Bus Stop density heatmap
--- a/include/common-session.inc.php
+++ b/include/common-session.inc.php
@@ -51,7 +51,7 @@
session_destroy();
session_start();
}
-debug(print_r($_SESSION, true) , "session");
+//debug(print_r($_SESSION, true) , "session");
function current_time() {
return ($_SESSION['time']? $_SESSION['time'] : date("H:i:s"));
--- /dev/null
+++ b/labs/busstopdensity.php
@@ -1,1 +1,77 @@
+<?php
+include ('../include/common.inc.php');
+//include_header("Bus Stop Density", "busstopdensity")
+?>
+<style type="text/css">
+
+ #map_container{
+ width:100%;
+ height:100%;
+ }
+ #status, #legend {
+ background-color: #eeeeee;
+ padding: 3px 5px 3px 5px;
+ opacity: .9;
+ }
+ </style>
+
+ <div id="map_container"></div>
+ <div id="status">
+ Status: <span id="log"> <img alt="progess bar" src="progress_bar.gif" width="150" height="16"/></span>
+ </div>
+ <script type="text/javascript" src="http://www.google.com/jsapi?autoload={%22modules%22:[{%22name%22:%22maps%22,version:3,other_params:%22sensor=false%22},{%22name%22:%22jquery%22,%22version%22:%221.4.2%22}]}"></script>
+ <script type="text/javascript">
+ //<![CDATA[
+ //Google Map API v3
+
+ var googleMap = null;
+ var previousPos = null;
+
+ $(function($){//Called when page is loaded
+ googleMap = new google.maps.Map(document.getElementById("map_container"), {
+ zoom: 17,
+ center: new google.maps.LatLng(-35.25,149.125),
+ mapTypeId: google.maps.MapTypeId.SATELLITE});
+ //Set status bar
+ googleMap.controls[google.maps.ControlPosition.TOP_LEFT].push($("#status").get(0));
+ //Set legend
+ googleMap.controls[google.maps.ControlPosition.BOTTOM_LEFT].push($("#legend").get(0));
+
+ google.maps.event.addListener(googleMap, "zoom_changed", function(){
+ google.maps.event.trigger(googleMap, "mousemove", previousPos);
+ });//onzoomend
+
+ //Add a listener when mouse moves
+ google.maps.event.addListener(googleMap, "mousemove", function(event){
+ var latLng = event.latLng;
+ var xy = googleMap.getProjection().fromLatLngToPoint(latLng);
+ var ratio = Math.pow(2,googleMap.getZoom());
+ $("#log").html("Zoom:" + googleMap.getZoom() + " WGS84:(" + latLng.lat().toFixed(5) + ", " + latLng.lng().toFixed(5) + ") Px:(" + Math.floor(xy.x * ratio) + "," + Math.floor(xy.y *ratio) + ")");
+ previousPos = event;
+ });//onmouseover
+
+ //Add a listener when mouse leaves the map area
+ google.maps.event.addListener(googleMap, "mouseout", function(event){
+ $("#log").html("");
+ });//onmouseout
+
+ //Add tile overlay
+ var myOverlay = new google.maps.ImageMapType({
+ getTileUrl: function(coord, zoom) {
+ return 'busstopdensity.tile.php?x=' + coord.x + '&y=' + coord.y + '&zoom=' +zoom;
+ },
+ tileSize: new google.maps.Size(256, 256),
+ isPng: true,
+ opacity:1.0
+ });
+ googleMap.overlayMapTypes.insertAt(0, myOverlay);
+ $("#log").html("Map loaded!");
