Inline quaternion to rotation matrix in fromTranslationQuaternionRota…

…tionScale.
CesiumGS · Oct 31, 2013 · 1bf524b · 1bf524b
1 parent a62ed71
commit 1bf524b
Showing 1 changed file with 32 additions and 10 deletions.
diff --git a/Source/Core/Matrix4.js b/Source/Core/Matrix4.js
@@ -266,19 +266,41 @@ define([
         var scaleX = scale.x;
         var scaleY = scale.y;
         var scaleZ = scale.z;
-        scratchTrsRotation = Matrix3.fromQuaternion(rotation, scratchTrsRotation);
 
-        result[0]  = scratchTrsRotation[0] * scaleX;
-        result[1]  = scratchTrsRotation[1] * scaleX;
-        result[2]  = scratchTrsRotation[2] * scaleX;
+        var x2 = rotation.x * rotation.x;
+        var xy = rotation.x * rotation.y;
+        var xz = rotation.x * rotation.z;
+        var xw = rotation.x * rotation.w;
+        var y2 = rotation.y * rotation.y;
+        var yz = rotation.y * rotation.z;
+        var yw = rotation.y * rotation.w;
+        var z2 = rotation.z * rotation.z;
+        var zw = rotation.z * rotation.w;
+        var w2 = rotation.w * rotation.w;
+
+        var m00 = x2 - y2 - z2 + w2;
+        var m01 = 2.0 * (xy - zw);
+        var m02 = 2.0 * (xz + yw);
+
+        var m10 = 2.0 * (xy + zw);
+        var m11 = -x2 + y2 - z2 + w2;
+        var m12 = 2.0 * (yz - xw);
+
+        var m20 = 2.0 * (xz - yw);
+        var m21 = 2.0 * (yz + xw);
+        var m22 = -x2 - y2 + z2 + w2;
+
+        result[0]  = m00 * scaleX;
+        result[1]  = m10 * scaleX;
+        result[2]  = m20 * scaleX;
         result[3]  = 0.0;
-        result[4]  = scratchTrsRotation[3] * scaleY;
-        result[5]  = scratchTrsRotation[4] * scaleY;
-        result[6]  = scratchTrsRotation[5] * scaleY;
+        result[4]  = m01 * scaleY;
+        result[5]  = m11 * scaleY;
+        result[6]  = m21 * scaleY;
         result[7]  = 0.0;
-        result[8]  = scratchTrsRotation[6] * scaleZ;
-        result[9]  = scratchTrsRotation[7] * scaleZ;
-        result[10] = scratchTrsRotation[8] * scaleZ;
+        result[8]  = m02 * scaleZ;
+        result[9]  = m12 * scaleZ;
+        result[10] = m22 * scaleZ;
         result[11] = 0.0;
         result[12] = translation.x;
         result[13] = translation.y;