].value.length; i++) {
+                if (value.value[0].value[i].is !== 'tag') return false;
+            }
+            return true;
         } else {
             if (tree.Reference.selector(selector).validate) {
                 var valid = false;

lib/carto/tree/reference.json

@@ -575,6 +575,28 @@
                     "gaussian",
                     "lanczos"
                 ]
+            },
+            "colorizer-default-mode": {
+                "css": "raster-colorizer-default-mode",
+                "type": [
+                    "discrete",
+                    "linear",
+                    "exact"
+                ]
+            },
+            "colorizer-default-color": {
+                "css": "raster-colorizer-default-color",
+                "type": "color"
+            },
+            "colorizer-epsilon": {
+                "css": "raster-colorizer-epsilon",
+                "type": "float"
+            },
+            "stop": {
+                "css": "raster-colorizer-stops",
+                "type": "tags",
+                "serialization": "tag",
+                "tagname": "tagname"
             }
         },
         "point": {

test/rendering/rastercolorizer.mml

@@ -0,0 +1,14 @@
+{
+    "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+    "Stylesheet": [
+        "rastercolorizer.mss"
+    ],
+    "Layer": [{
+        "name": "world",
+        "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+        "Datasource": {
+            "file": "http://tilemill-data.s3.amazonaws.com/test_data/shape_demo.zip",
+            "type": "shape"
+        }
+    }]
+}

test/rendering/rastercolorizer.mss

@@ -0,0 +1,10 @@
+#world {
+  raster-opacity:0;
+  raster-colorizer-default-mode:discrete;
+  raster-colorizer-default-color:#f00;
+  raster-colorizer-epsilon:0.05;
+  raster-colorizer-stops:
+    stop(5, #f00)
+    stop(10, #f40, linear)
+    stop(10, #f80);
+}