From 20eafaf9f4e18ddc9f810e4cd025b610b012d4bb Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop+git@gmail.com>
Date: Fri, 23 Jan 2009 16:44:39 +0000
Subject: [PATCH] fixed view plane distance calculation to use tan() and
 convert degrees to radians

git-svn-id: svn://anubis/fart/trunk@41 7f9b0f55-74a9-4bce-be96-3c2cd072584d
---
 main/Scene.cc  |  4 ++--
 util/Vector.cc | 18 +++++++++++++++---
 util/Vector.h  |  2 ++
 3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/main/Scene.cc b/main/Scene.cc
index ec2ae0c..09ea73c 100644
--- a/main/Scene.cc
+++ b/main/Scene.cc
@@ -54,7 +54,7 @@ Scene::Scene(map<string, const char *> options,
     }
 
     /* view plane distance is calculated based on the field of view */
-    m_view_plane_dist = (m_height / 2.0) / atan(m_vfov / 2.0);
+    m_view_plane_dist = (m_height / 2.0) / tan(M_PI * m_vfov / 360.0);
 }
 
 Scene::~Scene()
@@ -73,7 +73,7 @@ void Scene::load(const char * filename)
 {
     /* TODO: parse file somehow */
     Shape * shape = new Sphere(1.0);
-    m_transform.translate(2.0, 2.0, 0.0);
+    m_transform.translate(2.0, 4.0, 1.0);
     shape->setTransform(m_transform);
     m_shapes.push_back(shape);
 }
diff --git a/util/Vector.cc b/util/Vector.cc
index 744214c..b373843 100644
--- a/util/Vector.cc
+++ b/util/Vector.cc
@@ -19,15 +19,27 @@ Vector::Vector(double x, double y, double z)
 
 Vector & Vector::normalize()
 {
-    double length = sqrt(m_array[0] * m_array[0]
-                       + m_array[1] * m_array[1]
-                       + m_array[2] * m_array[2]);
+    double length = mag();
     m_array[0] /= length;
     m_array[1] /= length;
     m_array[2] /= length;
     return *this;
 }
 
+double Vector::mag()
+{
+    return sqrt(m_array[0] * m_array[0]
+              + m_array[1] * m_array[1]
+              + m_array[2] * m_array[2]);
+}
+
+double Vector::mag2()
+{
+    return m_array[0] * m_array[0]
+         + m_array[1] * m_array[1]
+         + m_array[2] * m_array[2];
+}
+
 std::ostream & operator<<(std::ostream & out, const Vector & v)
 {
     out << "[" << v[0] << ", " << v[1] << ", " << v[2] << "]";
diff --git a/util/Vector.h b/util/Vector.h
index 390e89c..3857780 100644
--- a/util/Vector.h
+++ b/util/Vector.h
@@ -12,6 +12,8 @@ class Vector
         double & operator[](int idx) { return m_array[idx]; }
         double operator[](int idx) const { return m_array[idx]; }
         Vector & normalize();
+        double mag();
+        double mag2();
 
     private:
         double  m_array[3];