Add GPS coordintes helper.

hMatoba · May 20, 2017 · eb3c91e · eb3c91e
1 parent f8fc3c8
commit eb3c91e
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diff --git a/docs/sample.rst b/docs/sample.rst
@@ -174,6 +174,19 @@ Generates Rotated JPEG
 
     document.getElementById("files").onchange = previewJpeg;
 
+GPS Coordinates
+---------------
+
+::
+
+    var lat = 59.43553989213321;
+    var lng = 24.73842144012451;
+    gpsIfd[piexif.GPSIFD.GPSLatitudeRef] = lat < 0 ? 'S' : 'N';
+    gpsIfd[piexif.GPSIFD.GPSLatitude] = piexif.GPSHelper.degToDmsRational(lat);
+    gpsIfd[piexif.GPSIFD.GPSLongitudeRef] = lng < 0 ? 'W' : 'E';
+    gpsIfd[piexif.GPSIFD.GPSLongitude] = piexif.GPSHelper.degToDmsRational(lng);
+
+
 Node.js
 -------
 

diff --git a/piexif.js b/piexif.js
@@ -2445,6 +2445,18 @@ SOFTWARE.
     that.InteropIFD = {
         InteroperabilityIndex:1,
     };
+
+    that.GPSHelper = {
+        degToDmsRational:function (degFloat) {
+            var minFloat = degFloat % 1 * 60;
+            var secFloat = minFloat % 1 * 60;
+            var deg = Math.floor(degFloat);
+            var min = Math.floor(minFloat);
+            var sec = Math.round(secFloat * 100);
+
+            return [[deg, 1], [min, 1], [sec, 100]];
+        }
+    };
 
 
     if (typeof exports !== 'undefined') {

diff --git a/samples/CanvasSample.html b/samples/CanvasSample.html
@@ -62,6 +62,14 @@
             exifIfd[piexif.ExifIFD.LensSpecification] = [[1, 1], [1, 1], [1, 1], [1, 1]];
             gpsIfd[piexif.GPSIFD.GPSVersionID] = [7, 7, 7, 7];
             gpsIfd[piexif.GPSIFD.GPSDateStamp] = "1999:99:99 99:99:99";
+
+            var lat = 59.43553989213321;
+            var lng = 24.73842144012451;
+            gpsIfd[piexif.GPSIFD.GPSLatitudeRef] = lat < 0 ? 'S' : 'N';
+            gpsIfd[piexif.GPSIFD.GPSLatitude] = piexif.GPSHelper.degToDmsRational(lat);
+            gpsIfd[piexif.GPSIFD.GPSLongitudeRef] = lng < 0 ? 'W' : 'E';
+            gpsIfd[piexif.GPSIFD.GPSLongitude] = piexif.GPSHelper.degToDmsRational(lng);
+
             var exifObj = {"0th":zerothIfd, "Exif":exifIfd, "GPS":gpsIfd};
 
             // get exif binary as "string" type