From a926cde165b41b3f64bc66e287e9602c2661b948 Mon Sep 17 00:00:00 2001
From: Harald Steinlechner <haraldsteinlechner@gmail.com>
Date: Tue, 19 Dec 2023 17:47:04 +0100
Subject: [PATCH] extended RuntimeConfig & version bump

---
 RELEASE_NOTES.md                                 |  3 +++
 src/Aardvark.Rendering.GL/Core/Config.fs         |  2 ++
 src/Aardvark.Rendering.GL/Instructions/OpenGL.fs | 12 ++++++++++--
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 7f85997a..9e26b132 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -1,3 +1,6 @@
+### 5.4.10-prerelease0003
+- [GL] added flag to disable multidraw (experimental)
+
 ### 5.4.10-prerelease0003
 - [FontResolve] fixed null family name failure
 
diff --git a/src/Aardvark.Rendering.GL/Core/Config.fs b/src/Aardvark.Rendering.GL/Core/Config.fs
index 213906d0..a127cc28 100644
--- a/src/Aardvark.Rendering.GL/Core/Config.fs
+++ b/src/Aardvark.Rendering.GL/Core/Config.fs
@@ -101,6 +101,8 @@ module RuntimeConfig =
     /// </summary>
     let mutable AllowConcurrentResourceAccess = false
 
+    let mutable AllowMultiDrawIndirect = false
+
 
 /// Reporting modes for OpenGL errors.
 type ErrorFlagCheck =
diff --git a/src/Aardvark.Rendering.GL/Instructions/OpenGL.fs b/src/Aardvark.Rendering.GL/Instructions/OpenGL.fs
index f06fdfe4..cd9239c8 100644
--- a/src/Aardvark.Rendering.GL/Instructions/OpenGL.fs
+++ b/src/Aardvark.Rendering.GL/Instructions/OpenGL.fs
@@ -665,12 +665,20 @@ module OpenGl =
         /// <summary>
         /// https://www.opengl.org/sdk/docs/man/html/glMultiDrawArraysIndirect.xhtml
         /// </summary>
-        let MultiDrawArraysIndirect = getProcAddress "glMultiDrawArraysIndirect"
+        let MultiDrawArraysIndirect = 
+            if RuntimeConfig.AllowMultiDrawIndirect then
+                getProcAddress "glMultiDrawArraysIndirect"
+            else 
+                0n
 
         /// <summary>
         /// https://www.opengl.org/sdk/docs/man/html/glMultiDrawElementsIndirect.xhtml
         /// </summary>
-        let MultiDrawElementsIndirect = getProcAddress "glMultiDrawElementsIndirect"
+        let MultiDrawElementsIndirect = 
+            if RuntimeConfig.AllowMultiDrawIndirect then
+                 getProcAddress "glMultiDrawElementsIndirect"
+            else
+                0n
 
 
         /// <summary>