<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On Dec 2, 2013, at 12:44 AM, Brent Wood wrote:</div><div><br></div><div>Hi,</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><div style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-family: 'times new roman', 'new york', times, serif; font-size: 12pt; position: static; z-index: auto; "><div><span>The same applies to a rectangle - 5 points stored instead of 4 - so where do we draw the line? <br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: times new roman,new york,times,serif; background-color: transparent; font-style: normal;"><span>How many vertices must a polygon have before we follow the spec & explicitly close it?</span></div></div></div></blockquote><div><br></div><div>Well the point was not to want to change anything in the spec implementation (e.g WKT/WKB import/export)</div><div>but 'only' a thought on the PostGIS triangle internal representation, </div><div>in order to avoid redundant coordinates internal storage.</div><div><br></div><div>On Polygon it will be harder to do the same, because a Polygon could have several rings</div><div>(a triangle not), so if we wanted to do so (e.g flag is_closed on polygon), </div><div>we would loose information on which rings is/are not closed (if any).</div><div><br></div><br><blockquote type="cite"><div><div style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-family: 'times new roman', 'new york', times, serif; font-size: 12pt; position: static; z-index: auto; "><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: times new roman,new york,times,serif; background-color: transparent; font-style: normal;">I agree that the closing vertex is redundant, & can be replaced by a bit in the header - but by doing so we lose the
ability to test for is it REALLY closed, rather than just saying it is closed, perhaps less important for triangles, but a capability I'm reluctant to lose.</div></div></div></blockquote><div><br></div><div>As the flag would be internal, the only information lost, for triangles, would be: </div><div>what are the final coordinates if unclosed (and so invalid).</div><div><br></div><div>But i agree it's already a lost.</div><div><br></div><br></div><div>O.</div></body></html>