Matrix4::translateBy() implemented by Eigen

Short-circuit the transformation by multiplying _transform directly with an Eigen::Translation3d, rather than calling getTranslation() and multiplyBy().
codereader · Mar 31, 2021 · 4141ee6 · 4141ee6
1 parent 0a71ad4
commit 4141ee6
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diff --git a/libs/math/Matrix4.cpp b/libs/math/Matrix4.cpp
@@ -249,12 +249,6 @@ Matrix4 Matrix4::getScale(const Vector3& scale)
     );
 }
 
-// Add a translation component
-void Matrix4::translateBy(const Vector3& translation)
-{
-    multiplyBy(getTranslation(translation));
-}
-
 // Add a scale component
 void Matrix4::scaleBy(const Vector3& scale)
 {

diff --git a/libs/math/Matrix4.h b/libs/math/Matrix4.h
@@ -351,13 +351,17 @@ class Matrix4
     }
 
     /**
-     * \brief
-     * Add a translation component to the transformation represented by this
-     * matrix.
+     * \brief Add a translation component to the transformation represented by
+     * this matrix.
      *
-     * Equivalent to multiplyBy(Matrix4::getTranslation(translation));
+     * Equivalent to multiplyBy(Matrix4::getTranslation(tr)); note that this is
+     * a post-multiplication so the translation will be applied before (and be
+     * affected by) any existing rotation/scale in the current matrix.
      */
-    void translateBy(const Vector3& translation);
+    void translateBy(const Vector3& tr)
+    {
+        _transform *= Eigen::Translation3d(tr.x(), tr.y(), tr.z());
+    }
 
     /**
      * \brief Add a translation component to the transformation represented by