From 8af03c3f3d7ce9fe2d5bf243f53065e9c2ccb7b0 Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Fri, 15 Aug 2014 22:32:44 -0700
Subject: [PATCH] Implement Object::Place

Places the object by manipulating its translation matrix.
---
 src/basics/matrix.cc | 10 ++++++++++
 src/basics/matrix.hh |  1 +
 src/object.cc        | 10 ++++++++++
 src/object.hh        |  3 +++
 4 files changed, 24 insertions(+)

diff --git a/src/basics/matrix.cc b/src/basics/matrix.cc
index 92fa60a..1a89f7f 100644
--- a/src/basics/matrix.cc
+++ b/src/basics/matrix.cc
@@ -44,6 +44,16 @@ Matrix4::Identity()
 }
 
 
+/*
+ * charles::basics::Translation --
+ */
+/* static */ Matrix4
+Matrix4::Translation(const Vector4& p)
+{
+    return Translation(p.X(), p.Y(), p.Z());
+}
+
+
 /*
  * charles::basics::TranslationMatrix --
  */
diff --git a/src/basics/matrix.hh b/src/basics/matrix.hh
index b6bae04..4e6ebdf 100644
--- a/src/basics/matrix.hh
+++ b/src/basics/matrix.hh
@@ -30,6 +30,7 @@ struct Matrix4
 
     /** Create a 4x4 translation matrix. */
     static Matrix4 Translation(Double x, Double y, Double z);
+    static Matrix4 Translation(const Vector4 &p);
 
     Matrix4();
     Matrix4(const Double *data);
diff --git a/src/object.cc b/src/object.cc
index 3b0bdf6..e9afe35 100644
--- a/src/object.cc
+++ b/src/object.cc
@@ -47,6 +47,16 @@ Object::GetMaterial()
 }
 
 
+/*
+ * charles::Object::Place --
+ */
+void
+Object::Place(const Vector4 &p)
+{
+    mTranslation = Matrix4::Translation(p);
+}
+
+
 /*
  * charles::Object::SetMaterial --
  */
diff --git a/src/object.hh b/src/object.hh
index 9bb47a7..6b9a58b 100644
--- a/src/object.hh
+++ b/src/object.hh
@@ -27,6 +27,8 @@ struct Object
     Material& GetMaterial();
     void SetMaterial(const Material& material);
 
+    void Place(const basics::Vector4 &p);
+
     /**
      * Determine if the given ray intersects with this object. Converts the
      * ray's origin and direction to object space before calling the protected
@@ -67,6 +69,7 @@ private:
     /** Convert `v` to global space from object space. */
     basics::Vector4 FromObjectSpace(const basics::Vector4& v) const;
 
+
     /** A translation matrix from global coordinates to this object's space. */
     basics::Matrix4 mTranslation;