Cycles Gamma Node

Node specially useful for Texture correction.

This is also a nice example of a simple node made from scratch in case someone wants to create their custom nodes.
Review by Brecht.

1 files changed, 37 insertions, 0 deletions

diff --git a/intern/cycles/kernel/svm/svm_gamma.h b/intern/cycles/kernel/svm/svm_gamma.h
new file mode 100644
index 00000000000..4a8967011c7
--- /dev/null
+++ b/intern/cycles/kernel/svm/svm_gamma.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2011, Blender Foundation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+CCL_NAMESPACE_BEGIN
+
+__device void svm_node_gamma(ShaderData *sd, float *stack, uint in_gamma, uint in_color, uint out_color)
+{
+	float3 color = stack_load_float3(stack, in_color);
+	float gamma = stack_load_float(stack, in_gamma);
+
+	if (color.x > 0.0)
+		color.x = powf(color.x, gamma);
+	if (color.y > 0.0)
+		color.y = powf(color.y, gamma);
+	if (color.z > 0.0)
+		color.z = powf(color.z, gamma);
+
+	if (stack_valid(out_color))
+		stack_store_float3(stack, out_color, color);
+}
+
+CCL_NAMESPACE_END