Debug GPU functionality from soc-viewport_fx by Jason Wilkins

patch number D706 with changes:

- WITH_GPU_DEBUG just creates a debug context (and enables the debug messaging
system functions) but leaves the checks we had intact. Old patch
added the debug functionality only if we had the flag on to save some
performance.

Rationale here is that we might not want to recompile blender just to get
the extra information, and having users start blender with a -d flag to
get the extra information is also useful for bug reports. Those checks already
existed and most expensive ones are hidden behind a debug mode check
so performance should not be that bad.

- Did some cleanup of existing functionality:
When things go wrong blender side, just print the error,
don't check for GL errors first.

- Did not port changes needed for GLES to regular glew.h

- Got rid of duplicate or very similar new functionality.

Generally, code is more moving things around/cleanup and should work exactly
as before apart from the debug context, so it's safe to add even now.

It also provides a nice substitute function for glu error descriptions

1 files changed, 49 insertions, 0 deletions

diff --git a/source/blender/gpu/intern/gpu_private.h b/source/blender/gpu/intern/gpu_private.h
new file mode 100644
index 00000000000..11bc2bd3119
--- /dev/null
+++ b/source/blender/gpu/intern/gpu_private.h
@@ -0,0 +1,49 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * 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.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file gpu_extensions_private.h
+ *  \ingroup gpu
+ */
+
+#ifndef __GPU_PRIVATE_H__
+#define __GPU_PRIVATE_H__
+
+/* call this before running any of the functions below */
+void gpu_extensions_init(void);
+void gpu_extensions_exit(void);
+
+
+/* gpu_debug.c */
+#ifdef WITH_GPU_DEBUG
+
+void gpu_debug_init(void);
+void gpu_debug_exit(void);
+
+#  define GPU_DEBUG_INIT() gpu_debug_init()
+#  define GPU_DEBUG_EXIT() gpu_debug_exit()
+
+#else
+
+#  define GPU_DEBUG_INIT() ((void)0)
+#  define GPU_DEBUG_EXIT() ((void)0)
+
+#endif
+
+#endif  /* __GPU_PRIVATE_H__ */