From 115b63a1178fedbd28ed98ec446b3f342d625814 Mon Sep 17 00:00:00 2001
From: Atlante45 <clement.brisset@gmail.com>
Date: Wed, 11 Nov 2015 15:54:48 -0800
Subject: [PATCH 1/3] Simplify rotationBetween

---
 libraries/shared/src/GLMHelpers.cpp | 25 +------------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

diff --git a/libraries/shared/src/GLMHelpers.cpp b/libraries/shared/src/GLMHelpers.cpp
index dc7887c9f8..b57754066b 100644
--- a/libraries/shared/src/GLMHelpers.cpp
+++ b/libraries/shared/src/GLMHelpers.cpp
@@ -201,30 +201,7 @@ float angleBetween(const glm::vec3& v1, const glm::vec3& v2) {
 
 //  Helper function return the rotation from the first vector onto the second
 glm::quat rotationBetween(const glm::vec3& v1, const glm::vec3& v2) {
-    float angle = angleBetween(v1, v2);
-    if (glm::isnan(angle) || angle < EPSILON) {
-        return glm::quat();
-    }
-    glm::vec3 axis;
-    if (angle > 179.99f * RADIANS_PER_DEGREE) { // 180 degree rotation; must use another axis
-        axis = glm::cross(v1, glm::vec3(1.0f, 0.0f, 0.0f));
-        float axisLength = glm::length(axis);
-        if (axisLength < EPSILON) { // parallel to x; y will work
-            axis = glm::normalize(glm::cross(v1, glm::vec3(0.0f, 1.0f, 0.0f)));
-        } else {
-            axis /= axisLength;
-        }
-    } else {
-        axis = glm::normalize(glm::cross(v1, v2));
-        // It is possible for axis to be nan even when angle is not less than EPSILON.
-        // For example when angle is small but not tiny but v1 and v2 and have very short lengths.
-        if (glm::isnan(glm::dot(axis, axis))) {
-            // set angle and axis to values that will generate an identity rotation
-            angle = 0.0f;
-            axis = glm::vec3(1.0f, 0.0f, 0.0f);
-        }
-    }
-    return glm::angleAxis(angle, axis);
+    return glm::quat(glm::normalize(v1), glm::normalize(v2));
 }
 
 bool isPointBehindTrianglesPlane(glm::vec3 point, glm::vec3 p0, glm::vec3 p1, glm::vec3 p2) {

From e4897a8de77345e08800946c3433f3115cd32cf1 Mon Sep 17 00:00:00 2001
From: Atlante45 <clement.brisset@gmail.com>
Date: Wed, 11 Nov 2015 15:58:27 -0800
Subject: [PATCH 2/3] Use new constants

---
 libraries/script-engine/src/Quat.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libraries/script-engine/src/Quat.cpp b/libraries/script-engine/src/Quat.cpp
index 14a6573415..bb74b20be0 100644
--- a/libraries/script-engine/src/Quat.cpp
+++ b/libraries/script-engine/src/Quat.cpp
@@ -64,15 +64,15 @@ glm::quat Quat::inverse(const glm::quat& q) {
 }
 
 glm::vec3 Quat::getFront(const glm::quat& orientation) {
-    return orientation * IDENTITY_FRONT;
+    return orientation * Vectors::FRONT;
 }
 
 glm::vec3 Quat::getRight(const glm::quat& orientation) {
-    return orientation * IDENTITY_RIGHT;
+    return orientation * Vectors::RIGHT;
 }
 
 glm::vec3 Quat::getUp(const glm::quat& orientation) {
-    return orientation * IDENTITY_UP;
+    return orientation * Vectors::UP;
 }
 
 glm::vec3 Quat::safeEulerAngles(const glm::quat& orientation) {

From 118d05d824935f6dfd067c41e2b31667fe6b0227 Mon Sep 17 00:00:00 2001
From: Atlante45 <clement.brisset@gmail.com>
Date: Wed, 11 Nov 2015 17:24:50 -0800
Subject: [PATCH 3/3] Use a clearer function

---
 libraries/shared/src/GLMHelpers.cpp | 2 +-
 libraries/shared/src/GLMHelpers.h   | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/libraries/shared/src/GLMHelpers.cpp b/libraries/shared/src/GLMHelpers.cpp
index b57754066b..fa010a85bd 100644
--- a/libraries/shared/src/GLMHelpers.cpp
+++ b/libraries/shared/src/GLMHelpers.cpp
@@ -201,7 +201,7 @@ float angleBetween(const glm::vec3& v1, const glm::vec3& v2) {
 
 //  Helper function return the rotation from the first vector onto the second
 glm::quat rotationBetween(const glm::vec3& v1, const glm::vec3& v2) {
-    return glm::quat(glm::normalize(v1), glm::normalize(v2));
+    return glm::rotation(glm::normalize(v1), glm::normalize(v2));
 }
 
 bool isPointBehindTrianglesPlane(glm::vec3 point, glm::vec3 p0, glm::vec3 p1, glm::vec3 p2) {
diff --git a/libraries/shared/src/GLMHelpers.h b/libraries/shared/src/GLMHelpers.h
index 9c1bbe23a4..8d3410aaf2 100644
--- a/libraries/shared/src/GLMHelpers.h
+++ b/libraries/shared/src/GLMHelpers.h
@@ -16,6 +16,7 @@
 
 #include <glm/glm.hpp>
 #include <glm/gtc/quaternion.hpp>
+#include <glm/gtx/quaternion.hpp>
 
 // Bring the most commonly used GLM types into the default namespace
 using glm::ivec2;