[Bf-blender-cvs] [949d6e360bf] temp-T101905-gpu-backend-argument: Add command line argument to swithc gpu backend.

[Jeroen Bakker]

Commit: 949d6e360bf5ca4168e694ae3f6e445a1b91e28e
Author: Jeroen Bakker
Date:   Tue Oct 18 18:08:36 2022 +0200
Branches: temp-T101905-gpu-backend-argument
https://developer.blender.org/rB949d6e360bf5ca4168e694ae3f6e445a1b91e28e

Add command line argument to swithc gpu backend.

===================================================================

M	source/blender/gpu/GPU_context.h
M	source/blender/gpu/intern/gpu_context.cc
M	source/creator/creator_args.c

===================================================================

diff --git a/source/blender/gpu/GPU_context.h b/source/blender/gpu/GPU_context.h
index b59ea9e55d2..e44da5b0640 100644
--- a/source/blender/gpu/GPU_context.h
+++ b/source/blender/gpu/GPU_context.h
@@ -21,6 +21,7 @@ extern "C" {
  * automatically initializes the back-end, and #GPU_context_discard frees it when there
  * are no more contexts. */
 bool GPU_backend_supported(void);
+void GPU_backend_type_set(const eGPUBackendType backend);
 eGPUBackendType GPU_backend_get_type(void);
 
 /** Opaque type hiding blender::gpu::Context. */
diff --git a/source/blender/gpu/intern/gpu_context.cc b/source/blender/gpu/intern/gpu_context.cc
index 48d7b2019c5..57f5f3a6d0d 100644
--- a/source/blender/gpu/intern/gpu_context.cc
+++ b/source/blender/gpu/intern/gpu_context.cc
@@ -223,9 +223,13 @@ void GPU_render_step()
 /* NOTE: To enable Metal API, we need to temporarily change this to `GPU_BACKEND_METAL`.
  * Until a global switch is added, Metal also needs to be enabled in GHOST_ContextCGL:
  * `m_useMetalForRendering = true`. */
-static const eGPUBackendType g_backend_type = GPU_BACKEND_OPENGL;
+static eGPUBackendType g_backend_type = GPU_BACKEND_OPENGL;
 static GPUBackend *g_backend = nullptr;
 
+void GPU_backend_type_set(const eGPUBackendType backend)
+{
+  g_backend_type = backend;
+}
 bool GPU_backend_supported(void)
 {
   switch (g_backend_type) {
diff --git a/source/creator/creator_args.c b/source/creator/creator_args.c
index 06b898587bf..73966b80f21 100644
--- a/source/creator/creator_args.c
+++ b/source/creator/creator_args.c
@@ -42,6 +42,8 @@
 #  include "BKE_scene.h"
 #  include "BKE_sound.h"
 
+#  include "GPU_context.h"
+
 #  ifdef WITH_FFMPEG
 #    include "IMB_imbuf.h"
 #  endif
@@ -1111,6 +1113,42 @@ static int arg_handle_debug_gpu_set(int UNUSED(argc),
   return 0;
 }
 
+static const char arg_handle_gpu_backend_set_doc[] =
+    "\n"
+    "\tForce to use a specific GPU backend. Valid options are "
+#  ifdef WITH_METAL_BACKEND
+    "'metal', "
+#  endif
+    "'opengl' and 'default'.";
+static int arg_handle_gpu_backend_set(int argc, const char **argv, void *UNUSED(data))
+{
+  if (argc == 0) {
+    printf("\nError: GPU backend must follow '--gpu-backend'.\n");
+    return 0;
+  }
+
+  eGPUBackendType gpu_backend = GPU_BACKEND_NONE;
+
+  if (STREQ(argv[1], "default")) {
+    gpu_backend = GPU_BACKEND_NONE;
+  }
+  else if (STREQ(argv[1], "opengl")) {
+    gpu_backend = GPU_BACKEND_OPENGL;
+  }
+#  ifdef WITH_METAL_BACKEND
+  else if (STREQ(argv[1], "metal")) {
+    gpu_backend = GPU_BACKEND_METAL;
+  }
+#  endif
+  else {
+    printf("\nError: Unrecognized GPU backend for '--gpu-backend'.\n");
+    return 0;
+  }
+  GPU_backend_type_set(gpu_backend);
+
+  return 1;
+}
+
 static const char arg_handle_debug_fpe_set_doc[] =
     "\n\t"
     "Enable floating-point exceptions.";
@@ -2095,6 +2133,8 @@ void main_args_setup(bContext *C, bArgs *ba)
 
   BLI_args_add(ba, "-a", NULL, CB(arg_handle_playback_mode), NULL);
 
+  BLI_args_add(ba, NULL, "--gpu-backend", CB(arg_handle_gpu_backend_set), NULL);
+
   BLI_args_add(ba, "-d", "--debug", CB(arg_handle_debug_mode_set), ba);
 
 #  ifdef WITH_FFMPEG