GPU: Add debug groups

Debug groups makes it easier to view from where an error comes from.

The backend can also implement its own callback to make it easier to
follow the API call structure in frame debuggers.

source/blender/draw/intern/draw_manager_profiling.c

@@ -32,6 +32,7 @@
 
 #include "draw_manager.h"
 
+#include "GPU_debug.h"
 #include "GPU_texture.h"
 
 #include "UI_resources.h"
@@ -133,10 +134,13 @@ static void drw_stats_timer_start_ex(const char *name, const bool is_query)
 void DRW_stats_group_start(const char *name)
 {
   drw_stats_timer_start_ex(name, false);
+
+  GPU_debug_group_begin(name);
 }
 
 void DRW_stats_group_end(void)
 {
+  GPU_debug_group_end();
   if (DTP.is_recording) {
     BLI_assert(!DTP.is_querying);
     DTP.end_increment++;
@@ -146,11 +150,14 @@ void DRW_stats_group_end(void)
 /* NOTE: Only call this when no sub timer will be called. */
 void DRW_stats_query_start(const char *name)
 {
+  GPU_debug_group_begin(name);
+  drw_stats_timer_start_ex(name, false);
   drw_stats_timer_start_ex(name, true);
 }
 
 void DRW_stats_query_end(void)
 {
+  GPU_debug_group_end();
   if (DTP.is_recording) {
     DTP.end_increment++;
     BLI_assert(DTP.is_querying);

source/blender/gpu/CMakeLists.txt

@@ -62,6 +62,7 @@ set(SRC
   intern/gpu_capabilities.cc
   intern/gpu_codegen.c
   intern/gpu_context.cc
+  intern/gpu_debug.cc
   intern/gpu_drawlist.cc
   intern/gpu_framebuffer.cc
   intern/gpu_immediate.cc
@@ -112,6 +113,7 @@ set(SRC
   GPU_capabilities.h
   GPU_common.h
   GPU_context.h
+  GPU_debug.h
   GPU_drawlist.h
   GPU_framebuffer.h
   GPU_immediate.h

source/blender/gpu/GPU_debug.h

@@ -0,0 +1,38 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ *
+ * Helpers for GPU / drawing debugging.
+ */
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void GPU_debug_group_begin(const char *name);
+void GPU_debug_group_end(void);
+void GPU_debug_get_groups_names(int name_buf_len, char *r_name_buf);
+
+#ifdef __cplusplus
+}
+#endif

source/blender/gpu/intern/gpu_context_private.hh

@@ -29,6 +29,7 @@
 
 #include "GPU_context.h"
 
+#include "gpu_debug_private.hh"
 #include "gpu_framebuffer_private.hh"
 #include "gpu_immediate_private.hh"
 #include "gpu_shader_private.hh"
@@ -61,6 +62,8 @@ class Context {
   FrameBuffer *back_right = NULL;
   FrameBuffer *front_right = NULL;
 
+  DebugStack debug_stack;
+
  protected:
   /** Thread on which this context is active. */
   pthread_t thread_;
@@ -84,6 +87,9 @@ class Context {
 
   virtual void memory_statistics_get(int *total_mem, int *free_mem) = 0;
 
+  virtual void debug_group_begin(const char *, int){};
+  virtual void debug_group_end(void){};
+
   bool is_active_on_thread(void);
 };
 

source/blender/gpu/intern/gpu_debug.cc

@@ -0,0 +1,91 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ *
+ * Debug features of OpenGL.
+ */
+
+#include "BKE_global.h"
+
+#include "BLI_string.h"
+
+#include "gpu_context_private.hh"
+
+#include "GPU_debug.h"
+
+using namespace blender::gpu;
+
+void GPU_debug_group_begin(const char *name)
+{
+  if (!(G.debug & G_DEBUG_GPU)) {
+    return;
+  }
+
+  DebugStack &stack = Context::get()->debug_stack;
+
+  if (stack.index >= DEBUG_STACK_LEN) {
+    stack.index = DEBUG_STACK_LEN - 1;
+    BLI_assert(!"GPUDebug: Debug group stack overflow!");
+  }
+
+  BLI_strncpy(stack.names[stack.index++], name, sizeof(stack.names[stack.index++]));
+
+  Context::get()->debug_group_begin(name, stack.index);
+}
+
+void GPU_debug_group_end(void)
+{
+  if (!(G.debug & G_DEBUG_GPU)) {
+    return;
+  }
+
+  DebugStack &stack = Context::get()->debug_stack;
+
+  if (stack.index < 0) {
+    stack.index = 0;
+    BLI_assert(!"GPUDebug: Debug group stack underflow!");
+  }
+
+  stack.index--;
+
+  Context::get()->debug_group_end();
+}
+
+/* Return a formated string showing the current group hierarchy in this format:
+ * "Group1 > Group 2 > Group3 > ... > GroupN : " */
+void GPU_debug_get_groups_names(int name_buf_len, char *r_name_buf)
+{
+  Context *ctx = Context::get();
+  if (ctx == nullptr) {
+    return;
+  }
+
+  DebugStack &stack = ctx->debug_stack;
+  if (stack.index == 0) {
+    r_name_buf[0] = '\0';
+    return;
+  }
+  size_t sz = 0;
+  for (int i = 0; i < stack.index; i++) {
+    sz += BLI_snprintf_rlen(r_name_buf + sz, name_buf_len - sz, "%s > ", stack.names[0]);
+  }
+  r_name_buf[sz - 2] = ':';
+}

source/blender/gpu/intern/gpu_debug_private.hh

@@ -0,0 +1,38 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2016 by Mike Erwin.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ *
+ * This interface allow GPU to manage GL objects for multiple context and threads.
+ */
+
+#pragma once
+
+namespace blender::gpu {
+
+#define DEBUG_STACK_LEN 64
+#define DEBUG_STACK_NAME_LEN 128
+
+struct DebugStack {
+  char names[DEBUG_STACK_LEN][DEBUG_STACK_NAME_LEN];
+  int index = 0;
+};
+
+}  // namespace blender::gpu