Added high-dpi / retina support to the no-game screen; additional minor tweaks and cleanup.

src/modules/graphics/opengl/GLBuffer.cpp

@@ -164,11 +164,9 @@ void GLBuffer::setMappedRangeModified(size_t offset, size_t modifiedsize)
 	// a and b are marked as modified.
 
 	size_t old_range_end = modified_offset + modified_size;
-
 	modified_offset = std::min(modified_offset, offset);
 
 	size_t new_range_end = std::max(offset + modifiedsize, old_range_end);
-
 	modified_size = new_range_end - modified_offset;
 }