From da376e0237517543aa21740ee2363234ee1c20ae Mon Sep 17 00:00:00 2001
From: Ton Roosendaal <ton@blender.org>
Date: Wed, 27 Apr 2011 11:58:34 +0000
Subject: Cycles render engine, initial commit. This is the engine itself,
 blender modifications and build instructions will follow later.

Cycles uses code from some great open source projects, many thanks them:

* BVH building and traversal code from NVidia's "Understanding the Efficiency of Ray Traversal on GPUs":
http://code.google.com/p/understanding-the-efficiency-of-ray-traversal-on-gpus/
* Open Shading Language for a large part of the shading system:
http://code.google.com/p/openshadinglanguage/
* Blender for procedural textures and a few other nodes.
* Approximate Catmull Clark subdivision from NVidia Mesh tools:
http://code.google.com/p/nvidia-mesh-tools/
* Sobol direction vectors from:
http://web.maths.unsw.edu.au/~fkuo/sobol/
* Film response functions from:
http://www.cs.columbia.edu/CAVE/software/softlib/dorf.php
---
 intern/cycles/kernel/osl/emissive.cpp | 107 ++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 intern/cycles/kernel/osl/emissive.cpp

(limited to 'intern/cycles/kernel/osl/emissive.cpp')

diff --git a/intern/cycles/kernel/osl/emissive.cpp b/intern/cycles/kernel/osl/emissive.cpp
new file mode 100644
index 00000000000..28d3c73e59b
--- /dev/null
+++ b/intern/cycles/kernel/osl/emissive.cpp
@@ -0,0 +1,107 @@
+/*
+ * Adapted from Open Shading Language with this license:
+ *
+ * Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al.
+ * All Rights Reserved.
+ *
+ * Modifications Copyright 2011, Blender Foundation.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * * Neither the name of Sony Pictures Imageworks nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <OpenImageIO/fmath.h>
+
+#include <OSL/genclosure.h>
+
+#include "osl_closures.h"
+
+CCL_NAMESPACE_BEGIN
+
+using namespace OSL;
+
+/// Variable cone emissive closure
+///
+/// This primitive emits in a cone having a configurable
+/// penumbra area where the light decays to 0 reaching the
+/// outer_angle limit. It can also behave as a lambertian emitter
+/// if the provided angles are PI/2, which is the default
+///
+class GenericEmissiveClosure : public EmissiveClosure {
+public:
+    GenericEmissiveClosure() { }
+
+    void setup() { }
+
+    size_t memsize () const { return sizeof(*this); }
+
+    const char *name () const { return "emission"; }
+
+    void print_on (std::ostream &out) const {
+        out << name() << "()";
+    }
+
+    Color3 eval (const Vec3 &Ng, const Vec3 &omega_out) const
+    {
+        float cosNO = fabsf(Ng.dot(omega_out));
+        float res = cosNO > 0 ? 1.0f / float(M_PI) : 0.0f;
+        return Color3(res, res, res);
+    }
+
+    void sample (const Vec3 &Ng, float randu, float randv,
+                 Vec3 &omega_out, float &pdf) const
+    {
+        // We don't do anything sophisticated here for the step
+        // We just sample the whole cone uniformly to the cosine
+        Vec3 T, B;
+        make_orthonormals(Ng, T, B);
+        float phi = 2 * (float) M_PI * randu;
+        float cosTheta = sqrtf(1.0f - 1.0f * randv);
+        float sinTheta = sqrtf(1.0f - cosTheta * cosTheta);
+        omega_out = (cosf(phi) * sinTheta) * T +
+                    (sinf(phi) * sinTheta) * B +
+                                 cosTheta  * Ng;
+        pdf = 1.0f / float(M_PI);
+    }
+
+    /// Return the probability distribution function in the direction omega_out,
+    /// given the parameters and the light's surface normal.  This MUST match
+    /// the PDF computed by sample().
+    float pdf (const Vec3 &Ng,
+               const Vec3 &omega_out) const
+    {
+        float cosNO = Ng.dot(omega_out);
+        return cosNO > 0 ? 1.0f / float(M_PI) : 0.0f;
+    }
+};
+
+
+
+ClosureParam closure_emission_params[] = {
+    CLOSURE_STRING_KEYPARAM("label"),
+    CLOSURE_FINISH_PARAM(GenericEmissiveClosure) };
+
+CLOSURE_PREPARE(closure_emission_prepare, GenericEmissiveClosure)
+
+CCL_NAMESPACE_END
+
-- 
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