You can now provide the TextMetrics as part of the config object, to avoid the expensive canvas scanning needed.

Text.getTextMetrics and TextStyle.getTextMetrics added to faciliate this. Plus added to toJSON.

Author: photonstorm

v3/src/checksum.js

@@ -1,4 +1,4 @@
 var CHECKSUM = {
-build: 'bbed2b40-2a8c-11e7-9394-818efff01abb'
+build: '9ef13fb0-2a8f-11e7-ae43-2f2e7e8ba14e'
 };
 module.exports = CHECKSUM;

v3/src/gameobjects/text/TextStyle.js

@@ -1,4 +1,5 @@
 var Class = require('../../utils/Class');
+var GetObjectValue = require('../../utils/object/GetObjectValue');
 var GetAdvancedValue = require('../../utils/object/GetAdvancedValue');
 var MeasureText = require('./MeasureText');
 
@@ -59,7 +60,22 @@ var TextStyle = new Class({
             }
         }
 
-        this.metrics = MeasureText(this);
+        var metrics = GetObjectValue(style, 'metrics', false);
+
+        //  Provide optional TextMetrics in the style object to avoid the canvas look-up / scanning
+        //  Doing this is un-done if you then change the font of this TextStyle after creation
+        if (metrics)
+        {
+            this.metrics = {
+                ascent: GetObjectValue(metrics, 'ascent', 0),
+                descent: GetObjectValue(metrics, 'descent', 0),
+                fontSize: GetObjectValue(metrics, 'fontSize', 0)
+            };
+        }
+        else
+        {
+            this.metrics = MeasureText(this);
+        }
     },
 
     reset: function ()
@@ -265,6 +281,17 @@ var TextStyle = new Class({
         return this.update(false);
     },
 
+    getTextMetrics: function ()
+    {
+        var metrics = this.metrics;
+
+        return {
+            ascent: metrics.ascent,
+            descent: metrics.descent,
+            fontSize: metrics.fontSize
+        };
+    },
+
     toJSON: function ()
     {
         var output = {};
@@ -274,6 +301,8 @@ var TextStyle = new Class({
             output[key] = this[key];
         }
 
+        output.metrics = this.getTextMetrics();
+
         return output;
     },
 

v3/src/gameobjects/text/static/Text.js

@@ -279,6 +279,11 @@ var Text = new Class({
         return this;
     },
 
+    getTextMetrics: function ()
+    {
+        return this.style.getTextMetrics();
+    },
+
     toJSON: function ()
     {
         var out = Components.ToJSON(this);