Accepting a lang option and applying it to canvas's ctx.lang (#58)

* include lang option in constructor and pass to ctx

* concept for test

* remove extra setting

Author: mapmeld

index.d.ts

@@ -6,6 +6,7 @@ export declare type TinySDFOptions = {
     fontFamily?: string;
     fontWeight?: string;
     fontStyle?: string;
+    lang?: string;
 };
 
 export default class TinySDF {

index.js

@@ -8,11 +8,13 @@ export default class TinySDF {
         cutoff = 0.25,
         fontFamily = 'sans-serif',
         fontWeight = 'normal',
-        fontStyle = 'normal'
+        fontStyle = 'normal',
+        lang = null
     } = {}) {
         this.buffer = buffer;
         this.cutoff = cutoff;
         this.radius = radius;
+        this.lang = lang;
 
         // make the canvas size big enough to both have the specified buffer around the glyph
         // for "halo", and account for some glyphs possibly being larger than their font size
@@ -67,6 +69,7 @@ export default class TinySDF {
         if (glyphWidth === 0 || glyphHeight === 0) return glyph;
 
         const {ctx, buffer, gridInner, gridOuter} = this;
+        if (this.lang) ctx.lang = this.lang;
         ctx.clearRect(buffer, buffer, glyphWidth, glyphHeight);
         ctx.fillText(char, buffer, buffer + glyphTop);
         const imgData = ctx.getImageData(buffer, buffer, glyphWidth, glyphHeight);

test/test.js

@@ -105,3 +105,13 @@ test('does not return negative-width glylphs', () => {
     assert.equal(glyph.glyphWidth, 0);
     assert.equal(glyph.width, 6); // zero-width glyph with 3px buffer
 });
+
+/*
+test('renders Chinese and Japanese versions of characters', () => {
+    const sdf1 = new MockTinySDF({lang: 'zh'});
+    const glyph1 = sdf1.draw('门');
+    const sdf2 = new MockTinySDF({lang: 'ja'});
+    const glyph2 = sdf2.draw('门');
+    assert.notDeepStrictEqual(glyph1.data, glyph2.data);
+});
+*/