Python: Added support for GPU python module in background mode

This commit adds an init method to the gpu module. It allows for a more
direct and intuitive way of enabling use of the gpu python module in
background mode.

Currently, a workaround exists to enable use of the gpu module which
involves calling the bpy.ops.render.render() operator. This is rather
uninituitive and hard to find. See `tests/python/modules/gpu_info.py`

Co-authored-by: tobias <tobiaskrantz33@gmail.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/155400

tests/python/CMakeLists.txt

@@ -265,6 +265,32 @@ add_blender_test(
   --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_bpy_app.py
 )
 
+if (WITH_GPU_BACKEND_TESTS)
+  if(WITH_OPENGL_BACKEND)
+    add_blender_test(
+      script_pyapi_gpu_opengl
+      --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_gpu.py
+      --gpu-backend opengl
+    )
+  endif()
+
+  if(WITH_METAL_BACKEND)
+    add_blender_test(
+      script_pyapi_gpu_metal
+      --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_gpu.py
+      --gpu-backend metal
+    )
+  endif()
+
+  if(WITH_VULKAN_BACKEND)
+    add_blender_test(
+      script_pyapi_gpu_vulkan
+      --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_gpu.py
+      --gpu-backend vulkan
+    )
+  endif()
+endif()
+
 add_blender_test(
   script_pyapi_bpy_app_tempdir
   --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_bpy_app_tempdir.py

tests/python/bl_pyapi_gpu.py

@@ -0,0 +1,31 @@
+# SPDX-FileCopyrightText: 2026 Blender Authors
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# blender -b --factory-startup --python tests/python/bl_pyapi_gpu.py
+
+import unittest
+
+import gpu
+
+
+class TestGpuInit(unittest.TestCase):
+    def test_gpu_module_is_usable_after_init(self):
+        gpu.init()
+
+        # GPU module functions will raise SystemError if the GPU has not been initialized.
+        gpu.platform.vendor_get()
+        gpu.platform.renderer_get()
+        gpu.platform.version_get()
+        gpu.platform.device_type_get()
+        gpu.types.GPUTexture(size=(1024, 1024), format="RGBA8")
+
+
+if __name__ == "__main__":
+    import sys
+
+    sys.argv = [__file__] + (
+        sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []
+    )
+
+    unittest.main()