From 97b9fa9eabecbfa26b3d4bedf8647fea673c9d5e Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop+git@gmail.com>
Date: Fri, 23 Jan 2009 15:28:53 +0000
Subject: [PATCH] added getInverse() to util/Transform, fixed transform_*()
 functions

git-svn-id: svn://anubis/fart/trunk@39 7f9b0f55-74a9-4bce-be96-3c2cd072584d
---
 main/Scene.cc     | 16 ++++++++++++----
 util/Transform.cc | 25 ++++++++++++++++---------
 util/Transform.h  |  9 +++++----
 3 files changed, 33 insertions(+), 17 deletions(-)

diff --git a/main/Scene.cc b/main/Scene.cc
index 79994e2..08d84c8 100644
--- a/main/Scene.cc
+++ b/main/Scene.cc
@@ -117,8 +117,16 @@ void Scene::renderPixel(int x, int y, unsigned char * pixel)
 
     Ray ray(Vector(0, 0, 0), Vector(rx, ry, rz));
 
-    // TODO: um... real work
-    pixel[BMP_RED] = 0;
-    pixel[BMP_GREEN] = 0;
-    pixel[BMP_BLUE] = 0;
+    /* loop through all shapes in the scene */
+    for (vector<Shape *>::iterator it = m_shapes.begin();
+         it != m_shapes.end();
+         it++)
+    {
+        /* transform the ray by the inverse of the shape's transform */
+        Transform inv = (*it)->getTransform().getInverse();
+        Ray transformed_ray = inv.transform_ray(ray);
+
+        /* then intersect this inversely transformed ray with the shape */
+        Solver::Result intersections = (*it)->intersect(transformed_ray);
+    }
 }
diff --git a/util/Transform.cc b/util/Transform.cc
index 1ca90b3..7d0978a 100644
--- a/util/Transform.cc
+++ b/util/Transform.cc
@@ -7,6 +7,13 @@ Transform::Transform()
     m_matrix = Matrix::identity();
 }
 
+Transform Transform::getInverse()
+{
+    Transform inv;
+    inv.m_matrix = m_matrix.getInverse();
+    return inv;
+}
+
 void Transform::translate(double x, double y, double z)
 {
     Matrix t = Matrix::identity();
@@ -54,25 +61,25 @@ void Transform::scale(double xs, double ys, double zs)
     m_matrix *= t;
 }
 
-Vector Transform::transform_point(Transform & t, const Vector & v)
+Vector Transform::transform_point(const Vector & v)
 {
-    return t.getMatrix() * v;
+    return m_matrix * v;
 }
 
-Vector Transform::transform_direction(Transform & t, const Vector & v)
+Vector Transform::transform_direction(const Vector & v)
 {
-    return t.getMatrix() % v;
+    return m_matrix % v;
 }
 
-Vector Transform::transform_normal(Transform & t, const Vector & v)
+Vector Transform::transform_normal(const Vector & v)
 {
-    return (t.getMatrix() % v).normalize();
+    return (m_matrix % v).normalize();
 }
 
-Ray Transform::transform_ray(Transform & t, const Ray & r)
+Ray Transform::transform_ray(const Ray & r)
 {
-    Vector newPosition = t.getMatrix() * r.getOrigin();
-    Vector newDirection = t.getMatrix() % r.getDirection();
+    Vector newPosition = m_matrix * r.getOrigin();
+    Vector newDirection = m_matrix % r.getDirection();
     Ray res(newPosition, newDirection);
     return res;
 }
diff --git a/util/Transform.h b/util/Transform.h
index d03e7d2..fb1babc 100644
--- a/util/Transform.h
+++ b/util/Transform.h
@@ -11,14 +11,15 @@ class Transform
 {
     public:
         Transform();
+        Transform getInverse();
         void translate(double x, double y, double z);
         void rotate(double angle, double xv, double yv, double zv);
         void scale(double xs, double ys, double zs);
         Matrix & getMatrix() { return m_matrix; }
-        Vector transform_point(Transform & t, const Vector & v);
-        Vector transform_direction(Transform & t, const Vector & v);
-        Vector transform_normal(Transform & t, const Vector & v);
-        Ray transform_ray(Transform & t, const Ray & r);
+        Vector transform_point(const Vector & v);
+        Vector transform_direction(const Vector & v);
+        Vector transform_normal(const Vector & v);
+        Ray transform_ray(const Ray & r);
 
     protected:
         Matrix m_matrix;