From 4bb4d03d5a6a0252083d6bc45b8a50fe7b504c51 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 24 May 2013 09:06:29 +0300
Subject: [PATCH] Put ray and bounding box transformations in
 AffineTransformation

This makes them easier to use elsewhere, in cases where creating a
TransformedShape would be overkill.
---
 source/geometry/affinetransformation.h | 42 ++++++++++++++++++++++++++
 source/geometry/transformedshape.h     | 42 ++------------------------
 2 files changed, 44 insertions(+), 40 deletions(-)

diff --git a/source/geometry/affinetransformation.h b/source/geometry/affinetransformation.h
index 0e377ba..15bd926 100644
--- a/source/geometry/affinetransformation.h
+++ b/source/geometry/affinetransformation.h
@@ -3,6 +3,8 @@
 
 #include <msp/linal/squarematrix.h>
 #include "angle.h"
+#include "boundingbox.h"
+#include "ray.h"
 
 namespace Msp {
 namespace Geometry {
@@ -70,6 +72,8 @@ public:
 
 	LinAl::Vector<T, D> transform(const LinAl::Vector<T, D> &) const;
 	LinAl::Vector<T, D> transform_linear(const LinAl::Vector<T, D> &) const;
+	Ray<T, D> transform(const Ray<T, D> &) const;
+	BoundingBox<T, D> transform(const BoundingBox<T, D> &) const;
 };
 
 template<typename T, unsigned D>
@@ -180,6 +184,44 @@ inline LinAl::Vector<T, D> AffineTransformation<T, D>::transform_linear(const Li
 	return LinAl::Vector<T, D>(matrix*LinAl::Vector<T, D+1>(v, T(0)));
 }
 
+template<typename T, unsigned D>
+inline Ray<T, D> AffineTransformation<T, D>::transform(const Ray<T, D> &ray) const
+{
+	LinAl::Vector<T, D> dir = transform_linear(ray.get_direction());
+	return Ray<T, D>(transform(ray.get_start()), dir, ray.get_limit()*dir.norm());
+}
+
+template<typename T, unsigned D>
+inline BoundingBox<T, D> AffineTransformation<T, D>::transform(const BoundingBox<T, D> &bbox) const
+{
+	LinAl::Vector<T, D> min_pt;
+	LinAl::Vector<T, D> max_pt;
+	for(unsigned i=0; i<(1<<D); ++i)
+	{
+		LinAl::Vector<T, D> point;
+		for(unsigned j=0; j<D; ++j)
+			point[j] = ((i>>j)&1 ? bbox.get_maximum_coordinate(j) : bbox.get_minimum_coordinate(j));
+
+		point = transform(point);
+
+		if(i==0)
+		{
+			min_pt = point;
+			max_pt = point;
+		}
+		else
+		{
+			for(unsigned j=0; j<D; ++j)
+			{
+				min_pt[j] = std::min(min_pt[j], point[j]);
+				max_pt[j] = std::max(max_pt[j], point[j]);
+			}
+		}
+	}
+
+	return BoundingBox<T, D>(min_pt, max_pt);
+}
+
 } // namespace Geometry
 } // namespace Msp
 
diff --git a/source/geometry/transformedshape.h b/source/geometry/transformedshape.h
index f214e4b..6a14b0b 100644
--- a/source/geometry/transformedshape.h
+++ b/source/geometry/transformedshape.h
@@ -31,9 +31,6 @@ public:
 
 	virtual BoundingBox<T, D> get_axis_aligned_bounding_box() const;
 	virtual bool contains(const LinAl::Vector<T, D> &) const;
-private:
-	Ray<T, D> make_local_ray(const Ray<T, D> &) const;
-public:
 	virtual unsigned get_max_ray_intersections() const { return shape->get_max_ray_intersections(); }
 	virtual unsigned get_intersections(const Ray<T, D> &, SurfacePoint<T, D> *, unsigned) const;
 };
@@ -76,34 +73,7 @@ inline TransformedShape<T, D> *TransformedShape<T, D>::clone() const
 template<typename T, unsigned D>
 inline BoundingBox<T, D> TransformedShape<T, D>::get_axis_aligned_bounding_box() const
 {
-	BoundingBox<T, D> inner_bbox = shape->get_axis_aligned_bounding_box();
-
-	LinAl::Vector<T, D> min_pt;
-	LinAl::Vector<T, D> max_pt;
-	for(unsigned i=0; i<(1<<D); ++i)
-	{
-		LinAl::Vector<T, D> point;
-		for(unsigned j=0; j<D; ++j)
-			point[j] = ((i>>j)&1 ? inner_bbox.get_maximum_coordinate(j) : inner_bbox.get_minimum_coordinate(j));
-
-		point = transformation.transform(point);
-
-		if(i==0)
-		{
-			min_pt = point;
-			max_pt = point;
-		}
-		else
-		{
-			for(unsigned j=0; j<D; ++j)
-			{
-				min_pt[j] = std::min(min_pt[j], point[j]);
-				max_pt[j] = std::max(max_pt[j], point[j]);
-			}
-		}
-	}
-
-	return BoundingBox<T, D>(min_pt, max_pt);
+	return transformation.transform(shape->get_axis_aligned_bounding_box());
 }
 
 template<typename T, unsigned D>
@@ -112,18 +82,10 @@ inline bool TransformedShape<T, D>::contains(const LinAl::Vector<T, D> &point) c
 	return shape->contains(inverse_trans.transform(point));
 }
 
-template<typename T, unsigned D>
-inline Ray<T, D> TransformedShape<T, D>::make_local_ray(const Ray<T, D> &ray) const
-{
-	LinAl::Vector<T, D> local_dir = inverse_trans.transform_linear(ray.get_direction());
-	float distortion = local_dir.norm();
-	return Ray<T, D>(inverse_trans.transform(ray.get_start()), local_dir, ray.get_limit()*distortion);
-}
-
 template<typename T, unsigned D>
 inline unsigned TransformedShape<T, D>::get_intersections(const Ray<T, D> &ray, SurfacePoint<T, D> *points, unsigned size) const
 {
-	Ray<T, D> local_ray = make_local_ray(ray);
+	Ray<T, D> local_ray = inverse_trans.transform(ray);
 
 	unsigned count = shape->get_intersections(local_ray, points, size);
 	if(points)
-- 
2.43.0