+
+vector<const BufferRange *> BufferRange::bound_uniform;
+
+BufferRange::BufferRange(Buffer &b, unsigned o, unsigned s):
+ buffer(b),
+ offset(o),
+ size(s)
+{
+ if(o>buffer.get_size() || o+s>buffer.get_size())
+ throw out_of_range("BufferRange::BufferRange");
+}
+
+void BufferRange::data(const void *d)
+{
+ buffer.sub_data(offset, size, d);
+}
+
+void BufferRange::bind_to(BufferType t, unsigned i)
+{
+ if(t!=buffer.type)
+ Buffer::require_buffer_type(t);
+ // Intentionally using bitwise | to avoid short-circuiting
+ if(Buffer::set_current(t, &buffer) | set_current(t, i, this))
+ glBindBufferRange(t, i, buffer.id, offset, size);
+}
+
+void BufferRange::unbind_from(BufferType t, unsigned i)
+{
+ if(set_current(t, i, 0))
+ {
+ Buffer::set_current(t, 0);
+ glBindBufferBase(t, i, 0);
+ }
+}
+
+const BufferRange *&BufferRange::binding(BufferType type, unsigned index)
+{
+ if(type==UNIFORM_BUFFER)
+ {
+ if(index>=get_n_uniform_buffer_bindings())
+ throw out_of_range("Buffer::binding");
+ if(bound_uniform.size()<=index)
+ bound_uniform.resize(index+1);
+ return bound_uniform[index];
+ }
+ else
+ throw invalid_argument("Buffer::binding");
+}
+
+bool BufferRange::set_current(BufferType type, unsigned index, const BufferRange *buf)
+{
+ const BufferRange *&ptr = binding(type, index);
+ if(ptr==buf)
+ return false;
+
+ ptr = buf;
+ return true;
+}
+
+unsigned BufferRange::get_n_uniform_buffer_bindings()
+{
+ static unsigned count = get_i(GL_MAX_UNIFORM_BUFFER_BINDINGS);
+ return count;
+}
+
+unsigned BufferRange::get_uniform_buffer_alignment()
+{
+ static unsigned align = get_i(GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT);
+ return align;
+}
+