From 16107c4ba1de6c17f4b77f3ed39c4b171024f5ee Mon Sep 17 00:00:00 2001
From: Recep Aslantas <info@recp.me>
Date: Sun, 8 Jan 2017 16:35:37 +0200
Subject: [PATCH] fix extract euler angles

---
 LICENSE              |  3 +++
 include/cglm-euler.h | 14 +++++++-------
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/LICENSE b/LICENSE
index 31c12c0..f22658b 100644
--- a/LICENSE
+++ b/LICENSE
@@ -49,3 +49,6 @@ LICENSE:
   David Eberly
   Geometric Tools, LLC http://www.geometrictools.com/
   Copyright (c) 1998-2016. All Rights Reserved.
+
+  Computing Euler angles from a rotation matrix (euler.pdf)
+  Gregory G. Slabaugh
diff --git a/include/cglm-euler.h b/include/cglm-euler.h
index d5ad22f..b0219ba 100644
--- a/include/cglm-euler.h
+++ b/include/cglm-euler.h
@@ -43,8 +43,8 @@ glm_euler_order(char newOrder[3]) {
 CGLM_INLINE
 void
 glm_euler_angles(mat4 m, vec3 dest) {
-  if (m[2][0] < 1.0f) {
-    if (m[2][0] > -1.0f) {
+  if (m[0][2] < 1.0f) {
+    if (m[0][2] > -1.0f) {
       vec3  a[2];
       float cy1, cy2;
       int   path;
@@ -66,13 +66,13 @@ glm_euler_angles(mat4 m, vec3 dest) {
 
       glm_vec_dup(a[path], dest);
     } else {
-      dest[0] = -atan2(m[0][1], m[2][1]);
-      dest[1] = -M_PI_2;
-      dest[3] = 0.0f;
+      dest[0] = atan2(m[1][0], m[2][0]);
+      dest[1] = M_PI_2;
+      dest[2] = 0.0f;
     }
   } else {
-    dest[0] = atan2f(m[0][1], m[1][1]);
-    dest[1] = M_PI_2;
+    dest[0] = atan2f(-m[1][0], -m[2][0]);
+    dest[1] =-M_PI_2;
     dest[2] = 0.0f;
   }
 }