From 8ddbd1977793ef1318d3557001310c59277321d0 Mon Sep 17 00:00:00 2001
From: Ferenc Arn <tagcup@users.noreply.github.com>
Date: Mon, 9 Oct 2017 08:49:53 -0400
Subject: [PATCH] Apply a few recent chages in Quat and Basis to their
 respective Mono counterparts. (#11899)

---
 modules/mono/glue/cs_files/Basis.cs     | 77 ++++++++++++++++++++-----
 modules/mono/glue/cs_files/Quat.cs      |  4 +-
 modules/mono/glue/cs_files/Transform.cs |  8 ++-
 3 files changed, 70 insertions(+), 19 deletions(-)

diff --git a/modules/mono/glue/cs_files/Basis.cs b/modules/mono/glue/cs_files/Basis.cs
index 6a73ebd554..c50e783349 100644
--- a/modules/mono/glue/cs_files/Basis.cs
+++ b/modules/mono/glue/cs_files/Basis.cs
@@ -160,26 +160,29 @@ namespace Godot
             Basis m = this.orthonormalized();
 
             Vector3 euler;
+            euler.z = 0.0f;
 
-            euler.y = Mathf.asin(m.x[2]);
+            float mxy = m.y[2];
 
-            if (euler.y < Mathf.PI * 0.5f)
+
+            if (mxy < 1.0f)
             {
-                if (euler.y > -Mathf.PI * 0.5f)
+                if (mxy > -1.0f)
                 {
-                    euler.x = Mathf.atan2(-m.y[2], m.z[2]);
-                    euler.z = Mathf.atan2(-m.x[1], m.x[0]);
+                    euler.x = Mathf.asin(-mxy);
+                    euler.y = Mathf.atan2(m.x[2], m.z[2]);
+                    euler.z = Mathf.atan2(m.y[0], m.y[1]);
                 }
                 else
                 {
-                    euler.z = 0.0f;
-                    euler.x = euler.z - Mathf.atan2(m.y[0], m.y[1]);
+                    euler.x = Mathf.PI * 0.5f;
+                    euler.y = -Mathf.atan2(-m.x[1], m.x[0]);
                 }
             }
             else
             {
-                euler.z = 0f;
-                euler.x = Mathf.atan2(m.x[1], m.y[1]) - euler.z;
+                euler.x = -Mathf.PI * 0.5f;
+                euler.y = -Mathf.atan2(m.x[1], m.x[0]);
             }
 
             return euler;
@@ -273,7 +276,7 @@ namespace Godot
 
         public Basis rotated(Vector3 axis, float phi)
         {
-            return this * new Basis(axis, phi);
+            return new Basis(axis, phi) * this;
         }
 
         public Basis scaled(Vector3 scale)
@@ -281,13 +284,13 @@ namespace Godot
             Basis m = this;
 
             m[0, 0] *= scale.x;
-            m[1, 0] *= scale.x;
-            m[2, 0] *= scale.x;
-            m[0, 1] *= scale.y;
+            m[0, 1] *= scale.x;
+            m[0, 2] *= scale.x;
+            m[1, 0] *= scale.y;
             m[1, 1] *= scale.y;
-            m[2, 1] *= scale.y;
-            m[0, 2] *= scale.z;
-            m[1, 2] *= scale.z;
+            m[1, 2] *= scale.y;
+            m[2, 0] *= scale.z;
+            m[2, 1] *= scale.z;
             m[2, 2] *= scale.z;
 
             return m;
@@ -347,6 +350,48 @@ namespace Godot
             );
         }
 
+		public Quat Quat() {
+			float trace = x[0] + y[1] + z[2];
+
+			if (trace > 0.0f) {
+				float s = Mathf.sqrt(trace + 1.0f) * 2f;
+				float inv_s = 1f / s;
+				return new Quat(
+					(z[1] - y[2]) * inv_s,
+					(x[2] - z[0]) * inv_s,
+					(y[0] - x[1]) * inv_s,
+					s * 0.25f
+				);
+			} else if (x[0] > y[1] && x[0] > z[2]) {
+				float s = Mathf.sqrt(x[0] - y[1] - z[2] + 1.0f) * 2f;
+				float inv_s = 1f / s;
+				return new Quat(
+					s * 0.25f,
+					(x[1] + y[0]) * inv_s,
+					(x[2] + z[0]) * inv_s,
+					(z[1] - y[2]) * inv_s
+				);
+			} else if (y[1] > z[2]) {
+				float s = Mathf.sqrt(-x[0] + y[1] - z[2] + 1.0f) * 2f;
+				float inv_s = 1f / s;
+				return new Quat(
+					(x[1] + y[0]) * inv_s,
+					s * 0.25f,
+					(y[2] + z[1]) * inv_s,
+					(x[2] - z[0]) * inv_s
+				);
+			} else {
+				float s = Mathf.sqrt(-x[0] - y[1] + z[2] + 1.0f) * 2f;
+				float inv_s = 1f / s;
+				return new Quat(
+					(x[2] + z[0]) * inv_s,
+					(y[2] + z[1]) * inv_s,
+					s * 0.25f,
+					(y[0] - x[1]) * inv_s
+				);
+			}
+		}
+
         public Basis(Quat quat)
         {
             float s = 2.0f / quat.length_squared();
diff --git a/modules/mono/glue/cs_files/Quat.cs b/modules/mono/glue/cs_files/Quat.cs
index 6345239f47..9b4b7fb297 100644
--- a/modules/mono/glue/cs_files/Quat.cs
+++ b/modules/mono/glue/cs_files/Quat.cs
@@ -201,12 +201,12 @@ namespace Godot
             }
             else
             {
-                float s = Mathf.sin(-angle * 0.5f) / d;
+                float s = Mathf.sin(angle * 0.5f) / d;
 
                 x = axis.x * s;
                 y = axis.y * s;
                 z = axis.z * s;
-                w = Mathf.cos(-angle * 0.5f);
+                w = Mathf.cos(angle * 0.5f);
             }
         }
 
diff --git a/modules/mono/glue/cs_files/Transform.cs b/modules/mono/glue/cs_files/Transform.cs
index 2010f0b3af..74271e758b 100644
--- a/modules/mono/glue/cs_files/Transform.cs
+++ b/modules/mono/glue/cs_files/Transform.cs
@@ -35,7 +35,7 @@ namespace Godot
 
         public Transform rotated(Vector3 axis, float phi)
         {
-            return this * new Transform(new Basis(axis, phi), new Vector3());
+            return new Transform(new Basis(axis, phi), new Vector3()) * this;
         }
 
         public Transform scaled(Vector3 scale)
@@ -104,6 +104,12 @@ namespace Godot
             this.origin = origin;
         }
 
+        public Transform(Quat quat, Vector3 origin)
+        {
+            this.basis = new Basis(quat);
+            this.origin = origin;
+        }
+
         public Transform(Basis basis, Vector3 origin)
         {
             this.basis = basis;