Add Chromium-only Blender WebEngine parity work

blender-5.2.0/intern/cycles/kernel/sample/mis.h

@@ -0,0 +1,41 @@
+/* SPDX-FileCopyrightText: 2009-2010 Sony Pictures Imageworks Inc., et al. All Rights Reserved.
+ * SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Adapted code from Open Shading Language. */
+
+#pragma once
+
+#include "util/defines.h"
+
+CCL_NAMESPACE_BEGIN
+
+/* Multiple importance sampling utilities. */
+
+ccl_device float balance_heuristic(const float a, const float b)
+{
+  return (a) / (a + b);
+}
+
+ccl_device float balance_heuristic_3(const float a, const float b, float c)
+{
+  return (a) / (a + b + c);
+}
+
+ccl_device float power_heuristic(const float a, const float b)
+{
+  return (a * a) / (a * a + b * b);
+}
+
+ccl_device float power_heuristic_3(const float a, const float b, float c)
+{
+  return (a * a) / (a * a + b * b + c * c);
+}
+
+ccl_device float max_heuristic(const float a, const float b)
+{
+  return (a > b) ? 1.0f : 0.0f;
+}
+
+CCL_NAMESPACE_END