+ });//onload
+ //]]>
+ </script>
+<?php
+include_footer()
+?>
+
+
--- /dev/null
+++ b/labs/busstopdensity.tile.php
@@ -1,1 +1,121 @@
+<?php
+include ('../include/common.inc.php');
+$debugOkay = Array();
+/*
+*DISCLAIMER
+* http://blog.gmapify.fr/create-beautiful-tiled-heat-maps-with-php-and-gd
+*THIS SOFTWARE IS PROVIDED BY THE AUTHOR 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES *OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, *INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF *USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT *(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+* @author: Olivier G. <olbibigo_AT_gmail_DOT_com>
+* @version: 1.0
+* @history:
+* 1.0 creation
+*/
+ set_time_limit(120);//2mn
+ ini_set('memory_limit', '256M');
+error_reporting(E_ALL ^ E_DEPRECATED);
+ require_once ('lib/GoogleMapUtility.php');
+ require_once ('lib/HeatMap.php');
+
+ //Root folder to store generated tiles
+ define('TILE_DIR', 'tiles/');
+ //Covered geographic areas
+ define('MIN_LAT', -35.48);
+ define('MAX_LAT', -35.15);
+ define('MIN_LNG', 148.98);
+ define('MAX_LNG', 149.25);
+ define('TILE_SIZE_FACTOR', 0.5);
+ define('SPOT_RADIUS', 30);
+ define('SPOT_DIMMING_LEVEL', 50);
+
+ //Input parameters
+ if(isset($_GET['x']))
+ $X = (int)$_GET['x'];
+ else
+ exit("x missing");
+ if(isset($_GET['y']))
+ $Y = (int)$_GET['y'];
+ else
+ exit("y missing");
+ if(isset($_GET['zoom']))
+ $zoom = (int)$_GET['zoom'];
+ else
+ exit("zoom missing");
+
+ $dir = TILE_DIR.$zoom;
+ $tilename = $dir.'/'.$X.'_'.$Y.'.png';
+ //HTTP headers (data type and caching rule)
+ header("Cache-Control: must-revalidate");
+ header("Expires: " . gmdate("D, d M Y H:i:s", time() + 86400) . " GMT");
+ if(!file_exists($tilename)){
+ $rect = GoogleMapUtility::getTileRect($X, $Y, $zoom);
+ //A tile can contain part of a spot with center in an adjacent tile (overlaps).
+ //Knowing the spot radius (in pixels) and zoom level, a smart way to process tiles would be to compute the box (in decimal degrees) containing only spots that can be drawn on current tile. We choose a simpler solution by increeasing geo bounds by 2*TILE_SIZE_FACTOR whatever the zoom level and spot radius.
+ $extend_X = $rect->width * TILE_SIZE_FACTOR;//in decimal degrees
+ $extend_Y = $rect->height * TILE_SIZE_FACTOR;//in decimal degrees
+ $swlat = $rect->y - $extend_Y;
+ $swlng = $rect->x - $extend_X;
+ $nelat = $swlat + $rect->height + 2 * $extend_Y;
+ $nelng = $swlng + $rect->width + 2 * $extend_X;
+
+ if( ($nelat <= MIN_LAT) || ($swlat >= MAX_LAT) || ($nelng <= MIN_LNG) || ($swlng >= MAX_LNG)){
+ //No geodata so return generic empty tile
+ echo file_get_contents(TILE_DIR.'empty.png');
+ exit();
+ }
+
+ //Get McDonald's spots
+ $spots = fGetPOI('Select * from stops where
+ (stop_lon > '.$swlng.' AND stop_lon < '.$nelng.')
