From 79a2e409a8f9500ebe9b03a0fd5e4dabf38980f1 Mon Sep 17 00:00:00 2001
From: Andrzej Kapolka <drzej.k@gmail.com>
Date: Wed, 11 Dec 2013 13:52:52 -0800
Subject: [PATCH] Basic voxel visitation with multiple attributes.

---
 interface/src/renderer/MetavoxelSystem.cpp | 14 +++++++
 libraries/metavoxels/src/MetavoxelData.cpp | 46 +++++++++++++++++++++-
 libraries/metavoxels/src/MetavoxelData.h   | 14 ++++---
 3 files changed, 66 insertions(+), 8 deletions(-)

diff --git a/interface/src/renderer/MetavoxelSystem.cpp b/interface/src/renderer/MetavoxelSystem.cpp
index fea4c374f3..76ad824f65 100644
--- a/interface/src/renderer/MetavoxelSystem.cpp
+++ b/interface/src/renderer/MetavoxelSystem.cpp
@@ -10,6 +10,17 @@
 
 #include "MetavoxelSystem.h"
 
+class DebugVisitor : public MetavoxelVisitor {
+public:
+    
+    virtual bool visit(const QVector<AttributeValue>& attributeValues);
+};
+
+bool DebugVisitor::visit(const QVector<AttributeValue>& attributeValues) {
+    qDebug() << decodeInline<float>(attributeValues.at(0).getValue()) << "\n";
+    return true;
+}
+
 void MetavoxelSystem::init() {
     MetavoxelPath p1;
     p1 += 0;
@@ -28,5 +39,8 @@ void MetavoxelSystem::init() {
     AttributeValue value = _data.getAttributeValue(p2, blerp);
     
     qDebug("fliggedy bloo %g\n", decodeInline<float>(value.getValue()));
+    
+    DebugVisitor visitor;
+    _data.visitVoxels(QVector<AttributePointer>() << blerp, visitor);
 }
 
diff --git a/libraries/metavoxels/src/MetavoxelData.cpp b/libraries/metavoxels/src/MetavoxelData.cpp
index acedea05d1..e75b51697c 100644
--- a/libraries/metavoxels/src/MetavoxelData.cpp
+++ b/libraries/metavoxels/src/MetavoxelData.cpp
@@ -15,9 +15,51 @@ MetavoxelData::~MetavoxelData() {
     }
 }
 
-void MetavoxelData::visitVoxels(const QVector<Attribute*>& attributes, VoxelVisitor* visitor) {
-    // map attributes to layers, indices
+class Visitation {
+public:
+    MetavoxelVisitor& visitor;
+    QVector<MetavoxelNode*> nodes;
+    QVector<AttributeValue> attributeValues;
+
+    void apply();
+};
+
+void Visitation::apply() {
+    Visitation nextVisitation = { visitor, QVector<MetavoxelNode*>(nodes.size()), attributeValues };
+    for (int i = 0; i < nodes.size(); i++) {
+        MetavoxelNode* node = nodes.at(i);
+        if (node) {
+            nextVisitation.attributeValues[i] = node->getAttributeValue(attributeValues[i].getAttribute());
+        }
+    }
     
+    if (!visitor.visit(nextVisitation.attributeValues)) {
+        return;
+    }
+    
+    for (int i = 0; i < MetavoxelNode::CHILD_COUNT; i++) {
+        bool anyChildrenPresent = false;
+        for (int j = 0; j < nodes.size(); j++) {
+            MetavoxelNode* node = nodes.at(j);
+            if ((nextVisitation.nodes[j] = node ? node->getChild(i) : NULL)) {
+                anyChildrenPresent = true;
+            }            
+        }
+        if (anyChildrenPresent) {
+            nextVisitation.apply();
+        }
+    }
+}
+
+void MetavoxelData::visitVoxels(const QVector<AttributePointer>& attributes, MetavoxelVisitor& visitor) {
+    // start with the root values/defaults
+    Visitation firstVisitation = { visitor, QVector<MetavoxelNode*>(attributes.size()),
+        QVector<AttributeValue>(attributes.size()) };
+    for (int i = 0; i < attributes.size(); i++) {
+        firstVisitation.nodes[i] = _roots.value(attributes[i]);
+        firstVisitation.attributeValues[i] = attributes[i];
+    }
+    firstVisitation.apply();
 }
 
 void MetavoxelData::setAttributeValue(const MetavoxelPath& path, const AttributeValue& attributeValue) {
diff --git a/libraries/metavoxels/src/MetavoxelData.h b/libraries/metavoxels/src/MetavoxelData.h
index aafc0f6e44..11b9db2505 100644
--- a/libraries/metavoxels/src/MetavoxelData.h
+++ b/libraries/metavoxels/src/MetavoxelData.h
@@ -12,12 +12,13 @@
 #include <QBitArray>
 #include <QHash>
 #include <QScopedPointer>
+#include <QVector>
 
 #include "AttributeRegistry.h"
 
 class MetavoxelNode;
 class MetavoxelPath;
-class VoxelVisitor;
+class MetavoxelVisitor;
 
 /// The base metavoxel representation shared between server and client.
 class MetavoxelData {
@@ -27,7 +28,7 @@ public:
 
     /// Applies the specified function to the contained voxels.
     /// \param attributes the list of attributes desired
-    void visitVoxels(const QVector<Attribute*>& attributes, VoxelVisitor* visitor);
+    void visitVoxels(const QVector<AttributePointer>& attributes, MetavoxelVisitor& visitor);
 
     /// Sets the attribute value corresponding to the specified path.
     void setAttributeValue(const MetavoxelPath& path, const AttributeValue& attributeValue);
@@ -93,13 +94,14 @@ private:
     QBitArray _array;    
 };
 
-/// Interface for visitors to voxels.
-class VoxelVisitor {
+/// Interface for visitors to metavoxels.
+class MetavoxelVisitor {
 public:
     
-    /// Visits a voxel.
+    /// Visits a metavoxel.
     /// \param attributeValues the values of the desired attributes
-    virtual void visit(const QVector<void*>& attributeValues) = 0;
+    /// \param if true, continue descending; if false, stop
+    virtual bool visit(const QVector<AttributeValue>& attributeValues) = 0;
 };
 
 #endif /* defined(__interface__MetavoxelData__) */