scanning scene files for camera definitions before shapes and lights

git-svn-id: svn://anubis/fart/trunk@194 7f9b0f55-74a9-4bce-be96-3c2cd072584d

.todo

@@ -1,5 +1,4 @@
 FART To-Do List
 ===============
-- Scan for cameras before scene items
 - Test subtractions of subtractions
 - Add built-in timing around Scene::render()

main/Scene-load.cc

@@ -23,7 +23,7 @@ void Scene::processNode(refptr<Node> node)
 
     if      ( typeid(*node) == typeid(SceneNode) )
     {
-        processChildren(node);
+        processScene(node);
     }
     else if ( node->isShape() )
     {
@@ -37,10 +37,6 @@ void Scene::processNode(refptr<Node> node)
         if ( ! light.isNull() )
             m_lights.push_back(light);
     }
-    else if ( typeid(*node) == typeid(CameraNode) )
-    {
-        processCamera(node);
-    }
     else if ( typeid(*node) == typeid(OptionsNode) )
     {
         processOptions(node);
@@ -68,6 +64,47 @@ void Scene::processNode(refptr<Node> node)
     }
 }
 
+void Scene::processChildren(refptr<Node> node)
+{
+    std::vector< refptr<Node> > & children = node->getChildren();
+    for (int i = 0, sz = children.size(); i < sz; i++)
+    {
+        processNode(children[i]);
+    }
+}
+
+void Scene::processScene(refptr<Node> node)
+{
+    /* first process any cameras present */
+    int cameras_found = 0;
+    for (Node_Iterator it = node->getChildren().begin();
+         it != node->getChildren().end();
+         it++)
+    {
+        if ( typeid(**it) == typeid(CameraNode) )
+        {
+            cameras_found++;
+            if (cameras_found == 1)
+                processCamera(*it);
+            else
+            {
+                cerr << "Error: multiple camera definitions found!" << endl;
+                exit(5);
+            }
+        }
+    }
+
+    for (Node_Iterator it = node->getChildren().begin();
+         it != node->getChildren().end();
+         it++)
+    {
+        if ( typeid(**it) != typeid(CameraNode) )
+        {
+            processNode(*it);
+        }
+    }
+}
+
 refptr<Shape> Scene::processShape(refptr<Node> node)
 {
     if      ( typeid(*node) == typeid(BoxNode) )
@@ -102,15 +139,6 @@ refptr<Shape> Scene::processShape(refptr<Node> node)
     return refptr<Shape>(NULL);
 }
 
-void Scene::processChildren(refptr<Node> node)
-{
-    std::vector< refptr<Node> > & children = node->getChildren();
-    for (int i = 0, sz = children.size(); i < sz; i++)
-    {
-        processNode(children[i]);
-    }
-}
-
 void Scene::processCamera(refptr<Node> node)
 {
     Vector position(0, 0, 0);

main/Scene.h

@@ -63,6 +63,7 @@ class Scene
         void load(const char * filename);
         void processNode(refptr<Node> node);
         void processChildren(refptr<Node> node);
+        void processScene(refptr<Node> node);
         refptr<Material> processMaterial(refptr<Node> node);
         refptr<Shape> processBox(refptr<Node> node);
         refptr<Shape> processCyl(refptr<Node> node);