1 files changed, 56 insertions, 0 deletions
diff --git a/intern/cycles/kernel/kernel_lookup_table.h b/intern/cycles/kernel/kernel_lookup_table.h
new file mode 100644
index 00000000000..33d9d5ae1f0
--- /dev/null
+++ b/intern/cycles/kernel/kernel_lookup_table.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2011-2013 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+CCL_NAMESPACE_BEGIN
+
+/* Interpolated lookup table access */
+
+ccl_device float lookup_table_read(const KernelGlobals *kg, float x, int offset, int size)
+{
+  x = saturate(x) * (size - 1);
+
+  int index = min(float_to_int(x), size - 1);
+  int nindex = min(index + 1, size - 1);
+  float t = x - index;
+
+  float data0 = kernel_tex_fetch(__lookup_table, index + offset);
+  if (t == 0.0f)
+    return data0;
+
+  float data1 = kernel_tex_fetch(__lookup_table, nindex + offset);
+  return (1.0f - t) * data0 + t * data1;
+}
+
+ccl_device float lookup_table_read_2D(
+    const KernelGlobals *kg, float x, float y, int offset, int xsize, int ysize)
+{
+  y = saturate(y) * (ysize - 1);
+
+  int index = min(float_to_int(y), ysize - 1);
+  int nindex = min(index + 1, ysize - 1);
+  float t = y - index;
+
+  float data0 = lookup_table_read(kg, x, offset + xsize * index, xsize);
+  if (t == 0.0f)
+    return data0;
+
+  float data1 = lookup_table_read(kg, x, offset + xsize * nindex, xsize);
+  return (1.0f - t) * data0 + t * data1;
+}
+
+CCL_NAMESPACE_END