From f4781e2889d441ba10daefb3e1c1a4ea05ad8022 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop+git@gmail.com>
Date: Tue, 27 Jan 2009 01:34:00 +0000
Subject: [PATCH] updated getRayHits(), fixed bug in Scene::ShapeDistance(Shape
 *, double)

git-svn-id: svn://anubis/fart/trunk@53 7f9b0f55-74a9-4bce-be96-3c2cd072584d
---
 main/Scene.cc | 37 ++++++++++++++++++++++++++++++++++++-
 main/Scene.h  |  3 ++-
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/main/Scene.cc b/main/Scene.cc
index 44dcb27..b41b596 100644
--- a/main/Scene.cc
+++ b/main/Scene.cc
@@ -172,6 +172,7 @@ Vector Scene::traceRay(const Ray & ray)
 vector<Scene::ShapeDistance> Scene::getRayHits(const Ray & ray)
 {
     vector<ShapeDistance> hits;
+    double minSolidDist = 0.0;
 
     /* loop through all shapes in the scene */
     for (vector<Shape *>::iterator it = m_shapes.begin();
@@ -187,7 +188,19 @@ vector<Scene::ShapeDistance> Scene::getRayHits(const Ray & ray)
             double dot = normal % ray.getDirection();
             if (dot < 0.0) /* cull back faces */
             {
-                hits.push_back(ShapeDistance(*it, intersections.results[i]));
+                double transparency = (*it)->getTransparency();
+                if (transparency == 0.0 &&
+                        (minSolidDist == 0.0
+                         || minSolidDist > intersections.results[i]))
+                {
+                    minSolidDist = intersections.results[i];
+                }
+                if (minSolidDist == 0.0
+                    || minSolidDist >= intersections.results[i])
+                {
+                    hits.push_back(ShapeDistance(*it,
+                                                 intersections.results[i]));
+                }
             }
         }
     }
@@ -195,6 +208,28 @@ vector<Scene::ShapeDistance> Scene::getRayHits(const Ray & ray)
     /* now that we have ALL the hits, sort them by distance */
     sort(hits.begin(), hits.end());
 
+    double transparency = 1.0;
+    /* now go through them all until we get to the maximum number
+     * of hits, or until the transparency left is below the threshold */
+    for (unsigned int hits_index = 0, sz = hits.size();
+         hits_index < sz;
+         hits_index++)
+    {
+        transparency *= hits[hits_index].first->getTransparency();
+        if (hits_index >= (SCENE_MAX_TRANSPARENT_HITS - 1)
+         || transparency < SCENE_TRANSPARENCY_THRESHOLD)
+        {
+            /* delete the rest of the hits */
+            for (int i = 0, num_to_del = sz - hits_index - 1;
+                 i < num_to_del;
+                 i++)
+            {
+                hits.pop_back();
+            }
+            break;
+        }
+    }
+
     return hits;
 }
 
diff --git a/main/Scene.h b/main/Scene.h
index 4e1a0ae..a82f5c6 100755
--- a/main/Scene.h
+++ b/main/Scene.h
@@ -20,7 +20,8 @@ class Scene
         class ShapeDistance : public std::pair<Shape *, double>
         {
             public:
-                ShapeDistance(Shape *, double) : std::pair<Shape *, double>()
+                ShapeDistance(Shape * shape, double dist)
+                    : std::pair<Shape *, double>(shape, dist)
                 {
                 };
         };