From 7a5d84b06d0217c5edad5d9f4ef51404de0cb911 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 25 Sep 2022 19:45:34 +0300
Subject: [PATCH] Add a tint property for PBR materials

---
 blender/io_mspgl/material.py     | 18 ++++++++++++++++++
 shaderlib/cooktorrance.glsl      |  5 +++--
 source/materials/pbrmaterial.cpp |  7 +++++++
 source/materials/pbrmaterial.h   |  2 ++
 4 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/blender/io_mspgl/material.py b/blender/io_mspgl/material.py
index ccbf0083..3e2bce00 100644
--- a/blender/io_mspgl/material.py
+++ b/blender/io_mspgl/material.py
@@ -19,6 +19,7 @@ class PropertyNode:
 
 		checks = [self.check_group,
 			self.check_scale,
+			self.check_tint,
 			self.check_gray,
 			self.check_extract,
 			self.check_normal,
@@ -63,6 +64,17 @@ class PropertyNode:
 					self.data = self.node.inputs[i].default_value
 					return self.set_input_from_linked(self.node.inputs[1-i])
 
+	def check_tint(self):
+		if self.node.type!='MIX_RGB':
+			return
+
+		if self.node.blend_type=='MULTIPLY':
+			for i in range(2):
+				if not self.node.inputs[1+i].is_linked:
+					self.type = 'TINT'
+					self.data = self.node.inputs[1+i].default_value[:]
+					return self.set_input_from_linked(self.node.inputs[2-i])
+
 	def check_gray(self):
 		if self.node.type=='RGBTOBW':
 			self.type = 'GRAY'
@@ -152,6 +164,7 @@ class MaterialProperty:
 		self.texture = None
 		self.tex_channels = None
 		self.scale = 1.0
+		self.tint = None
 
 	def set_from_input(self, node_tree, input_socket, alpha_socket=None):
 		if self.keyword:
@@ -183,6 +196,8 @@ class MaterialProperty:
 						channels = ['~'+c if c in n.data else c for c in channels]
 					elif n.type=='SCALE':
 						self.scale = n.data
+					elif n.type=='TINT':
+						self.tint = n.data
 					elif n.type=='TEXTURE':
 						self.texture = n.node
 					n = n.input
@@ -253,12 +268,15 @@ class Material:
 			self.type = "pbr"
 
 			base_color = self.create_property("base_color", (0.8, 0.8, 0.8, 1.0))
+			tint = self.create_property("tint", (1.0, 1.0, 1.0, 1.0))
 			metalness = self.create_property("metalness", 0.0)
 			roughness = self.create_property("roughness", 0.5)
 			normal = self.create_property("normal_map")
 			emission = self.create_property("emission", (0.0, 0.0, 0.0))
 
 			base_color.set_from_input(material.node_tree, from_node.inputs["Base Color"], from_node.inputs["Alpha"])
+			if base_color.tint:
+				tint.value = base_color.tint
 			metalness.set_from_input(material.node_tree, from_node.inputs["Metallic"])
 			roughness.set_from_input(material.node_tree, from_node.inputs["Roughness"])
 			normal.set_from_input(material.node_tree, from_node.inputs["Normal"])
diff --git a/shaderlib/cooktorrance.glsl b/shaderlib/cooktorrance.glsl
index 1c564a04..8a69d473 100644
--- a/shaderlib/cooktorrance.glsl
+++ b/shaderlib/cooktorrance.glsl
@@ -6,6 +6,7 @@ import shadow;
 struct PbrMaterialParameters
 {
 	vec4 base_color;
+	vec4 tint;
 	vec4 emission;
 	float metalness;
 	float roughness;
@@ -36,9 +37,9 @@ layout(constant_id=auto) const bool use_image_based_lighting = false;
 virtual vec4 get_base_color()
 {
 	if(use_base_color_map)
-		return texture(base_color_map, texcoord.xy);
+		return texture(base_color_map, texcoord.xy)*pbr_material.tint;
 	else
-		return pbr_material.base_color;
+		return pbr_material.base_color*pbr_material.tint;
 }
 
 virtual float get_metalness_value()
diff --git a/source/materials/pbrmaterial.cpp b/source/materials/pbrmaterial.cpp
index ebd3321f..c5d849c1 100644
--- a/source/materials/pbrmaterial.cpp
+++ b/source/materials/pbrmaterial.cpp
@@ -116,6 +116,12 @@ void PbrMaterial::set_base_color_map(const Texture *tex)
 	base_color.texture = tex;
 }
 
+void PbrMaterial::set_tint(const Color &color)
+{
+	tint.value = color;
+	shdata.uniform("pbr_material.tint", color);
+}
+
 void PbrMaterial::set_normal_map(const Texture *tex)
 {
 	normal.texture = tex;
@@ -177,6 +183,7 @@ void PbrMaterial::Loader::init_actions()
 	add_property("roughness", &PbrMaterial::set_roughness, &PbrMaterial::set_roughness_map);
 	add_property("occlusion", &PbrMaterial::set_occlusion_map);
 	add_property("emission", &PbrMaterial::set_emission, &PbrMaterial::set_emission_map, false);
+	add_property("tint", &PbrMaterial::set_tint, 0, true);
 }
 
 } // namespace GL
diff --git a/source/materials/pbrmaterial.h b/source/materials/pbrmaterial.h
index 18719bd4..e863ca64 100644
--- a/source/materials/pbrmaterial.h
+++ b/source/materials/pbrmaterial.h
@@ -34,6 +34,7 @@ public:
 	
 private:
 	Property<Color> base_color;
+	Property<Color> tint;
 	Property<Vector3> normal;
 	Property<float> metalness;
 	Property<float> roughness;
@@ -60,6 +61,7 @@ public:
 
 	void set_base_color(const Color &);
 	void set_base_color_map(const Texture *);
+	void set_tint(const Color &);
 	void set_normal_map(const Texture *);
 	void set_metalness(float);
 	void set_metalness_map(const Texture *);
-- 
2.43.0