PyAPI: Support Python 3.9 (for VFX platform support)

Support Python 3.9, part of VFX platform support.

The intention of restoring Python 3.9 support is so it's possible to
build a (mostly) VFX compatible version of Blender, not to provide
official builds on the buildbot.

Includes contribution by Brecht.

Reviewed By: brecht

Ref D16030

7 files changed, 68 insertions, 60 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c998919622e..f36d16a6ec9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -956,8 +956,8 @@ if(WITH_PYTHON)
   # Do this before main 'platform_*' checks,
   # because UNIX will search for the old Python paths which may not exist.
   # giving errors about missing paths before this case is met.
-  if(DEFINED PYTHON_VERSION AND "${PYTHON_VERSION}" VERSION_LESS "3.10")
-    message(FATAL_ERROR "At least Python 3.10 is required to build, but found Python ${PYTHON_VERSION}")
+  if(DEFINED PYTHON_VERSION AND "${PYTHON_VERSION}" VERSION_LESS "3.9")
+    message(FATAL_ERROR "At least Python 3.9 is required to build, but found Python ${PYTHON_VERSION}")
   endif()
 
   file(GLOB RESULT "${CMAKE_SOURCE_DIR}/release/scripts/addons")
diff --git a/build_files/cmake/platform/platform_apple.cmake b/build_files/cmake/platform/platform_apple.cmake
index f84be3c5238..9487875033e 100644
--- a/build_files/cmake/platform/platform_apple.cmake
+++ b/build_files/cmake/platform/platform_apple.cmake
@@ -113,7 +113,7 @@ endif()
 
 if(WITH_PYTHON)
   # Use precompiled libraries by default.
-  set(PYTHON_VERSION 3.10)
+  SET(PYTHON_VERSION 3.10 CACHE STRING "Python Version (major and minor only)")
   if(NOT WITH_PYTHON_MODULE AND NOT WITH_PYTHON_FRAMEWORK)
     # Normally cached but not since we include them with blender.
     set(PYTHON_INCLUDE_DIR "${LIBDIR}/python/include/python${PYTHON_VERSION}")
diff --git a/build_files/cmake/platform/platform_win32.cmake b/build_files/cmake/platform/platform_win32.cmake
index 7e272ea26b0..456f02b0c05 100644
--- a/build_files/cmake/platform/platform_win32.cmake
+++ b/build_files/cmake/platform/platform_win32.cmake
@@ -497,7 +497,7 @@ if(WITH_JACK)
 endif()
 
 if(WITH_PYTHON)
-  set(PYTHON_VERSION 3.10) # CACHE STRING)
+  SET(PYTHON_VERSION 3.10 CACHE STRING "Python Version (major and minor only)")
 
   string(REPLACE "." "" _PYTHON_VERSION_NO_DOTS ${PYTHON_VERSION})
   set(PYTHON_LIBRARY ${LIBDIR}/python/${_PYTHON_VERSION_NO_DOTS}/libs/python${_PYTHON_VERSION_NO_DOTS}.lib)
diff --git a/release/scripts/startup/bl_ui/space_view3d_toolbar.py b/release/scripts/startup/bl_ui/space_view3d_toolbar.py
index 892dc9a1e42..49ac6841c35 100644
--- a/release/scripts/startup/bl_ui/space_view3d_toolbar.py
+++ b/release/scripts/startup/bl_ui/space_view3d_toolbar.py
@@ -483,68 +483,68 @@ class SelectPaintSlotHelper:
 
         have_image = False
 
-        match getattr(mode_settings, self.canvas_source_attr_name):
-            case 'MATERIAL':
-                if len(ob.material_slots) > 1:
-                    layout.template_list(
-                        "MATERIAL_UL_matslots", "layers",
-                        ob, "material_slots",
-                        ob, "active_material_index", rows=2,
-                    )
-                mat = ob.active_material
-                if mat and mat.texture_paint_images:
-                    row = layout.row()
-                    row.template_list(
-                        "TEXTURE_UL_texpaintslots", "",
-                        mat, "texture_paint_slots",
-                        mat, "paint_active_slot", rows=2,
-                    )
-
-                    if mat.texture_paint_slots:
-                        slot = mat.texture_paint_slots[mat.paint_active_slot]
-                    else:
-                        slot = None
-
-                    have_image = slot is not None
+        canvas_source = getattr(mode_settings, self.canvas_source_attr_name)
+        if canvas_source == 'MATERIAL':
+            if len(ob.material_slots) > 1:
+                layout.template_list(
+                    "MATERIAL_UL_matslots", "layers",
+                    ob, "material_slots",
+                    ob, "active_material_index", rows=2,
+                )
+            mat = ob.active_material
+            if mat and mat.texture_paint_images:
+                row = layout.row()
+                row.template_list(
+                    "TEXTURE_UL_texpaintslots", "",
+                    mat, "texture_paint_slots",
+                    mat, "paint_active_slot", rows=2,
+                )
+
+                if mat.texture_paint_slots:
+                    slot = mat.texture_paint_slots[mat.paint_active_slot]
                 else:
-                    row = layout.row()
+                    slot = None
 
-                    box = row.box()
-                    box.label(text="No Textures")
+                have_image = slot is not None
+            else:
+                row = layout.row()
 
-                sub = row.column(align=True)
-                sub.operator_menu_enum("paint.add_texture_paint_slot", "type", icon='ADD', text="")
+                box = row.box()
+                box.label(text="No Textures")
 
