OMGM Code

--- a
+++ b/omgm/gm.php
@@ -0,0 +1,178 @@
+<?php
+
+function Google_Tile_Factors($zoom, $tileSize = 256){
+
+ if ( !isset($zoom) || $zoom < 0 ) {
+     $zoom = 0;
+ }
+
+ $value = array();
+ 
+ $value['zoom']	= $zoom ;
+ $value['PI']	= pi(); //3.1415926536 ;
+ $value['bc']	= 2 * $value['PI'] ;
+ $value['Wa']	= $value['PI'] / 180 ;
+ $value['cp']	= pow(2, ($value['zoom'] + 8) );
+ $value['max']	= pow(2, $value['zoom']) - 1 ;		# Maximum Tile Number
+ $value['pixLngDeg']= $value['cp'] / 360;
+ $value['pixLngRad']= $value['cp'] / $value['bc'] ;
+ $value['bmO']	= $value['cp'] / 2 ;
+ $value['tileSize'] = $tileSize ;
+
+ return $value ;
+}
+
+function Google_Tile_Calc($value, $ty, $tx){
+
+  $result = array();
+  
+  $result["NAMEX"] = $tx;
+  $result["NAMEY"] = $ty;
+  
+  list( $result["PYN"], $result['PXW']) = Google_Tile_to_Pix( $value, $ty, $tx ) ;
+
+ // Convert Pixels to Coordinates (Upper Left Corner)...
+
+ list($result["LATN"],$result["LNGW"]) = PixtoCoordinate( $value, $result["PYN"], $result["PXW"] ) ;
+
+ $result["PYS"] = $result["PYN"] + 255 ;
+ $result["PXE"] = $result["PXW"] + 255 ;
+
+ // Convert Pixels to Coordinates (Lower Right Corner)...
+
+ list($result["LATS"],$result["LNGE"]) = PixtoCoordinate( $value, $result["PYS"], $result["PXE"] ) ;
+  
+ return $result;
+}
+
+function Google_Tile_to_Pix($value, $y, $x){
+  return array( sprintf("%0.0f", $y * $value["tileSize"]), sprintf("%0.0f", $x * $value["tileSize"]) ) ; 
+}
+
+function PixtoCoordinate($value, $y ,$x){
+ $e = (($y - $value["bmO"]) / $value["pixLngRad"]) * (-1) ;
+
+ $d = array();
+ 
+ $d[1]	= sprintf("%0.6f",($x - $value["bmO"]) / $value["pixLngDeg"]) ;
+ $d[0]	= sprintf("%0.6f", (2 * atan(exp($e)) - $value["PI"] / 2) / $value["Wa"]) ;
+ 
+ return $d; 
+}
+
+function Google_RelPix($lat, $lng, $zoom){
+    $PI	= pi(); //3.1415926536 ;
+    $bc	= 2 * $PI;
+    $Wa	= $PI / 180;
+    $cp = pow(2, ($zoom + 8) );
+    $pixLngDeg = $cp / 360;
+    $pixLngRad = $cp / $bc ;
+    $bmO = $cp / 2 ;
+    
+    $d = array(2);
+    
+    $d[1] = sprintf("%0.0f", $bmO + $lng * $pixLngDeg ) ;
+    
+    $e = sin($lat * $Wa) ;
+
+    if( $e > 0.99999 ){
+        $e = 0.99999 ;
+    }
+
+    if( $e < -0.99999 ){
+        $e = -0.99999 ;
+    }
+
+    $d[0] = sprintf("%0.0f", $bmO + 0.5 * log((1 + $e) / (1 - $e)) * (-1) * $pixLngRad ) ;
+
+    // 0:x 1:y
+    return $d;
+}
+
+function PixtoTileName($value, $y, $x, $yd, $xd, $parwho){
+  $yn = floor($y / $value["tileSize"]);
+  $xn = floor($x / $value["tileSize"]);
+
+  if( strcmp( $parwho, "Partial") != 0 ){
+    if( strcmp( $yd, "N") == 0 ){
+      $yn++;
+    }
+    else{
+      $yn--;
+    }
+
+    if( strcmp( $xd, "W" ) == 0 ){
+      $xn++;
+    }
+    else{
+      $xn--;
+    }
+  }
+
+  if( $yn > $value["max"] ){
+    $yn = $value["max"];
+  }
+  elseif( $yn < 0 ){
+    $yn = 0;
+  }
+
+  if( $xn > $value["max"] ){
+    $xn = $value["max"];
+  }
+  elseif( $xn < 0 ){
+    $xn = 0;
+  }
+
+  return array($yn, $xn);
+}
+
+/*
+# Call as: <array of Hashes> = Google_Tiles(<LatitudeS>, <LongitudeW>, <LatitudeN>, <LongitudeE>, <Zoom>, [<option: tileSize>], [<option: 
+Partial/Whole>]) ;
+# Partial/Whole option: (Default: Partial)
+#	Partial: Include the edge to create partial tiles
+#       Whole: Include only tiles that are contained by the bounds
+#
+#          Returned Array Specifications:
+#            Each element is a reference to a Hash:
+#              NAMEY - Tile Name y
+#              NAMEX - Tile Name x
+#              PYS - Pixel South
+#              PXW - Pixel West
+#              PYN - Pixel North
+#              PXE - Pixel East
+#              LATS - South Latitude
+#              LNGW - West Longitude
+#              LATN - North Latitude
+#              LNGE - East Longitude
+#
+#          Note: X is width, Y is height...
+*/
+function Google_Tiles($latS, $lngW, $latN, $lngE, $zoom, $tileSize = 256, $parwho = "Partial"){
+  $value = Google_Tile_Factors($zoom, $tileSize);
+
+  $ret = array();
+  $first = array();
+  $last = array();
+
+  list( $first["NORTH"], $first["WEST"] ) = Google_RelPix($latN, $lngW, $zoom);
+  list( $first["NAMEY"], $first["NAMEX"] ) = PixtoTileName( $value, $first["NORTH"], $first["WEST"], 'N', 'W', $parwho );
+
+  list( $last["SOUTH"], $last["EAST"] ) = Google_RelPix($latS, $lngE, $zoom ) ;
+  list( $last["NAMEY"], $last["NAMEX"] ) = PixtoTileName( $value, $last["SOUTH"], $last["EAST"], 'S', 'E', $parwho ) ;
+
+  for ( $ty = $first["NAMEY"] ; $ty <= $last["NAMEY"] ; $ty++ ){
+    for ( $tx = $first["NAMEX"] ; $tx <= $last["NAMEX"] ; $tx++ ){
+      $ret[] = Google_Tile_Calc( $value, $ty, $tx );
+    }
+  }
+
+  $ret[0]["NORTH"] = $first["NORTH"] ;
+  $ret[0]["WEST"] = $first["WEST"] ;
+
+  $ret[ count($ret) - 1 ]["SOUTH"] = $last["SOUTH"] ;
+  $ret[ count($ret) - 1 ]["EAST"] = $last["EAST"] ;
+ 
+  return $ret;
+}
+?>