From 0ec8f1d758be8fd9e2c7f190dba72c945675597d Mon Sep 17 00:00:00 2001
From: tobspr <tobias.springer1@googlemail.com>
Date: Sat, 15 Aug 2015 21:07:06 +0200
Subject: [PATCH] Make instance count override properly

---
 panda/src/pgraph/shaderAttrib.cxx | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/panda/src/pgraph/shaderAttrib.cxx b/panda/src/pgraph/shaderAttrib.cxx
index 29e78e9dd1..0587bbbaec 100644
--- a/panda/src/pgraph/shaderAttrib.cxx
+++ b/panda/src/pgraph/shaderAttrib.cxx
@@ -696,8 +696,18 @@ compose_impl(const RenderAttrib *other) const {
       }
     }
   }
-  // Just copy the instance count.
-  attr->_instance_count = over->_instance_count;
+
+  // In case no instance count is set, just copy it.
+  if (attr->_instance_count == 0) {
+    attr->_instance_count = over->_instance_count;
+  } else {
+    // If an instance count is set, check if the other attrib has an instance count set,
+    // if so, override it, otherwise just keep the current instance count
+    if (over->_instance_count > 0) {
+      attr->_instance_count = over->_instance_count;
+    }
+  }
+
   // Update the flags.
   attr->_flags &= ~(over->_has_flags);
   attr->_flags |= over->_flags;