+ AND (stop_lat < '.$nelat.' AND stop_lat > '.$swlat.')', $im, $X, $Y, $zoom, SPOT_RADIUS);
+
+
+ if(empty($spots)){
+ //No geodata so return generic empty tile
+ header('Content-type: image/png');
+ echo file_get_contents(TILE_DIR.'empty.png');
+ }else{
+ if(!file_exists($dir)){
+ mkdir($dir, 0705);
+ }
+ //All the magics is in HeatMap class :)
+ $im = HeatMap::createImage($spots, GoogleMapUtility::TILE_SIZE, GoogleMapUtility::TILE_SIZE, heatMap::$WITH_ALPHA, SPOT_RADIUS, SPOT_DIMMING_LEVEL, HeatMap::$GRADIENT_FIRE);
+ //Store tile for reuse and output it
+ header('content-type:image/png;');
+ imagepng($im, $tilename);
+ echo file_get_contents($tilename);
+ imagedestroy($im);
+ unset($im);
+ }
+ }else{
+ //Output stored tile
+ header('content-type:image/png;');
+ echo file_get_contents($tilename);
+ }
+ /////////////
+ //Functions//
+ /////////////
+ function fGetPOI($query, &$im, $X, $Y, $zoom, $offset){
+ global $conn;
+ $nbPOIInsideTile = 0;
+
+ $result = pg_query($conn, $query);
+ $spots = Array();
+ if (!$result) {
+ databaseError(pg_result_error($result));
+ return Array();
+ }
+ foreach( pg_fetch_all($result) as $row){
+ $point = GoogleMapUtility::getOffsetPixelCoords($row['stop_lat'], $row['stop_lon'], $zoom, $X, $Y);
+ //Count result only in the tile
+ if( ($point->x > -$offset) && ($point->x < (GoogleMapUtility::TILE_SIZE+$offset)) && ($point->y > -$offset) && ($point->y < (GoogleMapUtility::TILE_SIZE+$offset))){
+ $spots[] = new HeatMapPoint($point->x, $point->y);
+ }
+
+ }//while
+ return $spots;
+ }//fAddPOI
+?>
+
+
Binary files /dev/null and b/labs/gradient/classic.png differ
Binary files /dev/null and b/labs/gradient/fire.png differ
Binary files /dev/null and b/labs/gradient/pgaitch.png differ
--- a/labs/index.php
+++ b/labs/index.php
@@ -6,8 +6,10 @@
<li data-role="list-divider" > Experimental Features </li>
<li><a href="mywaybalance.php"><h3>MyWay Balance for mobile</h3>
<p>Mobile viewer for MyWay balance. Warning! No HTTPS security.</p></a></li>
- <li><a href="networkstats.php"><h3>Network/Route Statistics</h3>
- <p>Statistical analysis of network/routes</p></a></li>
+ <li><a href="networkstats.php"><h3>Route Statistics</h3>
+ <p>Analysis of route timing points</p></a></li>
+ <li><a href="busstopdensity.php"><h3>Bus Stop Density Map</h3>
+ <p>Analysis of bus stop coverage</p></a></li>
<li>More coming soon!</li>
</ul>
</div>
--- a/labs/networkstats.php
+++ b/labs/networkstats.php
@@ -1,6 +1,6 @@
<?php
include ('../include/common.inc.php');
-include_header("Network/Route Statistics", "networkstats")
+include_header("Route Statistics", "networkstats")
?>
<script type="text/javascript" src="js/flotr/lib/prototype-1.6.0.2.js"></script>
Binary files /dev/null and b/labs/tiles/empty.png differ
--- /dev/null
+++ b/lib/GoogleMapUtility.php
@@ -1,1 +1,97 @@
+<?php
+/*
+*DISCLAIMER
+*
+*THIS SOFTWARE IS PROVIDED BY THE AUTHOR 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES *OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, *INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF *USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT *(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+* @author: Olivier G. <olbibigo_AT_gmail_DOT_com>
