invalidate ctx style cache on plot resize. close #570.

Author: leeoniya

dist/uPlot.cjs.js

@@ -3814,6 +3814,10 @@ function uPlot(opts, data, then) {
 			can.width  = round(fullWidCss * pxRatio);
 			can.height = round(fullHgtCss * pxRatio);
 
+			// invalidate ctx style cache
+			ctxStroke = ctxFill = ctxWidth = ctxJoin = ctxCap = ctxFont = ctxAlign = ctxBaseline = ctxDash = null;
+			ctxAlpha = 1;
+
 			syncRect(false);
 
 			fire("setSize");

dist/uPlot.esm.js

@@ -3812,6 +3812,10 @@ function uPlot(opts, data, then) {
 			can.width  = round(fullWidCss * pxRatio);
 			can.height = round(fullHgtCss * pxRatio);
 
+			// invalidate ctx style cache
+			ctxStroke = ctxFill = ctxWidth = ctxJoin = ctxCap = ctxFont = ctxAlign = ctxBaseline = ctxDash = null;
+			ctxAlpha = 1;
+
 			syncRect(false);
 
 			fire("setSize");

dist/uPlot.iife.js

@@ -3815,6 +3815,10 @@ var uPlot = (function () {
 				can.width  = round(fullWidCss * pxRatio);
 				can.height = round(fullHgtCss * pxRatio);
 
+				// invalidate ctx style cache
+				ctxStroke = ctxFill = ctxWidth = ctxJoin = ctxCap = ctxFont = ctxAlign = ctxBaseline = ctxDash = null;
+				ctxAlpha = 1;
+
 				syncRect(false);
 
 				fire("setSize");

dist/uPlot.iife.min.js

@@ -1797,6 +1797,10 @@ export default function uPlot(opts, data, then) {
 			can.width  = round(fullWidCss * pxRatio);
 			can.height = round(fullHgtCss * pxRatio);
 
+			// invalidate ctx style cache
+			ctxStroke = ctxFill = ctxWidth = ctxJoin = ctxCap = ctxFont = ctxAlign = ctxBaseline = ctxDash = null;
+			ctxAlpha = 1;
+
 			syncRect(false);
 
 			fire("setSize");