Refactor the material node processing code

diff --git a/blender/io_mspgl/material.py b/blender/io_mspgl/material.py
index 519154449c25da11c7025784e9bae70e980705e5..db68d0ba2a41553ebc5ee1817fb6768f00d0c7f6 100644 (file)
--- a/blender/io_mspgl/material.py
+++ b/blender/io_mspgl/material.py
@@ -8,51 +8,90 @@ def compute_render_method_hash(material):
                descr += "{}={}".format(m.tag, m.shader)
        return hash(descr)
 
-def check_group(node_tree, group, func):
-       from .util import get_linked_node_and_socket
+class PropertyNode:
+       def __init__(self, node_tree, node, socket):
+               self.node_tree = node_tree
+               self.node = node
+               self.socket = socket
+               self.type = None
+               self.data = None
+               self.input = None
+
+               checks = [self.check_group,
+                       self.check_gray,
+                       self.check_normal,
+                       self.check_invert_green,
+                       self.check_additive_blend,
+                       self.check_texture]
+               for c in checks:
+                       if c():
+                               break
+
+       def set_input_from_linked(self, input_sock):
+               from .util import get_linked_node_and_socket
 
-       output = group.node_tree.nodes["Group Output"]
-       from_node, _ = get_linked_node_and_socket(group.node_tree, output.inputs[0])
-       if from_node:
-               from_node, _ = func(group.node_tree, from_node)
-               if from_node and from_node.type=='GROUP_INPUT':
-                       return get_linked_node_and_socket(node_tree, group.inputs[0])
-       return (None, None)
+               from_node, from_sock = get_linked_node_and_socket(self.node_tree, input_sock)
+               self.input = PropertyNode(self.node_tree, from_node, from_sock)
+               return self.input
 
-def check_invert_green(node_tree, node):
-       if node.type=='GROUP':
-               return check_group(node_tree, node, check_invert_green)
-       elif node.type!='COMBRGB':
-               return (None, None)
+       def check_group(self):
+               if self.node.type!='GROUP':
+                       return
 
-       from .util import get_linked_node_and_socket
+               from .util import get_linked_node_and_socket
+
+               output = self.node.node_tree.nodes["Group Output"]
+               from_node, from_sock = get_linked_node_and_socket(self.node.node_tree, output.inputs[0])
+               inner = PropertyNode(self.node.node_tree, from_node, from_sock)
+               if inner.input:
+                       # TODO This currently only supports a single operation inside the group
+                       if inner.input.node.type=='GROUP_INPUT':
+                               self.type = inner.type
+                               self.data = inner.data
+                               return self.set_input_from_linked(self.node.inputs[0])
+
+       def check_gray(self):
+               if self.node.type=='RGBTOBW':
+                       self.type = 'GRAY'
+                       self.set_input_from_linked(self.node.inputs["Color"])
+
+       def check_normal(self):
+               if self.node.type=='NORMAL_MAP':
+                       self.type = 'NORMAL'
+                       return self.set_input_from_linked(self.node.inputs["Color"])
+
+       def check_invert_green(self):
+               if self.node.type!='COMBRGB':
+                       return
+
+               from .util import get_linked_node_and_socket
 
-       green, _ = get_linked_node_and_socket(node_tree, node.inputs["G"])
-       if not green or green.type!='MATH' or green.operation!='SUBTRACT':
-               return (None, None)
-       green, _ = get_linked_node_and_socket(node_tree, green.inputs[1])
+               green, _ = get_linked_node_and_socket(self.node_tree, self.node.inputs["G"])
+               if not green or green.type!='MATH' or green.operation!='SUBTRACT':
+                       return
+               green, _ = get_linked_node_and_socket(self.node_tree, green.inputs[1])
 