-            case 'IMAGE':
-                mesh = ob.data
-                uv_text = mesh.uv_layers.active.name if mesh.uv_layers.active else ""
-                layout.template_ID(mode_settings, self.canvas_image_attr_name, new="image.new", open="image.open")
-                if settings.missing_uvs:
-                    layout.operator("paint.add_simple_uvs", icon='ADD', text="Add UVs")
-                else:
-                    layout.menu("VIEW3D_MT_tools_projectpaint_uvlayer", text=uv_text, translate=False)
-                have_image = getattr(settings, self.canvas_image_attr_name) is not None
+            sub = row.column(align=True)
+            sub.operator_menu_enum("paint.add_texture_paint_slot", "type", icon='ADD', text="")
 
-                self.draw_image_interpolation(layout=layout, mode_settings=mode_settings)
+        elif canvas_source == 'IMAGE':
+            mesh = ob.data
+            uv_text = mesh.uv_layers.active.name if mesh.uv_layers.active else ""
+            layout.template_ID(mode_settings, self.canvas_image_attr_name, new="image.new", open="image.open")
+            if settings.missing_uvs:
+                layout.operator("paint.add_simple_uvs", icon='ADD', text="Add UVs")
+            else:
+                layout.menu("VIEW3D_MT_tools_projectpaint_uvlayer", text=uv_text, translate=False)
+            have_image = getattr(settings, self.canvas_image_attr_name) is not None
 
-            case 'COLOR_ATTRIBUTE':
-                mesh = ob.data
+            self.draw_image_interpolation(layout=layout, mode_settings=mode_settings)
 
-                row = layout.row()
-                col = row.column()
-                col.template_list(
-                    "MESH_UL_color_attributes_selector",
-                    "color_attributes",
-                    mesh,
-                    "color_attributes",
-                    mesh.color_attributes,
-                    "active_color_index",
-                    rows=3,
-                )
+        elif canvas_source == 'COLOR_ATTRIBUTE':
+            mesh = ob.data
+
+            row = layout.row()
+            col = row.column()
+            col.template_list(
+                "MESH_UL_color_attributes_selector",
+                "color_attributes",
+                mesh,
+                "color_attributes",
+                mesh.color_attributes,
+                "active_color_index",
+                rows=3,
+            )
 
-                col = row.column(align=True)
-                col.operator("geometry.color_attribute_add", icon='ADD', text="")
-                col.operator("geometry.color_attribute_remove", icon='REMOVE', text="")
+            col = row.column(align=True)
+            col.operator("geometry.color_attribute_add", icon='ADD', text="")
+            col.operator("geometry.color_attribute_remove", icon='REMOVE', text="")
 
         if settings.missing_uvs:
             layout.separator()
diff --git a/source/blender/python/intern/bpy_capi_utils.h b/source/blender/python/intern/bpy_capi_utils.h
index 73a5d2ebc79..08d48c5763d 100644
--- a/source/blender/python/intern/bpy_capi_utils.h
+++ b/source/blender/python/intern/bpy_capi_utils.h
@@ -6,8 +6,8 @@
 
 #pragma once
 
-#if PY_VERSION_HEX < 0x030a0000
-#  error "Python 3.10 or greater is required, you'll need to update your Python."
+#if PY_VERSION_HEX < 0x03090000
+#  error "Python 3.9 or greater is required, you'll need to update your Python."
 #endif
 
 #ifdef __cplusplus
diff --git a/source/blender/python/intern/bpy_driver.c b/source/blender/python/intern/bpy_driver.c
index 04aa203d198..e11821090ab 100644
--- a/source/blender/python/intern/bpy_driver.c
+++ b/source/blender/python/intern/bpy_driver.c
@@ -389,7 +389,9 @@ static const bool secure_opcodes[255] = {
     OK_OP(BINARY_TRUE_DIVIDE),
     OK_OP(INPLACE_FLOOR_DIVIDE),
     OK_OP(INPLACE_TRUE_DIVIDE),
+#if PY_VERSION_HEX >= 0x030a0000 /* Python3.9 doesn't support. */
     OK_OP(GET_LEN),
+#endif
     OK_OP(INPLACE_ADD),
     OK_OP(INPLACE_SUBTRACT),
     OK_OP(INPLACE_MULTIPLY),
@@ -407,7 +409,9 @@ static const bool secure_opcodes[255] = {
     OK_OP(INPLACE_OR),
     OK_OP(LIST_TO_TUPLE),
     OK_OP(RETURN_VALUE),
+#if PY_VERSION_HEX >= 0x030a0000 /* Python3.9 doesn't support. */
     OK_OP(ROT_N),
+#endif
     OK_OP(BUILD_TUPLE),
     OK_OP(BUILD_LIST),
     OK_OP(BUILD_SET),
diff --git a/source/blender/python/mathutils/mathutils.c b/source/blender/python/mathutils/mathutils.c
index 1aa2cec861c..e709ed849d4 100644
--- a/source/blender/python/mathutils/mathutils.c
+++ b/source/blender/python/mathutils/mathutils.c
@@ -76,7 +76,11 @@ Py_hash_t mathutils_array_hash(const float *array, size_t array_len)
   x = 0x345678UL;
   i = 0;
   while (--len >= 0) {
+#if PY_VERSION_HEX < 0x030a0000
+    y = _Py_HashDouble((double)(array[i++]));
+#else
     y = _Py_HashDouble(NULL, (double)(array[i++]));
+#endif
     if (y == -1) {
       return -1;
     }