From f398c65c9e741ca4919a0770e096c15e8d33c1c2 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 21 Mar 2021 18:15:02 +0200
Subject: [PATCH] Add support for exporting vertex colors

---
 blender/io_mspgl/export_mesh.py |  6 ++++
 blender/io_mspgl/mesh.py        | 51 +++++++++++++++++++++++++++++++--
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/blender/io_mspgl/export_mesh.py b/blender/io_mspgl/export_mesh.py
index a6501bc6..0d27a71c 100644
--- a/blender/io_mspgl/export_mesh.py
+++ b/blender/io_mspgl/export_mesh.py
@@ -64,6 +64,8 @@ class MeshExporter:
 		statements = resource.statements
 
 		st = Statement("vertices", Token("NORMAL3"))
+		if mesh.vertices[0].color:
+			st.append(Token("COLOR4_UBYTE"))
 		if mesh.uv_layers:
 			for u in mesh.uv_layers:
 				size = str(len(u.uvs[0]))
@@ -79,6 +81,7 @@ class MeshExporter:
 		st.append(Token("VERTEX3"))
 
 		normal = None
+		color = None
 		uvs = [None]*len(mesh.uv_layers)
 		tan = None
 		bino = None
@@ -87,6 +90,9 @@ class MeshExporter:
 			if v.normal!=normal:
 				st.sub.append(Statement("normal", *v.normal))
 				normal = v.normal
+			if v.color!=color:
+				st.sub.append(Statement("color", *v.color))
+				color = v.color
 			for i, u in enumerate(mesh.uv_layers):
 				if v.uvs[i]!=uvs[i]:
 					if u.unit==0:
diff --git a/blender/io_mspgl/mesh.py b/blender/io_mspgl/mesh.py
index f5665256..da5e76aa 100644
--- a/blender/io_mspgl/mesh.py
+++ b/blender/io_mspgl/mesh.py
@@ -56,6 +56,7 @@ class Vertex:
 		self.index = vertex.index
 		self.co = mathutils.Vector(vertex.co)
 		self.normal = mathutils.Vector(vertex.normal)
+		self.color = None
 		self.flag = False
 		self.edges = []
 		self.faces = []
@@ -142,6 +143,12 @@ class UvLayer:
 				self.hidden = True
 
 
+class ColorLayer:
+	def __init__(self, l):
+		self.name = l.name
+		self.colors = [c.color[:] for c in l.data]
+
+
 class Mesh:
 	def __init__(self, mesh):
 		self.name = mesh.name
@@ -187,6 +194,10 @@ class Mesh:
 				if self.uv_layers[0].unit!=0:
 					self.uv_layers = []
 
+		self.colors = None
+		if mesh.vertex_colors:
+			self.colors = ColorLayer(mesh.vertex_colors[0])
+
 		# Rewrite links between elements to point to cloned data, or create links
 		# where they don't exist
 		edge_map = {e.key: e for e in self.edges}
@@ -242,6 +253,15 @@ class Mesh:
 		for i, u in enumerate(self.uv_layers):
 			u.uvs += other.uv_layers[i].uvs
 
+		if self.colors:
+			if other.colors:
+				self.colors.colors += other.colors.colors
+			else:
+				self.colors.colors += [(1.0, 1.0, 1.0, 1.0)]*len(other.loops)
+		elif other.colors:
+			self.colors = ColorLayer(other.colors.name)
+			self.colors.colors = [(1.0, 1.0, 1.0, 1.0)]*len(self.loops)+other.colors.colors
+
 		offset = len(self.vertices)
 		self.vertices += other.vertices
 		for v in self.vertices[offset:]:
@@ -453,6 +473,19 @@ class Mesh:
 			else:
 				v.uvs = [(0.0, 0.0)]*len(self.uv_layers)
 
+	def prepare_colors(self, progress):
+		if not self.colors:
+			return
+
+		self.split_vertices(self.find_color_group, progress)
+
+		for v in self.vertices:
+			if v.faces:
+				f = v.faces[0]
+				v.color = self.colors.colors[f.get_loop_index(v)]
+			else:
+				v.color = (1.0, 1.0, 1.0, 1.0)
+
 	def split_vertices(self, find_group_func, progress, *args):
 		vertex_count = len(self.vertices)
 		for i in range(vertex_count):
@@ -539,6 +572,18 @@ class Mesh:
 
 		return group
 
+	def find_color_group(self, vertex, face):
+		color = self.colors.colors[face.get_loop_index(vertex)]
+		face.flag = True
+
+		group = [face]
+		for f in vertex.faces:
+			if not f.flag and self.colors.colors[f.get_loop_index(vertex)]==color:
+				f.flag = True
+				group.append(f)
+
+		return group
+
 	def compute_normals(self, progress):
 		for i, v in enumerate(self.vertices):
 			v.normal = mathutils.Vector()
@@ -782,9 +827,11 @@ def create_mesh_from_object(context, obj, progress, *, material_map=None):
 	mesh.prepare_smoothing(progress)
 	progress.set_task("Vertex groups", 0.5, 0.6)
 	mesh.prepare_vertex_groups(obj)
-	progress.set_task("Preparing UVs", 0.6, 0.8)
+	progress.set_task("Preparing UVs", 0.6, 0.75)
 	mesh.prepare_uv(progress)
-	progress.set_task("Render sequence", 0.8, 1.0)
+	progress.set_task("Preparing vertex colors", 0.75, 0.85)
+	mesh.prepare_colors(progress)
+	progress.set_task("Render sequence", 0.85, 1.0)
 	mesh.prepare_sequence(progress)
 
 	progress.pop_task()
-- 
2.45.2