diff --git a/docs/textrendering.gv b/docs/textrendering.gv
index 90a897a6ae..26bf9fb1f1 100644
--- a/docs/textrendering.gv
+++ b/docs/textrendering.gv
@@ -1,13 +1,14 @@
-#process with: dot textrendering.gv -Tpng > textrendering.png
+/* process with: dot textrendering.gv -Tsvg > textrendering.svg */
 digraph textrendering {
-# Classes without important virtual members: Round
-# Classes with    important virtual members: Rect
-# Pointers [style=dashed]
-# Red: function is called
+  /* Classes without important virtual members: Round
+     Classes with    important virtual members: Rect
+     Pointers [style=dashed] */
+
+  Renderer [color=red]
+  rankdir="TD";
   text_placements[shape=box]
   text_placement_info[shape=box]
-  Renderer
-
+  node_ -> text_processor [label="tree_", style=dashed]
   TextSymbolizer -> text_placements [label="placement_options_", style=dashed]
   text_placements -> text_symbolizer_properties [label="properties"]
   text_placements -> text_placement_info [label="get_placement_info()", style=dashed]
@@ -16,9 +17,24 @@ digraph textrendering {
   text_placement_info -> text_placement_info [label="next()"]
   text_symbolizer_properties -> text_processor [label="processor"]
   text_processor ->  processed_text [label="process()", style=dashed]
-  processed_text -> string_info [label="get_string_info()"]
+  processed_text -> string_info [label="get_string_info()", style=dashed]
   text_path -> Renderer [color=red, label="used by"]
-  Renderer -> text_placement_info [color=red, label="init()"]
-  Renderer -> processed_text [color=red, label="initializes"]
+  processed_text -> Renderer [color=red, label="owned by"]
+  Renderer -> text_symbolizer_helper [color=red, label="creates"]
+  text_symbolizer_helper -> placement_finder [color=red, label="creates"]
+  placement_finder -> text_path [color=red, label="creates"]
+  string_info -> placement_finder [color=red, label="used by"]
+  text_processor -> Renderer [color=red, label="called by"]
+  text_placement_info -> Renderer [color=red, label="used by"]
+  
   
+  node_[label="node"]
+  node_ -> text_node [style=dashed]
+  node_ -> list_node [style=dashed]
+  node_ -> format_node [style=dashed]
+  list_node -> text_node [style=dashed]
+  list_node -> format_node [style=dashed]
+  format_node -> text_node [style=dashed]
+   { rank=same; text_path text_symbolizer_helper }
+   { rank=same; node_ TextSymbolizer}
 }
diff --git a/docs/textrendering.png b/docs/textrendering.png
new file mode 100644
index 0000000000..ee7b33c4b9
Binary files /dev/null and b/docs/textrendering.png differ
diff --git a/docs/textrendering.svg b/docs/textrendering.svg
new file mode 100644
index 0000000000..9a3e2f8345
--- /dev/null
+++ b/docs/textrendering.svg
@@ -0,0 +1,226 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
+ "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<!-- Generated by graphviz version 2.26.3 (20100126.1600)
+ -->
+<!-- Title: textrendering Pages: 1 -->
+<svg width="733pt" height="782pt"
+ viewBox="0.00 0.00 733.00 782.00" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+<g id="graph1" class="graph" transform="scale(1 1) rotate(0) translate(4 778)">
+<title>textrendering</title>
+<polygon fill="white" stroke="white" points="-4,5 -4,-778 730,-778 730,5 -4,5"/>
+<!-- Renderer -->
+<g id="node1" class="node"><title>Renderer</title>
+<ellipse fill="none" stroke="red" cx="220" cy="-216" rx="55.0898" ry="18"/>
+<text text-anchor="middle" x="220" y="-211.9" font-family="Times Roman,serif" font-size="14.00">Renderer</text>
+</g>
+<!-- text_symbolizer_helper -->
+<g id="node24" class="node"><title>text_symbolizer_helper</title>
+<ellipse fill="none" stroke="black" cx="257" cy="-108" rx="123.188" ry="18"/>
