Enhance image editing tests and functionality

- Added parameterized tests for image edit replacement to ensure alpha mode preservation.
- Refactored existing tests to utilize new image editing methods and improve clarity.
- Introduced new tests for image target functionality, ensuring proper handling of shared textures and context.
- Updated various tests to validate alpha mode handling across different scenarios.
- Improved undo/redo functionality in image operators to maintain state consistency.
- Added support for texture node actions, enhancing integration with Blender's node system.
- Ensured that image properties are preserved during operations and that invalid contexts are handled gracefully.

src/anyimage/common/image.py

@@ -8,6 +8,14 @@ from pathlib import Path
 
 import bpy
 
+VIEW_TRANSFORM_COLOR_SPACES = (
+    ("ACES 1.3", "ACES 1.3 sRGB"),
+    ("ACES 2.0", "ACES 2.0 sRGB"),
+    ("AgX", "AgX Base sRGB"),
+    ("Filmic", "Filmic sRGB"),
+    ("Khronos PBR Neutral", "Khronos PBR Neutral sRGB"),
+)
+
 IMAGE_NAME_SUFFIXES = (
     ".jpeg",
     ".jpg",
@@ -296,7 +304,7 @@ def video_total_frames(image):
 
 
 def image_user_settings(source_object):
-    """Return the Empty's image user settings as a four-item tuple."""
+    """Return an image owner's playback settings as a four-item tuple."""
     image_user = getattr(source_object, "image_user", None)
     if image_user is None:
         return 1, 0, 0, False
@@ -308,14 +316,13 @@ def image_user_settings(source_object):
     )
 
 
-def extract_frame_range(source_object):
+def extract_frame_range(image, image_user):
     """Return the clamped (start_frame, frame_count) range extracted from the source."""
-    total_frames = video_total_frames(getattr(source_object, "data", None))
+    total_frames = video_total_frames(image)
     if total_frames <= 1:
         return 1, total_frames
-    _frame_start, frame_offset, image_frames, _use_cyclic = (
-        image_user_settings(source_object)
-    )
+    frame_offset = int(getattr(image_user, "frame_offset", 0) or 0)
+    image_frames = int(getattr(image_user, "frame_duration", 0) or 0)
     frame_count = (
         min(image_frames, total_frames)
         if image_frames >= 1
@@ -326,14 +333,9 @@ def extract_frame_range(source_object):
     return start_frame, frame_count
 
 
-def default_extract_frames(source_object):
-    """Return the Empty's Image Frames value, or the full frame count when unset."""
-    return extract_frame_range(source_object)[1]
-
-
 def source_start_frame(source_object_name):
     source_object = bpy.data.objects.get(source_object_name)
-    return extract_frame_range(source_object)[0] if source_object else 1
+    return extract_frame_range(source_object.data, source_object.image_user)[0] if source_object else 1
 
 
 def image_path(image):
@@ -615,16 +617,22 @@ def load_normal_result_image(path, source_object):
     return image
 
 
+def color_alpha_mode(color_space):
+    """Pair inverse view color spaces with straight alpha."""
+    return "STRAIGHT" if color_space in dict(VIEW_TRANSFORM_COLOR_SPACES).values() else "PREMUL"
+
+
 def configure_color_alpha(image):
     """Apply the presentation mode to an owned Color image."""
-    if image.alpha_mode != "PREMUL":
+    alpha_mode = color_alpha_mode(image.colorspace_settings.name)
+    if image.alpha_mode != alpha_mode:
         pixels = (
             image_pixels(image)
             if getattr(image, "source", None) == "GENERATED"
             or getattr(image, "is_dirty", False)
             else None
         )
-        image.alpha_mode = "PREMUL"
+        image.alpha_mode = alpha_mode
         if pixels is not None:
             image.pixels.foreach_set(pixels)
             image.update()
@@ -645,7 +653,7 @@ def create_image_edit_result(source_image, pixels, output_size):
     )
     try:
         image.colorspace_settings.name = source_image.colorspace_settings.name
-        configure_color_alpha(image)
+        image.alpha_mode = source_image.alpha_mode
         image.pixels.foreach_set(pixels)
         image.pack()
         image.update()
@@ -801,11 +809,12 @@ def replace_empty_image(source_object, result_image, *, placement_bounds=None,
 
 
 def _load_packed_result_image(
-    source_object,
+    source_image,
     output_directory,
     *,
     frame_prefix,
     result_name,
+    alpha_mode,
 ):
     output_directory = Path(output_directory)
     color_paths = sorted_frame_paths(output_directory, frame_prefix)
@@ -813,7 +822,6 @@ def _load_packed_result_image(
         raise RuntimeError(
             f"Color result has no images: {output_directory}"
         )
-    source_image = source_object.data
     source_color_space = source_image.colorspace_settings.name
     animated = is_animated_image(source_image)
     try:
@@ -822,7 +830,7 @@ def _load_packed_result_image(
             check_existing=False,
         )
         result_image.colorspace_settings.name = source_color_space
-        configure_color_alpha(result_image)
+        result_image.alpha_mode = alpha_mode
         if animated:
             force_sequence_source(result_image)
     except (OSError, RuntimeError, TypeError, ValueError) as error:
@@ -843,17 +851,18 @@ def _load_packed_result_image(
 
 
 def load_image_edit_result(
-    source_object,
+    source_image,
     output_directory,
     *,
     frame_prefix="image.",
 ):
     """Load one packed Job result that directly edits the source Image."""
     return _load_packed_result_image(
-        source_object,
+        source_image,
         output_directory,
         frame_prefix=frame_prefix,
-        result_name=source_object.data.name,
+        result_name=source_image.name,
+        alpha_mode=source_image.alpha_mode,
     )
 
 
@@ -865,10 +874,11 @@ def load_color_result_image(
 ):
     """Load one packed Color texture result for a generated material."""
     return _load_packed_result_image(
-        source_object,
+        source_object.data,
         output_directory,
         frame_prefix=frame_prefix,
         result_name=color_data_name(source_object),
+        alpha_mode=color_alpha_mode(source_object.data.colorspace_settings.name),
     )