+* @version: 1.1
+* @history:
+* 1.0 creation
+ 1.1 disclaimer added
+*/
+class GoogleMapUtility {
+ const TILE_SIZE = 256;
+
+ //(lat, lng, z) -> parent tile (X,Y)
+ public static function getTileXY($lat, $lng, $zoom) {
+ $normalised = GoogleMapUtility::_toNormalisedMercatorCoords(GoogleMapUtility::_toMercatorCoords($lat, $lng));
+ $scale = 1 << ($zoom);
+ return new Point(
+ (int)($normalised->x * $scale),
+ (int)($normalised->y * $scale)
+ );
+ }//toTileXY
+
+ //(lat, lng, z) -> (x,y) with (0,0) in the upper left corner of the MAP
+ public static function getPixelCoords($lat, $lng, $zoom) {
+ $normalised = GoogleMapUtility::_toNormalisedMercatorCoords(GoogleMapUtility::_toMercatorCoords($lat, $lng));
+ $scale = (1 << ($zoom)) * GoogleMapUtility::TILE_SIZE;
+ return new Point(
+ (int)($normalised->x * $scale),
+ (int)($normalised->y * $scale)
+ );
+ }//getPixelCoords
+ //(lat, lng, z) -> (x,y) in the upper left corner of the TILE ($X, $Y)
+ public static function getOffsetPixelCoords($lat,$lng,$zoom, $X, $Y) {
+ $pixelCoords = GoogleMapUtility::getPixelCoords($lat, $lng, $zoom);
+ return new Point(
+ $pixelCoords->x - $X * GoogleMapUtility::TILE_SIZE,
+ $pixelCoords->y - $Y * GoogleMapUtility::TILE_SIZE
+ );
+ }//getPixelOffsetInTile
+
+ public static function getTileRect($X,$Y,$zoom) {
+ $tilesAtThisZoom = 1 << $zoom;
+ $lngWidth = 360.0 / $tilesAtThisZoom;
+ $lng = -180 + ($X * $lngWidth);
+ $latHeightMerc = 1.0 / $tilesAtThisZoom;
+ $topLatMerc = $Y * $latHeightMerc;
+ $bottomLatMerc = $topLatMerc + $latHeightMerc;
+ $bottomLat = (180 / M_PI) * ((2 * atan(exp(M_PI * (1 - (2 * $bottomLatMerc))))) - (M_PI / 2));
+ $topLat = (180 / M_PI) * ((2 * atan(exp(M_PI * (1 - (2 * $topLatMerc))))) - (M_PI / 2));
+ $latHeight = $topLat - $bottomLat;
+ return new Boundary($lng, $bottomLat, $lngWidth, $latHeight);
+ }//getTileRect
+
+ private static function _toMercatorCoords($lat, $lng) {
+ if ($lng > 180) {
+ $lng -= 360;
+ }
+ $lng /= 360;
+ $lat = asinh(tan(deg2rad($lat)))/M_PI/2;
+ return new Point($lng, $lat);
+ }//_toMercatorCoords
+
+ private static function _toNormalisedMercatorCoords($point) {
+ $point->x += 0.5;
+ $point->y = abs($point->y-0.5);
+ return $point;
+ }//_toNormalisedMercatorCoords
+}//GoogleMapUtility
+
+class Point {
+ public $x,$y;
+ function __construct($x,$y) {
+ $this->x = $x;
+ $this->y = $y;
+ }
+ function __toString() {
+ return "({$this->x},{$this->y})";
+ }
+}//Point
+
+class Boundary {
+ public $x,$y,$width,$height;
+ function __construct($x,$y,$width,$height) {
+ $this->x = $x;
+ $this->y = $y;
+ $this->width = $width;
+ $this->height = $height;
+ }
+ function __toString() {
+ return "({$this->x} x {$this->y},{$this->width},{$this->height})";
+ }
+}//Boundary
+?>
--- /dev/null
+++ b/lib/HeatMap.php
@@ -1,1 +1,275 @@
-
+<?php
+/*
+*DISCLAIMER
+* http://blog.gmapify.fr/create-beautiful-tiled-heat-maps-with-php-and-gd
