Workaround external engines with OpenGL rendering

For now just do the OpenGL render and don't render using the engine.
This is a slightly odd-use case since it makes more sense to do a regular render.

1 files changed, 8 insertions, 1 deletions

diff --git a/source/blender/draw/engines/external/external_engine.c b/source/blender/draw/engines/external/external_engine.c
index ad7c8ce7da3..34ca92038d1 100644
--- a/source/blender/draw/engines/external/external_engine.c
+++ b/source/blender/draw/engines/external/external_engine.c
@@ -175,8 +175,15 @@ static void external_draw_scene(void *UNUSED(vedata))
 
 static void EXTERNAL_draw_scene(void *vedata)
 {
+	const DRWContextState *draw_ctx = DRW_context_state_get();
 	EXTERNAL_PassList *psl = ((EXTERNAL_Data *)vedata)->psl;
-	external_draw_scene(vedata);
+
+	/* Will be NULL during OpenGL render.
+	 * OpenGL render is used for quick preview (thumbnails or sequencer preview)
+	 * where using the rendering engine to preview doesn't make so much sense. */
+	if (draw_ctx->evil_C) {
+		external_draw_scene(vedata);
+	}
 	DRW_draw_pass(psl->depth_pass);
 }