+<text text-anchor="middle" x="257" y="-103.9" font-family="Times Roman,serif" font-size="14.00">text_symbolizer_helper</text>
+</g>
+<!-- Renderer&#45;&gt;text_symbolizer_helper -->
+<g id="edge26" class="edge"><title>Renderer&#45;&gt;text_symbolizer_helper</title>
+<path fill="none" stroke="red" d="M226.277,-197.679C232.106,-180.665 240.865,-155.097 247.541,-135.609"/>
+<polygon fill="red" stroke="red" points="250.886,-136.645 250.816,-126.05 244.264,-134.376 250.886,-136.645"/>
+<text text-anchor="middle" x="269.5" y="-157.9" font-family="Times Roman,serif" font-size="14.00">creates</text>
+</g>
+<!-- text_placements -->
+<g id="node2" class="node"><title>text_placements</title>
+<polygon fill="none" stroke="black" points="320,-684 190,-684 190,-648 320,-648 320,-684"/>
+<text text-anchor="middle" x="255" y="-661.9" font-family="Times Roman,serif" font-size="14.00">text_placements</text>
+</g>
+<!-- text_placement_info -->
+<g id="node3" class="node"><title>text_placement_info</title>
+<polygon fill="none" stroke="black" points="245,-594 89,-594 89,-558 245,-558 245,-594"/>
+<text text-anchor="middle" x="167" y="-571.9" font-family="Times Roman,serif" font-size="14.00">text_placement_info</text>
+</g>
+<!-- text_placements&#45;&gt;text_placement_info -->
+<g id="edge8" class="edge"><title>text_placements&#45;&gt;text_placement_info</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M205.049,-647.841C196.813,-643.062 189.015,-637.176 183,-630 176.839,-622.65 173.05,-613.005 170.721,-603.902"/>
+<polygon fill="black" stroke="black" points="174.125,-603.084 168.661,-594.007 167.272,-604.511 174.125,-603.084"/>
+<text text-anchor="middle" x="255.5" y="-616.9" font-family="Times Roman,serif" font-size="14.00">get_placement_info()</text>
+</g>
+<!-- text_symbolizer_properties -->
+<g id="node10" class="node"><title>text_symbolizer_properties</title>
+<ellipse fill="none" stroke="black" cx="342" cy="-486" rx="141.756" ry="18"/>
+<text text-anchor="middle" x="342" y="-481.9" font-family="Times Roman,serif" font-size="14.00">text_symbolizer_properties</text>
+</g>
+<!-- text_placements&#45;&gt;text_symbolizer_properties -->
+<g id="edge6" class="edge"><title>text_placements&#45;&gt;text_symbolizer_properties</title>
+<path fill="none" stroke="black" d="M308.282,-647.955C315.947,-643.223 322.938,-637.323 328,-630 351.634,-595.806 350.563,-545.645 346.851,-514.45"/>
+<polygon fill="black" stroke="black" points="350.281,-513.701 345.464,-504.264 343.345,-514.645 350.281,-513.701"/>
+<text text-anchor="middle" x="383" y="-571.9" font-family="Times Roman,serif" font-size="14.00">properties</text>
+</g>
+<!-- text_placement_info&#45;&gt;Renderer -->
+<g id="edge36" class="edge"><title>text_placement_info&#45;&gt;Renderer</title>
+<path fill="none" stroke="red" d="M167.966,-557.734C168.843,-539.556 170,-510.858 170,-486 170,-486 170,-486 170,-306 170,-281.884 183.888,-258.188 197.026,-241.169"/>
+<polygon fill="red" stroke="red" points="199.765,-243.348 203.351,-233.378 194.331,-238.936 199.765,-243.348"/>
+<text text-anchor="middle" x="197" y="-391.9" font-family="Times Roman,serif" font-size="14.00">used by</text>
+</g>
+<!-- text_placement_info&#45;&gt;text_placement_info -->
+<g id="edge14" class="edge"><title>text_placement_info&#45;&gt;text_placement_info</title>
+<path fill="none" stroke="black" d="M245.347,-583.319C255.944,-582.092 263,-579.652 263,-576 263,-573.66 260.104,-571.818 255.237,-570.474"/>
+<polygon fill="black" stroke="black" points="255.811,-567.021 245.347,-568.681 254.562,-573.909 255.811,-567.021"/>
+<text text-anchor="middle" x="284.5" y="-571.9" font-family="Times Roman,serif" font-size="14.00">next()</text>
+</g>
+<!-- text_placement_info&#45;&gt;text_symbolizer_properties -->
+<g id="edge10" class="edge"><title>text_placement_info&#45;&gt;text_symbolizer_properties</title>
