From 8b433f8364a02bb07f57e96c6de9abbc2d42adce Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Thu, 25 May 2017 10:41:12 +0100
Subject: [PATCH] Replaced osg::DrawElementeUInt usage for a more flexible
 DrawElements base class approach with the default set to DrawElementUShort to
 ensure compatibility with GLES2 implementes that don't support uint for
 glDrawElements.

---
 include/osgText/Text |  2 +-
 src/osgText/Text.cpp | 29 ++++++++++++++++++-----------
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/include/osgText/Text b/include/osgText/Text
index 67d861461..3c7b5a58a 100644
--- a/include/osgText/Text
+++ b/include/osgText/Text
@@ -313,7 +313,7 @@ public:
         osg::buffered_object<Coords3>   _transformedBackdropCoords[8];
         ColorCoords    _colorCoords;
 
-        osg::ref_ptr<osg::DrawElementsUInt> _quadIndices;
+        osg::ref_ptr<osg::DrawElements> _quadIndices;
         void updateQuadIndices();
 
         GlyphQuads();
diff --git a/src/osgText/Text.cpp b/src/osgText/Text.cpp
index 5cedc7cb0..77bf8786b 100644
--- a/src/osgText/Text.cpp
+++ b/src/osgText/Text.cpp
@@ -2091,26 +2091,33 @@ void Text::GlyphQuads::initGlyphQuads()
         }
     }
 
-    _quadIndices = new DrawElementsUInt(PrimitiveSet::TRIANGLES);
+    _quadIndices = new DrawElementsUShort(PrimitiveSet::TRIANGLES);
 }
 
 void Text::GlyphQuads::updateQuadIndices()
 {
-    _quadIndices->clear();
-    if (_coords->size() % 4 != 0)
+    unsigned int numCoords = _coords->size();
+    unsigned int numQuads = numCoords/4;
+    unsigned int numVertices = numQuads*6;
+
+    if (numCoords % 4 != 0)
     {
         OSG_WARN << "size of _coords is not divisible by 4.";
     }
     
-    for (unsigned int i = 0; i < (unsigned int)_coords->size(); i += 4)
-    {
-        _quadIndices->push_back(i);
-        _quadIndices->push_back(i + 1);
-        _quadIndices->push_back(i + 3);
 
-        _quadIndices->push_back(i + 1);
-        _quadIndices->push_back(i + 2);
-        _quadIndices->push_back(i + 3);
+    _quadIndices->resizeElements(numVertices);
+
+    unsigned int vi=0;
+    for (unsigned int i = 0; i < numCoords; i += 4)
+    {
+        _quadIndices->setElement(vi++, i);
+        _quadIndices->setElement(vi++, i + 1);
+        _quadIndices->setElement(vi++, i + 3);
+
+        _quadIndices->setElement(vi++, i + 1);
+        _quadIndices->setElement(vi++, i + 2);
+        _quadIndices->setElement(vi++, i + 3);
     }
 }