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.

10 files changed, 117 insertions, 1 deletions

diff --git a/intern/cycles/app/cycles_xml.cpp b/intern/cycles/app/cycles_xml.cpp
index a0282988179..f5cc01cd062 100644
--- a/intern/cycles/app/cycles_xml.cpp
+++ b/intern/cycles/app/cycles_xml.cpp
@@ -446,6 +446,9 @@ static void xml_read_shader_graph(const XMLReadState& state, Shader *shader, pug
 			xml_read_enum(&mix->type, MixNode::type_enum, node, "type");
 			snode = mix;
 		}
+		else if(string_iequals(node.name(), "gamma")) {
+			snode = new GammaNode();
+		}
 		else if(string_iequals(node.name(), "combine_rgb")) {
 			snode = new CombineRGBNode();
 		}
diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index 4191fef4dcd..ecc85a92ae0 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -160,6 +160,10 @@ static ShaderNode *add_node(BL::BlendData b_data, ShaderGraph *graph, BL::Node *
 			node = new InvertNode();
 			break;
 		}
+		case BL::ShaderNode::type_GAMMA: {
+			node = new GammaNode();
+			break;
+		}
 		case BL::ShaderNode::type_MIX_RGB: {
 			BL::ShaderNodeMixRGB b_mix_node(b_node);
 			MixNode *mix = new MixNode();
diff --git a/intern/cycles/kernel/CMakeLists.txt b/intern/cycles/kernel/CMakeLists.txt
index 65338eeea6e..e17544bf7af 100644
--- a/intern/cycles/kernel/CMakeLists.txt
+++ b/intern/cycles/kernel/CMakeLists.txt
@@ -59,6 +59,7 @@ set(SRC_SVM_HEADERS
 	svm/svm_convert.h
 	svm/svm_displace.h
 	svm/svm_fresnel.h
+	svm/svm_gamma.h
 	svm/svm_geometry.h
 	svm/svm_gradient.h
 	svm/svm_hsv.h
diff --git a/intern/cycles/kernel/osl/nodes/CMakeLists.txt b/intern/cycles/kernel/osl/nodes/CMakeLists.txt
index 5c1fd8b75d8..1a207d6c139 100644
--- a/intern/cycles/kernel/osl/nodes/CMakeLists.txt
+++ b/intern/cycles/kernel/osl/nodes/CMakeLists.txt
@@ -19,6 +19,7 @@ set(SRC_OSL
 	node_emission.osl
 	node_environment_texture.osl
 	node_fresnel.osl
+	node_gamma.osl
 	node_geometry.osl
 	node_glass_bsdf.osl
 	node_glossy_bsdf.osl
diff --git a/intern/cycles/kernel/osl/nodes/node_gamma.osl b/intern/cycles/kernel/osl/nodes/node_gamma.osl
new file mode 100644
index 00000000000..4dae07d70bc
--- /dev/null
+++ b/intern/cycles/kernel/osl/nodes/node_gamma.osl
@@ -0,0 +1,33 @@
+/*
+ * 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.
+ */
+
+#include "stdosl.h"
+
+shader node_gamma(
+	color ColorIn = color(0.8, 0.8, 0.8),
+	float Gamma = 1.0,
+	output ColorOut = color(0.8, 0.8, 0.8)
+{
+	int i;
+	for (i=0;i<3;i++) {
+		if (ColorIn[i] > 0.0)
+			ColorIn[i] = powf(ColorIn[i], Gamma);
+	}
+
+	ColorOut = ColorIn;
+}
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 {
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index aec6f1f3e26..5cabb248709 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -1726,6 +1726,33 @@ void CombineRGBNode::compile(OSLCompiler& compiler)
 	compiler.add(this, "node_combine_rgb");
 }
 
+/* Gamma */
+GammaNode::GammaNode()
+: ShaderNode("gamma")
+{
+	add_input("Color", SHADER_SOCKET_COLOR);
+	add_input("Gamma", SHADER_SOCKET_FLOAT);
+	add_output("Color", SHADER_SOCKET_COLOR);
+}
+
+void GammaNode::compile(SVMCompiler& compiler)
+{
+	ShaderInput *color_in = input("Color");
+	ShaderInput *gamma_in = input("Gamma");
+	ShaderOutput *color_out = output("Color");
+
+	compiler.stack_assign(color_in);
+	compiler.stack_assign(gamma_in);
+	compiler.stack_assign(color_out);
+
+	compiler.add_node(NODE_GAMMA, gamma_in->stack_offset, color_in->stack_offset, color_out->stack_offset);
+}
+
+void GammaNode::compile(OSLCompiler& compiler)
+{
+	compiler.add(this, "node_gamma");
+}
+
 /* Separate RGB */
 SeparateRGBNode::SeparateRGBNode()
 : ShaderNode("separate_rgb")
diff --git a/intern/cycles/render/nodes.h b/intern/cycles/render/nodes.h
index 9d947de1af5..28fff22fc34 100644
--- a/intern/cycles/render/nodes.h
+++ b/intern/cycles/render/nodes.h
@@ -302,6 +302,11 @@ public:
 	SHADER_NODE_CLASS(CombineRGBNode)
 };
 
+class GammaNode : public ShaderNode {
+public:
+	SHADER_NODE_CLASS(GammaNode)
+};
+
 class SeparateRGBNode : public ShaderNode {
 public:
 	SHADER_NODE_CLASS(SeparateRGBNode)