+<path fill="none" stroke="black" d="M195.152,-557.999C212.864,-547.001 236.382,-532.987 258,-522 267.963,-516.936 278.802,-511.934 289.282,-507.342"/>
+<polygon fill="black" stroke="black" points="290.973,-510.425 298.77,-503.251 288.201,-503.997 290.973,-510.425"/>
+<text text-anchor="middle" x="293" y="-526.9" font-family="Times Roman,serif" font-size="14.00">properties</text>
+</g>
+<!-- text_path -->
+<g id="node14" class="node"><title>text_path</title>
+<ellipse fill="none" stroke="black" cx="58" cy="-108" rx="57.8712" ry="18"/>
+<text text-anchor="middle" x="58" y="-103.9" font-family="Times Roman,serif" font-size="14.00">text_path</text>
+</g>
+<!-- text_placement_info&#45;&gt;text_path -->
+<g id="edge12" class="edge"><title>text_placement_info&#45;&gt;text_path</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M126.007,-557.868C99.1525,-542.905 69,-518.802 69,-486 69,-486 69,-486 69,-216 69,-188.913 65.5331,-158.201 62.492,-136.471"/>
+<polygon fill="black" stroke="black" points="65.9132,-135.677 61.0058,-126.287 58.9866,-136.688 65.9132,-135.677"/>
+<text text-anchor="middle" x="108.5" y="-346.9" font-family="Times Roman,serif" font-size="14.00">placements</text>
+</g>
+<!-- node_ -->
+<g id="node4" class="node"><title>node_</title>
+<ellipse fill="none" stroke="black" cx="621" cy="-756" rx="34.2406" ry="18"/>
+<text text-anchor="middle" x="621" y="-751.9" font-family="Times Roman,serif" font-size="14.00">node</text>
+</g>
+<!-- text_processor -->
+<g id="node6" class="node"><title>text_processor</title>
+<ellipse fill="none" stroke="black" cx="369" cy="-396" rx="81.9961" ry="18"/>
+<text text-anchor="middle" x="369" y="-391.9" font-family="Times Roman,serif" font-size="14.00">text_processor</text>
+</g>
+<!-- node_&#45;&gt;text_processor -->
+<g id="edge2" class="edge"><title>node_&#45;&gt;text_processor</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M641.466,-741.272C661.17,-725.215 688,-697.556 688,-666 688,-666 688,-666 688,-486 688,-437.627 550.415,-413.974 455.959,-403.435"/>
+<polygon fill="black" stroke="black" points="456.134,-399.933 445.814,-402.334 455.379,-406.892 456.134,-399.933"/>
+<text text-anchor="middle" x="706.5" y="-571.9" font-family="Times Roman,serif" font-size="14.00">tree_</text>
+</g>
+<!-- text_node -->
+<g id="node32" class="node"><title>text_node</title>
+<ellipse fill="none" stroke="black" cx="600" cy="-486" rx="59.7599" ry="18"/>
+<text text-anchor="middle" x="600" y="-481.9" font-family="Times Roman,serif" font-size="14.00">text_node</text>
+</g>
+<!-- node_&#45;&gt;text_node -->
+<g id="edge38" class="edge"><title>node_&#45;&gt;text_node</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M621.64,-737.953C622.123,-723.392 622.745,-702.38 623,-684 624.004,-611.699 620.132,-593.283 608,-522 607.568,-519.46 607.073,-516.828 606.548,-514.197"/>
+<polygon fill="black" stroke="black" points="609.934,-513.295 604.426,-504.244 603.088,-514.754 609.934,-513.295"/>
+</g>
+<!-- list_node -->
+<g id="node34" class="node"><title>list_node</title>
+<ellipse fill="none" stroke="black" cx="560" cy="-666" rx="54.2008" ry="18"/>
+<text text-anchor="middle" x="560" y="-661.9" font-family="Times Roman,serif" font-size="14.00">list_node</text>
+</g>
+<!-- node_&#45;&gt;list_node -->
+<g id="edge40" class="edge"><title>node_&#45;&gt;list_node</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M609.239,-738.647C600.267,-725.41 587.763,-706.962 577.602,-691.97"/>
+<polygon fill="black" stroke="black" points="580.441,-689.921 571.933,-683.607 574.647,-693.848 580.441,-689.921"/>
+</g>
+<!-- format_node -->
+<g id="node36" class="node"><title>format_node</title>
+<ellipse fill="none" stroke="black" cx="502" cy="-576" rx="71.7694" ry="18"/>
