//======================================================================================================================
// Some utilities for working with gigapans and seadragon.
//
// Dependencies: Microsoft Seadragon Ajax (http://livelabs.com/seadragon-ajax/)
//
// Author: Chris Bartley (bartley@cmu.edu)
//======================================================================================================================

//======================================================================================================================
// VERIFY NAMESPACE
//======================================================================================================================
// Create the global symbol "org" if it doesn't exist.  Throw an error if it does exist but is not an object.
var org;
if (!org)
   {
   org = {};
   }
else if (typeof org != "object")
   {
   var orgExistsMessage = "Error: failed to create org namespace: org already exists and is not an object";
   alert(orgExistsMessage);
   throw new Error(orgExistsMessage);
   }

// Repeat the creation and type-checking for the next level
if (!org.gigapan)
   {
   org.gigapan = {};
   }
else if (typeof org.gigapan != "object")
   {
   var orgGigapanExistsMessage = "Error: failed to create org.gigapan namespace: org.gigapan already exists and is not an object";
   alert(orgGigapanExistsMessage);
   throw new Error(orgGigapanExistsMessage);
   }

// Repeat the creation and type-checking for the next level
if (!org.gigapan.seadragon)
   {
   org.gigapan.seadragon = {};
   }
else if (typeof org.gigapan.seadragon != "object")
   {
   var orgGigapanSeadragonExistsMessage = "Error: failed to create org.gigapan.seadragon namespace: org.gigapan.seadragon already exists and is not an object";
   alert(orgGigapanSeadragonExistsMessage);
   throw new Error(orgGigapanSeadragonExistsMessage);
   }
//======================================================================================================================

//======================================================================================================================
// DEPENDECIES
//======================================================================================================================
if (!window.Seadragon)
   {
   var noSeadragonMsg = "The Seadragon library is required by SeadragonUtils.js";
   alert(noSeadragonMsg);
   throw new Error(noSeadragonMsg);
   }
//======================================================================================================================

//======================================================================================================================
// CODE
//======================================================================================================================
(function()
   {
   org.gigapan.seadragon.SeadragonUtils = function()
      {
      };

   org.gigapan.seadragon.SeadragonUtils.convertGigapanRectToSeadragonRect = function(xmin, ymin, xmax, ymax, gigapanWidth)
      {
      var xmin2 = xmin / gigapanWidth;
      var ymin2 = ymin / gigapanWidth;
      var xmax2 = xmax / gigapanWidth;
      var ymax2 = ymax / gigapanWidth;

      return new Seadragon.Rect(
            xmin2,
            ymin2,
            xmax2 - xmin2,
            ymax2 - ymin2);
      };

   org.gigapan.seadragon.SeadragonUtils.convertSeadragonPointToGigapanPoint = function(seadragonPoint, gigapanWidth)
      {
      return new Seadragon.Point(
            seadragonPoint.x * gigapanWidth,
            seadragonPoint.y * gigapanWidth
            );
      };

   })();
//======================================================================================================================