Fix Eevee backround render crash after recent changes from D15463

Backend initialization needs to be delayed until after the OpenGL context
is created. This worked fine in foreground mode because the OpenGL context
already exists for the window at the point GPU_backend_init_once was called,
but not for background mode.

Create the backend just in time in GPU_context_create as before, and
automatically free it when the last context id discarded. But check if any
GPU backend is supported before creating the OpenGL context.

Ref D15463, D15465

1 files changed, 4 insertions, 8 deletions

diff --git a/source/blender/gpu/GPU_context.h b/source/blender/gpu/GPU_context.h
index c81296093a1..9d92ea2cad9 100644
--- a/source/blender/gpu/GPU_context.h
+++ b/source/blender/gpu/GPU_context.h
@@ -17,14 +17,10 @@
 extern "C" {
 #endif
 
-/* GPU backends abstract the differences between different APIs. These must be
- * initialized before creating contexts, and deleted after the last context is
- * discarded. GPU_context_create automatically initializes a backend if none
- * exists yet. */
-bool GPU_backend_init_once(void);
-void GPU_backend_exit(void);
-bool GPU_backend_supported(eGPUBackendType type);
-
+/* GPU backends abstract the differences between different APIs. GPU_context_create
+ * automatically initializes the backend, and GPU_context_discard frees it when there
+ * are no more contexts. */
+bool GPU_backend_supported(void);
 eGPUBackendType GPU_backend_get_type(void);
 
 /** Opaque type hiding blender::gpu::Context. */