From f7eb4cd4b92e54923bed8d79b419f8461274447e Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop+git@gmail.com>
Date: Tue, 24 Feb 2009 03:22:15 +0000
Subject: [PATCH] finished implementing shapes/Intersect::intersect()

git-svn-id: svn://anubis/fart/trunk@154 7f9b0f55-74a9-4bce-be96-3c2cd072584d
---
 shapes/Intersect.cc | 41 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/shapes/Intersect.cc b/shapes/Intersect.cc
index 3d58ba7..9ad50c8 100644
--- a/shapes/Intersect.cc
+++ b/shapes/Intersect.cc
@@ -1,5 +1,7 @@
 
 #include "Intersect.h"
+#include <iostream>
+using namespace std;
 
 Intersect::Intersect(refptr<Shape> shape1, refptr<Shape> shape2)
 {
@@ -15,14 +17,51 @@ Shape::IntersectionList Intersect::intersect(refptr<Shape> _this, const Ray & ra
 
     IntersectionList res;
     bool in1 = false, in2 = false;
+    bool in_bool = false;
 
     /* TODO: finish */
+    for (int i = 0, sz = merged.size(); i < sz; i++)
+    {
+        Vector normal = merged[i].intersection.shape->getNormalAt(
+                            merged[i].intersection.vector);
+        double dot = - (ray.getDirection() % normal);
+        bool front = dot > 0.0;
+        bool left = merged[i].left;
+        if (front)
+        {
+            if (left)
+                in1 = true;
+            else
+                in2 = true;
+            if (!in_bool && in1 && in2)
+            {
+                /* we found an intersection point with the boolean object */
+                in_bool = true;
+                res.add( merged[i].intersection );
+            }
+        }
+        else
+        {
+            if (in_bool && in1 && in2)
+            {
+                /* we found an intersection point with the boolean object */
+                res.add( merged[i].intersection );
+            }
+            if (left)
+                in1 = false;
+            else
+                in2 = false;
+            in_bool = false;
+        }
+    }
 
     return res;
 }
 
 Vector Intersect::getNormalAt(const Vector & pt)
 {
-    /* TODO: finish */
+    /* this should not be called */
+    cerr << __FILE__ << ": " << __LINE__ <<
+        ": error: Intersect::getNormalAt() was called!" << endl;
     return Vector(0, 0, 0);
 }