+*THIS SOFTWARE IS PROVIDED BY THE AUTHOR 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES *OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, *INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF *USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT *(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+* @author: Olivier G. <olbibigo_AT_gmail_DOT_com>
+* @version: 1.0
+* @history:
+* 1.0 creation
+*/
+ define('PI2', 2*M_PI);
+
+ class HeatMapPoint{
+ public $x,$y;
+ function __construct($x,$y) {
+ $this->x = $x;
+ $this->y = $y;
+ }
+ function __toString() {
+ return "({$this->x},{$this->y})";
+ }
+ }//Point
+
+ class HeatMap{
+ //TRANSPARENCY
+ public static $WITH_ALPHA = 0;
+ public static $WITH_TRANSPARENCY = 1;
+ //GRADIENT STYLE
+ public static $GRADIENT_CLASSIC = 'classic';
+ public static $GRADIENT_FIRE = 'fire';
+ public static $GRADIENT_PGAITCH = 'pgaitch';
+ //GRADIENT MODE (for heatImage)
+ public static $GRADIENT_NO_NEGATE_NO_INTERPOLATE = 0;
+ public static $GRADIENT_NO_NEGATE_INTERPOLATE = 1;
+ public static $GRADIENT_NEGATE_NO_INTERPOLATE = 2;
+ public static $GRADIENT_NEGATE_INTERPOLATE = 3;
+ //NOT PROCESSED PIXEL (for heatImage)
+ public static $KEEP_VALUE = 0;
+ public static $NO_KEEP_VALUE = 1;
+ //CONSTRAINTS
+ private static $MIN_RADIUS = 2;//in px
+ private static $MAX_RADIUS = 50;//in px
+ private static $MAX_IMAGE_SIZE = 10000;//in px
+
+ //generate an $image_width by $image_height pixels heatmap image of $points
+ public static function createImage($data, $image_width, $image_height, $mode=0, $spot_radius = 30, $dimming = 75, $gradient_name = 'classic'){
+ $_gradient_name = $gradient_name;
+ if(($_gradient_name != self::$GRADIENT_CLASSIC) && ($_gradient_name != self::$GRADIENT_FIRE) && ($_gradient_name != self::$GRADIENT_PGAITCH)){
+ $_gradient_name = self::$GRADIENT_CLASSIC;
+ }
+ $_image_width = min(self::$MAX_IMAGE_SIZE, max(0, intval($image_width)));
+ $_image_height = min(self::$MAX_IMAGE_SIZE, max(0, intval($image_height)));
+ $_spot_radius = min(self::$MAX_RADIUS, max(self::$MIN_RADIUS, intval($spot_radius)));
+ $_dimming = min(255, max(0, intval($dimming)));
+ if(!is_array($data)){
+ return false;
+ }
+ $im = imagecreatetruecolor($_image_width, $_image_height);
+ $white = imagecolorallocate($im, 255, 255, 255);
+ imagefill($im, 0, 0, $white);
+ if(self::$WITH_ALPHA == $mode){
+ imagealphablending($im, false);
+ imagesavealpha($im,true);
+ }
+ //Step 1: create grayscale image
+ foreach($data as $datum){
+ if( (is_array($datum) && (count($datum)==1)) || (!is_array($datum) && ('HeatMapPoint' == get_class($datum)))){//Plot points
+ if('HeatMapPoint' != get_class($datum)){
+ $datum = $datum[0];
+ }
+ self::_drawCircularGradient($im, $datum->x, $datum->y, $_spot_radius, $_dimming);
+ }else if(is_array($datum)){//Draw lines
+ $length = count($datum)-1;
+ for($i=0; $i < $length; ++$i){//Loop through points
+ //Bresenham's algorithm to plot from from $datum[$i] to $datum[$i+1];
+ self::_drawBilinearGradient($im, $datum[$i], $datum[$i+1], $_spot_radius, $_dimming);
+ }
+ }
+ }
+ //Gaussian filter
+ if($_spot_radius >= 30){
+ imagefilter($im, IMG_FILTER_GAUSSIAN_BLUR);
