glTF Exporter: optimizations & fixes

* image optimizations
* options refactoring
* Fix T59047

4 files changed, 38 insertions, 15 deletions

diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_export.py b/io_scene_gltf2/blender/exp/gltf2_blender_export.py
index f2cc9fa5..1ddeb6a5 100755
--- a/io_scene_gltf2/blender/exp/gltf2_blender_export.py
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_export.py
@@ -33,6 +33,7 @@ def save(context, export_settings):
 
 
 def __export(export_settings):
+    export_settings['gltf_channelcache'] = dict()
     exporter = GlTF2Exporter(__get_copyright(export_settings))
     __add_root_objects(exporter, export_settings)
     buffer = __create_buffer(exporter, export_settings)
diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_extract.py b/io_scene_gltf2/blender/exp/gltf2_blender_extract.py
index c26429d3..8762a90f 100755
--- a/io_scene_gltf2/blender/exp/gltf2_blender_extract.py
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_extract.py
@@ -975,10 +975,10 @@ def extract_primitives(glTF, blender_mesh, blender_vertex_groups, modifiers, exp
 
         if max_index >= range_indices:
             #
-            # Spliting result_primitives.
+            # Splitting result_primitives.
             #
 
-            # At start, all indicees are pending.
+            # At start, all indices are pending.
             pending_attributes = {
                 POSITION_ATTRIBUTE: [],
                 NORMAL_ATTRIBUTE: []
@@ -1038,6 +1038,7 @@ def extract_primitives(glTF, blender_mesh, blender_vertex_groups, modifiers, exp
             while len(pending_indices) > 0:
 
                 process_indices = pending_primitive[INDICES_ID]
+                max_index = max(process_indices)
 
                 pending_indices = []
 
@@ -1046,7 +1047,7 @@ def extract_primitives(glTF, blender_mesh, blender_vertex_groups, modifiers, exp
 
                 all_local_indices = []
 
-                for i in range(0, (max(process_indices) // range_indices) + 1):
+                for i in range(0, (max_index // range_indices) + 1):
                     all_local_indices.append([])
 
                 #
@@ -1063,7 +1064,7 @@ def extract_primitives(glTF, blender_mesh, blender_vertex_groups, modifiers, exp
                                          process_indices[face_index + 2])
 
                     # ... check if it can be but in a range of maximum indices.
-                    for i in range(0, (max(process_indices) // range_indices) + 1):
+                    for i in range(0, (max_index // range_indices) + 1):
                         offset = i * range_indices
 
                         # Yes, so store the primitive with its indices.
@@ -1075,7 +1076,7 @@ def extract_primitives(glTF, blender_mesh, blender_vertex_groups, modifiers, exp
                             written = True
                             break
 
-                    # If not written, the triangel face has indices from different ranges.
+                    # If not written, the triangle face has indices from different ranges.
                     if not written:
                         pending_indices.extend([process_indices[face_index + 0], process_indices[face_index + 1],
                                                 process_indices[face_index + 2]])
diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_gather_image.py b/io_scene_gltf2/blender/exp/gltf2_blender_gather_image.py
index d9583d08..b6131a59 100755
--- a/io_scene_gltf2/blender/exp/gltf2_blender_gather_image.py
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_gather_image.py
@@ -49,7 +49,7 @@ def __filter_image(sockets_or_slots, export_settings):
 
 def __gather_buffer_view(sockets_or_slots, export_settings):
     if export_settings[gltf2_blender_export_keys.FORMAT] != 'GLTF_SEPARATE':
-        image = __get_image_data(sockets_or_slots)
+        image = __get_image_data(sockets_or_slots, export_settings)
         return gltf2_io_binary_data.BinaryData(
             data=image.to_image_data(__gather_mime_type(sockets_or_slots, export_settings)))
     return None
@@ -81,7 +81,7 @@ def __gather_name(sockets_or_slots, export_settings):
 def __gather_uri(sockets_or_slots, export_settings):
     if export_settings[gltf2_blender_export_keys.FORMAT] == 'GLTF_SEPARATE':
         # as usual we just store the data in place instead of already resolving the references
-        return __get_image_data(sockets_or_slots)
+        return __get_image_data(sockets_or_slots, export_settings)
     return None
 
