1 files changed, 58 insertions, 0 deletions
diff --git a/src/illuminate/shadow.cpp b/src/illuminate/shadow.cpp
new file mode 100644
index 0000000..99e2b29
--- /dev/null
+++ b/src/illuminate/shadow.cpp
@@ -0,0 +1,58 @@
+#include "raytracer/raytracer.h"
+
+bool RayTracer::isShadowed(
+        glm::vec4 lightPosition,
+        float distanceToLight,
+        glm::vec4 directionFromIntersectionToLight,
+        glm::vec4 intersectionWorld,
+        const RayTraceScene &scene)
+{
+    // normalize direction
+    directionFromIntersectionToLight = glm::normalize(directionFromIntersectionToLight);
+
+     // acceleration causes "bad jaggies" so we disable it for now
+    if (m_config.enableAcceleration)
+    {
+        RenderShapeData shapeData;
+        auto pBias = intersectionWorld + .001f * directionFromIntersectionToLight;
+        float t = traverseBVH(pBias, directionFromIntersectionToLight, shapeData, scene.m_bvh);
+        return t != FINF;
+    }
+
+    for (const RenderShapeData &s: scene.getShapes()) {
+        // convert this world ray to object space
+        glm::vec4 dObject = glm::normalize(
+                s.inverseCTM * directionFromIntersectionToLight);
+        glm::vec4 pObject = s.inverseCTM * intersectionWorld;
+
+        // see if there is an intersection
+        glm::vec4 newIntersectionObj = findIntersection(pObject, dObject, s);
+
+        if (newIntersectionObj.w == 1.f) // hit!
+        {
+            // check if the intersection is the same as the pObject
+            if (floatEquals(glm::distance(newIntersectionObj, pObject), 0.f, 0.001f))
+            {
+                // don't consider self-intersections
+                continue;
+            }
+
+            // check if this intersection is closer than the direction to the light
+            auto newIntersectionWorld = s.ctm * newIntersectionObj;
+            if (distanceToLight == FINF)
+            {
+                // if the light is infinitely far away light, then any non-self intersection is valid
+                return true;
+            }
+
+            float newDist = glm::distance(newIntersectionWorld, lightPosition);
+            if (newDist < distanceToLight - 0.001f)
+            {
+                // an object in front of the camera is the way -> shadow
+                return true;
+            }
+        }
+    }
+
+    return false;
+}
+\ No newline at end of file