1 files changed, 89 insertions, 0 deletions
diff --git a/intern/cycles/kernel/shaders/node_ramp_util.h b/intern/cycles/kernel/shaders/node_ramp_util.h
new file mode 100644
index 00000000000..917fb65c6df
--- /dev/null
+++ b/intern/cycles/kernel/shaders/node_ramp_util.h
@@ -0,0 +1,89 @@
+/*
+ * 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.
+ */
+
+/* NOTE: svm_ramp.h, svm_ramp_util.h and node_ramp_util.h must stay consistent */
+
+color rgb_ramp_lookup(color ramp[], float at, int interpolate, int extrapolate)
+{
+	float f = at;
+	int table_size = arraylength(ramp);
+
+	if ((f < 0.0 || f > 1.0) && extrapolate) {
+		color t0, dy;
+		if (f < 0.0) {
+			t0 = ramp[0];
+			dy = t0 - ramp[1];
+			f = -f;
+		}
+		else {
+			t0 = ramp[table_size - 1];
+			dy = t0 - ramp[table_size - 2];
+			f = f - 1.0;
+		}
+		return t0 + dy * f * (table_size - 1);
+	}
+
+	f = clamp(at, 0.0, 1.0) * (table_size - 1);
+
+	/* clamp int as well in case of NaN */
+	int i = (int)f;
+	if (i < 0) i = 0;
+	if (i >= table_size) i = table_size - 1;
+	float t = f - (float)i;
+
+	color result = ramp[i];
+
+	if (interpolate && t > 0.0)
+		result = (1.0 - t) * result + t * ramp[i + 1];
+
+	return result;
+}
+
+float rgb_ramp_lookup(float ramp[], float at, int interpolate, int extrapolate)
+{
+	float f = at;
+	int table_size = arraylength(ramp);
+
+	if ((f < 0.0 || f > 1.0) && extrapolate) {
+		float t0, dy;
+		if (f < 0.0) {
+			t0 = ramp[0];
+			dy = t0 - ramp[1];
+			f = -f;
+		}
+		else {
+			t0 = ramp[table_size - 1];
+			dy = t0 - ramp[table_size - 2];
+			f = f - 1.0;
+		}
+		return t0 + dy * f * (table_size - 1);
+	}
+
+	f = clamp(at, 0.0, 1.0) * (table_size - 1);
+
+	/* clamp int as well in case of NaN */
+	int i = (int)f;
+	if (i < 0) i = 0;
+	if (i >= table_size) i = table_size - 1;
+	float t = f - (float)i;
+
+	float result = ramp[i];
+
+	if (interpolate && t > 0.0)
+		result = (1.0 - t) * result + t * ramp[i + 1];
+	
+	return result;
+}