 
@@ -93,14 +93,21 @@ def __is_slot(sockets_or_slots):
     return isinstance(sockets_or_slots[0], bpy.types.MaterialTextureSlot)
 
 
-def __get_image_data(sockets_or_slots):
+def __get_image_data(sockets_or_slots, export_settings):
     # For shared ressources, such as images, we just store the portion of data that is needed in the glTF property
     # in a helper class. During generation of the glTF in the exporter these will then be combined to actual binary
     # ressources.
-    def split_pixels_by_channels(image: bpy.types.Image) -> typing.List[typing.List[float]]:
+    def split_pixels_by_channels(image: bpy.types.Image, export_settings) -> typing.List[typing.List[float]]:
+        channelcache = export_settings['gltf_channelcache']
+        if image.name in channelcache:
+            return channelcache[image.name]
+
         pixels = np.array(image.pixels)
         pixels = pixels.reshape((pixels.shape[0] // image.channels, image.channels))
         channels = np.split(pixels, pixels.shape[1], axis=1)
+
+        channelcache[image.name] = channels
+
         return channels
 
     if __is_socket(sockets_or_slots):
@@ -118,15 +125,16 @@ def __get_image_data(sockets_or_slots):
                     }[elem.from_socket.name]
 
             if channel is not None:
-                pixels = [split_pixels_by_channels(result.shader_node.image)[channel]]
+                pixels = [split_pixels_by_channels(result.shader_node.image, export_settings)[channel]]
             else:
-                pixels = split_pixels_by_channels(result.shader_node.image)
+                pixels = split_pixels_by_channels(result.shader_node.image, export_settings)
                 channel = 0
 
             file_name = os.path.splitext(result.shader_node.image.name)[0]
 
             image_data = gltf2_io_image_data.ImageData(
                 file_name,
+                result.shader_node.image.filepath,
                 result.shader_node.image.size[0],
                 result.shader_node.image.size[1],
                 channel,
@@ -140,10 +148,11 @@ def __get_image_data(sockets_or_slots):
         return image
     elif __is_slot(sockets_or_slots):
         texture = __get_tex_from_slot(sockets_or_slots[0])
-        pixels = split_pixels_by_channels(texture.image)
+        pixels = split_pixels_by_channels(texture.image, export_settings)
 
         image_data = gltf2_io_image_data.ImageData(
             texture.name,
+            texture.image.filepath,
             texture.image.size[0],
             texture.image.size[1],
             0,
diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_gltf2_exporter.py b/io_scene_gltf2/blender/exp/gltf2_blender_gltf2_exporter.py
index b1408b62..6561567e 100755
--- a/io_scene_gltf2/blender/exp/gltf2_blender_gltf2_exporter.py
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_gltf2_exporter.py
@@ -20,6 +20,9 @@ from io_scene_gltf2.io.exp import gltf2_io_binary_data
 from io_scene_gltf2.io.exp import gltf2_io_image_data
 from io_scene_gltf2.io.exp import gltf2_io_buffer
 
+import bpy
+import os
+from shutil import copyfile
 
 class GlTF2Exporter:
     """
@@ -141,9 +144,18 @@ class GlTF2Exporter:
         :return:
         """
         for image in self.__images:
-            uri = output_path + image.name + ".png"
-            with open(uri, 'wb') as f:
-                f.write(image.to_png_data())
+            dst_path = output_path + image.name + ".png"
+
+            src_path = bpy.path.abspath(image.filepath)
+            if os.path.isfile(src_path):
+                # Source file exists.
+                if os.path.abspath(dst_path) != os.path.abspath(src_path):
+                    # Only copy, if source and destination are not the same.
+                    copyfile(src_path, dst_path)
+            else:
+                # Source file does not exist e.g. it is packed or has been generated.
+                with open(dst_path, 'wb') as f:
+                    f.write(image.to_png_data())
 
     def add_scene(self, scene: gltf2_io.Scene, active: bool = True):
         """