+void Buffer::require_size(unsigned req_sz) const
+{
+ if(size<req_sz)
+ throw buffer_too_small(format("buffer has %d bytes; %d required", size, req_sz));
+}
+
+BufferRange *Buffer::create_range(unsigned s, unsigned o)
+{
+ return new BufferRange(*this, s, o);
+}
+
+void *Buffer::map()
+{
+ if(ARB_map_buffer_range)
+ {
+ if(ARB_direct_state_access)
+ return glMapNamedBufferRange(id, 0, size, GL_MAP_READ_BIT|GL_MAP_WRITE_BIT);
+ else
+ {
+ BindRestore _bind(this, type);
+ return glMapBufferRange(type, 0, size, GL_MAP_READ_BIT|GL_MAP_WRITE_BIT);
+ }
+ }
+ else if(ARB_direct_state_access)
+ return glMapNamedBuffer(id, GL_READ_WRITE);
+ else if(OES_mapbuffer)
+ {
+ BindRestore _bind(this, type);
+ return glMapBuffer(type, GL_READ_WRITE);
+ }
+ else
+ throw invalid_operation("Buffer::map");
+}
+
+bool Buffer::unmap()
+{
+ // TODO check if it's mapped
+ if(ARB_direct_state_access)
+ return glUnmapNamedBuffer(id);
+ else if(OES_mapbuffer)
+ {
+ BindRestore _bind(this, type);
+ return glUnmapBuffer(type);
+ }
+ else
+ return true;
+}
+
+void Buffer::bind_to(BufferType t) const
+{
+ if(t!=type)
+ require_buffer_type(t);
+ if(t==ELEMENT_ARRAY_BUFFER)
+ if(const VertexSetup *vs = VertexSetup::current())
+ {
+ // Don't change the binding in a vertex array object
+ if(this==vs->get_index_buffer())
+ return;
+ throw invalid_operation("Buffer::bind_to(ELEMENT_ARRAY_BUFFER)");
+ }
+ if(set_current(t, this))
+ glBindBuffer(t, id);
+}
+
+const Buffer *Buffer::current(BufferType t)
+{
+ if(t==ELEMENT_ARRAY_BUFFER)
+ if(const VertexSetup *vs = VertexSetup::current())
+ return vs->get_index_buffer();
+ return binding(t);
+}
+
+void Buffer::unbind_from(BufferType type)
+{
+ if(type==ELEMENT_ARRAY_BUFFER && VertexSetup::current())
+ throw invalid_operation("Buffer::unbind_from(ELEMENT_ARRAY_BUFFER)");
+ if(set_current(type, 0))
+ glBindBuffer(type, 0);
+}
+