clamp for Mix node

the implementation was following my early commit for Math node
I haven't had a chance to run those through Brecht, but would like to do eventually. (they work fine though)

7 files changed, 42 insertions, 1 deletions

diff --git a/intern/cycles/app/cycles_xml.cpp b/intern/cycles/app/cycles_xml.cpp
index 5ec5cb929d6..5569df927fb 100644
--- a/intern/cycles/app/cycles_xml.cpp
+++ b/intern/cycles/app/cycles_xml.cpp
@@ -484,6 +484,7 @@ static void xml_read_shader_graph(const XMLReadState& state, Shader *shader, pug
 		else if(string_iequals(node.name(), "mix")) {
 			MixNode *mix = new MixNode();
 			xml_read_enum(&mix->type, MixNode::type_enum, node, "type");
+			xml_read_bool(&mix->use_clamp, node, "use_clamp");
 			snode = mix;
 		}
 		else if(string_iequals(node.name(), "gamma")) {
@@ -515,6 +516,7 @@ static void xml_read_shader_graph(const XMLReadState& state, Shader *shader, pug
 		else if(string_iequals(node.name(), "math")) {
 			MathNode *math = new MathNode();
 			xml_read_enum(&math->type, MathNode::type_enum, node, "type");
+			xml_read_bool(&math->use_clamp, node, "use_clamp");
 			snode = math;
 		}
 		else if(string_iequals(node.name(), "vector_math")) {
diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index 37ab1ddac26..b82fee5edf0 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -221,6 +221,7 @@ static ShaderNode *add_node(BL::BlendData b_data, BL::Scene b_scene, ShaderGraph
 			BL::ShaderNodeMixRGB b_mix_node(b_node);
 			MixNode *mix = new MixNode();
 			mix->type = MixNode::type_enum[b_mix_node.blend_type()];
+			mix->use_clamp = b_mix_node.use_clamp();
 			node = mix;
 			break;
 		}
diff --git a/intern/cycles/kernel/osl/nodes/node_mix.osl b/intern/cycles/kernel/osl/nodes/node_mix.osl
index 8a462c995d3..9ba58e2b56e 100644
--- a/intern/cycles/kernel/osl/nodes/node_mix.osl
+++ b/intern/cycles/kernel/osl/nodes/node_mix.osl
@@ -267,8 +267,20 @@ color node_mix_linear(float t, color col1, color col2)
 	return outcol;
 }
 
+color node_mix_clamp(color col)
+{
+	color outcol = col;
+
+	outcol[0] = clamp(col[0], 0.0, 1.0);
+	outcol[1] = clamp(col[2], 0.0, 1.0);
+	outcol[2] = clamp(col[2], 0.0, 1.0);
+
+	return outcol;
+}
+
 shader node_mix(
 	string type = "Mix",
+	int Clamp = false,
 	float Fac = 0.5,
 	color Color1 = color(0.0, 0.0, 0.0),
 	color Color2 = color(0.0, 0.0, 0.0),
@@ -312,5 +324,8 @@ shader node_mix(
 		Color = node_mix_soft(t, Color1, Color2);
 	if(type == "Linear Light")
 		Color = node_mix_linear(t, Color1, Color2);
+
+	if(Clamp)
+		Color = node_mix_clamp(Color);
 }
 
diff --git a/intern/cycles/kernel/svm/svm_mix.h b/intern/cycles/kernel/svm/svm_mix.h
index 6b455e713c2..888e4d9645e 100644
--- a/intern/cycles/kernel/svm/svm_mix.h
+++ b/intern/cycles/kernel/svm/svm_mix.h
@@ -276,6 +276,17 @@ __device float3 svm_mix_linear(float t, float3 col1, float3 col2)
 	return outcol;
 }
 
+__device float3 svm_mix_clamp(float3 col)
+{
+	float3 outcol = col;
+
+	outcol.x = clamp(col.x, 0.0f, 1.0f);
+	outcol.y = clamp(col.y, 0.0f, 1.0f);
+	outcol.z = clamp(col.z, 0.0f, 1.0f);
+
+	return outcol;
+}
+
 __device float3 svm_mix(NodeMix type, float fac, float3 c1, float3 c2)
 {
 	float t = clamp(fac, 0.0f, 1.0f);
@@ -299,6 +310,7 @@ __device float3 svm_mix(NodeMix type, float fac, float3 c1, float3 c2)
 		case NODE_MIX_COLOR: return svm_mix_color(t, c1, c2);
 		case NODE_MIX_SOFT: return svm_mix_soft(t, c1, c2);
 		case NODE_MIX_LINEAR: return svm_mix_linear(t, c1, c2);
+		case NODE_MIX_CLAMP: return svm_mix_clamp(c1);
 	}
 
 	return make_float3(0.0f, 0.0f, 0.0f);
diff --git a/intern/cycles/kernel/svm/svm_types.h b/intern/cycles/kernel/svm/svm_types.h
index df06b883cae..38232eb9c04 100644
--- a/intern/cycles/kernel/svm/svm_types.h
+++ b/intern/cycles/kernel/svm/svm_types.h
@@ -163,7 +163,8 @@ typedef enum NodeMix {
 	NODE_MIX_VAL,
 	NODE_MIX_COLOR,
 	NODE_MIX_SOFT,
-	NODE_MIX_LINEAR
+	NODE_MIX_LINEAR,
+	NODE_MIX_CLAMP /* used for the clamp UI option */
 } NodeMix;
 
 typedef enum NodeMath {
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index 07310cb4461..b35fe151bac 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -1971,6 +1971,8 @@ MixNode::MixNode()
 {
 	type = ustring("Mix");
 
+	use_clamp = false;
+
 	add_input("Fac", SHADER_SOCKET_FLOAT, 0.5f);
 	add_input("Color1", SHADER_SOCKET_COLOR);
 	add_input("Color2", SHADER_SOCKET_COLOR);
@@ -2019,11 +2021,17 @@ void MixNode::compile(SVMCompiler& compiler)
 
 	compiler.add_node(NODE_MIX, fac_in->stack_offset, color1_in->stack_offset, color2_in->stack_offset);
 	compiler.add_node(NODE_MIX, type_enum[type], color_out->stack_offset);
+
+	if(use_clamp) {
+		compiler.add_node(NODE_MIX, 0, color_out->stack_offset);
+		compiler.add_node(NODE_MIX, NODE_MIX_CLAMP, color_out->stack_offset);
+	}
 }
 
 void MixNode::compile(OSLCompiler& compiler)
 {
 	compiler.parameter("type", type);
+	compiler.parameter("Clamp", use_clamp);
 	compiler.add(this, "node_mix");
 }
 
diff --git a/intern/cycles/render/nodes.h b/intern/cycles/render/nodes.h
index 2e0acc32e51..650d6092f29 100644
--- a/intern/cycles/render/nodes.h
+++ b/intern/cycles/render/nodes.h
@@ -329,6 +329,8 @@ class MixNode : public ShaderNode {
 public:
 	SHADER_NODE_CLASS(MixNode)
 
+	bool use_clamp;
+
 	ustring type;
 	static ShaderEnum type_enum;
 };