Proof of concept sphere thing for metavoxels.

interface/resources/scripts/sphere.js

@@ -0,0 +1,171 @@
+//
+//  sphere.js
+//  interface
+//
+//  Created by Andrzej Kapolka on 12/17/13.
+//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
+//
+
+function strictIndexOf(array, element) {
+    for (var i = 0; i < array.length; i++) {
+        if (array[i] == element) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+var colorIndex;
+var normalIndex;
+var visitor;
+var info;
+
+var MAX_DEPTH = 5;
+
+var sphereCenter = [ 0.5, 0.5, 0.5 ];
+var sphereColor = 0xFFFF00FF;
+var sphereRadius = 0.25;
+var sphereRadiusSquared = sphereRadius * sphereRadius;
+
+function lengthSquared(x, y, z) {
+    return x*x + y*y + z*z;
+}
+
+function setNormal(vector) {
+    if (normalIndex != -1) {
+        var length = Math.sqrt(lengthSquared(vector[0], vector[1], vector[2]));
+        if (length == 0.0) {
+            info.attributeValues[normalIndex] = 0x007F00;
+            
+        } else {
+            var scale = 127.0 / length;
+            info.attributeValues[normalIndex] =
+                (Math.floor(vector[0] * scale) & 0xFF) << 16 |
+                (Math.floor(vector[1] * scale) & 0xFF) << 8 |
+                Math.floor(vector[2] * scale) & 0xFF;
+        }
+    }
+}
+
+function guide(minimum, size, depth) {
+    info.minimum = minimum;
+    info.size = size;
+    
+    // start with a relative fast bounding volume test to find most non-intersecting states
+    var maximum = [ minimum[0] + size, minimum[1] + size, minimum[2] + size ];
+    if (minimum[0] >= sphereCenter[0] + sphereRadius ||
+            minimum[1] >= sphereCenter[1] + sphereRadius ||
+            minimum[2] >= sphereCenter[2] + sphereRadius ||
+            maximum[0] <= sphereCenter[0] - sphereRadius ||
+            maximum[1] <= sphereCenter[1] - sphereRadius ||
+            maximum[2] <= sphereCenter[2] - sphereRadius) {
+        info.isLeaf = true;
+        if (colorIndex != -1) {
+            info.attributeValues[colorIndex] = 0x0;
+        }
+        visitor.visit(info);
+        return;
+    } 
+    
+    var halfSize = size / 2;
+    var center = [ minimum[0] + halfSize, minimum[1] + halfSize, minimum[2] + halfSize ];
+    var vector = [ center[0] - sphereCenter[0], center[1] - sphereCenter[1], center[2] - sphereCenter[2] ];
+    
+    // count the number of points inside the sphere
+    var inside = 0;
+    if (lengthSquared(sphereCenter[0] - minimum[0], sphereCenter[1] - minimum[1], sphereCenter[2] - minimum[2]) <=
+            sphereRadiusSquared) {
+        inside++;
+    }
+    if (lengthSquared(sphereCenter[0] - maximum[0], sphereCenter[1] - minimum[1], sphereCenter[2] - minimum[2]) <=
+            sphereRadiusSquared) {
+        inside++;
+    }
+    if (lengthSquared(sphereCenter[0] - minimum[0], sphereCenter[1] - maximum[1], sphereCenter[2] - minimum[2]) <=
+            sphereRadiusSquared) {
+        inside++;
+    }
+    if (lengthSquared(sphereCenter[0] - maximum[0], sphereCenter[1] - maximum[1], sphereCenter[2] - minimum[2]) <=
+            sphereRadiusSquared) {
+        inside++;
+    }
+    if (lengthSquared(sphereCenter[0] - minimum[0], sphereCenter[1] - minimum[1], sphereCenter[2] - maximum[2]) <=
+            sphereRadiusSquared) {
+        inside++;
+    }
+    if (lengthSquared(sphereCenter[0] - maximum[0], sphereCenter[1] - minimum[1], sphereCenter[2] - maximum[2]) <=
+            sphereRadiusSquared) {
+        inside++;
+    }
+    if (lengthSquared(sphereCenter[0] - minimum[0], sphereCenter[1] - maximum[1], sphereCenter[2] - maximum[2]) <=
+            sphereRadiusSquared) {
+        inside++;
+    }
+    if (lengthSquared(sphereCenter[0] - maximum[0], sphereCenter[1] - maximum[1], sphereCenter[2] - maximum[2]) <=
+            sphereRadiusSquared) {
+        inside++;
+    }
+    
+    // see if all points are in the sphere
+    if (inside == 8) {
+        info.isLeaf = true;
+        if (colorIndex != -1) {
+            info.attributeValues[colorIndex] = sphereColor;
+        }
+        setNormal(vector);
+        visitor.visit(info);
+        return;
+    }
+    
+    // if we've reached max depth, compute alpha using a volume estimate
+    if (depth == MAX_DEPTH) {
+        info.isLeaf = true;
+        if (inside >= 3) {
+            if (colorIndex != -1) {
+                info.attributeValues[colorIndex] = sphereColor;
+            }
+            setNormal(vector);
+        
+        } else {
+            if (colorIndex != -1) {
+                info.attributeValues[colorIndex] = 0x0;
+            }
+        }
+        visitor.visit(info);
+        return;
+    }
+    
+    // recurse
+    info.isLeaf = false;
+    if (!visitor.visit(info)) {
+        return;
+    }
+    depth += 1;
+    guide(minimum, halfSize, depth);
+    guide([ center[0], minimum[1], minimum[2] ], halfSize, depth);
+    guide([ minimum[0], center[1], minimum[2] ], halfSize, depth);
+    guide([ center[0], center[1], minimum[2] ], halfSize, depth);
+    guide([ minimum[0], minimum[1], center[2] ], halfSize, depth);
+    guide([ center[0], minimum[1], center[2] ], halfSize, depth);
+    guide([ minimum[0], center[1], center[2] ], halfSize, depth);
+    guide([ center[0], center[1], center[2] ], halfSize, depth);
+}
+
+(function(visitation) {
+    var attributes = visitation.visitor.getAttributes();
+    colorIndex = strictIndexOf(attributes, AttributeRegistry.colorAttribute);
+    normalIndex = strictIndexOf(attributes, AttributeRegistry.normalAttribute);
+    visitor = visitation.visitor;
+    info = { attributeValues: new Array(attributes.length) };
+    
+    // have the sphere orbit the center and pulse in size
+    var time = new Date().getTime();
+    var ROTATE_PERIOD = 400.0;
+    sphereCenter[0] = 0.5 + 0.25 * Math.cos(time / ROTATE_PERIOD); 
+    sphereCenter[2] = 0.5 + 0.25 * Math.sin(time / ROTATE_PERIOD);
+    var PULSE_PERIOD = 300.0;
+    sphereRadius = 0.25 + 0.0625 * Math.cos(time / PULSE_PERIOD);  
+    sphereRadiusSquared = sphereRadius * sphereRadius;
+    
+    guide(visitation.info.minimum, visitation.info.size, 0);
+})

