Bugfix: textures should be implemented as textures without changes

Fixes a small bug when using textures directly. Textures where different despite having the same hash.

pystencils/interpolation_astnodes.py

@@ -12,12 +12,11 @@ import itertools
 from enum import Enum
 from typing import Set
 
-import sympy as sp
-from sympy.core.cache import cacheit
-
 import pystencils
+import sympy as sp
 from pystencils.astnodes import Node
 from pystencils.data_types import TypedSymbol, cast_func, create_type
+from sympy.core.cache import cacheit
 
 try:
     import pycuda.driver
@@ -304,18 +303,19 @@ class TextureCachedField:
         self.filter_mode = filter_mode
         self.read_as_integer = read_as_integer
         self.use_normalized_coordinates = use_normalized_coordinates
+        self.interpolation_mode = interpolation_mode
         self.symbol = TypedSymbol(str(self), self.field.dtype.numpy_dtype)
         self.symbol.interpolator = self
         self.symbol.field = self.field
         self.required_global_declarations = [TextureDeclaration(self)]
-        self.interpolation_mode = interpolation_mode
 
         # assert str(self.field.dtype) != 'double', "CUDA does not support double textures!"
         # assert dtype_supports_textures(self.field.dtype), "CUDA only supports texture types with 32 bits or less"
 
     @classmethod
     def from_interpolator(cls, interpolator: LinearInterpolator):
-        if hasattr(interpolator, 'allow_textures') and not interpolator.allow_textures:
+        if (isinstance(interpolator, cls)
+                or (hasattr(interpolator, 'allow_textures') and not interpolator.allow_textures)):
             return interpolator
         obj = cls(interpolator.field, interpolator.address_mode, interpolation_mode=interpolator.interpolation_mode)
         return obj
@@ -327,11 +327,19 @@ class TextureCachedField:
         return TextureAccess(self.symbol, *offset)
 
     def __str__(self):
-        return '%s_texture_%x' % (self.field.name, abs(hash(self.field) + hash(str(self.address_mode))))
+        return '%s_texture_%x' % (self.field.name, abs(hash(self)))
 
     def __repr__(self):
         return self.__str__()
 
+    def __hash__(self):
+        return hash((str(type(self)),
+                     self.address_mode,
+                     self.filter_mode,
+                     self.read_as_integer,
+                     self.interpolation_mode,
+                     self.use_normalized_coordinates))
+
 
 class TextureAccess(InterpolatorAccess):
     def __new__(cls, texture_symbol, offsets, *args, **kwargs):