finish gradients refactor

lib/extract/extractFill.js

@@ -1,33 +1,15 @@
-import rgba from '../rgba';
 import extractBrush from './extractBrush';
-import patterns from './patterns';
+import extractOpacity from './extractOpacity';
 
 const fillRules = {
     evenodd: 0,
     nonzero: 1
 };
 
-function fillFilter(props) {
-    let {fill} = props;
-    let fillOpacity = +props.fillOpacity;
-
-    if (fill === 'none') {
-        return null;
-    } else if (fill) {
-        return patterns(fill, fillOpacity);
-    } else if (props.fill === undefined) {
-        return rgba('#000', isNaN(fillOpacity) ? 1 : fillOpacity).rgbaString();
-    } else {
-        return null;
-    }
-}
-
 export default function(props) {
-    let fill = extractBrush(fillFilter(props), props);
-    let fillRule = fillRules[props.fillRule] === 0 ? 0 : 1;
-
     return {
-        fill,
-        fillRule
+        fill: extractBrush(props.fill),
+        fillOpacity: extractOpacity(props.fillOpacity),
+        fillRule: fillRules[props.fillRule] === 0 ? 0 : 1
     };
 }