Index: trunk/src/gl/gl_device.cc
===================================================================
--- trunk/src/gl/gl_device.cc	(revision 121)
+++ trunk/src/gl/gl_device.cc	(revision 153)
@@ -53,10 +53,10 @@
 }
 
-vertex_buffer* gl_device::create_vertex_buffer( buffer_hint hint, size_t size, void* source /*= nullptr */ )
+vertex_buffer* gl_device::create_vertex_buffer( buffer_hint hint, size_t size, const void* source /*= nullptr */ )
 {
 	return new gl_vertex_buffer( hint, size, source );
 }
 
-index_buffer* gl_device::create_index_buffer( buffer_hint hint, size_t size, void* source /*= nullptr */ )
+index_buffer* gl_device::create_index_buffer( buffer_hint hint, size_t size, const void* source /*= nullptr */ )
 {
 	return new gl_index_buffer( hint, size, source );
Index: trunk/src/gl/gl_vertex_buffer.cc
===================================================================
--- trunk/src/gl/gl_vertex_buffer.cc	(revision 121)
+++ trunk/src/gl/gl_vertex_buffer.cc	(revision 153)
@@ -10,5 +10,5 @@
 using namespace nv;
 
-gl_vertex_buffer::gl_vertex_buffer( buffer_hint hint, size_t size, void* data ) 
+gl_vertex_buffer::gl_vertex_buffer( buffer_hint hint, size_t size, const void* data ) 
 	: vertex_buffer( hint, size ), m_name()
 {
@@ -18,5 +18,5 @@
 }
 
-void gl_vertex_buffer::update( void* data, size_t offset, size_t size )
+void gl_vertex_buffer::update( const void* data, size_t offset, size_t size )
 {
 	glBufferSubData( GL_ARRAY_BUFFER, (GLintptr)offset, (GLsizeiptr)size, data );
@@ -39,5 +39,5 @@
 }
 
-gl_index_buffer::gl_index_buffer( buffer_hint hint, size_t size, void* data ) 
+gl_index_buffer::gl_index_buffer( buffer_hint hint, size_t size, const void* data ) 
 	: index_buffer( hint, size ), m_name()
 {
@@ -47,5 +47,5 @@
 }
 
-void gl_index_buffer::update( void* data, size_t offset, size_t size )
+void gl_index_buffer::update( const void* data, size_t offset, size_t size )
 {
 	glBufferSubData( GL_ELEMENT_ARRAY_BUFFER, (GLintptr)offset, (GLsizeiptr)size, data );