Add ParserState class for better handling of cycles.py state

blender/arm/material/parser_state.py

@@ -0,0 +1,55 @@
+from enum import Enum
+from typing import Dict, Tuple, Union
+
+import bpy
+
+from arm.material.shader import Shader, vec3str, floatstr
+
+
+class ParserContext(Enum):
+    """Describes which kind of node tree is parsed."""
+    OBJECT = 0
+    # Texture node trees are not supported yet
+    # TEXTURE = 1
+    WORLD = 2
+
+
+class ParserState:
+    """Dataclass to keep track of the current state while parsing a
+    shader tree. The parser context defines which kind of tree on which
+    Blender data (object or world) is parsed."""
+    def __init__(self, context: ParserContext, context_data: Union[bpy.types.Object, bpy.types.World]):
+        self.context = context
+        self.context_data = context_data
+
+        # Active shader - frag for surface / tese for displacement
+        self.curshader: Shader = None
+
+        # Cache for computing nodes only once
+        self.parsed_nodes: Dict[str, bpy.types.Node] = {}
+
+        # What to parse from the node tree
+        self.parse_surface = True
+        self.parse_opacity = True
+        self.parse_displacement = True
+
+        # TODO: document those attributes
+        self.sample_bump = False
+        self.sample_bump_res = ''
+
+        # TODO: document those attributes
+        self.particle_info: Dict[str, bool] = {}
+
+        # Shader output values
+        self.out_basecol: vec3str = 'vec3(0.8)'
+        self.out_roughness: floatstr = '0.0'
+        self.out_metallic: floatstr = '0.0'
+        self.out_occlusion: floatstr = '1.0'
+        self.out_specular: floatstr = '1.0'
+        self.out_opacity: floatstr = '1.0'
+        self.out_emission: floatstr = '0.0'
+
+    def get_outs(self) -> Tuple[vec3str, floatstr, floatstr, floatstr, floatstr, floatstr, floatstr]:
+        """Return the shader output values as a tuple."""
+        return (self.out_basecol, self.out_roughness, self.out_metallic, self.out_occlusion, self.out_specular,
+                self.out_opacity, self.out_emission)

blender/arm/material/shader.py

@@ -2,6 +2,7 @@ import arm.utils
 
 # Type aliases for type hints to make it easier to see which kind of
 # shader data type is stored in a string
+floatstr = str
 vec2str = str
 vec3str = str
 vec4str = str