+<text text-anchor="middle" x="502" y="-571.9" font-family="Times Roman,serif" font-size="14.00">format_node</text>
+</g>
+<!-- node_&#45;&gt;format_node -->
+<g id="edge42" class="edge"><title>node_&#45;&gt;format_node</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M590.428,-747.872C560.614,-738.135 516.934,-718.626 497,-684 483.032,-659.737 487.038,-627.084 492.815,-604.055"/>
+<polygon fill="black" stroke="black" points="496.244,-604.787 495.536,-594.216 489.497,-602.921 496.244,-604.787"/>
+</g>
+<!-- text_processor&#45;&gt;Renderer -->
+<g id="edge34" class="edge"><title>text_processor&#45;&gt;Renderer</title>
+<path fill="none" stroke="red" d="M314.995,-382.308C284.546,-371.64 248.752,-353.535 229,-324 213.308,-300.537 212.917,-267.483 215.283,-244.138"/>
+<polygon fill="red" stroke="red" points="218.762,-244.519 216.518,-234.164 211.815,-243.658 218.762,-244.519"/>
+<text text-anchor="middle" x="259.5" y="-301.9" font-family="Times Roman,serif" font-size="14.00">called by</text>
+</g>
+<!-- processed_text -->
+<g id="node18" class="node"><title>processed_text</title>
+<ellipse fill="none" stroke="black" cx="382" cy="-306" rx="82.8866" ry="18"/>
+<text text-anchor="middle" x="382" y="-301.9" font-family="Times Roman,serif" font-size="14.00">processed_text</text>
+</g>
+<!-- text_processor&#45;&gt;processed_text -->
+<g id="edge18" class="edge"><title>text_processor&#45;&gt;processed_text</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M371.631,-377.787C373.428,-365.344 375.846,-348.605 377.895,-334.421"/>
+<polygon fill="black" stroke="black" points="381.408,-334.583 379.373,-324.186 374.479,-333.583 381.408,-334.583"/>
+<text text-anchor="middle" x="407" y="-346.9" font-family="Times Roman,serif" font-size="14.00">process()</text>
+</g>
+<!-- TextSymbolizer -->
+<g id="node7" class="node"><title>TextSymbolizer</title>
+<ellipse fill="none" stroke="black" cx="255" cy="-756" rx="84.7756" ry="18"/>
+<text text-anchor="middle" x="255" y="-751.9" font-family="Times Roman,serif" font-size="14.00">TextSymbolizer</text>
+</g>
+<!-- TextSymbolizer&#45;&gt;text_placements -->
+<g id="edge4" class="edge"><title>TextSymbolizer&#45;&gt;text_placements</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M255,-737.787C255,-725.344 255,-708.605 255,-694.421"/>
+<polygon fill="black" stroke="black" points="258.5,-694.186 255,-684.186 251.5,-694.186 258.5,-694.186"/>
+<text text-anchor="middle" x="323.5" y="-706.9" font-family="Times Roman,serif" font-size="14.00">placement_options_</text>
+</g>
+<!-- text_symbolizer_properties&#45;&gt;text_processor -->
+<g id="edge16" class="edge"><title>text_symbolizer_properties&#45;&gt;text_processor</title>
+<path fill="none" stroke="black" d="M347.464,-467.787C351.233,-455.222 356.317,-438.277 360.599,-424.005"/>
+<polygon fill="black" stroke="black" points="364.023,-424.77 363.544,-414.186 357.318,-422.758 364.023,-424.77"/>
+<text text-anchor="middle" x="390" y="-436.9" font-family="Times Roman,serif" font-size="14.00">processor</text>
+</g>
+<!-- text_path&#45;&gt;Renderer -->
+<g id="edge22" class="edge"><title>text_path&#45;&gt;Renderer</title>
+<path fill="none" stroke="red" d="M82.6849,-124.457C110.585,-143.056 156.131,-173.421 187.049,-194.033"/>
+<polygon fill="red" stroke="red" points="185.485,-197.196 195.747,-199.831 189.368,-191.372 185.485,-197.196"/>
+<text text-anchor="middle" x="190" y="-157.9" font-family="Times Roman,serif" font-size="14.00">used by</text>
+</g>
+<!-- processed_text&#45;&gt;Renderer -->
+<g id="edge24" class="edge"><title>processed_text&#45;&gt;Renderer</title>
+<path fill="none" stroke="red" d="M337.974,-290.733C323.299,-284.984 307.105,-277.902 293,-270 277.318,-261.215 261.124,-249.543 247.984,-239.299"/>