-       red, _ = get_linked_node_and_socket(node_tree, node.inputs["R"])
-       blue, _ = get_linked_node_and_socket(node_tree, node.inputs["B"])
-       if not red or red.type!='SEPRGB' or blue!=red or green!=red:
-               return (None, None)
+               red, _ = get_linked_node_and_socket(self.node_tree, self.node.inputs["R"])
+               blue, _ = get_linked_node_and_socket(self.node_tree, self.node.inputs["B"])
+               if not red or red.type!='SEPRGB' or blue!=red or green!=red:
+                       return
 
-       return get_linked_node_and_socket(node_tree, red.inputs["Image"])
+               self.type = 'INVERT_GREEN'
+               return self.set_input_from_linked(red.inputs["Image"])
 
-def check_additive_blend(node_tree, node):
-       if node.type=='GROUP':
-               return check_group(node_tree, node, check_additive_blend)
-       elif node.type=='ADD_SHADER':
-               from .util import get_linked_node_and_socket
+       def check_additive_blend(self):
+               if self.node.type=='ADD_SHADER':
+                       from .util import get_linked_node_and_socket
 
-               shader1, _ = get_linked_node_and_socket(node_tree, node.inputs[0])
-               shader2, _ = get_linked_node_and_socket(node_tree, node.inputs[1])
-               if shader1.type=='BSDF_TRANSPARENT':
-                       return get_linked_node_and_socket(node_tree, node.inputs[1])
-               elif shader2.type=='BSDF_TRANSPARENT':
-                       return get_linked_node_and_socket(node_tree, node.inputs[0])
+                       for i in range(2):
+                               shader, _ = get_linked_node_and_socket(self.node_tree, self.node.inputs[i])
+                               if shader.type=='BSDF_TRANSPARENT':
+                                       self.type = 'ADDITIVE'
+                                       return self.set_input_from_linked(self.node.inputs[1-i])
 
-       return (None, None)
+       def check_texture(self):
+               if self.node.type=='TEX_IMAGE':
+                       self.type = 'TEXTURE'
 
 def get_unlit_inputs(node_tree, node, additive):
        from .util import get_linked_node_and_socket
@@ -102,28 +141,29 @@ class MaterialProperty:
                if self.tex_keyword:
                        from .util import get_linked_node_and_socket
 
-                       from_node, _ = get_linked_node_and_socket(node_tree, input_socket)
+                       from_node, from_sock = get_linked_node_and_socket(node_tree, input_socket)
                        alpha_from = None
                        if from_node:
                                channels = None
-                               if from_node.type=='NORMAL_MAP':
-                                       from_node, _ = get_linked_node_and_socket(node_tree, from_node.inputs["Color"])
-                                       invert, _ = check_invert_green(node_tree, from_node)
-                                       channels = ['R', 'G', 'B']
-                                       if invert:
-                                               from_node = invert
-                                               channels[1] = '~G';
-                               elif from_node.type=='RGBTOBW':
-                                       from_node, _ = get_linked_node_and_socket(node_tree, from_node.inputs["Color"])
-                                       channels = ['Y']
+                               top_node = PropertyNode(node_tree, from_node, from_sock)
+                               n = top_node
+                               while n:
+                                       if n.type=='NORMAL':
+                                               channels = ['R', 'G', 'B']
+                                       elif n.type=='GRAY':
+                                               channels = ['Y']
+                                       elif n.type=='INVERT_GREEN':
+                                               channels[1] = '~G'
+                                       elif n.type=='TEXTURE':
+                                               self.texture = n.node
+                                       n = n.input
 
                                if alpha_socket:
                                        alpha_from, _ = get_linked_node_and_socket(node_tree, alpha_socket)
-                                       if alpha_from and alpha_from!=from_node:
+                                       if alpha_from and alpha_from!=self.texture:
                                                raise Exception("Separate textures for color and alpha are not supported")
 
-                               if from_node.type=='TEX_IMAGE':
-                                       self.texture = from_node
+                               if self.texture:
                                        if channels:
                                                self.tex_channels = channels
                                        elif alpha_from: