source/collada/XMLFix.cpp

   1 /* Copyright (C) 2023 Wildfire Games.
   2  * This file is part of 0 A.D.
   3  *
   4  * 0 A.D. is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * 0 A.D. is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "precompiled.h"
  19
  20 #include "XMLFix.h"
  21
  22 #include "CommonConvert.h"
  23
  24 #include "FUtils/FUXmlParser.h"
  25
  26 #include <libxml/parser.h>
  27
  28 /*
  29
  30 Things that are fixed here:
  31
  32 ----
  33
  34 3ds Max "file://" image URLs
  35
  36 Identifier: /COLLADA/asset/contributor/authoring_tool = "FBX COLLADA exporter"
  37
  38 Problem: /COLLADA/library_images/image/init_from = "file://" which crashes some versions of FCollada
  39
  40 Fix: Delete the whole library_images subtree, since we never use it anyway.
  41 Then delete library_effects and library_materials too, to avoid broken references.
  42
  43 ----
  44
  45 3ds Max broken material references
  46
  47 Identifier: /COLLADA/asset/contributor/authoring_tool = "FBX COLLADA exporter"
  48
  49 Problem: /COLLADA/library_visual_scenes/.../instance_material/@target sometimes
  50 refers to non-existent material IDs.
  51
  52 Fix: Delete the whole bind_material subtree, since we never use it anyway.
  53
  54 ----
  55
  56 */
  57
  58 static xmlNode* findChildElement(xmlNode* node, const char* name)
  59 {
  60         for (xmlNode* child = node->children; child; child = child->next)
  61         {
  62                 if (child->type == XML_ELEMENT_NODE && strcmp((const char*)child->name, name) == 0)
  63                         return child;
  64         }
  65         return NULL;
  66 }
  67
  68 static bool applyFBXFixesNode(xmlNode* node)
  69 {
  70         bool changed = false;
  71         for (xmlNode* child = node->children; child; child = child->next)
  72         {
  73                 if (child->type == XML_ELEMENT_NODE)
  74                 {
  75                         if (strcmp((const char*)child->name, "node") == 0)
  76                         {
  77                                 if (applyFBXFixesNode(child))
  78                                         changed = true;
  79                         }
  80                         else if (strcmp((const char*)child->name, "instance_geometry") == 0)
  81                         {
  82                                 xmlNode* bind_material = findChildElement(child, "bind_material");
  83                                 if (! bind_material) continue;
  84                                 Log(LOG_INFO, "Found a bind_material to delete");
  85                                 xmlUnlinkNode(bind_material);
  86                                 xmlFreeNode(bind_material);
  87
  88                                 changed = true;
  89                         }
  90                 }
  91         }
  92         return changed;
  93 }
  94
  95 static bool applyFBXFixes(xmlNode* root)
  96 {
  97         Log(LOG_INFO, "Applying fixes for 3ds Max exporter");
  98
  99         bool changed = false;
 100
 101         xmlNode* library_images = findChildElement(root, "library_images");
 102         if (library_images)
 103         {
 104                 Log(LOG_INFO, "Found library_images to delete");
 105                 xmlUnlinkNode(library_images);
 106                 xmlFreeNode(library_images);
 107                 changed = true;
 108         }
 109
 110         xmlNode* library_materials = findChildElement(root, "library_materials");
 111         if (library_materials)
 112         {
 113                 Log(LOG_INFO, "Found library_materials to delete");
 114                 xmlUnlinkNode(library_materials);
 115                 xmlFreeNode(library_materials);
 116                 changed = true;
 117         }
 118
 119         xmlNode* library_effects = findChildElement(root, "library_effects");
 120         if (library_effects)
 121         {
 122                 Log(LOG_INFO, "Found library_effects to delete");
 123                 xmlUnlinkNode(library_effects);
 124                 xmlFreeNode(library_effects);
 125                 changed = true;
 126         }
 127
 128         xmlNode* library_visual_scenes = findChildElement(root, "library_visual_scenes");
 129         if (library_visual_scenes) // (Assume there's only one of these)
 130         {
 131                 xmlNode* visual_scene = findChildElement(library_visual_scenes, "visual_scene");
 132                 if (visual_scene) // (Assume there's only one of these)
 133                 {
 134                         for (xmlNode* child = visual_scene->children; child; child = child->next)
 135                         {
 136                                 if (child->type == XML_ELEMENT_NODE && strcmp((const char*)child->name, "node") == 0)
 137                                         if (applyFBXFixesNode(child))
 138                                                 changed = true;
 139                         }
 140                 }
 141         }
 142
 143         return changed;
 144 }
 145
 146 static bool processDocument(xmlNode* root)
 147 {
 148         xmlNode* asset = findChildElement(root, "asset");
 149         if (! asset) return false;
 150         xmlNode* contributor = findChildElement(asset, "contributor");
 151         if (! contributor) return false;
 152         xmlNode* authoring_tool = findChildElement(contributor, "authoring_tool");
 153         if (! authoring_tool) return false;
 154
 155         xmlNode* authoring_tool_text = authoring_tool->children;
 156         if (! authoring_tool_text) return false;
 157         if (authoring_tool_text->type != XML_TEXT_NODE) return false;
 158         xmlChar* toolname = authoring_tool_text->content;
 159         Log(LOG_INFO, "Authoring tool: %s", toolname);
 160         if (strcmp((const char*)toolname, "FBX COLLADA exporter") == 0)
 161                 return applyFBXFixes(root);
 162         else
 163                 return false;
 164 }
 165
 166 void FixBrokenXML(const char* text, const char** out, size_t* outSize)
 167 {
 168         Log(LOG_INFO, "Running FixBrokenXML");
 169
 170         size_t textSize = strlen(text);
 171         xmlDocPtr doc = xmlParseMemory(text, (int)textSize);
 172
 173         xmlNode* root = xmlDocGetRootElement(doc);
 174         if (root && processDocument(root))
 175         {
 176                 // Reserialising the document, then parsing it again inside FCollada, is a bit ugly;
 177                 // but it's the only way I can see to make it work through FCollada's public API
 178                 xmlChar* mem = NULL;
 179                 int size = -1;
 180                 xmlDocDumpFormatMemory(doc, &mem, &size, 0);
 181                 *out = (const char*)mem;
 182                 *outSize = size;
 183         }
 184         else
 185         {
 186                 *out = text;
 187                 *outSize = textSize;
 188         }
 189
 190         xmlFreeDoc(doc);
 191 }