+<polygon fill="red" stroke="red" points="249.834,-236.298 239.827,-232.817 245.479,-241.779 249.834,-236.298"/>
+<text text-anchor="middle" x="327" y="-256.9" font-family="Times Roman,serif" font-size="14.00">owned by</text>
+</g>
+<!-- string_info -->
+<g id="node20" class="node"><title>string_info</title>
+<ellipse fill="none" stroke="black" cx="385" cy="-162" rx="61.8445" ry="18"/>
+<text text-anchor="middle" x="385" y="-157.9" font-family="Times Roman,serif" font-size="14.00">string_info</text>
+</g>
+<!-- processed_text&#45;&gt;string_info -->
+<g id="edge20" class="edge"><title>processed_text&#45;&gt;string_info</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M382.38,-287.762C382.892,-263.201 383.807,-219.247 384.409,-190.354"/>
+<polygon fill="black" stroke="black" points="387.914,-190.16 384.623,-180.09 380.916,-190.015 387.914,-190.16"/>
+<text text-anchor="middle" x="440" y="-256.9" font-family="Times Roman,serif" font-size="14.00">get_string_info()</text>
+</g>
+<!-- placement_finder -->
+<g id="node26" class="node"><title>placement_finder</title>
+<ellipse fill="none" stroke="black" cx="257" cy="-18" rx="93.8091" ry="18"/>
+<text text-anchor="middle" x="257" y="-13.9" font-family="Times Roman,serif" font-size="14.00">placement_finder</text>
+</g>
+<!-- string_info&#45;&gt;placement_finder -->
+<g id="edge32" class="edge"><title>string_info&#45;&gt;placement_finder</title>
+<path fill="none" stroke="red" d="M391.337,-143.803C395.524,-128.385 398.65,-106.256 389,-90 373.987,-64.7104 346.622,-47.7353 320.685,-36.6545"/>
+<polygon fill="red" stroke="red" points="321.803,-33.3312 311.22,-32.8342 319.183,-39.8225 321.803,-33.3312"/>
+<text text-anchor="middle" x="422" y="-103.9" font-family="Times Roman,serif" font-size="14.00">used by</text>
+</g>
+<!-- text_symbolizer_helper&#45;&gt;placement_finder -->
+<g id="edge28" class="edge"><title>text_symbolizer_helper&#45;&gt;placement_finder</title>
+<path fill="none" stroke="red" d="M257,-89.7872C257,-77.3443 257,-60.6053 257,-46.4211"/>
+<polygon fill="red" stroke="red" points="260.5,-46.1857 257,-36.1858 253.5,-46.1858 260.5,-46.1857"/>
+<text text-anchor="middle" x="282.5" y="-58.9" font-family="Times Roman,serif" font-size="14.00">creates</text>
+</g>
+<!-- placement_finder&#45;&gt;text_path -->
+<g id="edge30" class="edge"><title>placement_finder&#45;&gt;text_path</title>
+<path fill="none" stroke="red" d="M220.029,-34.7207C185.996,-50.1122 135.554,-72.9254 100.01,-89.0004"/>
+<polygon fill="red" stroke="red" points="98.53,-85.8285 90.8608,-93.1383 101.415,-92.2065 98.53,-85.8285"/>
+<text text-anchor="middle" x="201.5" y="-58.9" font-family="Times Roman,serif" font-size="14.00">creates</text>
+</g>
+<!-- list_node&#45;&gt;text_node -->
+<g id="edge44" class="edge"><title>list_node&#45;&gt;text_node</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M566.643,-647.87C571.723,-633.439 578.583,-612.642 583,-594 589.356,-567.176 593.972,-536.027 596.776,-514.095"/>
+<polygon fill="black" stroke="black" points="600.255,-514.481 598.007,-504.127 593.308,-513.623 600.255,-514.481"/>
+</g>
+<!-- list_node&#45;&gt;format_node -->
+<g id="edge46" class="edge"><title>list_node&#45;&gt;format_node</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M548.541,-648.219C540.175,-635.237 528.69,-617.415 519.222,-602.724"/>
+<polygon fill="black" stroke="black" points="521.993,-600.562 513.634,-594.052 516.109,-604.354 521.993,-600.562"/>
+</g>
+<!-- format_node&#45;&gt;text_node -->
+<g id="edge48" class="edge"><title>format_node&#45;&gt;text_node</title>
+<path fill="none" stroke="black" stroke-dasharray="5,2" d="M521.362,-558.219C536.318,-544.483 557.176,-525.328 573.652,-510.197"/>
+<polygon fill="black" stroke="black" points="576.346,-512.475 581.344,-503.134 571.611,-507.32 576.346,-512.475"/>
+</g>
+</g>
+</svg>