GPU: Add debug scope capture support for Renderdoc

This adds a new launch argument when building with
renderdoc support. It allows to trigger the capture
of a specific capture scope. This allows selective
capture of some commonly captured parts.

Pull Request: https://projects.blender.org/blender/blender/pulls/126791

source/blender/blenkernel/BKE_global.hh

@@ -173,6 +173,12 @@ struct Global {
   bool opengl_deprecation_usage_detected;
   const char *opengl_deprecation_usage_filename;
   int opengl_deprecation_usage_lineno;
+
+  /**
+   * Triggers a GPU capture if the name matches a DebugScope.
+   * Set using `--debug-gpu-scope-capture "debug_scope"`.
+   */
+  char gpu_debug_scope_name[200];
 };
 
 /* **************** GLOBAL ********************* */

source/blender/gpu/opengl/gl_debug.cc

@@ -435,17 +435,33 @@ void GLBackend::debug_capture_end()
 #endif
 }
 
-void *GLContext::debug_capture_scope_create(const char * /*name*/)
+void *GLContext::debug_capture_scope_create(const char *name)
 {
-  return nullptr;
+  return (void *)name;
 }
 
-bool GLContext::debug_capture_scope_begin(void * /*scope*/)
+bool GLContext::debug_capture_scope_begin(void *scope)
 {
+#ifdef WITH_RENDERDOC
+  const char *title = (const char *)scope;
+  if (StringRefNull(title) != StringRefNull(G.gpu_debug_scope_name)) {
+    return false;
+  }
+  GLBackend::get()->debug_capture_begin(title);
+#endif
+  UNUSED_VARS(scope);
   return false;
 }
 
-void GLContext::debug_capture_scope_end(void * /*scope*/) {}
+void GLContext::debug_capture_scope_end(void *scope)
+{
+#ifdef WITH_RENDERDOC
+  const char *title = (const char *)scope;
+  if (StringRefNull(title) == StringRefNull(G.gpu_debug_scope_name)) {
+    GLBackend::get()->debug_capture_end();
+  }
+#endif
+}
 
 void GLContext::debug_unbind_all_ubo()
 {

source/blender/gpu/vulkan/vk_debug.cc

@@ -62,17 +62,34 @@ void VKBackend::debug_capture_end()
 #endif
 }
 
-void *VKContext::debug_capture_scope_create(const char * /*name*/)
+void *VKContext::debug_capture_scope_create(const char *name)
 {
-  return nullptr;
+  return (void *)name;
 }
 
-bool VKContext::debug_capture_scope_begin(void * /*scope*/)
+bool VKContext::debug_capture_scope_begin(void *scope)
 {
+#ifdef WITH_RENDERDOC
+  const char *title = (const char *)scope;
+  if (StringRefNull(title) != StringRefNull(G.gpu_debug_scope_name)) {
+    return false;
+  }
+  GLBackend::get()->debug_capture_begin(title);
+#endif
+  UNUSED_VARS(scope);
   return false;
 }
 
-void VKContext::debug_capture_scope_end(void * /*scope*/) {}
+void VKContext::debug_capture_scope_end(void *scope)
+{
+#ifdef WITH_RENDERDOC
+  const char *title = (const char *)scope;
+  if (StringRefNull(title) == StringRefNull(G.gpu_debug_scope_name)) {
+    GLBackend::get()->debug_capture_end();
+  }
+#endif
+}
+
 }  // namespace blender::gpu
 
 namespace blender::gpu::debug {

source/creator/creator_args.cc

@@ -754,6 +754,7 @@ static void print_help(bArgs *ba, bool all)
   BLI_args_print_arg_doc(ba, "--debug-gpu-force-workarounds");
   BLI_args_print_arg_doc(ba, "--debug-gpu-compile-shaders");
   if (defs.with_renderdoc) {
+    BLI_args_print_arg_doc(ba, "--debug-gpu-scope-capture");
     BLI_args_print_arg_doc(ba, "--debug-gpu-renderdoc");
   }
   BLI_args_print_arg_doc(ba, "--debug-wm");
@@ -1408,6 +1409,19 @@ static int arg_handle_debug_gpu_compile_shaders_set(int /*argc*/,
   return 0;
 }
 
+static const char arg_handle_debug_gpu_scope_capture_set_doc[] =
+    "\n"
+    "\tCapture the GPU commands issued inside the give scope name.";
+static int arg_handle_debug_gpu_scope_capture_set(int argc, const char **argv, void * /*data*/)
+{
+  if (argc > 1) {
+    STRNCPY(G.gpu_debug_scope_name, argv[1]);
+    return 1;
+  }
+  fprintf(stderr, "\nError: you must specify a scope name to capture.\n");
+  return 0;
+}
+
 static const char arg_handle_debug_gpu_renderdoc_set_doc[] =
     "\n"
     "\tEnable Renderdoc integration for GPU frame grabbing and debugging.";
@@ -2726,6 +2740,11 @@ void main_args_setup(bContext *C, bArgs *ba, bool all)
                CB(arg_handle_debug_gpu_compile_shaders_set),
                nullptr);
   if (defs.with_renderdoc) {
+    BLI_args_add(ba,
+                 nullptr,
+                 "--debug-gpu-scope-capture",
+                 CB(arg_handle_debug_gpu_scope_capture_set),
+                 nullptr);
     BLI_args_add(
         ba, nullptr, "--debug-gpu-renderdoc", CB(arg_handle_debug_gpu_renderdoc_set), nullptr);
   }