+ }
+ //Step 2: create colored image
+ if(FALSE === ($grad_rgba = self::_createGradient($im, $mode, $_gradient_name))){
+ return FALSE;
+ }
+ $grad_size = count($grad_rgba);
+ for($x=0; $x <$_image_width; ++$x){
+ for($y=0; $y <$_image_height; ++$y){
+ $level = imagecolorat($im, $x, $y) & 0xFF;
+ if( ($level >= 0) && ($level < $grad_size) ){
+ imagesetpixel($im, $x, $y, $grad_rgba[imagecolorat($im, $x, $y) & 0xFF]);
+ }
+ }
+ }
+ if(self::$WITH_TRANSPARENCY == $mode){
+ imagecolortransparent($im, $grad_rgba[count($grad_rgba)-1]);
+ }
+ return $im;
+ }//createImage
+
+ //Heat an image
+ public static function heatImage($filepath, $gradient_name = 'classic', $mode= 0, $min_level=0, $max_level=255, $gradient_interpolate=0, $keep_value=0){
+ $_gradient_name = $gradient_name;
+ if(($_gradient_name != self::$GRADIENT_CLASSIC) && ($_gradient_name != self::$GRADIENT_FIRE) && ($_gradient_name != self::$GRADIENT_PGAITCH)){
+ $_gradient_name = self::$GRADIENT_CLASSIC;
+ }
+ $_min_level = min(255, max(0, intval($min_level)));
+ $_max_level = min(255, max(0, intval($max_level)));
+
+ //try opening jpg first then png then gif format
+ if(FALSE === ($im = @imagecreatefromjpeg($filepath))){
+ if(FALSE === ($im = @imagecreatefrompng($filepath))){
+ if(FALSE === ($im = @imagecreatefromgif($filepath))){
+ return FALSE;
+ }
+ }
+ }
+ if(self::$WITH_ALPHA == $mode){
+ imagealphablending($im, false);
+ imagesavealpha($im,true);
+ }
+ $width = imagesx($im);
+ $height = imagesy($im);
+ if(FALSE === ($grad_rgba = self::_createGradient($im, $mode, $_gradient_name))){
+ return FALSE;
+ }
+ //Convert to grayscale
+ $grad_size = count($grad_rgba);
+ $level_range = $_max_level - $_min_level;
+ for($x=0; $x <$width; ++$x){
+ for($y=0; $y <$height; ++$y){
+ $rgb = imagecolorat($im, $x, $y);
+ $r = ($rgb >> 16) & 0xFF;
+ $g = ($rgb >> 8) & 0xFF;
+ $b = $rgb & 0xFF;
+ $gray_level = Min(255, Max(0, floor(0.33 * $r + 0.5 * $g + 0.16 * $b)));//between 0 and 255
+ if( ($gray_level >= $_min_level) && ($gray_level <= $_max_level) ){
+ switch($gradient_interpolate){
+ case self::$GRADIENT_NO_NEGATE_NO_INTERPOLATE:
+ //$_max_level takes related lowest gradient color
+ //$_min_level takes related highest gradient color
+ $value = 255 - $gray_level;
+ break;
+ case self::$GRADIENT_NEGATE_NO_INTERPOLATE:
+ //$_max_level takes related highest gradient color
+ //$_min_level takes related lowest gradient color
+ $value = $gray_level;
+ break;
+ case self::$GRADIENT_NO_NEGATE_INTERPOLATE:
+ //$_max_level takes lowest gradient color
+ //$_min_level takes highest gradient color
+ $value = 255- floor(($gray_level - $_min_level) * $grad_size / $level_range);
+ break;
+ case self::$GRADIENT_NEGATE_INTERPOLATE:
+ //$_max_level takes highest gradient color
+ //$_min_level takes lowest gradient color
+ $value = floor(($gray_level - $_min_level) * $grad_size / $level_range);
+ break;
+ default:
+ }
+ imagesetpixel($im, $x, $y, $grad_rgba[$value]);
+ }else{
+ if(self::$KEEP_VALUE == $keep_value){
+ //Do nothing
+ }else{//self::$NO_KEEP_VALUE
