From 89eed589e2755803c788441a0b9e3fddbbd49f3e Mon Sep 17 00:00:00 2001
From: bwent <bwent@bowdoin.edu>
Date: Mon, 20 Jul 2015 10:59:55 -0700
Subject: [PATCH] Add Vec3 function to convert vec3 to/from euler angles

---
 examples/edit.js                     | 47 +--------------------
 libraries/script-engine/src/Vec3.cpp | 62 ++++++++++++++++++++++++++++
 libraries/script-engine/src/Vec3.h   |  2 +
 3 files changed, 66 insertions(+), 45 deletions(-)

diff --git a/examples/edit.js b/examples/edit.js
index 544f3c94b6..edf60110c4 100644
--- a/examples/edit.js
+++ b/examples/edit.js
@@ -1211,49 +1211,6 @@ PropertiesTool = function(opts) {
         webView.setVisible(visible);
     };
 
-    vecToPolar = function(direction) {
-        var x = direction.x;
-        var y = direction.y;
-        var z = direction.z;
-        var pitch, yaw;
-        pitch = -Math.asin(y);
-        var c = Math.cos(-pitch);
-        if (Math.abs(pitch) > (Math.PI / 2.0 - epsilon)) {
-            //handle gymbal lock
-            if (pitch > 0) {
-                pitch = Math.PI / 2.0;
-            } else {
-                pitch = -Math.PI / 2.0;
-            }
-            yaw = 0.0;
-            } else {
-                if (z < 0) {
-                    if(x > 0 && x < 1) {
-                        yaw = Math.PI - Math.asin(x / c); 
-                    } else {
-                        yaw = -Math.asin(x / c) - Math.PI;
-                    }
-                } else {
-                    yaw = Math.asin(x / c);
-                }  
-            }
-            return {
-                x: pitch * RADIANS_TO_DEGREES,
-                y: yaw * RADIANS_TO_DEGREES,
-                z: 0.0 //discard roll component
-            };
-    };
-
-    polarToVec = function(orientation) {
-        var pitch = orientation.x * DEGREES_TO_RADIANS;
-        var yaw = orientation.y * DEGREES_TO_RADIANS;
-        return {
-            x: Math.cos(pitch) * Math.sin(yaw),
-            y: Math.sin(-pitch),
-            z: Math.cos(pitch) * Math.cos(yaw)
-        };
-    }
-
     selectionManager.addEventListener(function() {
         data = {
             type: 'update',
@@ -1267,7 +1224,7 @@ PropertiesTool = function(opts) {
                 entity.properties.rotation = Quat.safeEulerAngles(entity.properties.rotation);
             }
             if (entity.properties.keyLightDirection !== undefined) {
-                entity.properties.keyLightDirection = vecToPolar(entity.properties.keyLightDirection);
+                entity.properties.keyLightDirection = Vec3.toPolar(entity.properties.keyLightDirection);
             }
             selections.push(entity);
         }
@@ -1297,7 +1254,7 @@ PropertiesTool = function(opts) {
                     data.properties.rotation = Quat.fromPitchYawRollDegrees(rotation.x, rotation.y, rotation.z);
                 }
                 if (data.properties.keyLightDirection !== undefined) {
-                    data.properties.keyLightDirection = polarToVec(data.properties.keyLightDirection);
+                    data.properties.keyLightDirection = Vec3.fromPolar(data.properties.keyLightDirection.x, data.properties.keyLightDirection.y);
                 } 
                 Entities.editEntity(selectionManager.selections[0], data.properties);
                 if (data.properties.name != undefined) {
diff --git a/libraries/script-engine/src/Vec3.cpp b/libraries/script-engine/src/Vec3.cpp
index 49a2ad2cbe..2bb28180d9 100644
--- a/libraries/script-engine/src/Vec3.cpp
+++ b/libraries/script-engine/src/Vec3.cpp
@@ -14,6 +14,7 @@
 #include <QDebug>
 
 #include "ScriptEngineLogging.h"
+#include "NumericalConstants.h"
 #include "Vec3.h"
 
 glm::vec3 Vec3::reflect(const glm::vec3& v1, const glm::vec3& v2) {
@@ -73,3 +74,64 @@ void Vec3::print(const QString& lable, const glm::vec3& v) {
 bool Vec3::equal(const glm::vec3& v1, const glm::vec3& v2) {
     return v1 == v2;
 }
+
+glm::vec3 Vec3::toPolar(const glm::vec3& v) {
+    glm::vec3 u = normalize(v);
+    float pitch, yaw, temp;
+    pitch = glm::asin(-u.y);
+    temp = glm::cos(pitch);
+    if (glm::abs(pitch) >= (PI - EPSILON)) {
+        yaw = 0.0;
+        if (pitch > 0) {
+            pitch = PI_OVER_TWO;
+        } else {
+            pitch = -PI_OVER_TWO;
+        }
+    } else {
+        if (u.z < 0.0) {
+            if (u.x > 0.0 && u.x < 1.0) {
+                yaw = PI - glm::asin(u.x / temp);
+            } else {
+                yaw = -PI - glm::asin(u.x / temp);
+            }
+        } else {
+            yaw = glm::asin(u.x / temp);
+        }
+    }
+    
+    // Round small values to 0
+    if (glm::abs(pitch) < EPSILON) {
+        pitch = 0.0;
+    }
+    if (glm::abs(yaw) < EPSILON) {
+        yaw = 0.0;
+    }
+    
+    // Neglect roll component
+    return glm::vec3(glm::degrees(pitch), glm::degrees(yaw), 0.0);
+}
+
+glm::vec3 Vec3::fromPolar(float pitch, float yaw) {
+    pitch = glm::radians(pitch);
+    yaw = glm::radians(yaw);
+    
+    float x = glm::cos(pitch) * glm::sin(yaw);
+    float y = glm::sin(-pitch);
+    float z = glm::cos(pitch) * glm::cos(yaw);
+    
+    // Round small values to 0
+    if (glm::abs(x) < EPSILON) {
+        x = 0.0;
+    }
+    if (glm::abs(y) < EPSILON) {
+        y = 0.0;
+    }
+    if (glm::abs(z) < EPSILON) {
+        z = 0.0;
+    }
+    
+    return glm::vec3(x, y, z);
+}
+
+
+
diff --git a/libraries/script-engine/src/Vec3.h b/libraries/script-engine/src/Vec3.h
index 2a2e145e8e..198d65004c 100644
--- a/libraries/script-engine/src/Vec3.h
+++ b/libraries/script-engine/src/Vec3.h
@@ -40,6 +40,8 @@ public slots:
     glm::vec3 mix(const glm::vec3& v1, const glm::vec3& v2, float m);
     void print(const QString& lable, const glm::vec3& v);
     bool equal(const glm::vec3& v1, const glm::vec3& v2);
+    glm::vec3 toPolar(const glm::vec3& v);
+    glm::vec3 fromPolar(float pitch, float yaw);
 };