From 99f9c5b4ba01860b348ef4b0b22c0c87ff818313 Mon Sep 17 00:00:00 2001
From: aavzz <aavzz@yandex.ru>
Date: Thu, 5 Apr 2018 12:46:02 +0400
Subject: [PATCH] Update ASCIIToSVG.php

Add more fine-grained control over which box is rendered above and which one is rendered below.
---
 ASCIIToSVG.php | 41 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 39 insertions(+), 2 deletions(-)

diff --git a/ASCIIToSVG.php b/ASCIIToSVG.php
index 10e7e65..d99d8c6 100644
--- a/ASCIIToSVG.php
+++ b/ASCIIToSVG.php
@@ -273,17 +273,19 @@ class SVGGroup {
   private $curGroup;
   private $groupStack;
   private $options;
+  private $index;
 
   public function __construct() {
     $this->groups = array();
     $this->groupStack = array();
     $this->options = array();
+    $this->index = 0;
   }
 
   public function getGroup($groupName) {
     return $this->groups[$groupName];
   }
-
+  
   public function pushGroup($groupName) {
     if (!isset($this->groups[$groupName])) {
       $this->groups[$groupName] = array();
@@ -304,10 +306,44 @@ public function popGroup() {
     $this->curGroup = array_pop($this->groupStack);
   }
 
+    /*
+    AAVZZ
+    Since SVG has no notion of layers, we emulate them by changing the order
+    of boxes. This involves tagging and reordering. Tagging is done in `addObject',
+    reordering in `rearrangeBoxes'. We tag a box with a layer prefix, like `a' (default),
+    `b', `c' and so on. So, the sequence numbers will be something like
+    a0, a1, b2, a3, a4, b5, c6 ...
+    Once all the boxes are parsed, we need to rearrange them like
+    a0, a1, a3, a4, b2, b5, c6 ...
+    and change the indices to be numeic (we rely on them being numeric!!)
+    XXX Some text lines belonging to overlying box are placed in underlying box
+    XXX and do not show up. Further investigation is necessary to place them correctly.
+    XXX This issue is not introduced with this patch.
+  */
+  
   public function addObject($o) {
-    $this->groups[$this->curGroup][] = $o;
+    if ($this->curGroup == "boxes") {
+      $layer = 'a';
+      if ($o->getOption('a2s:layer')) {
+          $layer = $o->getOption('a2s:layer');
+      }
+      $i =  $layer . $this->index++;
+      $this->groups[$this->curGroup][$i] = $o;
+    }
+    else {
+      $this->groups[$this->curGroup][] = $o;
+    }  
   }
 
+  public function rearrangeBoxes() {
+    $newboxes = array();
+    ksort($this->groups["boxes"], SORT_NATURAL);
+    foreach($this->groups["boxes"] as $index => $value) {
+        $newboxes[] = $value;
+    }
+    $this->groups["boxes"]=$newboxes;
+  }
+  
   public function setOption($opt, $val) {
     $this->options[$this->curGroup][$opt] = $val;
   }
@@ -1480,6 +1516,7 @@ private function parseBoxes() {
 
     /* Anything after this is not a subgroup */
     $this->svgObjects->popGroup();
+    $this->svgObjects->rearrangeBoxes();
   }
 
   /*