+ imagesetpixel($im, $x, $y, imagecolorallocatealpha($im,0,0,0,0));
+ }
+ }
+ }
+ }
+ if(self::$WITH_TRANSPARENCY == $mode){
+ imagecolortransparent($im, $grad_rgba[count($grad_rgba)-1]);
+ }
+ return $im;
+ }//heatImage
+
+ private static function _drawCircularGradient(&$im, $center_x, $center_y, $spot_radius, $dimming){
+ $dirty = array();
+ $ratio = (255 - $dimming) / $spot_radius;
+ for($r=$spot_radius; $r > 0; --$r){
+ $channel = $dimming + $r * $ratio;
+ $angle_step = 0.45/$r; //0.01;
+ //Process pixel by pixel to draw a radial grayscale radient
+ for($angle=0; $angle <= PI2; $angle += $angle_step){
+ $x = floor($center_x + $r*cos($angle));
+ $y = floor($center_y + $r*sin($angle));
+ if(!isset($dirty[$x][$y])){
+ $previous_channel = @imagecolorat($im, $x, $y) & 0xFF;//grayscale so same value
+ $new_channel = Max(0, Min(255,($previous_channel * $channel)/255));
+ imagesetpixel($im, $x, $y, imagecolorallocate($im, $new_channel, $new_channel, $new_channel));
+ $dirty[$x][$y] = 0;
+ }
+ }
+ }
+ }//_drawCircularGradient
+
+ private static function _drawBilinearGradient(&$im, $point0, $point1, $spot_radius, $dimming){
+ if($point0->x < $point1->x){
+ $x0 = $point0->x;
+ $y0 = $point0->y;
+ $x1 = $point1->x;
+ $y1 = $point1->y;
+ }else{
+ $x0 = $point1->x;
+ $y0 = $point1->y;
+ $x1 = $point0->x;
+ $y1 = $point0->y;
+ }
+
+ if( ($x0==$x1) && ($y0==$y1)){//check if same coordinates
+ return false;
+ }
+ $steep = (abs($y1 - $y0) > abs($x1 - $x0))? true: false;
+ if($steep){
+ list($x0, $y0) = array($y0, $x0);//swap
+ list($x1, $y1) = array($y1, $x1);//swap
+ }
+ if($x0>$x1){
+ list($x0, $x1) = array($x1, $x0);//swap
+ list($y0, $y1) = array($y1, $y0);//swap
+ }
+ $deltax = $x1 - $x0;
+ $deltay = abs($y1 - $y0);
+ $error = $deltax / 2;
+ $y = $y0;
+ if( $y0 < $y1){
+ $ystep = 1;
+ }else{
+ $ystep = -1;
+ }
+ $step = max(1, floor($spot_radius/ 3));
+ for($x=$x0; $x<=$x1; ++$x){//Loop through x value
+ if(0==(($x-$x0) % $step)){
+ if($steep){
+ self::_drawCircularGradient(&$im, $y, $x, $spot_radius, $dimming);
+ }else{
+ self::_drawCircularGradient(&$im, $x, $y, $spot_radius, $dimming);
+ }
+ }
+ $error -= $deltay;
+ if($error<0){
+ $y = $y + $ystep;
+ $error = $error + $deltax;
+ }
+ }
+ }//_drawBilinearGradient
+
+ private static function _createGradient($im, $mode, $gradient_name){
+ //create the gradient from an image
+ if(FALSE === ($grad_im = imagecreatefrompng('gradient/'.$gradient_name.'.png'))){
+ return FALSE;
+ }
+ $width_g = imagesx($grad_im);
+ $height_g = imagesy($grad_im);
+ //Get colors along the longest dimension
+ //Max density is for lower channel value
+ for($y=$height_g-1; $y >= 0 ; --$y){
+ $rgb = imagecolorat($grad_im, 1, $y);
+ //Linear function
+ $alpha = Min(127, Max(0, floor(127 - $y/2)));
+ if(self::$WITH_ALPHA == $mode){
+ $grad_rgba[] = imagecolorallocatealpha($im, ($rgb >> 16) & 0xFF, ($rgb >> 8) & 0xFF, $rgb & 0xFF, $alpha);
+ }else{
+ $grad_rgba[] = imagecolorallocate($im, ($rgb >> 16) & 0xFF, ($rgb >> 8) & 0xFF, $rgb & 0xFF);
+ }
+ }
+ imagedestroy($grad_im);
+ unset($grad_im);
+ return($grad_rgba);
+ }//_createGradient
+ }//Heatmap
+?>