interface/src/renderer/MetavoxelSystem.cpp

@@ -6,6 +6,8 @@
 //  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
 //
 
+#include <QFile>
+#include <QTextStream>
 #include <QtDebug>
 
 #include <SharedUtil.h>
@@ -41,17 +43,9 @@ void MetavoxelSystem::init() {
     
     _data.setAttributeValue(p1, AttributeValue(color, encodeInline(qRgba(0xFF, 0xFF, 0xFF, 0xFF))));
     
-    QScriptValue guideFunction = _scriptEngine.evaluate(
+    QFile scriptFile("resources/scripts/sphere.js");
-        "(function(visitation) { "
+    scriptFile.open(QIODevice::ReadOnly);
-        "    var attributes = visitation.visitor.getAttributes();"
+    QScriptValue guideFunction = _scriptEngine.evaluate(QTextStream(&scriptFile).readAll());
-        "    var colorIndex = attributes.indexOf(AttributeRegistry.colorAttribute);"
-        "    var normalIndex = attributes.indexOf(AttributeRegistry.normalAttribute);"
-        "    for (var i = 0; i < attributes.length; i++) {"
-        "       print(attributes[i].getName() + ' ');"
-        "    }"
-        "    print('\\n');"
-        "    visitation.visitor.visit(visitation.info);"
-        "})");
     _data.setAttributeValue(MetavoxelPath(), AttributeValue(AttributeRegistry::getInstance()->getGuideAttribute(),
         encodeInline(PolymorphicDataPointer(new ScriptedMetavoxelGuide(guideFunction)))));