The GDAL/OGR library uses an Envelope structure to hold the bounding box information for a geometry. The envelope (bounding box) contains two pairs of coordinates, one for the lower left coordinate and one for the upper right coordinate:
+----------o Upper right; (max_x, max_y) | | | | | |
Lower left (min_x, min_y) o----------+
| Class | ​OGREnvelope |
Represent the OGREnvelope C Structure. |