put pixelated style in constants

Author: almarklein

src/traces/image/constants.js

@@ -55,5 +55,17 @@ module.exports = {
             },
             suffix: ['°', '%', '%', '']
         }
-    }
+    },
+    // For pixelated image rendering
+    // http://phrogz.net/tmp/canvas_image_zoom.html
+    // https://developer.mozilla.org/en-US/docs/Web/CSS/image-rendering
+    pixelatedStyle: [
+        'image-rendering: optimizeSpeed',
+        'image-rendering: -moz-crisp-edges',
+        'image-rendering: -o-crisp-edges',
+        'image-rendering: -webkit-optimize-contrast',
+        'image-rendering: optimize-contrast',
+        'image-rendering: crisp-edges',
+        'image-rendering: pixelated'
+    ].join('; ')
 };

src/traces/image/plot.js

@@ -136,13 +136,8 @@ module.exports = function plot(gd, plotinfo, cdimage, imageLayer) {
 
         image3.exit().remove();
 
-        // Pixelated image rendering
-        // http://phrogz.net/tmp/canvas_image_zoom.html
-        // https://developer.mozilla.org/en-US/docs/Web/CSS/image-rendering
-        var style = '';
-        if(trace.interpolate === 'nearest') {
-            style = 'image-rendering: optimizeSpeed; image-rendering: -moz-crisp-edges; image-rendering: -o-crisp-edges; image-rendering: -webkit-optimize-contrast; image-rendering: optimize-contrast; image-rendering: crisp-edges; image-rendering: pixelated;';
-        }
+        var style = (trace.zsmooth === false) ? constants.pixelatedStyle : '';
+        
         if(fastImage) {
             var xRange = Lib.simpleMap(xa.range, xa.r2l);
             var yRange = Lib.simpleMap(ya.range, ya.r2l);