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.

3 files changed, 43 insertions, 1 deletions

diff --git a/intern/cycles/kernel/svm/svm.h b/intern/cycles/kernel/svm/svm.h
index 2beff7ff7e6..5a8d6d62c79 100644
--- a/intern/cycles/kernel/svm/svm.h
+++ b/intern/cycles/kernel/svm/svm.h
@@ -130,6 +130,7 @@ CCL_NAMESPACE_END
 #include "svm_geometry.h"
 #include "svm_hsv.h"
 #include "svm_image.h"
+#include "svm_gamma.h"
 #include "svm_invert.h"
 #include "svm_light_path.h"
 #include "svm_magic.h"
@@ -262,6 +263,9 @@ __device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, ShaderT
 			case NODE_INVERT:
 				svm_node_invert(sd, stack, node.y, node.z, node.w);
 				break;
+			case NODE_GAMMA:
+				svm_node_gamma(sd, stack, node.y, node.z, node.w);
+				break;
 			case NODE_MIX:
 				svm_node_mix(kg, sd, stack, node.y, node.z, node.w, &offset);
 				break;
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
diff --git a/intern/cycles/kernel/svm/svm_types.h b/intern/cycles/kernel/svm/svm_types.h
index e5e3175761b..c46df3f08c8 100644
--- a/intern/cycles/kernel/svm/svm_types.h
+++ b/intern/cycles/kernel/svm/svm_types.h
@@ -85,7 +85,8 @@ typedef enum NodeType {
 	NODE_HSV = 5200,
 	NODE_CAMERA = 5300,
 	NODE_INVERT = 5400,
-	NODE_NORMAL = 5500
+	NODE_NORMAL = 5500,
+	NODE_GAMMA = 5600
 } NodeType;
 
 typedef enum NodeAttributeType {